Getting off-road on a cross bike

[hozn]

@Raymo853 123716 wrote:

Stan’s technical folks warned me strongly & promptly when they saw I had non-tubeless 28c road tires set up tubeless on my Grails. CX and road tires that are not tubeless ready can easily seat up with sealant, but have a high tendency to blow out and deflate immediately. They made me promise to not even ride the 12 miles home before putting in tubes.

You’re mixing apples and oranges here. This is true for road tires, yes. On account of the pressure. But you can certainly run non-tubeless-ready ‘cross tires tubeless (at appropriately low pressures — e.g. 30-40psi). This isn’t substantively different than MTB. And especially steel-bead tires like the Trigger Sport, but you will likely struggle to get them to seat.

In short, do NOT run regular (non-tubeless) road clinchers tubeless. DO feel free to run whatever you want at CX or MTB pressures, but YMMV. In general, I find that the best tubeless setups are the ones designed for tubeless. If you have a compressor, though, the Trigger Sport tires are a lot cheaper and work fine once seated.

[Raymo853]

@hozn 123719 wrote:

DO feel free to run whatever you want at CX or MTB pressures, but YMMV.

I disagree.

[gtmandsager]

I rode on Triggers in Iowa on a borrowed Crux, they were amazing. I’ve ordered a set of Panaracer Comet 38s after seeing a glowing review by someone who also runs them on a caadx (and they’re cheeeeeeap), I’m looking forward to trying them on longer rides on the towpath and Loudon gravel.

I may try converting the maddux rims that came with the bike into a tubeless setup, but that would require some uninterrupted alone time and I spend pretty much all of that either sleeping or riding my bike… The tires the bike came with are schwalbe’s racing rob, which are not purported to be tubeless ready and I haven’t seen many reviews of people trying to convert them to tubeless. I may just train on them for now with tubes and keep an eye out for something to try running tubeless for cross season.

[Tania]

Pretty sure I’ve watched this at least a dozen times.

http://www.bicycling.com/culture/news/video-sending-whistlers-line-cyclocross-bike

Pro mountain biker rides Whistler on cx bike (and kit). Be sure you listen too, he’s having so much fun!

Hozn – agreed on the Wakefield berms. Was there Saturday (on my Titus) and that whole section is a rutted, eroded mess.

[hozn]

@Raymo853 123725 wrote:

I disagree.

Given that you actually thought it was a good idea to run RT with non-tubeless tires in the first place — when every mention of RT warns in huge letters not to do that, I’ll take your disagreement with a grain of salt

Edit, to be slightly more constructive, here is some helpful reading regarding tubeless cx:
– The classic 3-part series from cxmagazine (you’ll see a number of their recommended tires are non-tubeless):
1- http://www.cxmagazine.com/going-tubeless-cyclocross-racing-intro
2- http://www.cxmagazine.com/trying-tubeless-cyclocross-tires-setup-part-ii
3- http://www.cxmagazine.com/going-tubeless-cyclocross-tires-racing-recommendations
– November just published their findings: http://www.novemberbicycles.com/blog/2015/9/3/tubeless-testing-summary-report.html

[DaveK]

@gtmandsager 123726 wrote:

I rode on Triggers in Iowa on a borrowed Crux, they were amazing. I’ve ordered a set of Panaracer Comet 38s after seeing a glowing review by someone who also runs them on a caadx (and they’re cheeeeeeap), I’m looking forward to trying them on longer rides on the towpath and Loudon gravel.

I may try converting the maddux rims that came with the bike into a tubeless setup, but that would require some uninterrupted alone time and I spend pretty much all of that either sleeping or riding my bike… The tires the bike came with are schwalbe’s racing rob, which are not purported to be tubeless ready and I haven’t seen many reviews of people trying to convert them to tubeless. I may just train on them for now with tubes and keep an eye out for something to try running tubeless for cross season.

I would keep an eye out for someone selling a Stans wheelset or similar from a mountain bike. They’re easily converted to QR or thru-axle depending on what you run, then you can just swap the wheel in and out. Just make sure it’s 135mm rear and not 142mm.

