Tubeless CX wheel width - how big is too big?

[chrispino]

Putting together, on paper at least, my CX bike this year. First year on disc so new wheels are needed.

I've always ran tubulars for racing, but seeing as I probably won't be able to get a full CX season in this year, I think I'm going to try and run tubeless to save on some costs...and I'm curious about tubeless for racing as well.

Been eyeing the new Stans Crest MK3.

One concern I had is tire size. With an internal width of 23mm will a 33c tire (probably the new Clement tubeless stuff) ballon out past UCI size?

I race as Cat2, so in New England that means getting my head kicked in at a lot of UCI races where both tires are measured during staging.

[adamhell]

i feel like people shy away from tubeless for CX racing since it's riskier to run lower pressures to get that pro grip.

however, schwalbe has this crazy system with this tube that's smaller than the tire so you get the benefits of tubeless with the flat protection of...tubular (?)

i googled it and it's called pro core, not sure if they have CX options, looks mostly like MTB.

this photo will illustrate it better than my description:
http://bike-eu.com.s3-eu-central-1.amazonaws.com/app/uploads/2015/04/attachment-001_logistiek-image-1564496-272x204.png

[chrispino]

Yea that seems like such a faff, and silly money, unless you're smashing down a DH course on huge tires

Spoke to Timmerman who races for the Stans elite team. They ran the Valor with Kenda tires as low as 20psi all season with no burps at all. So not hugely concerned about pressure/burping as I am tire size/finding the right combo

The Valor is 21.3 internal and the Kenda's are listed as 32's. So we know that combo passes the test. Seems like 23 internal with 33 tire might be too much though

[shovelhd]

As an official who chocks tires during staging, if you're going to push the limits, get a gauge set and check them yourself before you report. The last thing I want to do is send you to the back of the field and hold up staging for everyone.

[eBAUMANN]

Yea that seems like such a faff, and silly money, unless you're smashing down a DH course on huge tires

Spoke to Timmerman who races for the Stans elite team. They ran the Valor with Kenda tires as low as 20psi all season with no burps at all. So not hugely concerned about pressure/burping as I am tire size/finding the right combo

The Valor is 21.3 internal and the Kenda's are listed as 32's. So we know that combo passes the test. Seems like 23 internal with 33 tire might be too much though

23 internal and a 33 tire would almost definitely measure out larger than 33, so I would avoid if possible. Tubulars or undersized tires (32 for example) are your safest bet, would suck to get a surprise during staging.

Dunno if you care about weight (not sure what the frame is) but it's real easy to build up a heavy disc bike, a lightweight tubular wheelset is a big help in keeping things reasonable. Try looking for something 2nd hand, already setup with tires, helps keep things reasonable $-wise.

[sandyrs]

Vittoria makes a 31 tubeless cx tire. I always sort of assumed it was for this situation.