Page 2 of 2

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Oct 13 2018 5:12pm
by 999zip999
Ok the tire has not slipped with the gasket cinch on the tire and rim. So the tire almost bald now and has not slipped yet 6400 watts.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Oct 22 2018 4:50pm
by Tony01
you guys must be doing something wrong. in over 20,000 miles of riding hard and fast on bicycle tires this has never happened. I have also never blown a tire off the rim. A good portion were on chrome rims as well.. which have about half the friction coefficient of aluminum.

Combinations that have worked for me: thorn resistant tubes (heavy ones but not slime) with Kenda Kwest 26x1.95, CST cyclops 26x2.4, hookworm 26x2.5, duro 26x3.0, and one small kenda 26x1.95 tire with the raised tread sides.

Maybe you are not getting those tires seated correctly? or maybe your tires just suck? Here's my process:

1. clean everything. make sure there is no grease or dirt on the rim or tire. I like using brake cleaner or similar.
2. pump up tube to 10psi and set in tire.
3. mount tire
4. pump up another 10psi
5. Make sure the bead is seated all the way around the rim. Grab it and rock it side to side and try to feel the beat seat.
6. repeat 4 and 5 until you get to your desired psi.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Oct 25 2018 7:43am
by MadRhino
Tony01 wrote:
Oct 22 2018 4:50pm
you guys must be doing something wrong. in over 20,000 miles of riding hard and fast on bicycle tires this has never happened. I have also never blown a tire off the rim. A good portion were on chrome rims as well.. which have about half the friction coefficient of aluminum.

Combinations that have worked for me: thorn resistant tubes (heavy ones but not slime) with Kenda Kwest 26x1.95, CST cyclops 26x2.4, hookworm 26x2.5, duro 26x3.0, and one small kenda 26x1.95 tire with the raised tread sides.

Maybe you are not getting those tires seated correctly? or maybe your tires just suck? ...
Electric torque is hard as compared to gassers. High power ebikes have the torque of MX motorcycles. You will soon experience the efficiency of power transfer that is possible to achieve building EV.

Of course we need to care properly mounting quality rims and tires, but nevertheless bicycle tires slipping on rims above 10 kw acceleration is not uncommon. I feed 20+ kw in acceleration and some tacky compound on the bead is a must. The smaller MX bead locks can be fitted on some bicycle rims, but they do affect wheel balance much more on a lighter wheel than MX wheels.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Oct 25 2018 2:22pm
by Tony01
MadRhino wrote:
Oct 25 2018 7:43am
Electric torque is hard as compared to gassers. High power ebikes have the torque of MX motorcycles. You will soon experience the efficiency of power transfer that is possible to achieve building EV.

Of course we need to care properly mounting quality rims and tires, but nevertheless bicycle tires slipping on rims above 10 kw acceleration is not uncommon. I feed 20+ kw in acceleration and some tacky compound on the bead is a must. The smaller MX bead locks can be fitted on some bicycle rims, but they do affect wheel balance much more on a lighter wheel than MX wheels.
Yeah forgot he was running “fun” power levels. And I have not yet experienced these levels, but SOON! My build is at about the halfway point. I’ll be running 19” wheels however. I can see that though. Especially on a tiny rhyno lite.

Just a thought though, maybe you can look into alloy rims that have a bigger beat seat area? Like the worksman alloy rims? They aren’t cheap but very heavy duty.

Personally though I’d end up fabbing up my own rim locks.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Oct 25 2018 3:55pm
by MadRhino
Tony01 wrote:
Oct 25 2018 2:22pm
...
Just a thought though, maybe you can look into alloy rims that have a bigger beat seat area? Like the worksman alloy rims?
My dirt bike is on Sun Double Track, a rim that requires tire levers to pull off a worn out tire, and are making Worksmans look like kids bike wheels. :mrgreen:

My street bike is on 65mm wide rims that are tubeless rated. Can’t find a better tire seating on any bicycle rim.

Tires are making a difference. UST rated tires are manufactured with better precision for bead shape and size. They are doing better to avoid slipping, yet none of them can stand repeated high power acceleration if they are not sticked to the rim with a tacky compound.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Nov 07 2018 4:12pm
by RageNR
Maybe some of the tips in this thread would help my situation?

Finished building my wheels, but can not get my tires to stay seated to save my life.

Using CST Cyclops tire on DX32 rims. Going tubeless.
Have managed to get them to seat about 3 times and hold air, but they leak down after a few days, then the bead comes loose.

I am using Stan's No Tubes sealant.
Also, the stem seals, so that is not the issue.

Should I use belt dressing on the tire and rim contact area?

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Nov 07 2018 5:14pm
by StuRat
Dx32's aren't 'tubeless ready' so you'll have leakage problems. Possibly worse because the seam is pinned instead of welded.

Re: Tire slipping on rim causing valve stem to tear and or flat

Posted: Nov 07 2018 7:36pm
by MadRhino
Some rim/tire combos are just mismatch.

If a tire doesn’t have a tight bead seat on one rim, you can’t expect it to be any better going tubeless. In fact, it should be even worse.

Newer rims that are tubeless rated are beadless, so do require a perfect fit, matching tire that is also tubeless rated. Some tubeless rated tires are begining to be made with an extra radial ply, meaning that the industry is definitely going toward tubeless standard for bicycle tires. I bet rims are soon coming flanged without any inside holes for spokes.