2008 CRF250R - QS138v3 70H - ANT - Sanyo UR18650-RX 20s20p - Votol EM260

[bananu7]

I got my 304 steel wire, so I got around to make a new spring:


I broke the mandrel in the first photo, so I moved to steel ones. Got this one only on my third or fourth try:


I couldn't wait and decided to do at least a brief test of a full system. Needless to say, that was almost a complete failure. I managed to push _some_ fluid out, but the sleeve being so loose meant when the fluid was added it almost floated freely in the cylinder housing. Even worse, it rotated so that the holes didn't line up with the holes in the cylinder.

On the upside, nothing broke or dissolved from the fluid, i managed to get a couple of bubbles from the right hole, and the spring seemed to work way better with a piston lubricated by the fluid. Unfortunately the piston goes so far into the housing that all the springs i made were invariably compressed past their plastic deformation point.

I attribute this to a couple of potential reasons:
1) the original spring being conical and able to fold onto itself better
2) the original spring made better (with more even windings and no flat sections at either end)
3) my spring not being annealed/de-stressed or otherwise made of poor quality metal (the wire came from aliexpress, remember)

The main issue remains the sleeve, though, and I'm a bit torn whether to continue this experiment. I am not sure if I can get it to work reliably, on the other hand i have a couple issues that i could immediately address and see if anything improves - mainly the sleeve being too loose. At the same time, I have a 9.5mm (I guess that's 9mm nominal piston diameter?) pump coming in the mail, probably next week. If that turns out okay, there will be zero reason for me trying to convert mine to 8mm.

Alternatively, I keep thinking about other ways to reduce the fluid flow. A larger rear caliper is an obvious solution, the problem is the original honda one comes with a carrier that also acts as a wheel spacer, and the brake is an integral part of it. Anything that would fit or replace it would likely be very expensive.

I don't get it. How do people normally do LHRB that actually works?

 

[j bjork]

Maybe buy a cylinder that works and mount?

Reservdelar för VARG

Hitta originalreservdelar till VARG, inklusive tillbehör, kompatibilitetsinformation och mer.

starkfuture.com

 

[bananu7]

Maybe buy a cylinder that works and mount?

Reservdelar för VARG

Hitta originalreservdelar till VARG, inklusive tillbehör, kompatibilitetsinformation och mer.

starkfuture.com

I've spent a good portion of the evening trying to find out what the piston diameter is in the Varg's formula master cylinder. Apparently they started with 10mm and then downsized to 9.5mm. I guess I'll buy it if the one I'm waiting for doesn't work...

 

[j bjork]

The brembo is supposed to be "better" not exactly sure how. Might very well be smaller piston.
Do you mean that there are 2 versions of the formula cylinders?
If buying new I would go for brembo, but you might find cheap formulas from varg owners who changed to brembo..

 

[bananu7]

I have received and mounted the 9.5mm master cylinder. I had some trouble bleeding it, so the results might still not be fully conclusive, but I got the lever to the semi-stiff state at least. I wasn't sure how long to bleed it for, as with the smaller diameter i expected it to be a bit spongy.

The conclusion is that it seems to put quite a lot of pressure on the pads, but STILL doesn't lock the wheel. I've noticed the disc actually gets quite warm from my tests (10-15 stops from moderate speed). The smaller cylinder doesn't really seem to help no matter how hard i squeeze. I'm starting to suspect either the piston or the pad/disc interface. The piston could be mechanically locking, or damaged in some other way, while the pads could, despite being a fresh set, already be contaminated. Actually the symptoms I'm getting are quite with line with what I'd expect from contaminated pads - reasonably stiff lever (when it's bled), good contact but poor braking performance.

Thankfully I have a second bike with a brand new brake, brand new disc and a brand new hose. I'll try it with the 10.5 MC first. If that works, I'll be 100% sure that the issue is somewhere in my old caliper. I need to modify the new caliper first because in China they forgot to add a a cutout for the hose in the casting...

 

[bananu7]

I guess running the old rotor was really a bad idea. The pads only made contact on the edges. So, I rebuilt the caliper:



With new sliding pins, rubbers etc. I kept the pads as I figured they were really unused other than slight bit missing at the edge which should even out. After all, the pads wear slower than the disc. Speaking of:



I'm sort of bummed I didn't get a matching rear wave disk, but at least it's a high quality model I bought for the CRF #2 by accident and was sitting here ever since.

So, with the rebuilt caliper new rotor and the 9.5mm pump, I finally managed to lock up the rear wheel. It's still not perfect, as bleeding that 2m long line is quite a challenge, but it's already a massive improvement.

 

[bananu7]

Ooookay. Did another bleed, reverse this time, and took the bike out for a spin. Works way better. Locks up on demand. It's making some noises still but I'll still have to replace the pad sliding pin as the one in the kit was slightly too thick at the end, I'll fix it when I have 5 minutes on the lathe.

