XC 29er wheels tubeless for CX - does it work?

[eBAUMANN]

I read somewhere recently that the reason tubeless cx tires/wheels haven't really caught on was because of the combination of a low volume tire + low air pressure (vs. high pressure/low volume of road and low pressure/high volume of mtn).

Any of you guys racing on a tubeless setup based around a XC/29er wheel set? Something like an Enve XC29 rim.

Real world insight (on the internet) is pretty sparse on the subject, hoping maybe one of you guys can share your 2c.

Thanks in advance!

[Oregonic]

Mrs Oregonic is still on an old set of Stan's 355's 29er rims. She loves them - lower pressure, good traction, no burps. Using Mich Mud 2 tires.

She's about 120. Doesn't dive into the corners too hard, but she can put down some power.

Annectodally, the riders that seem to have the biggest issue with burps either weigh more than she does, corner very aggressively, or have hit something unexpected in the course (unseen bump), and forced out some air. Or they're riding on converted (non tubeless specific) rims.

[Dude]

I have stans alphas with Vittoria XGs. Running about 40 psi, no burping I'm 175lbs. I'm not racing but riding it on my bony, east coast mtb trails with no problems - still dismounting and remounting because you never know when you'll race. I was trying to avoid spending more money on the whole thing and DIY, but buying the right tires was worth it. Couldn't be happier.

In fact I'm leaving to go on a ride now.

[eBAUMANN]

I have stans alphas with Vittoria XGs. Running about 40 psi, no burping I'm 175lbs. I'm not racing but riding it on my bony, east coast mtb trails with no problems - still dismounting and remounting because you never know when you'll race. I was trying to avoid spending more money on the whole thing and DIY, but buying the right tires was worth it. Couldn't be happier.

In fact I'm leaving to go on a ride now.

Im about the same size as you and 40 is the MOST I would run in a TUBED clincher for racing...for comparison I have done the first 3 races of this season on 40c WTB Nano (awesome tires by the way) at 35 in the rear and 30 in the front on 23mm rims.

Id be hoping to pull off around 25-30psi in a tubeless setup, nothing CRAZY but still low enough to offer comparable performance to a tubular setup.

This is all completely hypothetical and also dependent on me building up that disc cx rig that been floating around in my head for a few weeks...so long as I'm on mini-moto's ill be riding tubulars but who know what the future holds.

[bcroslin]

I rode my Santa Cruz Highball for the majority of last CX season with Stans ZTR 29'er wheels and Stans Ravens. They worked great until I got cute with the tire pressure and decided to see if I could get away with 24 in the rear. Took a corner hot and burped the tire. I went from 2nd to 5th and my race was over.

Unless you're willing to run 30+ psi in your tubeless tires you're risking burping you're wheel and being bummed out.

[Dude]

The stuff I'm riding, anything less than 40 and I'm hitting rim. Haven't tried it any lower yet.

[pakora]

I was interested in a dual duty XC race/CX race wheelset and emailed stans about Crests and Arches as you almost definitely cannot use the Iron Cross rim with a mtb tire.

They told me either would work if I had a very tight fitting tire, but I couldn't expect burp-free riding in cx racing conditions with any of their mountain rims UNLESS I could somehow get my hands on a pair of the old arches or 355s, which they said were nearly as reliable as the Iron Cross rim for burps and low pressure.

You didn't ask this, but I'm 215 and riding AmClassic Victory tubeless (24mm outer/20mm inner road/cross non-disc wheel, but I think they make a disc version) and this weekend rode crazy low pressure on a tough course (Granogue, serious off cambers) without a burp (vittoria XG TNT).

I say crazy low because I forgot my pressure gauge at home and went by feel, riding them so that in the root section I could feel the rim a little. I was so amazed I didn't burp that I remembered to check the pressure when I got home, and was even more amazed that it was 25r/20f :eek: If I had a mtb with vee brakes I would probably be tempted to race these on a buff course with 1.9s just for science, as they're the same inner/outer as some of the very old tubeless rims. And to be the weird guy with aero road wheels.

I have also raced the ICs and tried to burp them in practice as well and never did, but never went crazy low (28f/30r, also XGs).

[old fat man]

Eric, seems like the tire is the variable that will ultimately determine how low you can go. I've got a pair of the Grail wheels waiting for my disc cx bike and I'll try some Mud2's and maybe some Clement PDX that I already have, but I have a feeling the tubeless specific tires like the Vittoria XG TNT are the final ingredient that will let me get below 30psi.

[eBAUMANN]

Eric, seems like the tire is the variable that will ultimately determine how low you can go. I've got a pair of the Grail wheels waiting for my disc cx bike and I'll try some Mud2's and maybe some Clement PDX that I already have, but I have a feeling the tubeless specific tires like the Vittoria XG TNT are the final ingredient that will let me get below 30psi.

oooooh boy, do i smell a aluminum zank in your future? :banana:

[muchness]

I concur about tubeless tires being quite important. I've used Vittorias and Kendas with zero burps. I raced below 25 last year, but I tend to smash the A23s a bit, on trail, below 30ish psi. I use more than recommended amounts of tape, it makes seating and sealing instantaneous.

I dig the Nano 40s, I haven't had a go at tubeless with the race version. WTB says the tubeless version should be along soon, same with the cross boss.

I've been all A23s thus far, but have a pair of chriss cross rims to lace up, hopefully soon.

[Britishbane]

Eric, seems like the tire is the variable that will ultimately determine how low you can go. I've got a pair of the Grail wheels waiting for my disc cx bike and I'll try some Mud2's and maybe some Clement PDX that I already have, but I have a feeling the tubeless specific tires like the Vittoria XG TNT are the final ingredient that will let me get below 30psi.

I think not using tubeless specific tires (especially in races conditions) is asking for trouble.

[benb]

It depends on setup, the right rim, and the right tire..

I don't have a 29er but I've been running 20-30psi on my MTB for years now with no burping.. I'm like 180 and my bike isn't light either. My rims are Mavic Crossmax, pretty much any tire designed for tubeless use has been fine.

It should not be a problem for cross but the tires are smaller so maybe the pressure still ends up higher.

[old fat man]

oooooh boy, do i smell a aluminum zank in your future? :banana:

just waiting for a fork at this point. everything else is ready to go!