SUITABLE FULL SUSPENSION FRAMES?
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Gordo
100 kW
The lack of space because of the rear suspension is a real problem. I have been unsuccessful in my search for such a frame. On Friday I ordered 2 of these;
Today I bought a used one for $60 so I won`t have to cut up a new bike to satisfy my brain fart. I am going to move the suspension shock/spring, behind the seat post, so I have the entire triangle for a battery. This means moving the pivot points for the swing arm and rear suspension, back @ 10". What can be the downside of this?
Today I bought a used one for $60 so I won`t have to cut up a new bike to satisfy my brain fart. I am going to move the suspension shock/spring, behind the seat post, so I have the entire triangle for a battery. This means moving the pivot points for the swing arm and rear suspension, back @ 10". What can be the downside of this?
MadRhino
100 GW
You're going to need more power to wheelie.Gordo said:
John in CR
100 TW
Gordo,
Lengthening the wheelbase is great. There are some issues though.
Moving the pivot point is likely to create chain issues. eg The length of the chain required will change as the suspension compresses. The extra length could cause the chain to bang or rub on the chain stay.
The biggest issue will be in handling. Moving the location of the saddle reward will probably cure most of the issue, but allow for a lot of adjustment because it's a bit of a shot in the dark. Since that also changes the relationship to the pedals, you'll probably need to lower the saddle too.
Once you get the weight distribution and distance to the pedals how you want it, you may still not like the handling because you've changed the geometry of the bike. With the steel MTB that I added 16" to the wheelbase, I ended up hacking off the headset to decrease the head tube angle. I probably went a bit too far and created too much trail at just over 4", which makes the bike a bit sluggish and awkward at very low speeds, but at anything from 10mph to 60mph she tracks like on rails. I also went with a motorcycle seat, so I can fine tune the ride by moving my position on the seat slightly. This comes in handy with the various loads I carry. It's also nice to change positions for ass relief on long rides.
I know you can pull off whatever mods you want, so I look forward to what you come up with. If you have second thoughts though, I see lots of room for batts without changing anything. Batteries mounted saddlebag style over the top tube works surprisingly well. You also have some room in the triangle and below the down tube, so don't feel obligated to hack into the bike just yet.
John
Lengthening the wheelbase is great. There are some issues though.
Moving the pivot point is likely to create chain issues. eg The length of the chain required will change as the suspension compresses. The extra length could cause the chain to bang or rub on the chain stay.
The biggest issue will be in handling. Moving the location of the saddle reward will probably cure most of the issue, but allow for a lot of adjustment because it's a bit of a shot in the dark. Since that also changes the relationship to the pedals, you'll probably need to lower the saddle too.
Once you get the weight distribution and distance to the pedals how you want it, you may still not like the handling because you've changed the geometry of the bike. With the steel MTB that I added 16" to the wheelbase, I ended up hacking off the headset to decrease the head tube angle. I probably went a bit too far and created too much trail at just over 4", which makes the bike a bit sluggish and awkward at very low speeds, but at anything from 10mph to 60mph she tracks like on rails. I also went with a motorcycle seat, so I can fine tune the ride by moving my position on the seat slightly. This comes in handy with the various loads I carry. It's also nice to change positions for ass relief on long rides.
I know you can pull off whatever mods you want, so I look forward to what you come up with. If you have second thoughts though, I see lots of room for batts without changing anything. Batteries mounted saddlebag style over the top tube works surprisingly well. You also have some room in the triangle and below the down tube, so don't feel obligated to hack into the bike just yet.