More concerning is my front wheel. The tyre grabs like crazy, I had amazing confidence boost. The issue is that I came back with 0 bar in the tyre. I pumped it up and it seemed to stay up, so the hole, if there's any, must be quite small... Good opportunity to move to tubeless?

 

[Balgaroth]

Ooookay. Did another bleed, reverse this time, and took the bike out for a spin. Works way better. Locks up on demand. It's making some noises still but I'll still have to replace the pad sliding pin as the one in the kit was slightly too thick at the end, I'll fix it when I have 5 minutes on the lathe.

More concerning is my front wheel. The tyre grabs like crazy, I had amazing confidence boost. The issue is that I came back with 0 bar in the tyre. I pumped it up and it seemed to stay up, so the hole, if there's any, must be quite small... Good opportunity toove to tubeless?

Personnal preference I guess but I love my Tubliss. Once you are used to how to change the tires I find it easier than swapping a tire with a tube. And then you can run different pressure depending on the type of riding you are doing on a given day. I already put one in front of my eRMZ and will do in the back as well when I will change the tire.

 

[bananu7]

Personnal preference I guess but I love my Tubliss. Once you are used to how to change the tires I find it easier than swapping a tire with a tube. And then you can run different pressure depending on the type of riding you are doing on a given day. I already put one in front of my eRMZ and will do in the back as well when I will change the tire.

I have heard very mixed opinions about Tubliss. The people that had them work well praised them - and why not, if you can run down to 0 and still have rim protection. The issue is that I've heard a lot of people with leaks, installation troubles etc.

I have my big KTM converted to tubeless with individually sealed nipples, and that's been rock solid. On the other hand, bicycles seem to use tape with reasonable success, albeit supported with sealant. Tape is great because it's the lightest and costs nothing, and can be easily reapplied, so it offsets the same issues as tubliss with just being cheaper. I guess you lose some of the pressure holding the tyre to the rim, but when ran at reasonable pressures i believe that's largely irrelevant. The new Nuetech 360 mechanical lock system looks great, but it's still not available, and similarly to Tubliss it'll be quite expensive.

So the one remaining option is mousse, which is about 2/3 the cost of Tubliss, is perfectly reliable and for the speeds my eCRF goes should last a very long time. I'm kinda tempted to try it, as it's one method I've had least experience with. I know that a lot of people tend to run mousse front, tubliss rear setups as well, as the need to change the pressure is larger for the rear wheel.

 

[bananu7]

After a night in the garage, the front wheel seems perfectly pressurized. I'm suspecting it might be a slightly torn rubber near the valve stem, that only opens up when the pressure drops. I noticed the stem got slightly bent. I'll ride with it for a while and in the meantime I have to finally realize my small tape-cutting contraption.

 

[Balgaroth]

I have heard very mixed opinions about Tubliss. The people that had them work well praised them - and why not, if you can run down to 0 and still have rim protection. The issue is that I've heard a lot of people with leaks, installation troubles etc.

I have my big KTM converted to tubeless with individually sealed nipples, and that's been rock solid. On the other hand, bicycles seem to use tape with reasonable success, albeit supported with sealant. Tape is great because it's the lightest and costs nothing, and can be easily reapplied, so it offsets the same issues as tubliss with just being cheaper. I guess you lose some of the pressure holding the tyre to the rim, but when ran at reasonable pressures i believe that's largely irrelevant. The new Nuetech 360 mechanical lock system looks great, but it's still not available, and similarly to Tubliss it'll be quite expensive.

So the one remaining option is mousse, which is about 2/3 the cost of Tubliss, is perfectly reliable and for the speeds my eCRF goes should last a very long time. I'm kinda tempted to try it, as it's one method I've had least experience with. I know that a lot of people tend to run mousse front, tubliss rear setups as well, as the need to change the pressure is larger for the rear wheel.

My main sport is DH mtb so I can tell you that the setup is vastly different than MX wheels as we use double walled rims. The tape is put on the second wall which is basically flat with some holes so the tape has a somewhat even surface to hold onto and seal. The sealant will help with tire porosity, sometimes it will help if the bead/rim connection isn't perfect but if it goes anywhere near the tape is will get the tape unstuck and usually result in a slow leak that can leave you chasing your tail for a while if you never had the issue. One last issue is pressure. Unless the tire/rim combo is good, meaning very tight, you will often need more pressure than ideal to not unseat the bead, even just momentarily which will cause a big drop in tire pressure. For many years this was a big issue in mtb, now rim and tire manufacturers got it right and you can ride at low pressure without too many issues, rim strikes are more frequent but that's the sacrifice to get traction I guess.