[hozn]

Yup, a stock Stans wheelset can be easily converted between different axle formats. And would be a good value. Personally I’m a fan of Hope Pro 2 Evo hubs (and Stans rims, obviously), but I doubt the extra cost is comensurate with value (and Hope hubs weigh more too). The parts for a Hope Pro 2 + Stans Grail rim wheelset run about $500.

I believe the 142×12 mm is convertible to 135x* too (but obviously confirm before buying). Contrary to what the label suggests, 142mm hubs are really just 135mm wide but in 142×12 the end caps simply extend into/through the frame dropouts.

I have sworn that my next cross bike will have thru-axles — at least front. I don’t know that the additional stiffness is really that noticeable (the disc forks are generally really stiff), but I really like the consistent rotor alignment on my road bike.

[Raymo853]

@hozn 123736 wrote:

Given that you actually thought it was a good idea to run RT with non-tubeless tires in the first place — when every mention of RT warns in huge letters not to do that, I’ll take your disagreement with a grain of salt

Edit, to be slightly more constructive, here is some helpful reading regarding tubeless cx:
– The classic 3-part series from cxmagazine (you’ll see a number of their recommended tires are non-tubeless):
1- http://www.cxmagazine.com/going-tubeless-cyclocross-racing-intro
2- http://www.cxmagazine.com/trying-tubeless-cyclocross-tires-setup-part-ii
3- http://www.cxmagazine.com/going-tubeless-cyclocross-tires-racing-recommendations
– November just published their findings: http://www.novemberbicycles.com/blog/2015/9/3/tubeless-testing-summary-report.html

I rechecked, the recommendation is no tires above 40 PSI unless they are tubeless-ready, UST, LUST, TNT, UST-lite, 2Bliss, etc…. Plus, kevlar beads are safer than wire beads as Kevlar has a much lower chance to stretch.

[Raymo853]

@hozn 123765 wrote:

Personally I’m a fan of Hope Pro 2 Evo hubs (and Stans rims, obviously), but I doubt the extra cost is comensurate with value (and Hope hubs weigh more too).

Hope hubs are simply wonderful for durability and smoothness, but yes pricey and not super light. About to build one into the it’s third rim.

The older (current) Stan’s hubs are less durable, but once you learn how to change the bearings, convert the axles from one standard to another, and replace the freehubs, you can fall in love with them as well. My oldest pair is in a factor set of White Arch wheels: many years old, third owner, left outside for years. New bearings, new freehub and a few new spokes and I expect them to last at least another two years as CX wheels. (Yes with Bonti CX3 TLR tires) One thing, if you order the kit to convert a 135 rear to a 142 by 12, make sure to ask for the extra spacer. It is not in the kit, or I am hoping by now that is a was. For many of the hubs, if you do not have the extra spacer, the quick release will lock the freehub body and you will end up riding a multi-speed fixed gear.

I know little about the newer (upcoming) Stan’s hubs beyond the marketing copy.

A great source about working on Stan’s hubs: https://www.youtube.com/watch?v=I1E3AI9QH4E

[hozn]

@Raymo853 123802 wrote:

I rechecked, the recommendation is no tires above 40 PSI unless they are tubeless-ready, UST, LUST, TNT, UST-lite, 2Bliss, etc…. Plus, kevlar beads are safer than wire beads as Kevlar has a much lower chance to stretch.

Where are you getting this information? The rim also has an opinion on max tire pressures and the force on the rim is a factor of the pressure and the tire volume. If you look at the label on a Stans Arch rim, for example, it says “MAX RIM PRESSURES: 1.0 tires = 55psi, 1.5 tires = 50psi, 2.0 tires = 40psi, 2.2 tires = 38psi”. So a typical tubeless MTB tire should be no more than 40psi, regardless of whether it is tubeless-ready or a converted-to-tubeless MTB tire; Stans makes no distinction there (and indeed they explicitly say “Stan’s NoTubes mountain rims and converted tube-type mountain rims will work successfully tubeless with most types of tires including standard tube-type tires, tubeless ready tires, and tubeless specific tires.”). So math says you should be able to get away with higher pressures on lower-volume CX tires, from the rim’s perspective; however, I do not know why you would need/want to run a tubeless tire at more than 40psi, so that isn’t really a point worth debating.

