Brake track split. Now what?

[MarkJohnston]

Hey guys my rim blew out today. It was very hot and I was coming down several hills braking hard. My tires are too wide for rims i.e. It was nearly impossible to mount them. Maybe that adds extra strain on the rims. And the heat may have increases.my tire pressure above the max which is what they were at. Anyhow I am in a bad spot now because I rely on this as my only means of transportation. Which means I only have two days off to re build the wheel.

Do any of you guys know a down and dirty rebuild that will get my wheel true (enough). I have a wider rim that accepts the tire much more easily however the braking surface looks shot and there is rust on it and in the spoke holes seems like. Maybe not a good idea.

Let me know and time is of the essence here

I have limited tools, only a spoke tool, and no truing stand. Can I just simple copy the spoke pattern and just tighten up all spokes pretty much to the same pressure and call it good?

Oh yeah I don't trust bike shops. They are monkeys with wrenches and a lot of them won't work on ebikes.i refuse to go to them.

 

[MarkJohnston]

So the hub motor rim had a bead seat diameter of 19 mm. Swalbe recommends 30 mm for their 559x 55 tires but ERTO says that 19mm is just barely acceptable for a 55. Sheldon Brown says a tire that is too wide for the rim is at risk of the brake shoes causing excessive wear. I like to keep my pressure nice and high to avoid flats at 60 PSI. These are maxed out at 65 PSI. We have been experiencing 100 degree F weather here. I was stuck on a really sketchy road and my front brake was locking up. I was relying on the rear brake too heavily. I could hear the rim getting hot.

Maybe just all the hills on my commute, along with the new wide tires, sent this thing on an early death. Shouldve Lasted at least 8000 more miles damn it.

 

[MarkJohnston]

I need something like

https://www.starbike.com/en/ryde-andra-40-rim/

Tough heat treated rims that are hard wearing. But Christ in. A cracker barrel ! I have a big old hub motor which requires special spokes and everything has to be measured and calibrated. This is f'ed. I want to rethink my entire design at this point. I want a new much much more heavy duty steel frame along with a much better fork. I want to rebuild the battery so it's on the midtube. Better weight distribution.

Maybe for now the best idea is to part out this motor, sell it, and just buy a new one.

 

[MarkJohnston]

Does my braking surface look shot?

This too

Brake Track Splitting

"A less common form of rim failure is along the brake track. This is said to be attributed to exceeding the maximum tyre pressure of the rim, in combination with a heavy load. If you’re really unlucky, it’ll simply be a manufacturing defect."

 

[marty]

Does my braking surface look shot?

This too

Brake Track Splitting

"A less common form of rim failure is along the brake track. This is said to be attributed to exceeding the maximum tyre pressure of the rim, in combination with a heavy load. If you’re really unlucky, it’ll simply be a manufacturing defect."

Can't tell from the picture. Try feeling with your finger. Sometimes you can feel better then you can see. Ask any auto body paint guy about feeling a surface to see if it is smooth.

If rim is not cracked or bent it is OK. Stop worrying about problems you don't have.

My feeling on Walmart bikes verses Super Duper Chalo style bicycles built from the very best parts and pieces. If all ya ever had was garbage picked Walmart bikes. A brand new Walmart bike in a box is like WOW! Just the quality of paint on the frame is unbelievable. Note: The assembly skills of a retarded Walmart bike assembler might not be the best? I would rather buy a bike in a box and put it together myself.

I have been known to clean up car brake rotors with sand paper. No need to replace rotors every time ya replace the pads.

 

[ynot]

Couple of comments that came to mind on reading through the above.
Just took my old much modified iron bike to a shop two towns over for brake work.
Josh the owner was working on the bike when I got back from lunch, I asked him if it was ok to hang out, he said sure. Many years ago was building yachts & hated having the owner looking over my shoulder as I worked, so I always ask, if I can hang out & seldom get sent to the waiting room.
A tip about rust, again from my yachtie days, Ospho (similar to naval jelly but much easier to use) paint it on the rust and within minutes the rust is turned into ferrous sulphate, rinse it off with water before it dries. cleans up areas you cannot grind, and even makes stainless steel shine like new.

 

[RunForTheHills]

I am not sure where you are located, but if you go to the bike parts section of Craigslist and search for motor, you might get lucky and find a motor already laced into a rim that will work for you. Just remember that some rims do not have a braking surface as they are intended for wheels with disk brakes.

https://sfbay.craigslist.org/search/bip?query=motor&min_price=&max_price=

There are also inexpensive ebike kits on eBay and Amazon for under $300. You might be able to get one shipped to you before the weekend.

 

[Chalo]

How is a tire that’s too wide for a rim harder to get on?

