junkyardking

I'm going to be using my touring bike for my first CX season. If I like the sport, then I'll invest in a new bike, or at least a new wheelset. For the time being, I'm sticking with what I've got.

Now, I know that tubulars are preferred for CX, but I've got clinchers, and I'm not ready to throw a lot of cash into new wheels. My question: how low should the PSI of clinchers be for a CX race? How low is too low/unsafe. How high is too high?

Also, as long as I'm at it, can anyone point me in the direction of a good knobby tire? Is everyone running Vittoria or is there a cheaper option?

flargle

Everyone is different. You have to find out for yourself.

Latex tubes might help.

Andy_K 

It depends on the course, the tires, your weight and your riding style. I weigh around 200 pounds and have run Michelin Mud2's as low as 30 psi. The only time I've pinch-flatted I was running Schwalbe Racing Ralphs and forgot to check before the race -- probably a bit below 30.

You definitely don't need tubulars. Start out around 45 psi and lower your pressure from there. You'll definitely notice better handling as the pressure goes down. If you pinch flat, you went too low. Be sure you're using big enough tubes.

Cynikal 

For tires I like the Specialized Captains Pros but I mostly use them in muddy conditions. I have ran them low, like 28 psi but I had tubes with sealant just in case. They were tubes with replaceable valve cores.

All this being said, just go out and have fun. I spent too much of my first season worrying about gear choices.

ridethatbike

I would say this, run them at a PSI where you can see both tires just start to deform when you are in your riding position. That should be pretty safe. Latex will help as well. You will need to be careful if there are lots of rocks, roots, or other obstacles that may make you pinch flat. If the course doesn't have any of those, you could probably go 1-2 psi lower.

mr.smith.pdx

I weigh 225 lbs. I run 40-42psi on Michelin MUD2s and have never pinch flatted in a race.

YMMV.

Just go for it. Figure it out as you go.

Cynikal 

Don't forget to talc you tube/tires. That will help with pinch flats.

fietsbob

Low pressure studded tire trick:

Sew-Up Glue one bead to the rim, so it won't creep,
and carry the tube around with it,
until you shear the stem out of the tube.

the unglued side will let you mend punctures..

the clincher bead hook is what can cause pinch flats ,
the sharp hard place , on one side of the pinch with what you run over.

STP

I weigh 150 lbs. and run 32mm tires on a 23mm rim at 40-45 p.s.i. typically.

JeffS

Start at 40 psi and try up and down from there to find what works for you.

One of the Michelin tires (mud/jet) is a safe bet. The Mud is an all-around tire, despite the name. If local courses are going to be fast/dry, then the Jet, or something with even less tread.

holychipotle

A lot of the other folks are mentioning the Michelin Mud2 and I also agree they work really well all around. Clinchers are a good deal but the next level is tubies and they are WAY better.

It is the best upgrade you can make in most cross equipment situations. This year I have built a set of tubular wheels with the new Major Tom rims from Velocity. They are 23mm wide (wider than most rims which are often times 19mm). My opinion is a wider tire requires a wider rim. Build these up with DT Comp spokes and inexpensive 105 or Tiagra hubs and you have economical but awesome set of tubular wheels.

Debusama

Nobody said anything about going tubeless. I have a ghetto tubeless set up on my mountain bike with Stan's sealant and It has worked great for avoiding pinch flats. Is there a reason why that kind of setup is not practical on a cross bike? I have been thinking about doing it.

holychipotle

It would be great to run tubeless, sure but the riding properties of tubulars for cross is unmatched. If you are willing to go through the trouble of tubeless just go tubular. It is unpredictable even with rims that are made specifically tubeless ready to have it all work without fuss. All the professionals swear by tubulars over any clincher setup including tubeless for a reason. The construction of the tubular rim and tire is different offering better characteristics of handling, feel, speed and durablilty.

Handling & Feel- Tubulars have flexible sidewalls so the tread can remain in contact with the ground better

Speed- Tubulars are lighter

Durability- tubular rims do not have the sidewalls sticking out but instead have a completely inclosed box. Bottoming out on any clincher is often going to leave dents.

mr.smith.pdx

Here is my take on tubulars, tubeless and clinchers. Take it for what you think it is worth.

Clinchers - Use the wheels you have, pay as little as $35 per tire and patch your tubes. Pit wheels are cheap and you can use any old set. You can feel like a bad ass with pit wheels and be ready to go the next day with patched tubes.

Tubular - all tubular riders (including many who don't pay for heir own tires (i.e. - high level pros) and others) will tell you they are the most awesomest invention since sliced bread. Tubulars go for over $70 a tire. I had a team mate who punctured two tubies in two races in one weekend, $150 dollars and a lot of glue drying time (he was brave enough to glue his own tires...are you?) later and he was back out 2 weeks later.

Tubeless - great until you burp 'em. But you will be good to go tomorrow with more sealant.

Th OP was talking about using his TOURING bike to see if he liked 'cross. Recommending tubular wheels is completely outside what this guy wants and/or needs.

The OP is in San Jose. If it rains in the fall there, he/she should get mud tires. If it doesn't rain in the fall, think file tread or some Kenda Small Block 8's. Start on the high end of pressure (for your weight), work your way down from there. If you don't "bottom out" you may have too much air in there.

Whatever you do junkyardking, don't get worked up about the NEVER ENDING tire pressure and tubie/tubeless/clincher debates your first year. Just ride, race and enjoy yourself.

That's my $0.25. (it was way more than two cents)

mr.smith.pdx

Are you saying that gluing tubulars is "predictable" compared to running tubeless? Really? Are you serious?

