Tubeless has been the standard for most active mountain bikers for a bunch of years, and it’s been an increasingly viable option on road for a while. In cross, the adoption hasn’t been as smooth. A new crop of tires and rims has held promise that 2015 would be the year that tubeless became a viable option for cross. Since we’re inveterate testing nerds, we needed to see for ourselves if it was ready for prime time. Here’s what we learned.
But first! a two second primer on tubeless. You need to prep your rims to make them airtight. Ours come sealed with tape, so there’s nothing left to do there. Beyond that, you’ll need tubeless valve stems and sealant. There’s nothing fancy or complicated about either. You can buy valves or even make them out of old punctured tubes (just cut the stem out, but it has to be threaded and you need the nut), and there are several brands of sealant that work just fine.
Testers were Michael Wissell of the Cuppow/Geekhouse/B2C2 CX Team, who’s really really good at cross, and me (Dave). I kind of suck at cross but love it so long as there isn’t much running or getting off the bike of any sort involved. Neither of us is too heavy, I'm the fattie of the pair at a fighting 160 pounds. Most testing occurred on disc brake bikes, on Stan’s Grail and Pacenti SL25 rims. Pacenti SL23 (rim brake) rims were also tested. The inner shape of the SL23 and the SL25 are indistinguishable, and the Grail is also very similar.
Testing protocol was basically “throw whatever hatred and evil you’ve got at the things, and see how they do.” This included terrain which no cx bike should ever see, as well as terrain that every cx bike should see, cobbled roads, drop offs, roots, rock gardens – you name it. All tests were done with sealant (either Stan’s or Orange Seal, both of which work well), and two wraps of the tape we supply on alloy rims (TESA 4289, if you want to go get some).
A successful test means that we unreservedly recommend the tire for use at low psi, with little to no risk of burping. In general, for us, this meant pressures down to around 22 front, 25 rear. Security of tire/rim interface was the overwhelming consideration in these tests. Any tire’s success in that measure doesn’t mean that either of us particularly like or plan to use it, merely that if you like that tire, feel free to use it because the shit works. Well.
If a tire is not specifically listed here, it means we haven’t tested it. These results are only applicable to the rims on which we tested. Success of any partial combo should not be assumed, nor should it be assumed that a tire we found not to work with our rims is a flop. It may work great on some other rim(s).
We’ve included some notes on each tire. Enjoy.
Tires We Don’t Recommend:
Challenge, Clement clinchers (can’t wait until they come out with tubeless), Kenda non-tubeless, Kenda tubeless (these probably work great on some rims, and the Stan’s CX team uses and endorses these, so YMMV), Schwalbe non-tubeless (these didn’t even inflate)
Tires We Recommend:
Hutchinson Black Mamba Tubeless 34 Weight: 348g Inflated width: 33.75. A file tread-ish tire with side knobs that seems to like grass more than a lot of other file treads. Probably great in frozen conditions, which we fortunately haven’t yet gotten to try. Seats with a loud bang. Comparable to Clement LAS, Challenge Chicane, Kenda Happy Medium
Hutchinson Toro Tubeless 32 Weight: 330 Inflated width: 32. Dave’s favorite all-rounder, Mike likes it but not as much. It may be a better tire for less aggressive riders, giving less of a loose and fast feel, with a more defined and secure traction limit. Works great on hard, loose over hard, hero dirt, slight mud, and short grass. Miserable in sand and loose dirt. Soap the beads when installing to ensure easy bead seating. Seats with a loud bang. Comparable to most of the mtb tires that Dave likes – not a traditional cx tread.
Maxxis Mud Wrestler EXO TR 33 Weight: 362 Inflated width: 33. Mike’s favorite all-rounder, which he finds works well on everything but deeper sand. Looks a light beer version of a mud tire, but not a top choice for really muddy conditions – it will pack up with gloppy mud. Can be hesitant to inflate with pump, but it can be done reliably. A compressor inflates it instantly. Comparable to a Clement PDX or Challenge Baby Limus.
