Urgent TT Question - Big race Tuesday

Pendejo

Let's say you have an out-and-back TT, with a 180-degree turn around a cone at the halfway point. What's the quickest way to handle the turnaround? Start slowing up before the cone so you can cut the turn fairly close to the cone? Or keep your speed up until you're just about on the cone, then slow as quick as you can and make the turn (though you'll be lengthening the course just a little bit with this method)?

I've always used the first method, but now I'm beginning to wonder.

RapDaddyo

It sort of depends on the roadway width at the turnaround point. If it's wide, then I think you want to use the entire width and carry as much speed as possible through the turn. It takes a little practice to learn how much speed you can carry into the turn based on the roadway width. If it's narrow, my preference is to carry my speed as deep into the turn as possible, brake hard, turn sharply and accelerate hard back to speed after the turn. If you accelerate <15 seconds, you won't pay too high of a price physiologically. I try to accelerate to speed in <5 seconds.

bikeguy

I'd say slow down a fair bit before you're 8 meters or so from the cone then brake and come cleanly around close to the cone. If you come in too fast you might go off the road and have to brake suddenly. I did one like that this year, I was off into the gravel and almost came to a stop, coming in a bit slower would have been better. Better yet, practice pulling U's and you'll get better.

-bikeguy

Pendejo

Thanks for the suggestions, guys, though you both seemed to have opposite philosophies. It was a very tight turnaround today, and to be honest I don't know what the hell I did to get around it. Pain is an excellent awareness blotter. What I do know is I missed being Florida state age-group champion in the 10K TT by three seconds, so it's probably better that I don't know.

wilmar13

Hey while we are on the subject, what is the consensus regarding power pacing for the turnaround? Do you coast for a bit then take hard sprint back up to speed, or stay on the gas until you brake, then accelerate smoothly... or take a break, then accelerate smoothly again?

RapDaddyo

My response is stay on the throttle as late as possible into the turn to maintain speed, brake hard, make the turn and then do a hard acceleration to speed. If you keep the accleration to ~5sec, it won't cost much due to the half-life (lagged) physiological response. I think you want to view it as total elapsed time from a point ~60' from the turn to ~60' after the turn. The objective is to minimize this elapsed time by carrying as much speed as long as possible and then getting back up to speed as quickly as possible after the turn. I think the turn is more of a distraction than an opportunity to gain time. The key is deceleration/acceleration, not the turn itself.

CannonChick

I read in a TT book that the most efficient way is to pass the cone a little, while on the far right side of the road, and then make a tight turn angling to the far side of the road at a 45 degree-ish angle. that way you can be under full power quickly without worrying about hitting the cone or cutting it too short.
I tried it and it works well, but like anything else, a little practice does wonders!

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CannonChick
'06 Cannondale Six13
'05 Quintana Roo Lucero

Do or do not, there is no try.

wilmar13

If you are already maxed out, you will go into the red trying to accelerate back up to speed without a 5-10 sec break. I usually TT at 27+mph and when you let off the gas at that speed you really don’t slow down much… in other words, there comes a point where to minimize total time spent decelerating/accelerating it may make sense to slow down at a slower rate… kind of like driving your car for high fuel mileage (air resistance is cubed with speed)… coast for a bit when you see the light is red… I guess what I am saying is that I feel you SHOULD let off the gas a little (even if just reducing power 20%) before the turnaround to make sure you got enough gas to get back up to speed without blowing, not sure on how to determine that based on power levels…

Not sure what to think about your 5 second half life comment… I know that if I am TTing at 400 watts (20 min FT) and I burst it to 600+watts for 5 sec, I can’t maintain 400 watts after that(need to do a minute or two at 380 roughly), or rather that at the end of the ride, my NP will still be 400 watts, so my avg speed would be higher if I reduced power to 200 watts for 10-15 seconds, then nailed it at 1000 watts with power degrading until reaching my FTP at the same time I reach terminal speed… at least I think it would… ahhh I don’t know. At least I haven’t experienced losing a TT by 3 seconds yet.

RapDaddyo

Yes, you go into "the red" as you call it, by which I assume you mean that you go anaerobic. It's a classic case of where and when to use more power and where and when to back off. You're better off using more power when you're slow as in the first few seconds after a turnaround. And of course you have to back off your sustainable power for 2-4x the amount of time spent anaerobic once you get up to speed. So, if you go +200W for 5secs to get up to speed, you might have to ride at -50W for 20secs after you get up to speed. I think it's worth the price, but it's simple math and easy to prove for oneself one way or the other. And, easy to test.

wilmar13

Heh heh, I thought I was anaerobic for the entire TT.

I guess I am making the assumption I can “save” power by easing off before the burst… you are recommending going into power “debt” for the acceleration, can you not stockpile power for something like this? Or is it six of one half dozen of another?