AND

Is the OP a professional, with a professional mechanic gluing the tires. Are ANY of the posters in this thread professionals with a professional mechanic (or at least the sponsoring LBS) gluing tires and providing them for free?

junkyardking

Yeah, I do enjoy a good wheel build, so thanks for the tip on the rim. Just for future reference, in case I one day decide to go this route, do you know off hand what spoke length I would need for these rims with Tiagra hubs?

Thanks for the advice. Would you elaborate a little bit more on what you mean by patching tubes? Do you mean reenforcing them with extra patches around? I also wasn't planning on having a set of pit wheels. Should I? (This is going on the assumption that pit wheels are extras you have for in case you get a flat. Not gonna be afraid to admit that I am a full on noob when it comes to racing.)

Cynikal 

I think he means that you can patch your tubes and easily. Pit wheels are nice if you have a flat and you care about finishing the race (for points or whatnot). I use a pit bike (my SS cross bike) but I've never really had to grab it.

rithem

I popped a challenge grifo XS off in Sunday's race ... sucked because I was 7th or 8th to hole shot and was feeling good and ready to start chipping off as many guys in front of me as I could once we made it out of the woods ... I hopped the rear to avoid a root and *BURP* bead came off when I touched down .. I was running 35-37psi on a DT RR465. I managed to hop off and let the air out so the tube didn't blow, then I ran the course until I got to grass and rode the flat to pit. Aired up and ended up +1 lap ... BOUGUS. Oh well.

GrayJay

Last year I "burped" a maxxis raze and had the tube immediatly explode like a gunshot!

couchman

You can also pre-ride the course with different amounts of pressure to see what works on any given day and conditions. If you are out to have fun, a could of extra lbs of pressure won't ruin your race results.

flargle

As long as this thread has been derailed....

You're overmystifying tubulars. I'm an amateur racer who glues his own tubulars; it's not rocket science. It's more like 3rd grade Arts & Crafts. I recommend that people glue their own tubulars and NOT let the shop mechanic do it.

The reason so many amateur racers go to the trouble of using tubulars is because it's worth it. At the risk of jinxing myself, I've never flatted over multiple seasons, despite bottoming out all the time. I had one slow leak that I fixed with sealant. During this time, I've seen multiple guys lose their tubeless set-ups and basically give up their races; unlike tubulars, you can't ride a flat tubeless to the pit. I've also seen multiple pinch-flats, and similar story, you're not riding that bike to the pits.

During the same time period, I've seen one (1) guy roll a tubular. Which he didn't glue himself.

mr.smith.pdx

I wasn't trying to mystify them. But I will agree they are a bit of a mystery to me as I have never glued them and have heard (admittedly 2nd, 3rd and 4th hand information) they are a pain, or you don't want to screw it up. I guess I've just seen what to me seems like a lot of rolled tubulars at races here. However, that may just be because they are easy to spot. If you get a flat on clinchers or tubies, or burp, you can just push your bike. If the tubluar rolls of the side of the wheel, you are carrying your bike and are significantly more noticeable. I'd say I see at least one rolled tubular a week at the Cross Crusade races. Of course those races are rather huge, so there are obviously more tire issues because there are simply more people.

I still think recommending tubulars to a guy who is gonna use his touring bike is unhelpful.

I haven't tried them because I am simply not fast enough to justify new wheels. (in my own opinion)

Andy_K 

+1

If the reports are true about how wonderful tubulars are, I might be able to finish 150th instead of 178th. If I ever thought I could make the top 20 with tubulars I might do it. I almost talked myself into a set this year anyway, and then I did a reality check and laughed at myself.

ambro

Here's my take. First, I'm 6'1, 195 lbs, so I have to be real careful about how low I got. My first season I used Clinchers (Maxxis Raze). I was, and still am, a lower CAT 4 racer and new to CX. I used to run them in the mid 40's with no issues. Last year, my second season, I upgraded to Tubulars - and ran Challenge Fangos at pressures between 30 and 35 lbs. I have to say, there was a world of difference between tubulars and clinchers. With tubulars, they conform to the ground so much better and I wasn't getting bounced all around. That said, I was still a lower Cat 4 racer. This year (season 3) I rolled a tubular just last weekend. The race before that, I was running Michelin Mudd 2s at low 40's and pinched flatted but it could have been from riding over some large gravel in the race too.

I considered running Mich Muds as Tubeless but decided against it. If I'm going to go through all that trouble - I may as well go tubular and I'm concerned about burping the tire.

With three races left this season, I am opting to just run the clinchers. Too much $$$ and hassle to get a new tubular and glue it and I've heard mixed things about Tubeless. I'm sure I'll enjoy myself just as much but I will certainly miss the feel of tubulars - honestly, it was like night and day over clinchers. I won't miss spending $75 on one tire and cleaning the old glue off the rim. The actual gluing isn't a big deal - it just takes 4-5 days. Also, after rolling two tubulars now, I'm getting a little gun-shy. I love the feel, but clinchers are so much easier. Also, no matter how good the glue job from a Tubular - if it's a muddy, wet season, like it is here in the NorthEast this year - you always run the risk of the glue losing it's bond from all the water.

I know a lot of guys running Tubeless with mostly good results - but they can burp and require a lot of maintenance and watching to make sure they don't leak. Too much of a headache for me.

Surfer34

I have two bikes, one with clinchers and one with tubless. I have never gotten a flat with my clinchers and I have run them down to 20 psi. I cant seem to go more than a race without a flat on my tubless.

I am no pro so I ditched my tubless and just have fun not worrying at all about my clinchers. I think I am 3 years racing and training and not a single flat on my clinchers. Maybe it helps that I am 125 lbs.