John
AussieJester
1 TW
You can easily lengthen the rear and not alter anything else, there' s a
young French chap that's done a great job with lengthening one of
those 4 pivot point rear ends AND in doing so moved the shock
behind the seat post (apologies his nick alludes me dammit, I read all
his threads too) .. plenty of room in the triangle for lipo, some nice side
covers and she would be stealthy looking e- bicycle. ... best of luck with
it Gordon
KiM
young French chap that's done a great job with lengthening one of
those 4 pivot point rear ends AND in doing so moved the shock
behind the seat post (apologies his nick alludes me dammit, I read all
his threads too) .. plenty of room in the triangle for lipo, some nice side
covers and she would be stealthy looking e- bicycle. ... best of luck with
it Gordon
KiM
Gordo
100 kW
John;
Tomorrow I'm off to the shallow end of the swamp we call Canada and hope to visit with DocBas. If I have time in the morning, I will take some quick measurements of this frame so I have something ebike good to occupy my mind for 10 days. I know dam welll I should just pull a Timma and do it right the first time, but I will hack and fux up the first try, as usual. Too old to start doing things correctly the first time. I am kicking myself for giving away my 4' x 4' x 3/4" thick steel table, because I will now have to build a jig to keep things straight. I'm also going to get my 16 Ton tube bender back asap.
I will take my battery packs apart and see what I can do for fitting them in the frame. This takes all the fun out of watching Aluminum twist and bend as the heat goes in and out or it.
I will definitely ask you about angles and spacing, when I get to that point.
Thanks
Kim;
This post stuttered and while it was bouncing around, I got off the couch, found a pencil and ruler and did some measurements. I would leave the seat post where it is and only have to move the pivots back 6". Even 5" could do it if I had to.
I will go looking for the guy in your reference.
Thanks
Tomorrow I'm off to the shallow end of the swamp we call Canada and hope to visit with DocBas. If I have time in the morning, I will take some quick measurements of this frame so I have something ebike good to occupy my mind for 10 days. I know dam welll I should just pull a Timma and do it right the first time, but I will hack and fux up the first try, as usual. Too old to start doing things correctly the first time. I am kicking myself for giving away my 4' x 4' x 3/4" thick steel table, because I will now have to build a jig to keep things straight. I'm also going to get my 16 Ton tube bender back asap.
I will take my battery packs apart and see what I can do for fitting them in the frame. This takes all the fun out of watching Aluminum twist and bend as the heat goes in and out or it.
I will definitely ask you about angles and spacing, when I get to that point.
Thanks
Kim;
This post stuttered and while it was bouncing around, I got off the couch, found a pencil and ruler and did some measurements. I would leave the seat post where it is and only have to move the pivots back 6". Even 5" could do it if I had to.
I will go looking for the guy in your reference.
Thanks
Grinhill
10 kW
AussieJester said:
Is this the one Kim, from bzhwindtalker?
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=30490#p440669
AussieJester
1 TW
Gordo said:
Soz about that, was my doing, i was posting from my mobile and sometimes it copies a section of the post and pastes it at the end with my name
no matter how many times i try edit it out and re-post it doesn't fix it, i ended up delteing the post and redoing it hence the "stuttering"
@Grinhill ...YES! bzhwindtalker? be the fella, he has made some great rides and hes still in school! what great skillz
from such a young chap...
KiM
dogman dan
1 PW
I just took it like a dog, and resorted to saddlebag style battery boxes attached to the side of the frame. Various reasons for it, particularly the abilty to swap to fresh charged batteries in about 60 seconds.
While riding along yesterday, as usual wishing the boxes were just a bit narrower, I realized that a different lipo pack would make a narrower box possible. Instead of 5s or 6s packs, you could build from 3s packs. Then turn them so the narrow side is parallel to the frame. Vilola, the box would be longer, but at least an inch narrower for the two boxes and the frame.
Frome what I see, none of the full suspension bikes that still have a large triangle have one big enough to really hold enough battery for long rides. But if you only want to carry 5 ah, then it's a much different story. It just depends on the situation. Long ride to the trails, or short blasts around trails that ar more like a track you do laps on.
While riding along yesterday, as usual wishing the boxes were just a bit narrower, I realized that a different lipo pack would make a narrower box possible. Instead of 5s or 6s packs, you could build from 3s packs. Then turn them so the narrow side is parallel to the frame. Vilola, the box would be longer, but at least an inch narrower for the two boxes and the frame.