A stiff armored tire wants to hold itself open, with the bead wires apart. This makes it difficult to place the bead wire you're trying to install or remove into the middle of the rim so it can be lifted over the edge. The wider the tire and the narrower the rim, the more difficult it becomes.

 

[Chalo]

I need something like

https://www.starbike.com/en/ryde-andra-40-rim/

That's a badass rim if you can find one. It's one of my favorites for hub motor builds, because it offsets some of the deficiencies of hub motor wheels.

 

[MarkJohnston]

I need something like

https://www.starbike.com/en/ryde-andra-40-rim/

That's a badass rim if you can find one. It's one of my favorites for hub motor builds, because it offsets some of the deficiencies of hub motor wheels.

My plan now is to buy a new kit because

1) the hub motor wire is cracked and needs to be replaced. This seems like a difficult job. The wire from grin tech is expensive and out of stock. Shipping with grin is insane.

2) there's an open circuit somewhere, maybe because the wires are touching inside the axle

3) a hub motor rim replacement isn't so easy. Wheel building is clearly very difficult. I couldn't even true a wheel last time I tried. This requires specialty spokes, calibration of spokes lengths, etc. Hard to do all this stuff online in a timely manner

Going forward I will buy the same kit and lower pressure on tire by 5 PSI. I will also need new brake pads that don't create so much heat. If this rim blows out because the new tires I bought are too wide and putting too much strain on the rim, then this NEW wheel will have to be rebuilt with a quality touring rim. My current hub motor will need to be parted out and sold and maybe offset the purchase of the new one by $50 or $70 hopefully.

Anybody know what are good rim brake pads that won't create so much heat? Chalo?

 

[99t4]

Anybody know what are good rim brake pads that won't create so much heat?

Please understand the physics behind friction braking systems. The reduction in speed is directly converted into heat. Therefore any brakepad that creates less heat must also provide less braking force. I presume you want the best braking performance possible.

Do you ride the brakes on the long downhills? That's a sure way to elevate the rim temperatures to dangerous levels. Try pulsing the brakes (apply hard a few seconds, let off a few seconds, repeat, etc.).

 

[pwd]

Sounds like it would be worth investigating how to get regenerative braking working on your motor controller. That would take much of the strain off of your brake pads - just make sure your torque arm(s) are well secured.

 

[RunForTheHills]

Kool-Stop brake pads are widely considered the best. Make sure you get the correct ones for your type of brakes.

MTA: It looks like you have cantilever brakes, so these would work for you: https://www.amazon.com/Kool-Stop-Ca...rake+pads+kool+stop,aps,251&sr=8-1&th=1&psc=1

 

[RunForTheHills]

Also, when I was younger and my family was in a cycling club, I was taught to alternate brakes on long descents to scrub speed and prevent heat build up. I still do that, but I am not sure if there are any valid physics behind it vs just gently using both brakes.

 

[MarkJohnston]

It might have been the narrow rims, big wide tires, high pressure, and 50 lbs of cargo on a hot day dragging the rear rim a lot to save my ass because my front shock sucks and I was about to wipe out. Long story, and hard to explain over text.

There are 8000 miles on the rim. Rims last 1500 to 12000 miles.

My brake pads weren't set right. They needed to be replaced. Otherwise I wouldn't have needed to drag em. It got so hot I could hear the rims cooking. But I needed to get to work.

I've heard stories about touring bike tires blowing off on long descents. Good thing that didn't happen because that was precarious dirt road with no guard rails!

Time for a new cheapo kit. Beats paying gas :|. I HATE MY CURRENT SET UP. NEED A COMPLETE REDESIGN! $$$$

 

[99t4]

It might have been the narrow rims, big wide tires, high pressure, and 50 lbs of cargo on a hot day dragging the rear rim a lot to save my ass because my front shock sucks and I was about to wipe out. Long story, and hard to explain over text.

My brake pads weren't set right. They needed to be replaced. Otherwise I wouldn't have needed to drag em. It got so hot I could hear the rims cooking. But I needed to get to work.

Ah, ok. That helps explain it.

Time for a new cheapo kit.

No.

You put too many demands on your bike to expect good results from another "cheapo kit." From your high speeds, high weight concentration over the rear wheel, high dependence on your bike for you job, etc. You deserve (require) at one or two steps up from another "cheapo kit." Another "cheapo kit" is going to have another crap rim, how are you going to expect any better results from that?

 

[MarkJohnston]

If it happens again I'll need to get a beefy hard to cook touring rim and a professional wheel builder.

I now know you have to be extremely delicate with the fine china. Where else am I going to find a motor on short notice? $250 and two day shipping?

