Road Bike Racing - Quick TT advice needed

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View Full Version : Quick TT advice needed


branman1986
02-16-07, 08:04 AM
I've got my first time trial tomorrow(going to be COLD!) and I was wondering if a few of you experts can help me out.

Should I increase my power a bit into headwinds & up climbs and recover slightly on downhills & tailwinds? Or vice versa? Which saves more time?

There is going to be a very noticeable headwind on the way out and tailwind on the way back, plus it's uphill slightly on the way out and downhill slightly on the way back.

Thanks!


patentcad
02-16-07, 08:11 AM
I can only give you Slow TT advice. Sorry.

Duke of Kent
02-16-07, 08:24 AM
According to Kreuzotter.de, going from 300 to 320 will gain you 0.6mph going into a headwind of 10mph, in aerobars and with their normal heigh/weight (non-essential). 20.5 to 21.1mph.*

Going from 300 to 320 will gain you 0.7mph with a tailwind of 10mph, using the same baseline information. 32.8 to 33.5mph.*

*Both done with no slope factored in.

So, I would say pace yourself, and finish strong. Gaining 1mph on the way out at the cost of several on the way back is not worth it, obviously.

It's really a wash. Steady effort, methinks.


branman1986
02-16-07, 08:57 AM
thanks duke :)

asgelle
02-16-07, 09:47 AM
Should I increase my power a bit into headwinds & up climbs and recover slightly on downhills & tailwinds?
Yes. See http://www.biketechreview.com/power/supercomputers.htm http://www.biketechreview.com/power/Fitchburg.htm

branman1986
02-16-07, 09:57 AM
wow...pretty frickin awesome.

stea1thviper
02-16-07, 10:23 AM
goodluck!

waterrockets
02-16-07, 10:33 AM
+1 to those links. You get a better return on your investment in climbing vs. fighting wind. Ride a little harder on the climbs. Not much though...

Make sure you have the juice to get back up to a roaring speed as soon as you're over the top, but do go a little harder uphill.

curiouskid55
02-16-07, 12:28 PM
To do well in TT you have to go at max SUBSTAINABLE effort for the entire race. If you are "recovering" you are losing.

ri_us
02-16-07, 12:45 PM
While the highest constant effort system works well for some, I'm not one of them. I have tested this several times and found that breaking TTs into thirds works better, I usually go a little over my AT for the first third. Crank it up a few BPM for the second third, then go all out for the last. I'm a sprinter who clims like crap.

ratebeer
02-16-07, 12:48 PM
i hope it went well, branman!

grebletie
02-16-07, 12:56 PM
Good advice so far. Just resist the temptation to go out hard early. If anything, start out easier than you want to go, then pace yourself up to your TT pace. Finish hard, then throw up. :D

zimbo
02-16-07, 01:00 PM
At a given average wattage, the algorithm for the fastest TT time is generally to maintain the SAME SPEED throughout. If it's a flat course with no wind that means meting out the same effort throughout. In your case, though, it would be wise to go harder for the first half.

For example. Suppose you average 300 watts going out and 260 watts coming back and that the result is that it takes the same amount of time to go out as to go back. The average watts is obviously 280. This will give you a better overall time than if you average 280 watts for the duration.

--Steve

asgelle
02-16-07, 01:26 PM
At a given average wattage, the algorithm for the fastest TT time is generally to maintain the SAME SPEED throughout.
I don't know what alogrithm you're using to base this on, but the work done by Kraig at Biketechreview shows this is not true when taking into account the functional threshold and finite anaerobic work capacity or riders. That is, each rider has a maximum average (or normalized) power they can maintain for the duration of the time trial. If someone exceeds that limit to maintain a constant speed by too much early in the race, the rider will lose too much time later recovering from that effort.

waterrockets
02-16-07, 01:34 PM
While the highest constant effort system works well for some, I'm not one of them. I have tested this several times and found that breaking TTs into thirds works better, I usually go a little over my AT for the first third. Crank it up a few BPM for the second third, then go all out for the last. I'm a sprinter who clims like crap.
+1 me too

I was coaching a group, and over a couple weeks we tried various strategies on the same 8-to-9-minute course. Some of my riders clearly performed better with a "hit the hills harder" approach, while others did well trying to maintain a consistent effort. You have to learn what works for you, and test it, then test it again, until you're positive of your best strategy.

One approach that worked for EVERYONE in my group was to try to race with negative splits (as ri_us eludes). Go faster as the race goes on. It's really common to fail at negative splits, but even just riding with that goal will make you faster. You can divide the course into thirds, halves, fourths, whatever you think you can track. Obviously, it's a rather subtle change in speed, but a huge change in effort -- you have to go surprisingly easy in the beginning -- it's very uncomfortable.

branman1986
02-16-07, 01:57 PM
thanks everybody, I'll let you guys know how it goes tomorrow. There are usually about 5-8 pro triathletes that race in the 5's, so if I get top 10 I'll be estatic.

zimbo
02-16-07, 06:47 PM
I don't know what alogrithm you're using to base this on, but the work done by Kraig at Biketechreview shows this is not true when taking into account the functional threshold and finite anaerobic work capacity or riders.

