Tubeless - 2 strikes, 1 home run

Home run - 26 Hans Dampf Snakeskin

  This is on my 26 guni.  Clean the rim, apply Gorilla tape cut to size, install tubeless stem from LBS, put tire on one side of rim, add Stans, put other bead on (nice tight fit), pump up with stand pump, done!  This thing is light and rides great.  I have run it as low as 15 psi with no burps, no issues whatsoever - LOVE IT.

Strike one - 29 Hans Dampf Snakeskin

 Started down the same path.  The bead went on waaay too easily.  Had to use the pressurized line at the LBS to get it to seat.  First ride started great, near the end of the 4 miles went over a rocky outcrop in high-gear - BAM!! the tire blew off the rim - DONE.

Strike two - 26 Hans Damp SUPER GRAVITY

  Wanted to repeat the magic of the 26 guni on a straight 26.  Same deal with installation, everything seemed good.  Rides nicely, no blowouts, but... It burps Stans when I have harder landings. These are just small burps that don't release much air, but... I just don't trust it. The sidewall is stiffer on the SuperGravity than the normal Snakeskin.  I think that is the root of the problem.  This thing is just does not have that bomb-proof seal.  I am heading to the CA Muni weekend with this, and decided not to risk it and tubed it.  I will have to see how I like it like that.  When it wears out, I might have to get an HD SnakeSkin and make it tubeless.

I’ve had the same problem you had with your Super Gravity Hans Dampf once on my 27,5 Hans Dampf, which is the TrailStar compound. Did it happen more than once on yours? Mine was in a really techy section, I landed on an angled rock while trying to get past a runner.

I still didn’t ride in the most techy trails on mine so I can’t tell if it’s holding on well when doing drops and stuff, I should be able to test it out properly in the next weekends.

It happened a lot, but never catastrophically. I could get it to burp in my driveway by hopping and landing sideways. It might have gotten better with time, but I’m not sure. I did ride the first 26 HD with a tube for a couple of months before going tubeless with it. With the SG, I went straight to tubeless. The SG is stiffer, and I notice it pops away from the rim when it is de-pressurized. My other tire just stays welded to the rim. When I mounted the SG, I had to push down on the wheel while pumping to get it to seat.

It’s not the tire. If it was the tire, then everyone woudl have the same problem including bikers. All Schwalbes are tubeless compatible except the wire bead version.

What rim are you guys using?

A rim that has a hook designed for tubeless is going to be far better at retaining a tire.

I like the Velocity P35, I run that on 29 and 650, no problems with tires coming off the rim ever, occassional burps on the 29 HD, but I haven’t had a burp on my HD Super Gravity since it was new.

Tires shouldn’t come off rims, that suggests a rim issue, i.e rim is too wide for the tire or the rimm hook is not tubeless compatible.

Keep in mind that KH and Nimbus rims are not tubeless compatible, though they can be made to work, and they also too wide for tubeless with a 2.35" tire.

These are all KH rims.

And that’s the problem, the KH rim hook is designed for wire beads and at 47mm it’s too wide for a 2.35tire to be run tubeless.

All my tubeless set ups are 2.35" tires running on rims that are 35mm, still quite wide by MTB standards, but not so wide as to cause the bead to pull away from the hook.

My tubeless wheels are so stable that I can get a seal with a floor pump every time, so even on the trail I can do a remount; though I have yet to have a blow out in more than two hundred days of riding.

The hardest tubeless set up I have was on my 36er, in part due to the wide rim (42mm), but mostly because it is a wire bead; wire beads are more rigid and tend to pull off the hook. Still, I have over a year of muni on my tubeless 36er, too many quirts to count, and never a blow out, drops up to two feet, and I weigh 200#.

Having been riding narrower rims for a while now, I am beginning to think that wide rims are not an advantage. Yes, they increase the tire volume, but it is not a significant increase (5% from a 47mm to a 35mm??). Now that we have good tire choices (Enduro and foldingbead DH tire), we don’t need to run an old school Duro or Gazz. I think the need for fat rims is fading unless you ride a truly fat tire (4-5").

My number one reason for avoiding fat rims: They cause tire fold.

Yes, I said it, “fat rims cause tire fold”, and here’s why:

A bike tire is meant to have a certain amount of sidewall curvature, based on a predetermined shape (when molded). When we stretch the tire beads apart to flatten the tread and increase volume, we also destabalize the tire by oversteepening the sidewall. This destabalization leads to increased tire fold, so to compensate we end up running higher pressures or running tires with stiffer casings.

I don’t know that there is a formula for tire width to tire rim compatibility, but for sure you guys are learning that a 47mm rim is too wide for a 2.35" tire.

Shrink your rims, save some weight, gain some strength, and be successful in your tubeless applications. For a 2.35" tire, a rim width of 30-35mm is a good choice.