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.
You're gonna need to getcha some of these
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).
Partial class picture
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.
Plus size model
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.
29 comments
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.
Thanks for the input Bob.Over the last five years I've been running tubeless mountain bike, road, and cross.Mountain bike flawlessly, road mostly successfully and CX miserably.I've tried Kenda, Michelin, Clement on my Stan's Iron Cross rims and generally ended up with 45 psi to actually make anything reliable. On most rides I end up putting a tube in.The problem right now with tubeless is that UST didn't catch on so we're left with (as you pointed out) an infinite number of wheel rim designs and dimensions, tire bead dimension and designs, etc etc etcFor some people two layers of Stan's tape and a rubber strip work, for others one layer of tape and some holy water. Yet others use Gorilla brand duct tape, or thick foam weatherstripping. People swear by this tire brand or that tire brand. The other wheel is better, or just run tubular and quite messing around.Rider weight, riding style, and course conditions play a role in success or failure as well.I asked specific questions about a specific tire and specific rim.
Hi David -We restricted the scope of the test to the rims that we work with which we knew had potential for being used tubeless for cross. As such, only Pacenti SL23s and SL25s, and Stan's Grails were included as rims in the test. We definitely didn't test any hookless beads, and when the Grail came out we so strongly preferred that over the Iron Cross that we stopped doing Iron Cross builds. To keep things simple and avoid the million different variables of holy water and Gorilla Tape, we just used two wraps of our tape as a base on all rims. The designed outcome was what we got – the ability to say "if you use this with this, we have had good success with that combination and we believe that you will too." Exactly as you said, we wanted to cut it down to "this works, period." It's a closed answer set. A fairly broad closed answer set, but a closed answer set nonetheless. We're comfortable that anyone who's using one of the wheel systems using the rims we tested and using one of the tires we approve will have both a great experience using them tubeless, and that they have a broad enough selection of tires available within those choices in order to match to any condition.It's beyond our capacity to do the wide range of testing whatever's out there – as limited as it was, this was as expensive and more time consuming than any single piece of wind tunnel work that we've done. So we really couldn't do more, and it makes sense that we'd limit it to things you can buy from us, right? Like a lot of the testing work we've done, there's a lot of spillover into the domain of the public good, but we've got to eat, too.Incidentally, I actually raced a cross race on a cross bike yesterday. Our testing was orders of magnitude more demanding than anything I faced on the race course yesterday.Dave.
Thanks for the response. Of course I don't expect you to do an exhaustive test of every possible tire, wheel, pressure, tape, brake type, and riding condition!I mean you're superman but… even Cyclocross Magazine couldn't do that.Seriously though, I asked a question and you answered it, thanks.I wish something I had read about the Vittoria tires (including their web-site) had thought to mention they don't recommend mounting them on hookless rims…Now I'm second-guessing my decision to use the Specialized Roval Control wheels, seeing as they're hookless.After I bought DT Swiss free hubs and end caps to convert them to Shimano 11-speed and everything!Hmmm…Well, my other middle name is guinea pig!
Did you have any trouble mounting WTB or Vittoria tires to Stan's rims? I got a cheap build of Stan's Arch wheels, but am thinking to get your Grail build in the future when I have the cash. I've seen forum posts and even Stan's website saying that WTB tubeless are too tight to mount on their rims (and similar comments about Vittoria), but maybe this is only in reference to older rims like the Iron Cross? In any case, thanks for the exhaustive testing! This is super cool, and it says a lot about you that you are able to do a better job giving real world data than even Stan's own team! Kudos!