Yeah, but the work done by other guys on other forums shows it can be true.

I'll say this... The person who has a tendency to go out too hard for the first half of a TT (a pretty common occurrance) will be better off for this particular course than on a totally flat course.

--Steve

asgelle
02-16-07, 07:02 PM
Yeah, but the work done by other guys on other forums shows it can be true.
You mean like it's true that the time can be exactly 11:23? Sure in most cases it isn't but you have to admit it will be true some of the time. Sure there could be courses where a constant speed pacing happens to give the fastest time, but that's because it happens to correspond to the optimum power-based strategy, not because there is a fundamental reason why speed based pacing works. Enough work has been done to show that for each rider there is a constraint on total work done and how much can be done above threshold. With this, a course profile, and a speed/power model, an optimized pacing strategy can be calculated. Since there is no corresponding limit on speed, a similar method can't be used with speed replacing work.

jamiewilson3
02-16-07, 07:09 PM
A2 is going to clean up on the field, but I saw the start times and the field looks pretty diverse. There are a few Greenville folks that will be down there. Good luck. I thought about heading down there, but have been sick all week and just now recovering. - and it will be cold as balls.

zimbo
02-16-07, 08:58 PM
Enough work has been done to show that for each rider there is a constraint on total work done and how much can be done above threshold. With this, a course profile, and a speed/power model, an optimized pacing strategy can be calculated.

Ok, I misunderstood you earlier. I totally agree with what you're saying. When I said one should try to maintain the same speed rather than the same power I only meant that in the general sense (i.e. for optimal results you have to work harder on the harder sections rather than trying to keep power constant). I did not mean that one would literally have the same speed throughout since that would be impossible given human wattage limits on a hilly course. I thought you were saying that someone had shown that the constant-power (or even the negative split) approach was better than variable pacing. As I said, I misunderstood.

Back to the OP. If the course is substantially harder going out than coming back, attempting a negative split may not be in your best interests. However, if you haven't done a lot of TTs, my vote is that you just go out there and do your best.

--Steve

DrWJODonnell
02-16-07, 10:19 PM
My strategy will sound silly, but the faster you go, concentrate on getting more aero. When on a climb bang out the power, when on a descent, sacrifice power for a lower position. Oh, and realize if you don't go faster, you are going to be passed. How embarrassing THAT would be. Don't be passed. Do the passing.

Snuffleupagus
02-17-07, 05:43 AM
Oh, and realize if you don't go faster, you are going to be passed. How embarrassing THAT would be. Don't be passed. Do the passing.

+1

That was my main motivator during the one TT I've done (4mi hill climb at 197lbs - what? I didn't get passed, and finished in the top half of the field :D). Getting passed is like having someone take your lunch money, kick you in the pants and make fun of your mom.

Or at least it is for me...

stea1thviper
02-17-07, 06:46 AM
+1

That was my main motivator during the one TT I've done (4mi hill climb at 197lbs - what? I didn't get passed, and finished in the top half of the field :D). Getting passed is like having someone take your lunch money, kick you in the pants and make fun of your mom.

Or at least it is for me...

snuff speaks from personal experience :D :D

branman1986
02-17-07, 02:22 PM
A2 is going to clean up on the field, but I saw the start times and the field looks pretty diverse. There are a few Greenville folks that will be down there. Good luck. I thought about heading down there, but have been sick all week and just now recovering. - and it will be cold as balls.

One would probably have expected Andy Applegate(40+ National Champ) to just clean house, but you'll never guess what happened. The 30+ Masters WORLD TT champion(rainbow n everything) showed up and DECIMATED the field. Took a minute and a half off of AA :eek: . Absolutely unbelievable.

But anyways, my ride was a complete disaster. I came in 6th/40, which I suppose is okay, but man, I had a lot left in me. I'll post the PT data when I DL it. But, believe it or not, I rode the first half in the small chain ring w/o even noticing it. My mind was just in a different place(not a good one)...at the turnaround, the chain FINALLY slipped into theh big ring and I felt like I made up a lot of time. I should have noticed when I spun out right after the ramp. Anyways, I'm sorta just laughing it off and know that I've got a much better time in me. Also I clearly paced myself way wrong because(as you'll see in the PT data) I almost sprinted the last 1/8th mile.

jamiewilson3
02-17-07, 07:36 PM
Congrats on the good finish. If I remember correctly, it was your first one, so there shouldnt be a ton of shock that you didnt pace properly. Negative splits is allot better than burnout!

I am very surprised that a world TT champ showed up, but I bet it was cool to watch them run. Hopefully I will be there next year. I did repack the bearings on my Hed3 rear this morning, in the spirit of getting ready for some racing.

I wish I could have seen that. We had some flurries up here. I ended up swimming in the pool at the Y and then went on a 4 mile jog. There was a good turn out for the Greenville Winter Bike League, but I was afraid to get out in the cold for that long when I am still fighting it off.