OK, I'll say up front that this is not another discussion of tubular vs. clincher. And this is not a discussion of this tread vs. that tread. This is simply about pressure.
A couple of us here at CXM are working on an article related to tire pressure for an upcoming issue. While we're reaching out to some of the gurus of our sport, mostly because it makes us feel cooler than we really are, we wanted to add another dimension to the article. Some of the best discussions and information I've seen has been relayed right here, through the beloved Cowbell forums. And since we are a community driven publication, here we go....
What's the method that you prefer for determining the appropriate tire pressure on a given day? Based on experience? Simply by feel during the warmup laps? NASA-Calibrated pressure gauge?
And whats the preferred method of inflation? Anyone else still use pumps? Or has everyone but me upgraded to the fancy electronic inflators?
I'm all about testing different tyre/pressure combos 'in the field' before race day (ie on practice/training rides).
this helps me get a faster idea of a baseline pressure and also how well a pressure is working (compared to how well i feel the tyres should work in the conditions). thats something that is important when you are a race organiser and racer and your course recon time is limited. ;)
apart from that i use a topeak digital gauge to make sure i dont let too much air out and so that im keeping to a rough standard.
i'll also say that here (australia) i have developed a reputation for encouraging people to try lower pressures. getting people to run clinchers below 40psi (let alone 35psi) can be a real challenge! one guy i ride with (~160lbs) wont run anything less than 50psi, and wonders why he dumps his bike all the time when its muddy.
the challenge in the last race here was that the course had a lot of thick, wet grass, but some spots of slick mud. i went for XG tubs @ 24/26 and they did well (fast through the grass and thicker mud) until the lack of mud clearing tripped me up (or sent me down to be more exact) late in the race. not sure my mud tyres (cross wolfs) would have been much better.
i like learning about how the handling changes with different tyres/pressures.
Totally by feel and traction. When training I run higher pressure so I can avoid pinch flats. On race day I go for maximum traction for the conditions. In the Pacific North West that pretty much means rain, and mud. Since I am so slow I get to eat the mud and rung out track from the faster, more talented riders.
Having just done the Cycle-Smart CX camp and having a coach tell me what to do really helped. I can run my Michelin Muds (blue!) clinchers at 35 psi and corner really aggressively. I'm about 78kg.
Before the camp, I would habitually over-inflate to 40psi or higher. 35 is more than enough. You just have to make sure to look out for obstacles.