|   Higher tire pressure in races??? | Philip
Mar 12, 2002 5:43 PM | | I am a beginner level racer who does the snow summit cup in big bear. The races consist of 10 miles of fireroad climbing (what fun) and a fast decent.
I have tried the theory of using Panracer fires in a thin set up (1.8) and pumping them up to 55-60psi. I figure that it will help my climbing speed. Am I crazy? or is that a good theory. I figure that I am 75% out of control on the downhill anyway, just becuase the race environment makes you ride more dangerously going down than I normally would.
Also, will lowering the PSI hurt my speed going up?
Thanks. |
| Every trail is different | mtnbkaz
Mar 13, 2002 6:24 AM | | I've never ridden at Big Bear so my comments are general. If the terrain is mostly smooth fire road I usually increase pressure to decrease rolling resistance. If the terrain is loose I usually decrease pressure to get better traction. Every trail is different. (Tire choice can also affect pressure - some tires need more pressure than others).
Generally, lower pressure = better traction, good rolling resistance on rocky terrain (tire absorbs & deflects impacts), bad rolling resistance on hard & smooth terrain, increased chance of pinch flat. Higher pressure is the opposite. It's always a trick to find the perfect balance of pressure/traction while minimizing pinch-flat danger. I recommend starting at a higher pressure and gradually decreasing until you find the right balance. I personally run 60psi because the trails I ride are very rocky and at 190lbs, I want to minimize pinch flats.
As for training vs. race environment, I'm a big believer in racing what you train. You don't want any surprises in a race so don't tweak your ride before a race. |
| Hey mtnbikaz | fsrazracer
Mar 13, 2002 12:35 PM | | Hey there, sorry this is not related to the posted subject. just wondering if this is the same mtnbikeaz that posts on the mbaa message boards. If so, don't you just love getting ripped by the cep guys! Talk about condescending, at least two of those guys need a serious lesson in interpersonal communication skills! |
| Yep, that's me | mtnbkaz
Mar 13, 2002 2:38 PM | |
Yeah, I was pretty pissed at that Sierra Vista comment (although I really tried to be diplomatic in my reply). If anyone asks a question they jump all over you for "starting rumors" but they never volunteer information and keep everyone in the dark. Notice that I originally asked about SV in October and they ignored my questions for months until they thought that my comments might persuade people to skip the race (and therefore reduce CEP's paycheck).
Then they want everyone to pity them for all of the work they do. I do appreciate the work they do, but come on, we all paid our registration fees. This isn't a charity. We pay them for a service. I try to be courteous to them and expect the same in return.
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| Amen! | fsrazracer
Mar 13, 2002 7:42 PM | | Well said. I've had a few not-so-positive encounters with one cep staffer in particular (the same I'm sure who responded to your post), nothing too heated, but I can honestly say that each time I was treated like an 8 year old. Security or not, I'm looking forward to racing sierra vista again. I did it last year and just got spanked, so I'm ready for redemption. I'd love to race Mcdowell this weekend, I've got to miss it for a wedding in boston, but hopefully I'll be able to do all the rest of the races so as to not drop too far in the standings. ride on. |
| That you Scott? | mtnbkaz
Mar 13, 2002 8:52 PM | | We'll miss you on Saturday. I need some redemption from the last race. Put in a 51 minute lap in training last week. We'll see how things go.
-cb |
| re: Higher tire pressure in races??? | alFred
Mar 13, 2002 6:26 AM | | I wouldn't do it at least with front tire. Front wash out on fast downhill is a sure recipe for ER visit.
Lowering PSI will have lesser effect on climbing speed then on flats. If you're that concerned with rolling resistance put some fast rolling semi-slick in the rear and pump it up good luck. |
| re: The Am Cup? | Jrm
Mar 13, 2002 8:13 AM | | I used a 2.1 XC Pro and a 2.0 Huntinson Python in the rear set at 50 psi. In front i ran a 2.25 back country with 50 Psi. With the 4 or 5 variations on the course over the seires i found this to work for me. |
| re: Higher tire pressure in races??? | AZ biker girl
Mar 13, 2002 4:00 PM | | I did a women's only mountain bike weekend last year a week or two after the NORBA race was held there. The trails were REALLY dusty--6 inches of fine powder on some sections. Our instructor had us let air out of tires--down to upper 30-some PSI to climb better. Increased traction was noticeably helpful on the climbs.
Keep in mind, though, that I only weigh 145, and there's definitely a pinch-flat concern when you get to the downhills. Your best bet is to try different pressures in practice and see what works for you. Very high pressures make climbing traction a problem, low pressures make pinch flats a concern. |
| No, lower... | MTBDOC
Mar 16, 2002 3:44 PM | | I have become a big believer in the Pythons at low pressure. This is why people like the tubeless route so much. I run the pythons in the upper 30's, down to about 32 lbs. when using the "green" tubes. Yeah, I know, they are heavy (220-230 g). As a sometime weight weenie, the tires are SO much faster because you don't get bounced off line and have better control. Climbing traction is better as well.
I am waiting for someone to actually do a bit of research on this whole idea of rolling resistance. MBA did a a chainless, downhill bike roll a few years ago. Trouble is, that does not replicate what we actually do (eg tire deformation under pedal force, deflection from a straight line, etc.).
Perhaps if this "Stan's no-tube" thing proves out, then a lighter tubeless approach may become reasonable. I can tell you, in the technical courses we see in the Southeast, a soft, high volume tire is the way to go. Anybody want to buy some skinny, light tires cheap? |
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