Regarding Tubliss if your local riding area has very sharp stones it might be a problem as it can cut the tire, if your stones are not too sharp you will likely have no issues. Aside from that some people have issues with tubliss that is mostly human error, not checking the pressure in your high pressure chamber regularly will likely cause the tire to not be properly supported and to move. For example my 125 was last used in March, I restarted it 2 days agi and the high pressure chamber was at 2 bars instead of 8 bars. If I didn't check it and went on a ride like that I would certainly have had a bad time. Another frequent issue is dried up sealant in the low pressure chamber. This will cause the tire to slow leak, sometimes at a fast enough pace that you start your ride a 1bar and finish at 0. But like in Mtb, you need to top up your sealant in order to keep a good tire performance, unless you change tires every few months of course.
Mousses are obviously a great option too but they are less versatile and tend to make the bike feel a bit dead so it depends on what you are looking for, maybe a 0.7/0.8bar mousse would be a good options in that regard.

 

[bananu7]

The tape is put on the second wall which is basically flat with some holes

Isn't that the case with a typical MX rim too, though?

As far as I understand, the more curvature in the rim profile, the more flexible should the tape be to conform to its shape. It's still being pressed down by the tyre sidewall after the tyre seats on the bead, just like with the MTB tyre. And you can of course add sealant to a moto tyre just as well - I did that with good results on my big adv rims.

a slow leak that can leave you chasing your tail for a while

Which is the issue i might currently have with my tubed front wheel, i suppose?

you will often need more pressure than ideal to not unseat the bead, even just momentarily which will cause a big drop in tire pressure

That's a fair point. I think at the low pressures required in enduro riding, it requires a careful balance to maintain traction but not allow the tyre to depressurize too easily.

All things considered, it's always a compromise. In this particular situation, though, I'm never more than ~20km away from home. Topping air up after a ride is no problem. Taking the wheels and tyres off to fix punctures is much more annoying than adding sealant or air occasionally - at least that's what it seems for me. Plus the tubeless systems completely eliminate the risk of ripping the valve stem off, even if the tyre slips.

I think my ideal setup would be front mousse and Nuetech 360 in the rear, but factoring in the cost, i'll prolly stick to tubes and maybe try out the tape

 

[Balgaroth]

The issue with single walled rims is that you need to seal the head of the spoke nipples with the wall itself. This would need a very flexible type of tape, yet strong enough to not tear when putting the tire on.

In comparaison in a double walled rim the nipple head is in the cavity so you seal a flat surface with hole in it. Which is why the tape isn't super flexible, allowing it to resist well when putting tires on and allow for high enough pressure when used for road bikes.

 

[bananu7]

I did an exceedingly stupid thing today. I was fixing my throttle and didn't disconnect the battery. I flipped the switch to on by accident...





Of course right before a group ride. The front tyre is holding air at least... Also it pays to have a second motorbike to steal parts from. New levers (new and spare) ordered already.

That being said, the group ride has been quite eventful, as I finally could compare the bike to a worthy competitor.



Did only a bit, but immediately: SV is lower, much heavier, the cluster switch is great, the screen is nice and readable, suspension is very calm, enduro like, very good at first glance. Rear brake unsurprisingly worked much better than mine even now (and it's the brembo MC). I rode it in 30 and 40HP modes, the 30 pulls very similar to my 20kW sport mode. 40 is definitely more peppy, but it's always a balance between traction and power.

At the end of the day, while it's undeniably a great bike, I don't think I'd trade the price of mine (about 1/4) and the extra 20kg for twice the battery, more power than I'd need and great suspension out of the box. Once I sort the minor niggles with my bike, I'll be even more happy with it now, knowing it can still beat the best OEM on the market in certain conditions.

 

[harrisonpatm]

I flipped the switch to on by accident...

Wait, so what happened? Did the bike take off on its own and hit something, breaking the brake lever?

 

[bananu7]

Wait, so what happened? Did the bike take off on its own and hit something, breaking the brake lever?

I yanked the cable, bike took off, dragged me with it and stopped on my garage door. Fell on the lever, i broke the multiswitch with my body somehow. Fortunately nothing major but could've been much worse.

 

[amberwolf]

Yeah, the door could've been open.... Wheeeeeee!


I did something similar with SB Cruiser once, but thankfully I'm heavy enough and the trike is not powerful enough to be stopped by digging my feet into the ground until I could flip the cutoff up. Been a while but IIRC I had it turned on to verify throttle voltages before attempting repair of a broken thumb throttle, to ensure I got the same range after as before, or at least to know what it had been and what it was now...and when I thoughtlessly disconnected the ground wire first, well, you know what happens then.

 

[j bjork]

On votol you set the trottle overvoltage protection, so this shuldn't happen if you have the settings right

 

[bananu7]

On votol you set the trottle overvoltage protection, so this shuldn't happen if you have the settings right

Nah, it was 100% correct input. I was trying to get the throttle cable (mechanical) into the housing and physically pulled on it as if I twisted the throttle.