Frome what I see, none of the full suspension bikes that still have a large triangle have one big enough to really hold enough battery for long rides. But if you only want to carry 5 ah, then it's a much different story. It just depends on the situation. Long ride to the trails, or short blasts around trails that ar more like a track you do laps on.
antarctic74
1 µW
- Joined
- Oct 14, 2009
- Messages
- 4
I'm also looking for a full-suspension frame. Since batteries should be down and center, I looked for frames where the rear shock is at the top of the triangle. Bottom of triangle would then be free space. Even this configuration won't suit those who need the entire triangle for batteries. But like dogman said, you should be able to fit 5 Ah of batteries below the shock.
Cube AMS
Ghost AMR 9000 (except Lector variant)
Radon QLT Litening
Cube AMS
Ghost AMR 9000 (except Lector variant)
Radon QLT Litening
izeman
1 GW
if looking for a frame, i would also suggest looking for a frame with STEEL dropouts.
i'm looking for a downhill frame, but can't find any. all of them i've seen so far have a very "compact" frame to better withstand the forces i guess.
i'm looking for a downhill frame, but can't find any. all of them i've seen so far have a very "compact" frame to better withstand the forces i guess.
dogman dan
1 PW
Only the cheap mongoose blackcomb has steel rear dropouts, and it's an old school y frame.
But John in CR fabricated a very nice extended length rear swingarm for his cannondale frame. That's pretty much the best option, if you really want a steel rear end on a DH mountainbike. Build it. Once you are getting into high quality, high wattage builds, the cost may be less than you think to get a rear swingarm fabricated. Nothing compared to what you are about to spend on batteries and fried motors.
But John in CR fabricated a very nice extended length rear swingarm for his cannondale frame. That's pretty much the best option, if you really want a steel rear end on a DH mountainbike. Build it. Once you are getting into high quality, high wattage builds, the cost may be less than you think to get a rear swingarm fabricated. Nothing compared to what you are about to spend on batteries and fried motors.
Gordo
100 kW
The swingarm is steel.Gordo said:
dogman dan
1 PW
Just took a close look at the CCM bike. Looks OK, but it's no DH bike. Same basic rear suspension geometry as the blackcomb which is good. The 4 bar link really helps improve the ride given the same cheap pogo stick shock. The rear dropouts may be steel, but they aren't as wide and flat as the mogoose ones, so slightly harder to install a pinch dropout. The CCM I looked close at had rim rear brakes, but there may be disk mounts. I was looking at a poor video of one on y tube.
All in all, a suitable FS with steel rear drops for most riders, but not suitable for somebody wanting real suspesnsion performance, and like the blackcomb, it likely has a lot less lateral stiffness to the frame than a real DH or quality crosscountry FS frame. The vid I was watching mentioned an MSRP of $400.
There are many other wallbikes, or sometimes called bike shaped objects out there with steel rear suspension. But I still think the blackcomb is the best one out there I have seen for making an easy install of a torque plate or pinch dropout. The big flat plate of steel is really nice on those. The mongoos does of course, suck for carrying the batteries. You have to resort to this, or do a backpack.
All in all, a suitable FS with steel rear drops for most riders, but not suitable for somebody wanting real suspesnsion performance, and like the blackcomb, it likely has a lot less lateral stiffness to the frame than a real DH or quality crosscountry FS frame. The vid I was watching mentioned an MSRP of $400.
There are many other wallbikes, or sometimes called bike shaped objects out there with steel rear suspension. But I still think the blackcomb is the best one out there I have seen for making an easy install of a torque plate or pinch dropout. The big flat plate of steel is really nice on those. The mongoos does of course, suck for carrying the batteries. You have to resort to this, or do a backpack.
Gordo
100 kW
Our MSRP is $449 and with tax bcomes $503. The sale was $180, tax in. This is why I ordered 2 and Arlo ordered one. The used one I bought had rim brakes, but the new ones have disks. The bracket for a caliper is on the front forks of the used one and I got the parts with it. The purpose of this bike is road riding in comfort. No death defying leaps into space. I just need some more suitable tires for the road.
