e-beach
10 MW
And I forgot to say, In my experience, that kind of a washout was due to weight distribution. Not enough in the front.
The SB Cruiser : Amberwolf's 2WD Heavy Cargo Trike & Dog Carrier
- Thread starter amberwolf
- Start date
And that is indeed the final cause...but the reason there wasn't enough weight was the wind lifting the front end by pushing the trike sideways and lifting it up, even just a bit, by the gusts on the side and the canopy as I turned.
I've taken that same corner 5 (or more) days each week the same way for years, without this problem...even in gusty wind, but this time it just caught me wrong. :/
(of course, teh trike has only been built up in it's present configuration since mid/late last year, but that's still many dozens of turns there...and the trike was lighter and easier to blow around before that, yet it didnt' happen).
I'm off work for a week ATM, and after I get some other stuff done around the house that has to be done while I can, I'll be dealing with the front fork / brake issues. (making mounts for the brake bosses for a non-suspension fatbike fork to replace the whole crappy suspension fork/clamped-on bosses/U/etc I'm presently stuck with).
Doing that will very likely include a DD hubmotor up there which will add some weight, (and braking) but I also have a plan (that there may be time to complete) to move the traction battery (around 40lbs with the new structure) up to the front triangle above the cranks, just out of the way of my feet and knees.
If it turns out to not work very well with the weight shift, I'll leave the structure there but instead use it for the tools, air compressor, etc., that presently also use up space in my cargo area. And the lighting pack, if possible. It'd be less weight, but still some up there.
I still need to rewire the rightside hubmotor, too, but that shouldnt' take very long after I deal with the fork / brakes. (the battery move will be after those things are done).
The biggest issue I have to do something about, that probably won't happen this week, is completely replacing the axles in both hubmotors in the rear, and making a new clamping system / dropouts, as described a bit previously, using a hollow tube for axle. Bad sketches drawn at lunch while at work will be uploaded when I find where I put them....
Mainly it's a probelm of finding the same size in three things: The tube's OD, and bearings for the covers with the same ID as the tube's OD and the motor's stator support's ID. It's very possible these don't exist, and I'll have to make some form of compromise requiring machining the stator support's ID out to match the bearing's ID, and then finding a tube that is just enough smaller for me to find or make adapter rings to go between the tube and the stator, and the bearings. (or another tube that fits around the first one, to be welded to it). Then keyways or...something...that will lock the tube to the stator.
And...something to press out the axles already in the motors, and press in the tubes.
Everything else I think I can make with stuff I have here already. But the bearings I have to order for sure, and possibly the tubing (something steel, and thickwalled as possible).
Tubing is so I can run all the wires thru that, instead of gaps between bearing and axle, like the axle flats.
Then clamps that grip and hold the surface of the tubing itself, instead of axle flats, or splines, etc. If necessary, some form of keyway or grub screws, but I don't think I'll need that.
Anyway...it's just a pipe dream (haha) right now.
I've taken that same corner 5 (or more) days each week the same way for years, without this problem...even in gusty wind, but this time it just caught me wrong. :/
(of course, teh trike has only been built up in it's present configuration since mid/late last year, but that's still many dozens of turns there...and the trike was lighter and easier to blow around before that, yet it didnt' happen).
I'm off work for a week ATM, and after I get some other stuff done around the house that has to be done while I can, I'll be dealing with the front fork / brake issues. (making mounts for the brake bosses for a non-suspension fatbike fork to replace the whole crappy suspension fork/clamped-on bosses/U/etc I'm presently stuck with).
Doing that will very likely include a DD hubmotor up there which will add some weight, (and braking) but I also have a plan (that there may be time to complete) to move the traction battery (around 40lbs with the new structure) up to the front triangle above the cranks, just out of the way of my feet and knees.
If it turns out to not work very well with the weight shift, I'll leave the structure there but instead use it for the tools, air compressor, etc., that presently also use up space in my cargo area. And the lighting pack, if possible. It'd be less weight, but still some up there.
I still need to rewire the rightside hubmotor, too, but that shouldnt' take very long after I deal with the fork / brakes. (the battery move will be after those things are done).
The biggest issue I have to do something about, that probably won't happen this week, is completely replacing the axles in both hubmotors in the rear, and making a new clamping system / dropouts, as described a bit previously, using a hollow tube for axle. Bad sketches drawn at lunch while at work will be uploaded when I find where I put them....
Mainly it's a probelm of finding the same size in three things: The tube's OD, and bearings for the covers with the same ID as the tube's OD and the motor's stator support's ID. It's very possible these don't exist, and I'll have to make some form of compromise requiring machining the stator support's ID out to match the bearing's ID, and then finding a tube that is just enough smaller for me to find or make adapter rings to go between the tube and the stator, and the bearings. (or another tube that fits around the first one, to be welded to it). Then keyways or...something...that will lock the tube to the stator.
And...something to press out the axles already in the motors, and press in the tubes.
Everything else I think I can make with stuff I have here already. But the bearings I have to order for sure, and possibly the tubing (something steel, and thickwalled as possible).
Tubing is so I can run all the wires thru that, instead of gaps between bearing and axle, like the axle flats.
Then clamps that grip and hold the surface of the tubing itself, instead of axle flats, or splines, etc. If necessary, some form of keyway or grub screws, but I don't think I'll need that.
Anyway...it's just a pipe dream (haha) right now.
Made a question thread for figuring out front braking options
https://endless-sphere.com/forums/viewtopic.php?f=3&t=99837&p=1461811#p1461792
other than the rim brake kluge I've been using so far.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=99837&p=1461811#p1461792
other than the rim brake kluge I've been using so far.
e-beach
10 MW
Thick steel spacers between the bosses and the adapters that might also drop down and also become inside clamp-able dropouts on either side?
e-beach
10 MW
e-beach said:Thick steel spacers between the bosses and the adapters that might also be long enough to become inside clamp-able dropouts on either side?