I'm going to retire this frame soon, get a new frame and rebuild the battery. I want a much more heavy duty frame because I'm tired of looking and wondering if something's cracking. I want an extremely heavy duty reinforced steel frame with a huuuuge mid tube area. I then want a huuuuge 72 volt 50 Amp battery to fill that space. I'm going to need to drill a bunch of holes for M6 BOLTS with lock nuts. I want to camouflage the midtube battery compartment as a bag with canvas material around the wood.

This one will be sold or parted out. Probably parted out.

 

[MarkJohnston]

Kool-Stop brake pads are widely considered the best. Make sure you get the correct ones for your type of brakes.

MTA: It looks like you have cantilever brakes, so these would work for you: https://www.amazon.com/Kool-Stop-Ca...rake+pads+kool+stop,aps,251&sr=8-1&th=1&psc=1

I have V brakes not cantis

 

[Chalo]

Anybody know what are good rim brake pads that won't create so much heat? Chalo?

Kinetic energy becomes heat when you brake. Same mass, same speed, same braking-- same amount of heat. But sinking that heat, or getting it away from sensitive areas, is more the rim's job than the brake pads'.

Aluminum has substantially higher heat capacity per gram, and much much higher thermal conductivity, than steel. So an aluminum rim heats up more slowly and the heat spreads out much more quickly all over the rim, and thus can be air cooled more efficiently.

That said, I highly doubt your blowout was due to heat or any heat-related effects. Pressure, sure. Tire fit, maybe. But I think if things got hot enough to cause a blowout, you'd have noticed some smoke and burning rubber stink.

 

[defuzo]

Does my braking surface look shot?

This too

Brake Track Splitting

"A less common form of rim failure is along the brake track. This is said to be attributed to exceeding the maximum tyre pressure of the rim, in combination with a heavy load. If you’re really unlucky, it’ll simply be a manufacturing defect."

? shot? or Short?

The problem of cutting (aluminum) wheel-rims have happened to me also. Hard to tell if the brakes don't have any rubber left..

Just google "respoke a bike wheel". Its easy, may just takes time. Search for a replacement wheel or just a rim, of same diameter and height. Or whatever wheel, and order new spooks online..

 

[MarkJohnston]

It's not that bad. Just purchased the same hub motor for $240. I will recoup some losses hopefully by delacing and selling my current hub motor along with the controller and other crap that comes with the kit I don't need. So maybe it will be a $140 hit to me if all works out good.

 

[MarkJohnston]

Look at the difference between the rim and tire!!! It's astonishing! And no difference inner tube in or out.

The bead seat of the crappy steel rim is 25 mm.the beat seat of the hub motor rim is 19mm. The 25mm much more readily accepts the wide tire.

Why is swalbes bead so wide?

Can using metal tire levers damage a rim when mounting?

 

[Hummina Shadeeba]

Kool-Stop brake pads are widely considered the best. Make sure you get the correct ones for your type of brakes.

MTA: It looks like you have cantilever brakes, so these would work for you: https://www.amazon.com/Kool-Stop-Ca...rake+pads+kool+stop,aps,251&sr=8-1&th=1&psc=1

I have V brakes not cantis

they come for either style brakes.

metal tire lever! yuk

 

[calab]

Tire levers or tire spoons, I bought some big metal spoons from the Honda Motorsports dealership when I was messing around with moped tires, I ran flat on a mc knobby and never knew it :lol: I want to go back to that, but its just a real pain in theass if I have to lift the ebike up, even just over a big log. Moped tires are thinner and very strong as they have to be. Moped tires also lighter then motorcycle tires, I am front hub so the mc/moped rim in 1.40 or 1.60 width in whatever diameter you can get and lace.

 

[Chalo]

metal tire lever! yuk

Yeah, great way to ruin some perfectly good rims. If you're going to use those, you may as well have some nasty heavy ugly steel MC rims to deface with them.

 

[MarkJohnston]

metal tire lever! yuk

Yeah, great way to ruin some perfectly good rims. If you're going to use those, you may as well have some nasty heavy ugly steel MC rims to deface with them.

That's it? They get a little scuffed up? I'm more worried about about bending the rims. Also this bead is so tight I don't think a little plastic dinky one is going to cut it

Also how about these as replacement pads? Pricy but the cartridges can be replaced

https://www.ebay.com/itm/294518672693?chn=ps&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=294518672693&targetid=4580496732614417&device=m&mktype=&googleloc=&poi=&campaignid=418233788&mkgroupid=1230353745471221&rlsatarget=pla-4580496732614417&abcId=9300542&merchantid=51291&msclkid=f5fe46e61448175252fb244c3dd4a541


Does anybody know if the salmon pads are better than the electric pads from Kool stop? They have a new compound for electric bikes