Arlo has a nice flat plate with pinch clamp designed and it is easy to weld onto the rear dropouts. Doing this may also reduce the amount of stretch needed for the suspension.
Arlo has a nice flat plate with pinch clamp designed and it is easy to weld onto the rear dropouts. Doing this may also reduce the amount of stretch needed for the suspension.
dogman dan
1 PW
Sounds like a deal. And it does look a bit better than some of the similar looking wallbikes. No super cheap twist shifters, and at least mechanical disks. All good. Definitely not a steal at MSRP, but you got a great price! Steel in the back means you can easliy weld on whatever you need to controll the axle. Even if you weld as poorly as I do. :lol:
Sometimes in these frame discussions, one guy is talking building a commuter with suspension to soak up potholes, while the other wants something that rides DH trails. So one persons perfect choice may not cut it for heavier duty use another is planning on.
The common denominator on the many versions of the bike shaped object seems to be frames that have less stiffness from side to side. Even the blackcomb wags it's tail if you load it heavy for touring, or grocery getting. Real FS frames have a lot less of that tendency to flex from side to side when loaded up. Thicker tubes, or maybe there is internal structure in the tubes. For sure they ride nicer, especially when lugging a set of full panniers. Trouble is, thes nicer frames tend to have rear dropouts that are not easy shapes to fit a torque plate onto, and you can't weld steel onto em.
Sometimes in these frame discussions, one guy is talking building a commuter with suspension to soak up potholes, while the other wants something that rides DH trails. So one persons perfect choice may not cut it for heavier duty use another is planning on.
The common denominator on the many versions of the bike shaped object seems to be frames that have less stiffness from side to side. Even the blackcomb wags it's tail if you load it heavy for touring, or grocery getting. Real FS frames have a lot less of that tendency to flex from side to side when loaded up. Thicker tubes, or maybe there is internal structure in the tubes. For sure they ride nicer, especially when lugging a set of full panniers. Trouble is, thes nicer frames tend to have rear dropouts that are not easy shapes to fit a torque plate onto, and you can't weld steel onto em.
nuevomexicano
100 W
The mid-1990's Specialized Stumpjumper FSR might have the most frame space of a full suspension bike I've seen. There's a 1995 model for sale at $200 right now on the Albuquerque Craigslist (the picture below isn't that one, which is a full bike with all the parts rather than this stripped image). I'm sort of interested, but I'm looking at other bikes that are less of a build up.
Gordo
100 kW
dogman said:
neuvo;
I really like that suspension system being out of the triangle. When looking at the triangle and comparing to the size of a brick in the background, I wonder just how small it is? 18" or 16", almost looks like BMX size?
John;
My guess it that someone in the crew who designed this CCM realized steel was the best way to make an adequate swingarm? This steel dropout is very small, but we have the technology, to improve on it. I even have some square steel tubing in my pile of angle iron bedframes.
You actually can weld aluminum to steel. I have even welded aluminum to SS which can be done with an ordinary MIG, using aluminum wire. I remember being very excited when I discouvered this. I told the most experienced welder I knew, expecting to impress him. He just laughed and asked me if I just figured this out? I had loose SS inserts in aluminum tabs and was just attempting to tighten them up, when to my surprise, they fused very well. I was unable to break them apart with a very large hammer.
The last 80' boat I worked on was steel up to the weather deck and aluminum from there on, including all the rigging. The interface was a strip of aluminum/steel which is joined via a flash powder. The two metal are pressed together at 50,000psi and then the powder is lit. detacouple is the trade name; http://www.dynamicmaterials.com/Home
Even in salt water, it takes 25-30 years for electrolysis to compromise an unprotected joint. With cathodic protection, the integrity of the joint can be maintained.
Pothole Gord
nuevomexicano
100 W
Gordo said:
For what its worth, the one I saw in person was a full size mountain bike but I really don't know the dimensions. I remember there being a bit of a trend in the '90's toward small framed mountain bikes being used with long seat tubes and long handle bar necks. The one I saw in person had 26" wheels, so its safe to assume the one in this pictures has as well if you want to extrapolate dimensions.