If you mean spacers for the brake bosses also being part of the torque arms/plates/etc., well, those would be some really long spacers, as they would essentially run most of the length of each fork leg. I guess it might make the torque arms/plates easier to secure and given the length more resistant to movement. There are a number of threaded spots along the fork to secure things though.
The catch is that the plates/etc (taht will replace the dropouts, because of width of axle shoulders) have to be on the *outside* of the fork / original dropouts, as the motor shoulders are actually several millimeters wider than the fork dropouts.
Don't know if you can clearly see it here in this pic from the linked thread:
but the axle is at an angle in this test-fit, because the non-disc side isn't actually seated in the dropout (looks like it is, because of the flat the wires are meant to run on, but it's not really an axle flat there; it's a D shape).
This is about how the U with the bosses on it sits:
The catch is that the plates/etc (taht will replace the dropouts, because of width of axle shoulders) have to be on the *outside* of the fork / original dropouts, as the motor shoulders are actually several millimeters wider than the fork dropouts.
Don't know if you can clearly see it here in this pic from the linked thread:
but the axle is at an angle in this test-fit, because the non-disc side isn't actually seated in the dropout (looks like it is, because of the flat the wires are meant to run on, but it's not really an axle flat there; it's a D shape).
This is about how the U with the bosses on it sits:
Managed to get the trike on it's side to get the right rear wheel off, and am in process of readding the thick phase wires to it so it can be a motor (and brake) again and not just a wheel. 
Once that's done I need to roll it over the other way, take the other one off, and fix the dropouts there, to prevent rocking of axle during regen/acceleration (so far it's defeated all of the stuff I've tried, going to see if I can make a clamping bolt on the bottom end of the outboard dropout to fix it).
Still needing help over in the previously-linked thread for brake options, for anyone reading *this* thread.
Once that's done I need to roll it over the other way, take the other one off, and fix the dropouts there, to prevent rocking of axle during regen/acceleration (so far it's defeated all of the stuff I've tried, going to see if I can make a clamping bolt on the bottom end of the outboard dropout to fix it).
Still needing help over in the previously-linked thread for brake options, for anyone reading *this* thread.
e-beach
10 MW
amberwolf said:
Yes that is exactly what I mean. They would be long, a lot of grinding or welding would be required. But, they would work albeit long an heavy.
First, I got the solid 10g wires (changing to stranded a short distance outside the axle) reinstalled on the 4503, and put it back on the trike, verified it works. Updated firmware on SFOC5 controller to latest to get it's new features/etc., and now it doesn't work.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=30680&p=1463411#p1463411
Next, I got the new brake (AVID bb7 200mm disc) for the front, based on this thread
https://endless-sphere.com/forums/viewtopic.php?f=3&t=99837
and have the phase and hall wires installed in the old Stromer Mountain 33 wheel, but I haven't got the wheel reassembled yet (you have to take the spokes off half of it, then press the case apart with a puller, to get to the insides!). I intend to test it with an old "ebike tester" first, if possible, to verify it's working.
(pics of the original, in-wheel, controller are here, for those interested in it's inner construction under the potting:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=86600&p=1463423#p1463423
)
I also have to make the adapter plates / arms to hold the wheel to the fork (or expand the fork, which I might do, instead, and just use wrenches for torque arms temporarily).
https://endless-sphere.com/forums/viewtopic.php?f=2&t=30680&p=1463411#p1463411
Next, I got the new brake (AVID bb7 200mm disc) for the front, based on this thread
https://endless-sphere.com/forums/viewtopic.php?f=3&t=99837
and have the phase and hall wires installed in the old Stromer Mountain 33 wheel, but I haven't got the wheel reassembled yet (you have to take the spokes off half of it, then press the case apart with a puller, to get to the insides!). I intend to test it with an old "ebike tester" first, if possible, to verify it's working.
(pics of the original, in-wheel, controller are here, for those interested in it's inner construction under the potting:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=86600&p=1463423#p1463423
)
I also have to make the adapter plates / arms to hold the wheel to the fork (or expand the fork, which I might do, instead, and just use wrenches for torque arms temporarily).
Attachments
The Toecutter
100 kW
- Joined
- Feb 8, 2015
- Messages
- 1,466
I'm glad you weren't badly hurt in the wreck.
You should consider redesigning the canopy and installing a windshield to be less vulnerable to crosswinds. As tall as it is with as much lift as it's generating from the lip of the existing canopy, the moment produced by errant crosswinds is truly massive and it shows because your trike is quite heavy. Rounding out the canopy and installing a windshield to have your vehicle catch less wind could cut the lift to possibly 1/3 or less versus what it is now. It may very well have prevented your accident.
An example of what you could emulate:
As your trike currently is, it is possible that a strong thunderstorm could lift it off the ground.
You should consider redesigning the canopy and installing a windshield to be less vulnerable to crosswinds. As tall as it is with as much lift as it's generating from the lip of the existing canopy, the moment produced by errant crosswinds is truly massive and it shows because your trike is quite heavy. Rounding out the canopy and installing a windshield to have your vehicle catch less wind could cut the lift to possibly 1/3 or less versus what it is now. It may very well have prevented your accident.
An example of what you could emulate:
As your trike currently is, it is possible that a strong thunderstorm could lift it off the ground.
It's possible that it would have helped. However, the canopy is actually relatively fragile, and if a sufficient gust to acutally lift the trike off the ground were to occur, it would just break it at the forward top connection of the diagonals that support it. (they are only held on with zip ties--quite sufficient for keeping it from coming down in my face, :lol: but deliberately weak enough to fail in that kind of instance).The Toecutter said:
Iv'e been in some serious storms with this, that buffeted and rocked the trike, with much higher winds than present that day, especially when funneled down streets as I passed intersecitons, or the canal (like on that day), and never had this problem, or loss of control. I realize that conditions *could* recur to cause this sort of thing again, but as long as I don't round corners like I did that day, they aren't very likely to cause this same sort of problem.
