Another WTB rim tire blowoff, is it me?
I've got the WTB i23 Rims on my Santa Cruz tallboy LT. I'm running tubeless on them and for the second time I've had a tire blow off. Both times have been on a tight steep switchback descent. I've also had this happen with two different tires the: the Maxxis Ardent, and now a Schwalbe Hans dampf, Obviously both in the 29er. I was running the tires at about 26 PSI both times. For reference I am 190 pounds. Are these rims giving anyone else trouble? Am i using the wrong tires. I used plenty of stans. Is my technique wrong to take switchback, Maybe turning the front too much putting too much lateral force on the front tire? Or am I running just too little PSI? I see people talking all the time about how they're running 20 or less. Both falls have resulted in a blast of air coming out of my tires and me going over the handlebars, So I'd like to get this sorted… I like running tubeless mostly for the low PSI advantage but this is getting ridiculous.
i23's have a UST bead, so unless you are running the Lust Ardent or the TL Hans that would explain your problem.
Is this a 'burp' or a 'blowoff'?
The term blowoff is commonly used for tires blowing off the rim, destroying the tire bead in most cases. The tire bead ends up on the outside of the rim.
With a burp the bead stays inside of the bead hooks, but moves too much to the centre, breaking the air seal, causing air and sealant to escape.
Burps do not happen when the bead-rim interface is tight. Most 'tubeless ready' rims have elevated flat bits in the rim bed for that, sometimes with an added ridge (American Classic f.e.) to prevent the bead to go to the centre of the rim. A UST specific bead has a square profile, that has the same shape of the bead hooks, creating a very safe interface.
If it is burps you are suffering from, you could try an extra layer (or 2) of tubeless tape. Tires that take some 'encouragement' to mount by hand are the least prone to burps.
Yes I guess to clarify its a big burp not a blowoff, but enough to flatten my tire completely most recently, and enough movement to buck me off the bike. The Schwalbe is a "tubless ready" tire apparently. But it burped easier than the Ardent. I thought the i23s with the bead hooks and UST would be the ideal tubless rims. I'll try more tape. The Schwalbe's in particular are very easy to get on the rim, probably too easy
Have also had a few burps while running tubeless with both Flows & P-35's.
When this has occurred it's been from either landing off-angle, or jamming hard into a turn.
[This too happened on a WTB ldt rim with a tubed Rampage.]
Each time, too little PSI was the culprit. At 210# on big volume 2.2 - 2.4 tires, I must keep a minimum of 24(f) & 28(r) to avoid.
How people ride tubeless @ such low PSI w/o burping is beyond me.
I am trying to imagine how you are coming into these switchbacks to put that much lateral force on the front tire. Please tell me, because your problem sounds interesting.
I imagine there must be great traction, for one. Then I imagine you are going very slow, and at the crux putting all your weight on the front wheel as you jack-knife turn. Otherwise, I am envisioning you trying to rail berms like the kids in the videos.
Either way, I would guess it is your technique causing it, and you could change that, or go to tubes, because your equipment seems pretty solid to me, especially for 29ers where there isn't much that is beefier.
The only tire I've had come off my i23 (26") is a non-TL-ready Schwalbe. Otherwise they've been fine, and I've used Specialized 2bliss, Schwalbe, and WTB TCS tires.
continuous growth is the strategy of a cancer cell.
Here's a blowoff in progress with Stan's rim strips on WTB Freeride rims. Maxxis Advantage 2.4 at 30 PSI.
Wow, how did that turn out?