Thanks for all the responses. I'm at work 12 hours tomorrow so will not be able to respond further for a bit, just got back home now.
I'm a shorter rider with a long torso (road bike is 40 cm ST, 56.5 cm TT). I don't think I qualify for any morphological exceptions except possibly my quads are so short that it might do something (I vaguely recall something about that, but I will look at it later). My torso is long enough that I'll be pretty stretched out if I use aero bars.
Originally Posted by
Morelock
1.) weight should have very, very little impact (almost nil) on a flat track. Peak power for another second however... likely means you are accelerating (standing start is where you'll hit peak power) considerably faster, which will have an impact.
2.) The last few years they have been pretty lax with the jig. That said... you should at the bare minimum contact them and get the head comm's opinion. Quite a few bikes without a uci sticker get used... but it can change on the whim of an official.
3.) To my knowledge, so long as front/back are the same size, you're good
4.) *rough guideline* it comes out a wash. People thought similarly in regards to aerodynamics... smaller leading edge *should* be more aero (vs a 700c wheel) but to compensate you have a longer head tube, again basically a wash.
5.) ride discs when you can. Indoors in a TT, that's always.
6.) when aerobars are legal, you should use them (assuming you have an optimized position, etc etc)
7.) you get to choose one exemption, no questions asked (they don't measure you on the bike, just the bike) - with aerobars it's either a.) at least -5cm saddle to bb and up to 80cm reach, or b.)at most 0cm saddle to bb and up to 75cm reach. There is an extra 5cm reach available to people over 6ft (I can't remember exactly how tall you have to be, again, check out the uci technical guide)
8.) run what you have... again assuming it checks out ok.
My thought on the smaller wheels was more geared toward acceleration, i.e. they should be much easier to accelerate up to speed. They'd require more work to keep going, and they'll have higher rolling resistance.
My concerns include spares (no one has any), and investing in a custom frame that may or may not have available wheels or even gearing. I'd have to run crazy big gears to make a 24" wheel work.
Originally Posted by
tobukog
2) Bikes no longer have to be UCI compliant at Masters Nationals. Of course, this may change.
4) 24" wheels will also usually have better aerodynamics because of lower rotational drag. However this is probably offset by the higher rolling resistance of smaller wheels. Rotational drag is hard to test, and I can't think of anyone who has current rolling resistance data of 24" tires.
Another issue is that it's really challenging to find good fast tires at 24" since it's such a rare rim size.
I didn't know Masters didn't have to follow UCI guidelines. It doesn't mean I'm going to go hogwild, it just means that maybe a non-UCI frame would work (guy that built my frames is not UCI certified).
Originally Posted by
Clythio
1 - AC model works well if peakpower time is corrected, they use sec 4 I think, and reality is maybe 7 or 8 after the time start. Model is maybe 0,5sec faster because its model is for pros position/equipment. 1kg + gives 0,1sec worst time. I'm afraid the model is for a 333 track, it also affects results. How is you measuring the power data you're using at the model?
2 - Believe that anything with 2 triangles, 3:1 rule ok, etc., would be allowed to start.
3 - If faster, someone were using it, those 24" wheels.
4 -
5 - Really fast guys use front discs - but only indoor, of course.
6 - Same with me - I'm 61 and race 500m TT. Checked first lap top/ave power with both configs, and as I don't loose anything with clips, decided to keep it in order to go faster on the final 300m. From pro women videos, you can see bigger riders go on clips, smaller on handlebars, and smoother riders go on clip, the more "explosives" prefer handlebars, each one looking for best suitable setup. Or, finally, "it depends"...
7 - Bontrager Hilo RXL for me. I'm large, heavy, need good support, and a like a front long flat nose with little ramp on the rear part of this seat.
8 - Tested a lot, and for the standing start, better high for side handles is not too low..
I'm not sure what you mean by "sec 4" vs "7 or 8". Could you explain?
I'll add 0.5 sec, or make my aero drag significant, to give me a more realistic prediction.
I'm using an SRM (Cannondale SI model, not sure how precise it is, wireless) to measure power. I was using my best recent 35 second power number as an average, and my best recent 2 second number for 2 seconds (both numbers hit in one effort). I'm not that fast so the AC number didn't make sense to me.
I don't understand the second bit. Are you saying that it's better that the base bar handles not be too low? I was thinking it would be good to match my drop position (BB->Drops relationship) as that's what seems to determine stability under acceleration. I experimented with sprint position on the road and found that having the bars a certain relationship to the BB was the best. Higher up, further forward, or even further back, not as good. On the other hand I have never ever done max effort standing starts so there's that. Only standing starts I've done were for regular long time trials, 16-65 minutes long, so I started pretty gently relatively speaking.
Time for bed, thanks for giving me all these things to think about.