I do have a MC windshield that I'd like to mount on the bars such that it sticks up a bit above the top of the canopy, to redirect airflow from the front over it, instead of under it, partly for aero improvement, and partly for stuff like the above. I've just got so many things to get done (both on the trike and around the house) and so little time and energy to do them all, and this one isn't very high priority compared to functional stuff like the drivetrain, etc. :/
Another issue is that it's very hot here in the summer, and the more enclosed the trike is, the less usable it would be; I'd just roast (especially sitting in traffic) without the occasional breeze that flows thru the open area from whatever direction it's coming from. I only even *have* the canopy to prevent the sun from roasting me directly (since mostly I ride with the sun overhead, or near the horizon or at night, not a lot in between, esepcially for my work commutes).
The Avid BB7 is now installed on the fork, it's rotor on the old Stromer hubmotor, and the fork/wheel on the trike. But Kirin says, no, I can't ride it unless I take her with me.
View attachment 6
Pics of the phase/hall wire install for the Stromer motor are here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=86600&p=1463762#p1463762
Took a bit to get it adjusted to not rub, but now it works and is braking normally. Will prbably still need to do some adusting of cable tension and such at the lever, but they work far better than the crappy suspension fork with the double rim brake (though about the same as the doulbe rim brake on the better fork that broke in the crash). Had to use some washers to space the caliper away from the fork a tiny bit to line up iwth the disc. (I don't have any disc spacers so this was the only option I had, other than putting one of my smaller 160mm rotors "under" the 200mm rotor, whcih I didn't actually think of until this very moment ).
SOme pics of the brakes as they came, and test-installed to the fork/wheel prior to actual installation on the trike.
View attachment 12
View attachment 11
View attachment 10
The fatbike fork flexes significantly on hard braking (can't see it while riding but simulating by pulling lever hard and rocking the trike back and forth it's obvious). Not sure if that's a problem or not; the total flex is not much different from the crappy suspension fork. But since I would like to build a stiff nonsuspension fork with crowns/clamps above and below the headtube, then it shouldn't be an issue once I get the clamps/crowns to do that.
The fork is enough wider that reaching the magnets on spokes with the speedo sensor for the CA was problematic, even with a piece of tubing between the sensor and the fork. So I glued the magnets directly to the hubmotor casing instead, and then it fit closely and owrked perfectly. (sure, I could use the hall sensors in the motor, but the risk (though small) of a phase wire short to hall sensor signal or power line to the CA's input/5v supply is of sufficiently dire consequence that I won't do that. That's what destroyed my oriiginal CAv3, though the short was to battery voltage in the CA's external shunt).
View attachment 3
A very short test ride up and down the street for the fork/wheel/brake worked, but I found the SFOC controller too hot to touch (though barely used at all, and the motor it's attached to still at ambient), and disconnected it from power and motor/etc., to set aside for troubleshooting later.
Hooked up the generic 12fet sensorless to the 4503 instead, so at least I'll ahve motor power on both sides again, and can use the CA to control it via PAS as well as throttle (was problematic to do PAS with the SFOC due to settings issues/conflicts of operation, makig it work the way I wanted requires a lot of tuning).
Didn't have time to make torque arms (even just wrenches) for the motor in front, so I didn't bother setting up the controller on it, or even moutning one yet. For now it jsut has the phase wires isolated from each ohter...though I did consider making a plug-braking switch for it, that switches two phases together for some braking, and all three for full...but this would also need torque arms (even more than acceleration would!). I have a few generic controllers that should work, once I get that far. How I'd operate a third throttle...that's an issue to deal with, but I think the simplest way is to use the PAS from the CA to do that, and use the independent throttles for the left and right rear motors.
So, at least I'm back to an operational trike, just in time to go back to work tomorrow. Wish I'd had time to test it more thoroughly...guess it's trial by fire.
Jelly says it's all so very very boring....
View attachment 1
View attachment 6
Pics of the phase/hall wire install for the Stromer motor are here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=86600&p=1463762#p1463762
Took a bit to get it adjusted to not rub, but now it works and is braking normally. Will prbably still need to do some adusting of cable tension and such at the lever, but they work far better than the crappy suspension fork with the double rim brake (though about the same as the doulbe rim brake on the better fork that broke in the crash). Had to use some washers to space the caliper away from the fork a tiny bit to line up iwth the disc. (I don't have any disc spacers so this was the only option I had, other than putting one of my smaller 160mm rotors "under" the 200mm rotor, whcih I didn't actually think of until this very moment
).SOme pics of the brakes as they came, and test-installed to the fork/wheel prior to actual installation on the trike.
View attachment 12
View attachment 11
View attachment 10
The fatbike fork flexes significantly on hard braking (can't see it while riding but simulating by pulling lever hard and rocking the trike back and forth it's obvious). Not sure if that's a problem or not; the total flex is not much different from the crappy suspension fork. But since I would like to build a stiff nonsuspension fork with crowns/clamps above and below the headtube, then it shouldn't be an issue once I get the clamps/crowns to do that.
The fork is enough wider that reaching the magnets on spokes with the speedo sensor for the CA was problematic, even with a piece of tubing between the sensor and the fork. So I glued the magnets directly to the hubmotor casing instead, and then it fit closely and owrked perfectly. (sure, I could use the hall sensors in the motor, but the risk (though small) of a phase wire short to hall sensor signal or power line to the CA's input/5v supply is of sufficiently dire consequence that I won't do that. That's what destroyed my oriiginal CAv3, though the short was to battery voltage in the CA's external shunt).
View attachment 3
A very short test ride up and down the street for the fork/wheel/brake worked, but I found the SFOC controller too hot to touch (though barely used at all, and the motor it's attached to still at ambient), and disconnected it from power and motor/etc., to set aside for troubleshooting later.
Hooked up the generic 12fet sensorless to the 4503 instead, so at least I'll ahve motor power on both sides again, and can use the CA to control it via PAS as well as throttle (was problematic to do PAS with the SFOC due to settings issues/conflicts of operation, makig it work the way I wanted requires a lot of tuning).