 

[j bjork]

Ah, there aint no protection against that

 

[bananu7]

While I'm slowly gathering bits to build a 2nd battery for #2, I keep riding the #1. The evenings are getting shorter and i often find myself in a need of a lamp. I decided to go with a tested 16-led KTM-style unit, as it attaches with rubber rings to the fork legs so should be very easy to adapt. I have some issues designing the electrical system, though.

Since I'm using my BMS's common port to charge the battery via battery-controller wires, everything is hooked up right at the controller. This is getting a bit annoying at times, as replacing the loom requires detaching the nuts holding the main battery wires. Right now there's a set of three lugs there:

1. main battery ones, discharge/charge, AWG1
2. charger port, AWG7
3. auxiliary loom/enable switch, thin

What I'd like is to reduce that to just 2, battery and aux; the aux would stay at AWG7 but go to a sort of a "distribution box". The plan is to use an antispark XT90 and a matching panel connector. We enter the box, and go right on the 20A fuse. From there, it splits into two lines. One goes to the charge port, the other goes to the 72V-to-13.8V DC/DC converter.

From here it's more annoying. Ideally, the 13.8V (12V nominal) line would go into a separate distribution box. There I could split off a line to my display, a line to headlight, and another to e.g. USB port. Choosing the components/parts/connectors to wire it all in a tidy way is a bit tiresome, though.

I also need to do a practical test if the controller will boot up with 13.8V on enable pin. If so, I could stop running 72V to the handlebars...

 

[bananu7]

I am sick in bed, so decided to do some free-handed design this time. I have a shoddy 3D-scan of the bike:



So I wanted to see how it would look with a nice cover:



At first I wanted to make it very small, but now the bigger one is growing on me, to utilize side mounting points. With some foam underneath it'd be strong enough to act as a battery cover, so that's nice.

So at first I had a narrow version:



But then I wanted to see how one with some more leg support would look like:



And I like this one better I think. It's unlikely I will go straight from this model to a form, that'd require a pretty big CNC router and a large foam block; I think I'll just use it as an inspiration and freehand the entire shape myself.

Still, one can dream how easy it'd be to go from the visualization to a finished part like that...

 

[bananu7]

I'm still sick and working on Votol port settings, and it's just so annoying... nothing matches up.

The only way the inputs work reliably is when they're left in F (floating) state, which doesn't make sense, they should use a pullup. No matter what settings I try, i can't get side stand and park to work reliably...

 

[j bjork]

That model is really cool, wish I could draw like that
If you can draw that you could just as well 3d print a mold for it.
Could make it in several pieces and glue together.

 

[bananu7]

That model is really cool, wish I could draw like that

Aw, thanks. It's been sculpted in Blender. I am really not very good at it yet, that's why it's all wavy and stuff, so my method is probably very suboptimal.

That being said, if you wanted to take a stab at it, I typically start with a flat Plane, cut it in half and add a Mirror modifier so that I only work with a half of it but see both halves. Then I start with very few points, and move them into shape (with grab command, typically fixed to the axis, so the shortcut is G-X, G-Y or G-Z). Just be careful to not move the "seam" in the middle away from the symmetry plane or that will make a hole because the mirrored halves won't meet.



Then I cut into more sections, move those more precisely and so on. "Proportional Editing" is very helpful here because you can easily move more points at once and it's almost like "low-poly sculpting".


At some point when I feel it's close enough I make a copy (if I inevitably break it at this point). Then subdivide by a large factor (e.g. into 1000x1000 cells) and switch to the Sculpt mode. There you can work with it as if was clay, add/subtract material etc., so it becomes much more "organic". I often make mistakes here and have to start over because i make a crease etc.



Afterwards for the final look I just downloaded a free set of carbon textures, made a material and added a Thickness modifier to give it some volume.

If you can draw that you could just as well 3d print a mold for it.
Could make it in several pieces and glue together.

Ideally that would go to a large CNC mill to be cut out of some dense model board or foam, sealed and then covered with the Pattern Coat Primer. Well, at least I have that...



I think printing the entire shell would be too annoying even in parts, but I think I'll just print some cross-sections to use as reference. I've seen some people use laser-cut 3mm plywood as well. Then you put foam in between and just blend the cross sections. Low density PIR foam is very easy to cut with a wood saw, and then fine adjustments can be made with a woodworking plane, as I've recently discovered...



Plane is a good tool for it because it slices the foam leaving a very nice surface and makes a bit less of a mess, the saw makes the fluffly dust go everywhere and stick to everything

I plan to put the model on the bike and finalize the design "in situ" so i can see it in person, maybe even sit on it and see how it fits ergonomically. The cross sections are really needed the most to ensure the battery will snugly fit underneath it.