Originally Posted by
shovelhd
That's high but I am light and run wide wheels. With the 27mm clinchers I run 100/95 for training. The 27mm tubulars I run between 110-120 rear and 10 pounds less front but this is completely dependent on the course. I am not doing TT's this is elbow to elbow crit racing where 5 pounds can make a huge difference.
Originally Posted by
tetonrider
i run less. for me, i've never found a situation where lower press is slower on the road (if you're racing track, different story), and tubulars have reduced risk of pinching. pinching is the reason i won't run clinchers lower.
consider terrain that pushes the tire. an extreme example is MTB (yes, i do have tubulars for MTB), but cross also illustrates the point. you can run 20 or more psi lower with tubulars. for road, the difference is less dramatic due to smoother terrain overall, but at a micro level the same stuff is happening.
for the same pressure and otherwise apples-to-apples (handmade tubular with cotton casing + latex tube vs open tubular of similar construction and latex tube), the tubular will be a bit more supple than the clincher. you can run a higher pressure on the tubular and maintain a similar fee.
Originally Posted by
tetonrider
how much do you weigh, rev chuck?
for a TT you can get away with lower pressure (IME) because the risk of hitting a square edge you don't see is much lower. for RRs in a pack, this is a higher risk.
i may be lighter than you guys (i'm ~145-150), but i'll run mid-90s for narrow tires. i'll run 65-70 for 700x27 (measure 28.5) tubulars.
road surface does matter, as does rider style and weight.
Hmmm...good thing I asked.
Some facts bearing on the problem: I weigh ~185. The tires I'm using (Specialized Espoir tubulars) are marketed as training tires and have butyl tubes; I wanted something relatively cheap but decent so if I screwed them up mounting them I wouldn't be out that much money. My boss, from whom I bought the wheels, helped me mount the tires using Tufo tape and they came out fine. I would've preferred 700x25s, but they're out of stock until November. Racing tires will go on in March.
There's no way I can do an apples-to-apples comparison on ride feel. The tubulars are mounted on Reynolds 66s, while most of my riding has been done on Open Pros with 700x25s which measure 27mm wide. Based on the duelling theories above, I'm going to run them at the same pressure I run my one wheelset with 23s at for a start and modify from there if necessary.
Road surfaces where I live in the sticks are decent or better, with railroad tracks being the only square edges. I often ride from where I work in a small city, and the roads there are concrete with expansion joints, so there are square edges there.
ETA: Rode for two hours on the new (to me) wheels and tires. I was singularly unmotivated to ride this morning due to having slept really poorly last night. I ended up running the tires at 105f/115r. I rode too slowly to feel any aero benefit, average speed was 17.9 mph. My average HR was only two bpm above my recovery HR range.
Predictably, I felt road imperfections more than I usually do, what with the 66mm rims and 23mm tires vs. the 19mm rims and 27mm tires I'm used to. I don't know how much the training tire with a butyl tube contributed to that. No judgement yet. I'll probably do the Tuesday Worlds to see how they feel at speed.