Didn't have time to make torque arms (even just wrenches) for the motor in front, so I didn't bother setting up the controller on it, or even moutning one yet. For now it jsut has the phase wires isolated from each ohter...though I did consider making a plug-braking switch for it, that switches two phases together for some braking, and all three for full...but this would also need torque arms (even more than acceleration would!). I have a few generic controllers that should work, once I get that far. How I'd operate a third throttle...that's an issue to deal with, but I think the simplest way is to use the PAS from the CA to do that, and use the independent throttles for the left and right rear motors.
So, at least I'm back to an operational trike, just in time to go back to work tomorrow. Wish I'd had time to test it more thoroughly...guess it's trial by fire.
Jelly says it's all so very very boring....
View attachment 1
well, it seems towork fine. i like the avid brake, it's quiet, sort of hissing, no sqeualing, etc. and it has good fine cntrol of stopping power. only issue with hard braking is that the fork flexes.
feel of the ride is very different, there must be some geometry change that's enough to really notice. it isn't bad or good, just different. once i get used to it then i'll try stuff that requires performance, on back streets that have no traffic/etc just in case.
then i can judge if the new stuf fis doing what i need it to.
the fork itself is acttually flexy enought o elp with some of the bumpy road stuff, just not anything more than about half an inch or so. but at the top of that range i can feel the vibrations in the tille rand handle bars, and above taht it actually shakes the mirrors enough to make it a bit hard to see stuff in them.
the flexyinses is kind of an issue with braking though, as if i pull them hard and suddenly i get a shudder in the fork and tiller/bars, because as a skid starts, it lets the fork unbend, which lets it grab again, which then bends the fork and it skids, over and over. as long as i can brake just below skid level that's fine, but if i encounter a patch of something that lets it skid hwile braking amost that hard, the shuddering makes it harder to control. i verified the headset/etc is all tightened properly, it shouldn't be able to wiggle the steerer back and forth, so the shudder is just the fork transferring to the frame/bars/etc..
i have'nt hit any big bumps with it, deliberately avoiding them until i can characterize het system to predict how it might behave, and be ready with a new wheel in the cargo pod of teh trike just in case it is damaged by the impact, along with the old junk fork and a wheel that fits that too. don't wanna be stranded with a broken fork again, if it is unable to handle the big bumps. i don't wanna not know what will happen on big stuff, cuz at some point i'll end up being unable to avoid some big hole in the road; there's just too many 4-6 inche or deeeper holes around just the area i live, much less further places i sometimes have to go.
feel of the ride is very different, there must be some geometry change that's enough to really notice. it isn't bad or good, just different. once i get used to it then i'll try stuff that requires performance, on back streets that have no traffic/etc just in case.
then i can judge if the new stuf fis doing what i need it to.
the fork itself is acttually flexy enought o elp with some of the bumpy road stuff, just not anything more than about half an inch or so. but at the top of that range i can feel the vibrations in the tille rand handle bars, and above taht it actually shakes the mirrors enough to make it a bit hard to see stuff in them.
the flexyinses is kind of an issue with braking though, as if i pull them hard and suddenly i get a shudder in the fork and tiller/bars, because as a skid starts, it lets the fork unbend, which lets it grab again, which then bends the fork and it skids, over and over. as long as i can brake just below skid level that's fine, but if i encounter a patch of something that lets it skid hwile braking amost that hard, the shuddering makes it harder to control. i verified the headset/etc is all tightened properly, it shouldn't be able to wiggle the steerer back and forth, so the shudder is just the fork transferring to the frame/bars/etc..
i have'nt hit any big bumps with it, deliberately avoiding them until i can characterize het system to predict how it might behave, and be ready with a new wheel in the cargo pod of teh trike just in case it is damaged by the impact, along with the old junk fork and a wheel that fits that too. don't wanna be stranded with a broken fork again, if it is unable to handle the big bumps. i don't wanna not know what will happen on big stuff, cuz at some point i'll end up being unable to avoid some big hole in the road; there's just too many 4-6 inche or deeeper holes around just the area i live, much less further places i sometimes have to go.
Apparently the fatbike fork is relatively soft metal, compared to the axle shoulder. I've felt / heard increasing "shimmer" from the disc brake over the last several trips, and when checking the nut would find that it wasn't fully tight anymore (but it was not rotating, based on a witness mark made when tightening it).
So the shoulder was pushing into the dropout steel, moving the disc further against the outboard pad in the caliper.
Today, on the way home from work, it began ticking against the disc support struts, and I ended up having to loosen the nut on that side just to ensure it wasn't possible for the caliper to jam in the disc struts, and either break something or lockup the wheel, and just ride really slow the rest of the mile and a half left to get home, just in case.
When I got home I did what I should've done to start with, which was to put stiff flat washers between the shoulders and inboard dropout faces, to prevent this. Once I build them, the torque arms/plates will do this job, but I haven't had time / energy yet. (hence, the motor is still just a hub, not a motor or brake yet, no controller attached).
Other than that, the Avid BB7 disc is working as it should, given the flexiness of the fatbike fork.
So the shoulder was pushing into the dropout steel, moving the disc further against the outboard pad in the caliper.
Today, on the way home from work, it began ticking against the disc support struts, and I ended up having to loosen the nut on that side just to ensure it wasn't possible for the caliper to jam in the disc struts, and either break something or lockup the wheel, and just ride really slow the rest of the mile and a half left to get home, just in case.
When I got home I did what I should've done to start with, which was to put stiff flat washers between the shoulders and inboard dropout faces, to prevent this. Once I build them, the torque arms/plates will do this job, but I haven't had time / energy yet. (hence, the motor is still just a hub, not a motor or brake yet, no controller attached).
Other than that, the Avid BB7 disc is working as it should, given the flexiness of the fatbike fork.
The fork is even softer metal than I thought--it's actively bending permanently at the "crown" area under braking loads, even very gentle braking down from 20MPH to zero over more than 100feet.
I didn't actually notice the permanent bending until this morning when I was about to leave for work, probably because I've been sick with a cold for several days now and unable to focus properly on many things, pretty much just going to bed as soon as I left work each day and got home.
I *had* noticed that handling felt like it was changing, but I thought it was from the way I felt from my cold.
