I know cyclists come in a variety of sizes and weights. So taking that into preface, tire pressure would vary depending on the weight of the rider. 100 pounds less pressure 200+ pounds more pressure. At least that makes sense to me.
So now let us take this wisdom or complete jacked up thought (you may choose) and apply it to tubulars.
I see guys talking about how much to use for this or that course. 18 to 32 psi. Seems to be the most common number range heard.
But for bigger cats, tyhe 200+ fellas, does 40 or 40+ psi make sense as the psi makes up for heavier riders? Does a tubular lose the wonderful benefits I keep hearing about as the psi climbs?
Do heavy guys need to look to tubeless systems for sturdier sidewalls and similiar pinch flat wonderment?
I am on the bigger fella side easily and have tried running lower pressures, but literally fell on my face a few times. Enough to question lower pressures (for skinny riders).
Any thoughts or experience would be mucho helpful!
I'm 200-205 pounds, 6'2" if that matters, and I usually run tubulars about 32-38psi, depends on the cours and the tire. I'm still figuring it all out myself. So far I'm not sold on tubeless. A friend of mine just got the Dura-Ace tubeless wheels and Hutchinson tubeless cx tires and we both did a practice cx race. He's about 185lbs and he said it burped a little bit on every ugly remount, but at the end of the race the tires still had enough air to race in them. He was running sealant. Doesn't sound good to me, and what if you get dirt or woodchips in the bead interface? Game over. I like tubulars so far. Wouldn't every run over 40psi in tubulars I don't think, nor would I run the super-low stuff, like 25psi you hear about. That's for the little guys. As stated elsewhere, a too-soft tire will want to fold over in the corners.
I once had an old hand and very experienced racer set my psi for me at the start of a cx race. He basically told me "run as low as you can, until it's almost bottoming out all the time." He was mabe 150lbs. That was a scary race! I didn't feel fast. I'm sure it was about 25psi in there, or less.
Just started racing tubulars this year and can't believe the difference. I confirmed ceramic bearing and upgrade denying, I wasn't really ready to be wowed. Second race on tubbys and I found myself comfortable dropping the pressure and that's when they really lit it up. Didn't take long to get used to them, but we have a weekly cx practice that has allowed me to get the feeling of pushing them a little at a time. Liked the comment about them staying 'upright' which is a pretty good description. Much more manageable traction, even when they cut loose. Just make sure they're glued on tight!
Something to consider for a larger rider and tubulars is the method you use to glue the tubular. This weekend two super experienced riders, Myerson and Bishop rolled tires at different courses, but similar scenarios. Sharp off camber corners while accelerating. These guys have glued more tubulars in their days than most bike shops ever, and Myerson is OCD about his equipment. So, when you get into the first timers gluing, remember a few things:
1) Consider the shape of the tubular bed on the wheel and the profile of the tire. Challenges have a slightly flatter bottom to them than something like a Tufo Flexus. The "glue and tape" method is a better set up on the Challenges while you can get away with just glue on the Tufo.
2) All wheels are tires are not the same- especially when you are getting into the cotton or silk tires. Deflection is normal for these tires- even if its super subtle it can affect the contact patches of the tire to the bed of the tubular. Zipp has a deeper channel than our HED wheels or an alloy tubular surface. So,when you're setting up the gluing, check all the variables.
3) There are minimum tire pressures to run on a tubular for courses with high speed off camber corners. The volume of the tire can help in keeping it on the rim along with the adhesion methods. We've experienced some trouble with Grifos losing pressure through the valve core base and having a 5psi change in pressure by the end of the race. It has changed the way we set up the Grifos on Zipp rims- because of the change in deflection of the tire through the race. This is the same problem Myerson experienced with his set up this weekend, too.
Bishop rolled it because he hadn't checked the glue job since gluing them last year. That's a direct quote. Bishop does not have the best reputation for maintaining his own equipment, cf the recent VeloNews interview with him.
I run Grifos and have experienced the valve core base leaking with a few of them, but am wondering what you do to prevent it? I also run Grifo's on deep (404) rims with valve extenders (aluminum screw-in type). Is there any thing I can do to prevent leakage at the valve base? (I assume I'd have to do it before gluing & mounting).