The bottom line is that running non-tubeless tires without tubes at road pressures (80+ psi?) is universally acknowledged as a very dangerous thing to do. I have never seen any opinions on relative safety of tires used tubeless at <40psi, except that some will simply work (seat up, not burp air) better than others. We're not talking about road tires here, so I just wanted to correct the misconception that running non-tubeless *CX* tires without tubes [at appropriately low pressures] is somehow dangerous.

To close out my part, I’ll just say that for safety, follow the recommendations on the tire and rim; for a [hopefully] painless setup experience, follow the recommendations from folks that are conducting real-world evaluation of these tires: CX Magazine, November, etc.

[Raymo853]

@hozn 123807 wrote:

Where are you getting this information?

From a engineer that works for Stan’s, who I trust without reservation, and an ex-gf working for Bonti, who I trust a little less.

@hozn 123807 wrote:

If you look at the label on a Stans Arch rim, for example, it says “MAX RIM PRESSURES: 1.0 tires = 55psi, 1.5 tires = 50psi, 2.0 tires = 40psi, 2.2 tires = 38psi”.

Those numbers are regarding the failure of the rim, not the tire.

The 40 PSI threshold has nothing to do with seating or burping of non-tubeless tires. I have have easily seated and ran non-tubleless tires on Stans, Mavic, Shimano, and Bonti rims ranging from 20 to a 70 psi. None have ever burped or failed on me since a Mavic/WTB failure back in 2004. (Why I stayed away from tubeless until 2009) The risk is anything over 40 PSI can cause a tire to stretch enough to blow off the rim without warning. A tube keeps that form happening by locking the tire onto the rim in a way that air pressure without a tube cannot.

[hozn]

Ok, I don’t have any special connections; I just base my understanding on their website and the rim/tire sidewalls, when applicable. I agree that a 40psi threshold is unrelated to burping/seating. I think we all agree that you wouldn’t run a mtb tire tubeless at > 40psi. Or ‘cross for that matter. Even a tubeless-specific cross tire can blow off the rim at high pressure; I’ve blown a tubeless Hutchinson Piranha off at 65psi (and that was well with stated pressure range on the tire), kevlar bead and all. Maybe a fluke; Hutchinson tires are garbage IMO.

[mikoglaces]

What I want to know is, can I ride my cross bike with current tires — 32C with tubes – on the CCT north of the W&OD? Either all the way or even part way? I do rides to Great Falls area/Riverbend Park from Dunn Loring/Vienna on my road bike and Route 7 doesn’t offer many places to cross (Towlston Rd., Beulah or Springvale primarilly) so I thought about the trails I see off of the W&OD, but not sure my normal 32C cross tires will do the trick.

[gtmandsager]

DaveK and I were on cross bikes, my tires were 35mm and I think the other were ~32-33ish. I ran mine at 40psi, I think he was similar. We were fine on the way up, but had a couple pinch flats on the way back (south). But I’d say it’s manageable on a cross bike, it may not be quick b/c you have to take some of the sections a bit gingerly (or walk, or both). I can’t speak to what it would be like if it were muddy.

[mikoglaces]

@gtmandsager 124190 wrote:

DaveK and I were on cross bikes, my tires were 35mm and I think the other were ~32-33ish. I ran mine at 40psi, I think he was similar. We were fine on the way up, but had a couple pinch flats on the way back (south). But I’d say it’s manageable on a cross bike, it may not be quick b/c you have to take some of the sections a bit gingerly (or walk, or both). I can’t speak to what it would be like if it were muddy.

Thanks. Very helpful. I might plan a loop where I ride north on the trail and back on roads so back won’t be a problem anyway.

[Author]

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