Basically, under normal conditions, the wheel "flops" over, especially with me sitting on it, so the tiller / handlebars are around 45 ish degrees away from center.
But this morning, it flopped past *90* degrees, so the wheel was actually pointing so far right ti was backwards a little bit. I got off the trike and looked at it, cuz that was just wierd, and for just a moment I wondered if somehow I had installed the fork backwards, because it looked like it. But I knew I couldn't have, because it wasn't bent that way before.
I examined it and found it was "ok" but I can't trust it. I had to leave for work right then, or I would've swapped it back out for the old crappy suspension fork--which would've taken a couple of hours or more the way I feel with teh cold.
I considered bending it back, but decided better to leave bad enough alone, and not break it off or something even worse like a structural crack that would fail on the road.
I rode as slowly as possible to work, so average around 12MPH, to still get there on time, without incident.
Made ti home from work fine, too, though I had to go normal speeds due to traffic conditions, and just start braking a lot early to not put stress on the fork I didn't have to. (lots of impatient drivers out today vs other days).
Some pics that show paint actually flaked away at the bending areas, overview shot showing it's actually bent backwards, etc.
Scary stuff. :/
This is the angle the fork *should* be at:
This is the angle it's at *now*:
I didn't actually notice the permanent bending until this morning when I was about to leave for work, probably because I've been sick with a cold for several days now and unable to focus properly on many things, pretty much just going to bed as soon as I left work each day and got home.
I *had* noticed that handling felt like it was changing, but I thought it was from the way I felt from my cold.
Basically, under normal conditions, the wheel "flops" over, especially with me sitting on it, so the tiller / handlebars are around 45 ish degrees away from center.
But this morning, it flopped past *90* degrees, so the wheel was actually pointing so far right ti was backwards a little bit. I got off the trike and looked at it, cuz that was just wierd, and for just a moment I wondered if somehow I had installed the fork backwards, because it looked like it. But I knew I couldn't have, because it wasn't bent that way before.
I examined it and found it was "ok" but I can't trust it. I had to leave for work right then, or I would've swapped it back out for the old crappy suspension fork--which would've taken a couple of hours or more the way I feel with teh cold.
I considered bending it back, but decided better to leave bad enough alone, and not break it off or something even worse like a structural crack that would fail on the road.
I rode as slowly as possible to work, so average around 12MPH, to still get there on time, without incident.
Made ti home from work fine, too, though I had to go normal speeds due to traffic conditions, and just start braking a lot early to not put stress on the fork I didn't have to. (lots of impatient drivers out today vs other days).
Some pics that show paint actually flaked away at the bending areas, overview shot showing it's actually bent backwards, etc.
Scary stuff. :/
This is the angle the fork *should* be at:
This is the angle it's at *now*:
Attachments
Chalo
100 TW
Yikes!
Back in the late 1980s, I used to bend about a fork a month by overexuberant braking. Those were the days of 1" steer tubes on MTBs with unprecedentedly strong brakes. Some of them bent back at the steer tube, but some bent at the heat affected zone around the brake posts.
Steel forks do get stronger progressively after they fail, but at some point they rupture without further ado. It's time to put another fork on that bike.
Back in the late 1980s, I used to bend about a fork a month by overexuberant braking. Those were the days of 1" steer tubes on MTBs with unprecedentedly strong brakes. Some of them bent back at the steer tube, but some bent at the heat affected zone around the brake posts.
Steel forks do get stronger progressively after they fail, but at some point they rupture without further ado. It's time to put another fork on that bike.
No kidding.
I wouldn't even have ridden it to work if I'd had any other options.
At least it isn't aluminum--that would probably just have snapped while riding.
If I'd been doing hard braking, even medium, I could understand...but I wasn't--though it was obviously more inertia than this fork was designed to handle. Not all that surprising given the mass of the trike vs the mass of the fatbike it was intended to work with (even with a hefty rider it's still probably double the mass).
IIRC, this fork was originally from Luna, and I *think* they were takeoffs from their complete fat-e-bike builds, sold separately to recoup costs or whatever, though I don't know if they swapped out forks because of the flimsiness of this model, or because they wanted some other feature from the bike that this fork wouldn't give. Just speculation--the only fact I am sure of is that I got this fork via Cvin when she was ordering ohter stuff from Luna, specifically so I could try this rearhubmotor-on-the-front experiment.
EDIT: found the original LUna page on it:
https://lunacycle.com/fat-tire-rigid-fork-26-non-tapered/
https://lunacycle.com/fusion-500-fat-ebike/
but since the fork on that bike in the pic looks very similar (not identical) to the one that came off of it, I wonder why they did change them out? The original fork has more accessory mounts....one would think it would be better?
Ah well, it did last about a week or two of riding (I forget what day I actually put it on there). Probably good that I didn't get to the motor testing stage. :lol:
Now, the good news is that I have most of the parts for a new, much stronger fork, thanks to Chalo. He actually sent them last week and they arrived Saturday, but I don't have quite the right size of tubing laying around for the fork legs, so I didn't get them built yet. Have to do this in the next couple days, though, so I can ride back to work.
I'll post pics of the pieces, and the plan, a bit later. Right now I'm trying not to cough my lungs out...feels like I inhaled a rasp, pulled it out, and repeated the process a few dozen times.
I wouldn't even have ridden it to work if I'd had any other options.
At least it isn't aluminum--that would probably just have snapped while riding.
If I'd been doing hard braking, even medium, I could understand...but I wasn't--though it was obviously more inertia than this fork was designed to handle. Not all that surprising given the mass of the trike vs the mass of the fatbike it was intended to work with (even with a hefty rider it's still probably double the mass).
IIRC, this fork was originally from Luna, and I *think* they were takeoffs from their complete fat-e-bike builds, sold separately to recoup costs or whatever, though I don't know if they swapped out forks because of the flimsiness of this model, or because they wanted some other feature from the bike that this fork wouldn't give. Just speculation--the only fact I am sure of is that I got this fork via Cvin when she was ordering ohter stuff from Luna, specifically so I could try this rearhubmotor-on-the-front experiment.
