burnthesheep

The more hardcore topic appears dead in the "33".

I figured out my Velocity USA wheels that came on my cross bike are the 23mm wide tubeless. They're setup already also with the right tape, it appears. Looks like I just need the valve stem and sealant and tires. I have a shop compressor I can inflate it with first time to seat it.

Thing is, I race 4/5. I'm not old enough for masters 40+ for another 4 years. So, I'm pretty much limited to racing 4/5 as around here there isn't a 3/4 like for crits. In 4/5 it always seems I have the smallest tires. I didn't know any better and bought 33mm way back. I read up on it, and it seems even if I ever went to a USAC regional for my level that 35mm would still be the larger max. Not 33. Now, in 4/5 around here everyone looks like they're on easily 38mm or larger off road tires. Once in a while some young kid on a mountain bike laps the field in 4/5.

If that's all true.........any harm in going with a 38 (most I can fit) instead of a 33? Even a 35 seems like it would gain me some grip (which is where I currently suck).

I really don't want to train/race on different tires since I train a lot on gravel riding in cross season and would prefer the 38 for that.

If I'm out to have fun and not make Cat 3 or win regionals..........no harm in the 38's? I was thinking something like a Terreno 38. Then put my clincher mud tires on the spare wheelset just in case weather throws a wrench in plans. I can't convert that set tubeless as it is road tubeless, too high a pressure for seating/running a cross/gravel tire I think.

Thanks.

aggiegrads

It really depends on the conditions in your region, and on race day.

Sometimes you want a tire that can cut through the “Peanut butter” mud, or that will pick up less “Mashed Potato” mud. These are the two conditions where I would want a tire more on the narrow side.

shoota 

Everything up to this point makes sense and I support your line of thinking.

But the quoted sentence above doesn't make any sense.

burnthesheep

I would really like to be wrong, as I like that set of wheels better.

There was an article on one of the cyclocross sites about tubeless that brought this up.

https://www.cxmagazine.com/going-tub...ecommendations

quote:
"Road Tubeless Does Not ApplyThe Road Tubeless system developed by Hutchinson and Shimano is not relevant to the world of cyclocross, in our opinion. Although road tubeless can allow lower pressures in road riding without the fear of pinch flats, the Hutchinson Tires’ Road Tubeless bead is still built for high pressure and designed to be very stiff so that it will not blow off the rim under the high psi’s required by road tires (at the high pressures of road tires, you never want to try to convert a conventional road tire because its bead will stretch).

But the whole goal is to ride lower pressures without flatting, right? Our experience has been that because the road tubeless bead is so stiff, it has a slightly looser fit in order to fit over the sidewall of a rim without stretching and without requiring tools. While the mechanical lock between the tire and a tubeless-ready rim is excellent at the high pressures it was designed for, to run at really low pressures (with sealant), you need a tighter fit, not a stiffer bead. This is why the early versions (non-carbon bead) of the Hutchinson Bulldog and Piranha tires weren’t super-reliable low-pressure performers as tubeless cyclocross tires, and as a result, tubeless tires in cyclocross quickly gained a bad reputation. Many have hear stories of someone giving it a try, and not having much luck at low pressures.

But if you already have a pair of tubeless-ready wheels and want to ride lower pressures without burping, don’t fret. You may just have to make a few mods. The Redline cyclocross team raced tubeless extensively the last few seasons, and has found a reliable, low-pressure setup by adding rim strips to the Shimano Dura Ace wheels. (Note: the newer carbon bead versions of the Hutchinson tires sit very tightly – and can be inflated with a floor pump – but require very high pressures (80+ psi and some soapy water to ensure a complete bead seat/seal.)"

shoota 

Ah yeah, that's an old article. "Road" tubeless is basically not a thing anymore. What is your spare wheelset? That will help determine what kind of tire will work with it.

burnthesheep

Giant PA2. Circa 2015. Alloy.

I thought they're tubeless. I am trying to search through specs online again and am having a hard time locating it. The 2015 Propel had them stock and their page doesn't list if it is or not. They're a hair wider than the Velocity wheels and the spoke count on the Velocity wheels was for like a 250lb dude. I'm 150lb or so, so don't need a million spoked wheel.

shoota 

I'd be shocked if those were tubeless ready rims.

msu2001la

I wouldn't worry about running 38c tires if that works for you. The 33c requirement is really just for UCI. If you're planning on racing USA CX Nationals or Regionals, I guess it might be an issue, but for a local series just run whatever you want. There are guys who race our Cat 4/5 on fat bikes and MTB's every week.

That said, I feel like most of the time a 33c CX tire is still the fastest choice. Unless your tracks are aggressively rough, singletrack type of courses or have really extreme gravel I'm not sure there's much to gain by going wider. The only time the MTBers seem to have an advantage is on courses with tons of sand, where they can ride more of it vs running. Most of our races are grass/hardpack dirt unless it's been raining a lot, in which case they turn into sloppy mud fests.

You'd also want to make sure you have plenty of clearance for 38s. Wet grass will quickly clog up narrow gaps, as will any mud.

chas58

I run 38's. I see people running 20psi on 33mm tires, but it seems to me I'd be riding on the rims most of the time doing that. 38's gives me a little more security (in my head at least) running low pressure. CX is all about low pressure.

As for what size is better - its really balancing out weight vs bottoming out your rim and cornering stability. I've used ramblers, and they are lighter than a lot of CX tires. But yeah, depends on mud and the clearance on your bike and the conditions of the day. I'd run some deep lugged 33mm tires on a muddy course - because flotation is NOT something I want in mud.

If you are worried about burping, I use "skinny strippers" (basically a latex strip) that actually ends up bonding to the tire creating a sort of tubular tub less tire (i.e. it holds (some) air even when off the wheel). It seems to be impossible to burp using these.

Road tubeless is rather a new hot mess, but the beads on those tires are so so tight to take 120psi. Not sure that is at all relevant to CX though. I don't think a beaded rim is going to do much help at low pressure - you really need a good tight bead seat on the rim bed.

burnthesheep

Wound up they're hooked and have the center profile at least. So, has the tubeless center channel shape instead of the clincher shape and has the bead shelves. I put some Stan's tape on it (my namesake) and the proper amount of sealant. They actually held air with tape only overnight, no sealant. They lost a bit of pressure, but not much.

With sealant, losing no pressure. I rode them gravel that weekend and it's a game changer. No more pinch flat worries. They were silly faster also than my 32/33 tires I had. I went with a 38mm Terreno mix. Good comfort also.

Felt like a new bike with that setup and some fresh brake pads!

shoota 

Awesome! It's pretty hard to beat a tubeless 38mm gravel tire setup.