Kingfish
100 MW
Bare frame as purchased from eBay.
I spec’d out the 2009 Felt Compulsion 1 for my latest version. Overall, it is a good frame and can support 18 LiPo bricks in the triangle, and another 12 in a pair of saddlebags draped over the top. However the problem areas are: Rear suspension cannot handle too much load up high; if you keep the load near the axels then handling will be a lot better. That said – I had 9 more bricks in each pannier when fully loaded. In addition, the rear suspension can only handle up to 2.5-inch wide tires, such as Hookworms. Lastly the rear suspension was not designed to mount fenders conveniently and I struggled with this aspect on my entire time On the Road. Still – it is a good interim frame and served its’ purpose well enough. Absolutely a blast as a 2WD for commuting!
Near the end of my road trip.
Cheers, KF
Gordo
100 kW
Kingfish said:
Bare frame as purchased from eBay.
I spec’d out the 2009 Felt Compulsion 1 for my latest version. Overall, it is a good frame and can support 18 LiPo bricks in the triangle, and another 12 in a pair of saddlebags draped over the top. However the problem areas are: Rear suspension cannot handle too much load up high; if you keep the load near the axels then handling will be a lot better. That said – I had 9 more bricks in each pannier when fully loaded. In addition, the rear suspension can only handle up to 2.5-inch wide tires, such as Hookworms. Lastly the rear suspension was not designed to mount fenders conveniently and I struggled with this aspect on my entire time On the Road. Still – it is a good interim frame and served its’ purpose well enough. Absolutely a blast as a 2WD for commuting!
Near the end of my road trip.
Cheers, KF
So I am guessing 9Ah in the triangle? $1000 frame?
dogman dan
1 PW
You're the king of carry dude. And one of the few that can sit in the saddle long enough to discharge it all in one day too.
18 bricks in that frame, I guess that's stacking them crosswise. Most of us think in terms of two wide, making the box only 4" wide.
The most I ever packed onto a bike was for the race, where I had 26s 15 ah on there. 12 bricks in boxes aside the top tube, and 3 more on a rack in back. 15 bricks.
18 bricks in that frame, I guess that's stacking them crosswise. Most of us think in terms of two wide, making the box only 4" wide.
The most I ever packed onto a bike was for the race, where I had 26s 15 ah on there. 12 bricks in boxes aside the top tube, and 3 more on a rack in back. 15 bricks.
Kingfish
100 MW
To answer both… 
The frame was (I think) $850 off of eBay and came exactly as you see it in my previous post top picture – nec’cid and stripped. Batteries are all Zippy FlightMax 5S1P 15/2C 5000mAh weighing 1.27 lbs. each. I had them vertically-stacked. Here – lemme provide some layout concepts…
First I went through A LOT of permutations…
Then I went to physical modeling: This layout was overly optimistic with 12 bricks/side. In reality – it was impossible to package.
This layout didn’t have enough… (why am I reminded of Goldilocks and the Three Bears…)
But then this arrangement was just right :wink: with 9 in a row (per side): 8 turned edge-wise and the 9th near the front of the bike turned flat.
The orientation of the bag is then draped over the top-bar like a saddlebag; the ends of the batteries facing up. The bag was originally mounted on my 2009-2010 eBike (1991 Specilized Rockhopper) but after the front shock failed I migrated it over to the Felt Compulsion 1 frame. Today the B&W faring covers up the custom battery bag. For information on the construction of the bag, see the Epic Battery Bag Story.
Top-to-bottom, left-to-right: modified Timbuk2 saddlebags just below the H-D tool bag carry 6/side, custom triangle saddlebag (beneath faring) carry 9/side, panniers carry 9/side, trailer toolboxes carrying 15/side = 78 total, weighing 100 lbs. For commuting I only use the triangle. Pretty wild, huh? 8)
And yes – my arse was plenty sore. The first few days it was a problem but then it toughened up and could take more abuse.
So, in conclusion - this is a tough and rugged DH bike frame; not perfect - though good enough to get me to California and back. Felt changed the design of the DH frame in 2010 and I am not entirely sure I care for it.