EDIT: found the original LUna page on it:
https://lunacycle.com/fat-tire-rigid-fork-26-non-tapered/
This is the kind of biek it was taken off of
https://lunacycle.com/fusion-500-fat-ebike/
but since the fork on that bike in the pic looks very similar (not identical) to the one that came off of it, I wonder why they did change them out? The original fork has more accessory mounts....one would think it would be better?
Ah well, it did last about a week or two of riding (I forget what day I actually put it on there). Probably good that I didn't get to the motor testing stage. :lol:
Now, the good news is that I have most of the parts for a new, much stronger fork, thanks to Chalo. He actually sent them last week and they arrived Saturday, but I don't have quite the right size of tubing laying around for the fork legs, so I didn't get them built yet. Have to do this in the next couple days, though, so I can ride back to work.
I'll post pics of the pieces, and the plan, a bit later. Right now I'm trying not to cough my lungs out...feels like I inhaled a rasp, pulled it out, and repeated the process a few dozen times.
RunForTheHills
1 kW
That's scary. Good thing you caught it before it failed.
e-beach
10 MW
Good it didn't snap! 
On the other hand, ( and please tell me if this is waaay to obvious. ) I am beginning to think that the weight of your trike vs the rake of your head tube puts a larger amount of pressure on the fork then designed.
Time to reduce the weight of your trike?
On the other hand, ( and please tell me if this is waaay to obvious. ) I am beginning to think that the weight of your trike vs the rake of your head tube puts a larger amount of pressure on the fork then designed.
Time to reduce the weight of your trike?
This trike with me on it is definitely heavier than what most bicycle forks are designed for. However: The ones that broke in the crash (Suntour XCT?) worked just fine right up until that crash. Probably would've kept working until I either wore the bushings out or swapped them out for some other experiment (like the fatbike fork/rear hubmotor).
AFAICT, the fork being at a "slacker" angle ought to *reduce* the stress on the fork that caused it to bend backwards. If it were more vertical, the forces would more directly be perpendicular to the direction of travel. But I R Not A Physicist, and has been knownses to be wrong.
I sort of expected problems with it bending the *other* direction (upwards/forwards) from bump/shock loads of potholes and the like, washboard road sections, and so on, but apparently even though that's more or less a constant stress on the fork, along with the weight of the trike pushing down on it, it's nowhere near the amount of force exerted during braking.
As far as reducing the weight, sure, I'd love to...but since the cargo I carry generally weighs more than any reduction I could do, everything would still have to handle the same inertia in braking. If you look around on previous pages of this thread, you'll find a few posts talking about diets I'd like to put the trike on. :lol: All of them require essentialy completely rebuilding the trike...from scratch, with brand new materials of better steel to save a few pounds total, built around the idea of a hefty middrive system to both rear wheels with a differental that can take the torque presently provided by dual hubmotors. (and moving the pedal drivetrain to the front wheel, somewhat complex to do right).
I could probably save 25-50lbs by losing the hubmotors, even accounting for the midrive parts; a smaller primary traction battery would be needed for the same range, so would be part of that savings.
I could probably ditch 50lbs by losing the cargo/seatbox and the rear cargo deck/pod, and the canopy, between the wood and the steel frame, but those are essential parts of how the trike does the work I need it to do. (much more effective than previous attempts, like boxes bolted or strapped to the bare frame, fragile plastic dog carriers, suitcases, etc, and the insulated canopy lets me ride in relative comfort even in the middle of the day when it's 120F+ out there, cuz the sun isn't directly baking most of me).
Realistically, unless I win the lottery or something, so could go to part-time or less at work, but still have plenty of money to live on and then have the free time and money to actually do it, I don't imagine a version two of this thing happening anytime soon, as much as I'd love to design and build it.
Remember also that the front brake doesn't have to handle the full braking load--I use the rear regen brakes too, normally those are used more often than the front brake for harder stops (cuz the regen is just off/on). The front brake is used for gradual stops, or just slowing a bit under various conditions, and to hold the trike still at an intersection or other complete stop that's not on a level enough surface to stay otherwise.
AFAICT, the fork being at a "slacker" angle ought to *reduce* the stress on the fork that caused it to bend backwards. If it were more vertical, the forces would more directly be perpendicular to the direction of travel. But I R Not A Physicist, and has been knownses to be wrong.
I sort of expected problems with it bending the *other* direction (upwards/forwards) from bump/shock loads of potholes and the like, washboard road sections, and so on, but apparently even though that's more or less a constant stress on the fork, along with the weight of the trike pushing down on it, it's nowhere near the amount of force exerted during braking.
As far as reducing the weight, sure, I'd love to...but since the cargo I carry generally weighs more than any reduction I could do, everything would still have to handle the same inertia in braking. If you look around on previous pages of this thread, you'll find a few posts talking about diets I'd like to put the trike on. :lol: All of them require essentialy completely rebuilding the trike...from scratch, with brand new materials of better steel to save a few pounds total, built around the idea of a hefty middrive system to both rear wheels with a differental that can take the torque presently provided by dual hubmotors. (and moving the pedal drivetrain to the front wheel, somewhat complex to do right).
I could probably save 25-50lbs by losing the hubmotors, even accounting for the midrive parts; a smaller primary traction battery would be needed for the same range, so would be part of that savings.
I could probably ditch 50lbs by losing the cargo/seatbox and the rear cargo deck/pod, and the canopy, between the wood and the steel frame, but those are essential parts of how the trike does the work I need it to do. (much more effective than previous attempts, like boxes bolted or strapped to the bare frame, fragile plastic dog carriers, suitcases, etc, and the insulated canopy lets me ride in relative comfort even in the middle of the day when it's 120F+ out there, cuz the sun isn't directly baking most of me).
Realistically, unless I win the lottery or something, so could go to part-time or less at work, but still have plenty of money to live on and then have the free time and money to actually do it, I don't imagine a version two of this thing happening anytime soon, as much as I'd love to design and build it.