Vittoria Cross XG Pro TNT 31 Weight: 390 Inflated Width: 32 This is a Grifo. The sidewalls are quite stiff, but run at low pressures (22 is fine in the front), it feels not as good as a tubular but WAY better than a clincher at the pressure you’d need to not pinch flat. This is the most secure tire/rim lock I’ve ever seen. I don’t think it would burp at 15psi. It’s fairly heavy, though. Comparable to a Grifo, which it is, and as such it’s just about as good a grass tire as you’ll find.
WTB Cross Boss TCS Light 35 Weight: 410 Inflated width: 36.75. This thing is HUGE. If you use this, people will comment on the width. Inflates instantly, seats with a soft bang. I repeat, this thing is HUGE. Lower profile and more tightly spaced knobs than the Toro, with basically no side knobs – the tread pattern doesn’t overhang the sidewalls at all. Works well with insanely low pressure, and turns you into a hero in gravelly turns.
Despite what we’ve said about inapplicability of these results to any tire not tested, we feel comfortable that the Vittoria TNT and Hutchinson Tubeless series tires not tested would have similar tubeless performance.
Weight and inflated width are both measured brand new out of the box, with pressure set to 30psi. All tires have become at least slightly wider over time.
So there you have it. As many many many people have pointed out to me in the last weeks and months, tubeless doesn’t feel as good as an FMB tubular, but when was the last time you were able to switch your FMB tubulars to a different tread on the same wheel after your last pre-ride? They’re not for everyone and every purpose, but for what they’re good at, they’re great.
Tires vary from brand to brand, model to model, and tire to tire making some tires easy to mount and some tires more difficult to mount. With the proper technique most tires can be mounted by hand without tire levers. Use only one layer of Stan's yellow tape whether running tubeless or with tubes on Stan's mountain bike rims. Use two layers of yellow tape on Stan's Alpha road rims for high pressure tire use. Always mount the valve area last. The valve sticks out of the channel of the rim and interferes with the tire bead in that area – in effect making the tire have to stretch further than it would if the valve were not there. To avoid this, begin mounting the tire opposite the valve then work both sides around toward the valve area and mount the valve are last. Once the first side of the tire is mounted push the tire bead to the outside of the channel to make room for the second tire bead. Mount the valve area of the second bead last.
I tried to mount a set of the new Vittoria TNT XL tires on a pair of Stan's Iron Cross wheels and couldn't even get close to getting them on. Like the last bit of bead was stretched across a big part of the rim. I even broke a tire iron.Also, the sidewall says Mount Only On Rim With Bead Hook.Did you guys test them on any hookless rims?The Vittoria bead looks like a road tubeless bead with a kind if square cross section with corners pointing in towards the opposite bead and out through the brake track…
Hi Bill,Glad you're having success with them. Our parameters were that we had to be able to run low pressure without burping. We couldn't reliably do that with Kendas. As we mentioned in the post, we know others are having better results with Kendas than we had. Our results are also only relevant to SL23, SL25, and Grail rims. As it was, this was a MASSIVE undertaking and represented the maximum scope we could give it, and we prioritized rims we sell in order to be able to give our customers the best info we could. ThanksDave
Thanks Dave!The grail does look very appealing. Even though I tend toward trails (singeltrack on the cross bike is soooo much fun!) it would be nice to be able to mount road tubeless on occasion. The goat heads in New Mexico are murder, so the only other reasonable option is thick TR tubes.Not sure if you can comment (since you obviously want to sell these things!), but do you have a preference between the Grail and Pacenti rims? Any advantages/disadvantages?Thanks again for your help!
Luke – Thanks. I don't know that we've done what we've done better than Stan's or any other team, but we're happy that people find it useful.No trouble putting Cross Boss or Vittoria on Grail rims, no. Cross Boss is not at all tough to install and airs up instantly. Vittorias are very firm to mount but far from difficult, and also inflate with the first pump. I <<think>> the reason why Stan's recommended against some of those tires is that some Stan's rims are not very radially stiff, as you would expect of light, shallow section rims. The tight beads compress rims like that too much and can make it wobbly and easily put out of true, or perhaps worse. The spokes lose an unacceptable amount of tension. Grails are very radially stable (much deeper than other Stan's alloy rims), and the spoke tensions don't drop more than other rims when you mount tires on them. I think that's what it is. Both tires have a very secure interface with the rim. I really like Grails. Dave