Originally Posted by
carpediemracing
Several questions, all pertaining to 500m TT:
1. The Analytic Cycling site - is it really far off in predicting performance or even performance changes. Changing weight by 10 kg seems to have a minor effect but changing peak power duration just by a second has a massive effect.
2. For Nationals (USA) I assume that the UCI jig is used to measure the bike. Related to that if I have a custom built frame (it'd be a Tsunami or similar welded aluminum), would it be legal to race? It's definitely not on the UCI list. If not then I'd need to source a custom frame from a build that is UCI approved?
3. Related to that - are 24" wheels legal, if used as a pair? I see that 550mm is the minimum tire height and 24" tubular/road wheels are about 560?mm. However I don't see any pictures or mentions of any competitor using a 24" wheel. Nor 650c for that matter. (Related to that it seems there are no 24" rear wheels out there, and very few 650c rear wheels).
4. Related to that, would there be a measurable benefit to using a 24" or even 650c wheel for the 500m? I figure it would accelerate a bit quicker, and it seems like the most important thing is to get up to speed quickly - it takes a long time to accelerate, so reducing that time would be beneficial. I figured if there was an advantage then someone would be selling them but I don't see any out there.
5. Another wheel related question - is a front disc (700c) a hinderance in the 500m? For indoors I imagine it's okay, but even a 24" disc (I had one a long time ago) is pretty wiggly in any kind of wind.
6. 'm having a hard time seeing if there's an advantage to either sprint bars or aero bars for the 500m. I'm not a super powerful rider compared to some others so I assume that the aero bars would help maintain speed, but I've watched a gazillion 500m clips and it seems to go either way. I know personally that I saw a big pick up in speed with aero bars but that was in a normal time trial, not a 35-40 second effort.
7. For saddles I'm using an ISM now, so I'd either be right on the BB line (sprint bars) or 5 cm back (aero bars). I think those are the rules, unless I'm missing something.
8. Final related to that, if I was using 700c wheels and aero bars I'd have to raise the base bar quite high to clear the front tire, but for a 650c or 24" wheel I could leave the base bar height at the same height as my drops. For sprint bars it seems that they can be below the top of the tire by a decent amount so I'm okay. Running a 650c or 24" wheel would eliminate that measurement concern.
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..