Remember also that the front brake doesn't have to handle the full braking load--I use the rear regen brakes too, normally those are used more often than the front brake for harder stops (cuz the regen is just off/on). The front brake is used for gradual stops, or just slowing a bit under various conditions, and to hold the trike still at an intersection or other complete stop that's not on a level enough surface to stay otherwise.
e-beach
10 MW
Ok, so soon isn't in your life's trajectory at the moment. That doesn't mean you couldn't slowly build a second e-bike / e-trike for times when you can ride something besides a crazybike with a large load. In any case I just said a little prayer that your new forks last as long as you need them to work.
Yeah, slow building is the way I'd do it anyway...but getting the parts (at least the frame tubing) is one big expense all up front at once...and I'll have to design the frame first, which requires having the middrive design first, which will require me getting off my butt and actually doing the work.
I do need to get CrazyBike2 back in operation, as my spare cargo bike. (cuz whatever I ride, it almost always does have to be a cargo bike or trike of some form, able to carry a fair bit of stuff at a moment's notice without changing the way it rides...I've found that I don't just "go somewhere" anymore, I just go to get things or take things, except for work. And even going to / from work is safer with a bigger bike, making me more visible and "making" people go around me instead of forcing me off the road or running me over. Aside from me frequently needing the cargo area for dog food / etc.)
I *do* have a regular plain old bicycle that is almost complete, that I could probably ride a block or two at a time before sitting on the sidewalk for a while resting. ONce it's complete I will add an old Kepler drive to it for enough assist to at least get me to work and back home.
The biggest catch I have these days is time...and money, but mostly time/energy to do things--whenever I think I'm about to catch up, something happens to eat that up (like the crash and fork problems, or me being sick, and so worn out that my week and a half off mostly got spent resting and doing little things instead of the major stuff I'd planned on, other than the fork/wheel replacement).
Anyway, enough griping, on to the new fork stuff:
I do need to get CrazyBike2 back in operation, as my spare cargo bike. (cuz whatever I ride, it almost always does have to be a cargo bike or trike of some form, able to carry a fair bit of stuff at a moment's notice without changing the way it rides...I've found that I don't just "go somewhere" anymore, I just go to get things or take things, except for work. And even going to / from work is safer with a bigger bike, making me more visible and "making" people go around me instead of forcing me off the road or running me over.
Aside from me frequently needing the cargo area for dog food / etc.)I *do* have a regular plain old bicycle that is almost complete, that I could probably ride a block or two at a time before sitting on the sidewalk for a while resting. ONce it's complete I will add an old Kepler drive to it for enough assist to at least get me to work and back home.
The biggest catch I have these days is time...and money, but mostly time/energy to do things--whenever I think I'm about to catch up, something happens to eat that up (like the crash and fork problems, or me being sick, and so worn out that my week and a half off mostly got spent resting and doing little things instead of the major stuff I'd planned on, other than the fork/wheel replacement).
Anyway, enough griping, on to the new fork stuff:
The idea:
First, why do they call them 'triple clamp/triple crown" forks? They only have TWO. :lol: (I suppose there are three *clamps*, one for each fork leg and one for the steerer...but...?)
Anyway, so taht's the kind of fork this will be, which should eliminate (or reduce) teh ability to flex like the fatbike fork does, and to bend at teh crown like that.
The clamps, steerer, and graduates (really they'd be dropouts, but these didn't stop going to school and grew up big and strong ) were supplied by Chalo, who I thank immensely, as they came just in time with the fatbike fork being weak as it is and beginning to fail rapidly.
The clamps are for 1.25" tubing, and I have some thickwall steel pipe that is very close (Chalo estimates it is probably 1" Schedule40), but I'd have to machine it's OD down significantly to fit. I might still do that eventually. But he also suggested some bike frames may have the right OD tubing, so I dug thru my stuff, and I did find a couple of short lengths, around a foot and a half. Not long enough. But I also had an old Schwinn traveller frame that was probably meant for some giant 7foot tall rider :lol: that had top and down tubes that were almost long enough, too...but they are too small a diameter.
But the difference in diameter happens to be about the same as the thickness of teh larger tubing, so I'll just put the Traveller's tubes inside the other two (one piece off an old Trek (which I'd cut apart for other bits of tubing for CrazyBike2 years back), and one piece off an Eclipse (formerly the Velcro Eclipse ebike I used for a while years ago).
So I trimmed them to be symmetrical, and test fit them together, and adjusted them to have some inches extra length out the top of the top clamp, in case I want to adjust for longer fork legs (unlikely, but...worth experimenting with), and so that the bottom end of the tubes ends up at the bottom end of the broken suspension fork's legs (not dropouts), to approximate the same geometry it had before.
Then I cut the ends off some steel shelving fixtures that will end up as boxes around the bottom end of the legs. Teh dropouts will be placed on the front edges of these. (the back halves of the boxes are not yet cut and placed). The disc mounts are on the front for these (to keep the disc brake forces from pulling the axle out of dropouts, instead forcing them in), so the caliper will now be on the rigth side, in front of the fork. Since the motor isn't directional (is a DD hub), then that's fine, I'll just flip it over so the rotor mount is on the right.
I just have to make sure that the boxes and the fork legs aren't in the way of the motor or disc, etc., becuase ATM I"m pretty sure they are. I might have to just use a regular front disc-compatible wheel with this for now (I have one I dug out just in case), and then make fork legs that allow a wider axle/motor later. Not sure exactly how...but one way might be to use pieces of a nonsuspension fork that has the U bend, cut and butt-welded (with smaller tubing inside the joint) such that the U is now a kind of S, so that the bottom of the legs bend "around" the motor and disc.
Another way is to end the tubing of the main legs short of the entire disc/motor circumference, and mount the boxes in such a way as to more or less be on the outer edges of the tubing, extending about 3-4" or so to allow the dropouts to reach the axle, but everything clear the motor/ rotor. Then the main tubing would be pushed up farther past the top clamp, to keep the fork the same length.