Good hunting! KF
The frame was (I think) $850 off of eBay and came exactly as you see it in my previous post top picture – nec’cid and stripped. Batteries are all Zippy FlightMax 5S1P 15/2C 5000mAh weighing 1.27 lbs. each. I had them vertically-stacked. Here – lemme provide some layout concepts…
First I went through A LOT of permutations…
Then I went to physical modeling: This layout was overly optimistic with 12 bricks/side. In reality – it was impossible to package.
This layout didn’t have enough… (why am I reminded of Goldilocks and the Three Bears…)
But then this arrangement was just right :wink: with 9 in a row (per side): 8 turned edge-wise and the 9th near the front of the bike turned flat.
The orientation of the bag is then draped over the top-bar like a saddlebag; the ends of the batteries facing up. The bag was originally mounted on my 2009-2010 eBike (1991 Specilized Rockhopper) but after the front shock failed I migrated it over to the Felt Compulsion 1 frame. Today the B&W faring covers up the custom battery bag. For information on the construction of the bag, see the Epic Battery Bag Story.
Top-to-bottom, left-to-right: modified Timbuk2 saddlebags just below the H-D tool bag carry 6/side, custom triangle saddlebag (beneath faring) carry 9/side, panniers carry 9/side, trailer toolboxes carrying 15/side = 78 total, weighing 100 lbs. For commuting I only use the triangle. Pretty wild, huh? 8)
And yes – my arse was plenty sore. The first few days it was a problem but then it toughened up and could take more abuse.
So, in conclusion - this is a tough and rugged DH bike frame; not perfect - though good enough to get me to California and back. Felt changed the design of the DH frame in 2010 and I am not entirely sure I care for it.
Good hunting! KF
auraslip
10 MW
- Joined
- Mar 5, 2010
- Messages
- 3,535
It's funny that there are 2 people currently trying to design ebike frames now, and keep getting stuck in the design phase.
I'm like dude, copy a 90's mountain bike with the rear suspension verbatim (like the specialized stump jumper or the GT LTS) throw on disc tabs, clamping dropouts, and battery mounting provisions. Simple DONE. Sell it to us for $500 a pop. Totally worth it. Who cares about 1 foot of rear suspension travel? I'm not looking to spend $2k on a bike before the electronics and batteries.
Chances are the factories making the bike probably made a bike similar in that past, so making one now would be no big deal. God. That'll be the second thing I do if I ever win the lottery; make an ebike frame for the masses. First thing will be to send my ex roses with a note that says, "Too late. I'm rich now."
I'm like dude, copy a 90's mountain bike with the rear suspension verbatim (like the specialized stump jumper or the GT LTS) throw on disc tabs, clamping dropouts, and battery mounting provisions. Simple DONE. Sell it to us for $500 a pop. Totally worth it. Who cares about 1 foot of rear suspension travel? I'm not looking to spend $2k on a bike before the electronics and batteries.
Chances are the factories making the bike probably made a bike similar in that past, so making one now would be no big deal. God. That'll be the second thing I do if I ever win the lottery; make an ebike frame for the masses. First thing will be to send my ex roses with a note that says, "Too late. I'm rich now."
auraslip
10 MW
- Joined
- Mar 5, 2010
- Messages
- 3,535
The moots ybb is made of titanium and costs as much as a small car.
The salsa dos niner is only$1000.
The KHS solo one was available as a soft tail in 2005 for $600. Chromoly too. I wish they still made it!
The cheapest I've found is a Schwinn midtown for $300 through costco.
The frame geometry doesn't look good for mounting batteries.
In sumnation scour ebay and craigslist for khs solo one.
It turns out the solo one is a bad choice. It does have disc brake mounts, but no fender eyelets, braze ons for racks, or derailleur hanger.
I would suggest the other bikes on in there 2005 soft tail line up. Especially the police bike. (good luck finding it).
The gt lts-5:
1995-1994 Specialized stumpjumper fsr
From this thread http://endless-sphere.com/forums/viewtopic.php?f=3&t=18348
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