This also allows me to put regular front-axle-spaced dropouts on as well, at the end of the main tubing. Thus, if I need to, I can "simply" take the motor wheel out, put the plain front wheel in (moving the disc rotor over as I don't have another 200mm, moving the caliper from the main dropouts to the plain ones, and adjust the fork legs downward in the clamps to make the same geometry again.
For now, some pics of the guesstimated layout of the first design. Then a nap most likely as I'm still hacking my lungs out, and it's been pretty hot outside (over 100F and humid) while I was digging for bits and cutting, test fitting, etc., I'm bushed.
First, why do they call them 'triple clamp/triple crown" forks? They only have TWO. :lol: (I suppose there are three *clamps*, one for each fork leg and one for the steerer...but...?)
Anyway, so taht's the kind of fork this will be, which should eliminate (or reduce) teh ability to flex like the fatbike fork does, and to bend at teh crown like that.
The clamps, steerer, and graduates (really they'd be dropouts, but these didn't stop going to school and grew up big and strong
) were supplied by Chalo, who I thank immensely, as they came just in time with the fatbike fork being weak as it is and beginning to fail rapidly.The clamps are for 1.25" tubing, and I have some thickwall steel pipe that is very close (Chalo estimates it is probably 1" Schedule40), but I'd have to machine it's OD down significantly to fit. I might still do that eventually. But he also suggested some bike frames may have the right OD tubing, so I dug thru my stuff, and I did find a couple of short lengths, around a foot and a half. Not long enough. But I also had an old Schwinn traveller frame that was probably meant for some giant 7foot tall rider :lol: that had top and down tubes that were almost long enough, too...but they are too small a diameter.
But the difference in diameter happens to be about the same as the thickness of teh larger tubing, so I'll just put the Traveller's tubes inside the other two (one piece off an old Trek (which I'd cut apart for other bits of tubing for CrazyBike2 years back), and one piece off an Eclipse (formerly the Velcro Eclipse ebike I used for a while years ago).
So I trimmed them to be symmetrical, and test fit them together, and adjusted them to have some inches extra length out the top of the top clamp, in case I want to adjust for longer fork legs (unlikely, but...worth experimenting with), and so that the bottom end of the tubes ends up at the bottom end of the broken suspension fork's legs (not dropouts), to approximate the same geometry it had before.
Then I cut the ends off some steel shelving fixtures that will end up as boxes around the bottom end of the legs. Teh dropouts will be placed on the front edges of these. (the back halves of the boxes are not yet cut and placed). The disc mounts are on the front for these (to keep the disc brake forces from pulling the axle out of dropouts, instead forcing them in), so the caliper will now be on the rigth side, in front of the fork. Since the motor isn't directional (is a DD hub), then that's fine, I'll just flip it over so the rotor mount is on the right.
I just have to make sure that the boxes and the fork legs aren't in the way of the motor or disc, etc., becuase ATM I"m pretty sure they are. I might have to just use a regular front disc-compatible wheel with this for now (I have one I dug out just in case), and then make fork legs that allow a wider axle/motor later. Not sure exactly how...but one way might be to use pieces of a nonsuspension fork that has the U bend, cut and butt-welded (with smaller tubing inside the joint) such that the U is now a kind of S, so that the bottom of the legs bend "around" the motor and disc.
Another way is to end the tubing of the main legs short of the entire disc/motor circumference, and mount the boxes in such a way as to more or less be on the outer edges of the tubing, extending about 3-4" or so to allow the dropouts to reach the axle, but everything clear the motor/ rotor. Then the main tubing would be pushed up farther past the top clamp, to keep the fork the same length.
This also allows me to put regular front-axle-spaced dropouts on as well, at the end of the main tubing. Thus, if I need to, I can "simply" take the motor wheel out, put the plain front wheel in (moving the disc rotor over as I don't have another 200mm, moving the caliper from the main dropouts to the plain ones, and adjust the fork legs downward in the clamps to make the same geometry again.
For now, some pics of the guesstimated layout of the first design. Then a nap most likely as I'm still hacking my lungs out, and it's been pretty hot outside (over 100F and humid) while I was digging for bits and cutting, test fitting, etc., I'm bushed.
Attachments
A "sketch" to make it clearer.
clamps are gray, steerer and main tubes are black.
Red is the "boxes" that the motor dropouts will be mounted on.
darker blue is the "normal" dropouts, lighter blue is the wider ones for the motor.
Yellow is the caliper (won't be two of them, just gets moved between when a wheel changeover is necessary).
Purple is the axle point for each position.
clamps are gray, steerer and main tubes are black.
Red is the "boxes" that the motor dropouts will be mounted on.
darker blue is the "normal" dropouts, lighter blue is the wider ones for the motor.
Yellow is the caliper (won't be two of them, just gets moved between when a wheel changeover is necessary).
Purple is the axle point for each position.
Attachments
Still not feeling very well, though not hacking my lungs out constantly, so I'm going with the simple version today, then work on the motor-capable version later.
For extra simplicity, I'm taking the lowers off an old set of "element" shocks (pogo sticks, really, off what was left of some mongoose hatchet bso) cuz they already ahve the drpouts and disc mount, and will (hopefully) just slide those over the bottom of the main tubes, after I get the plastic bushings out. If I can keep teh lowers "intact" then the U bracket on top will keep everything aligned for me, and it'll take minimal work to get me a safe fork on the trike.
We'll see in a few hours, hopefully.
(I'd use the dropouts sent with the clamps, but I don't want to weld on those twice, and I'll still want to use them for the wider motor-capable dropouts once I get that far).
For extra simplicity, I'm taking the lowers off an old set of "element" shocks (pogo sticks, really, off what was left of some mongoose hatchet bso) cuz they already ahve the drpouts and disc mount, and will (hopefully) just slide those over the bottom of the main tubes, after I get the plastic bushings out. If I can keep teh lowers "intact" then the U bracket on top will keep everything aligned for me, and it'll take minimal work to get me a safe fork on the trike.
We'll see in a few hours, hopefully.
(I'd use the dropouts sent with the clamps, but I don't want to weld on those twice, and I'll still want to use them for the wider motor-capable dropouts once I get that far).
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