Power Meter and Pacing

mac_220

Hi Everyone,

I recently got a powertap and have been training with it and really enjoying it. I've been doing TT's for years but never been very good at them, anyway i took it out on my first time trial last night. Only 15miles over rolling hills with a couple of long drags. So i set off and from was surprised big time. For the first 5 mins i was holding myself back. My ftp is about is about 266 and i was pushing 400 to 500w at the start and realised why i'd always performed so badly in TT's in the past. I figured i was going to aim for 280-300w throughout the time trial, at the start keeping it at that level felt like soft pedalling. Got to the first hill and my power just rocket, again i held myself back and kept it steady at my target maybe up to 350 on the hills. As i got half way round it started to feel harder and i was having to put in more effort, i gave myself a little rest on one descent which seemed to clear my legs and allow me to push hard to the finish. Anway, i managed to hold 280 average for the whole TT, which is an improvement for me on my FTP. The winner did 34.47 (he is very good!!!!) he can do short 20mins for 10mile TT. i managed 38.25, which gave me 6th overall (can't beleive it)

Now what really surprised me was i beat a couple of friends who i've never been close to before and i think this was down to the power info. I still tried very hard all the way round but with a more consistent effort I went much faster overall. I just couldn't believe what a difference it made.

What it really drove home was that i am rubbish at pacing and that in the past i've killed myself in the first couple of minutes of a time trial. Very pleased with the results of being able to pace using a powermeter

I was wandering how other power meter users use them for pacing on time trials? and what strategy do they use?

The other question was does anyone know of 28 hole deep section rims you can buy, i've been thinking of upgrading the rims on my powertap wheel?

Regards,

Mark

rjjasick

I've got a HED Jet 50 with 28 spokes laced to my Powertap SL. I ride it everyday with no issues. They'll take your hub and build it up on a new wheel for the price of the normal rear wheel, around ~$635. To some that's pricey, to me it was worth it from my results this year so far.

As for the pacing strategy, I found out the same thing you have. I used to go out way to hard and die. I found that after a few rides of learning how the pace is, make sure not to limit yourself with your powermeter. I started riding paying too much attention to my powermeter. My rides, were significantly faster than last year and within a couple seconds of each other. Then one night I dropped my chain at the start and was mad about that I just relied on speed and cadence for that ride. I bumped up my cadence about 5 rpms. I ended up riding a full mintue faster than before. I thought it may have been a fluke. The following week I did the similar time. Because of increasing the cadence from 92 average to 97 average speeds were faster and suprising to me my power output average with within a few watts of the earlier rides. It is a short course though 6.8 miles flat out and back.

On a hilly course this past weekend I took second on a rolling 12.5 mile course. The only thing I really tried to make sure I didn't blow up on the hills. I still managed 297w average.

fastcat

Hi Mark

Funnily enough, I was thinking of emailing you to see what your average power was last night .... !

Well done on your effort. What was your normalised power ?

I managed an average of 263 (NP 273) over the course, which translated into 41.46 (per the PT, although the starter added about 15 seconds on!) for the 15. I'd estimated about 250 for my FTP so this was ahead of prior form, which is good progress.

Agree the power info was useful for pacing, as was looking at the power profile in CP afterwards, where I can see that there were a few places I pushed it a bit hard and a few where I let the power drop off too much .... probably also not as aero as I could be

But was my first TT so a good learning experience.

Ken

mac_220

Hi Ken,

I wandered if you might have been reading this forum. I managed 279 average and 281 normalised. I think i could have gone a bit harder, like you my positon is not good, i just threw those tri-bars on before i went over to the TT. I'm going to do the 10 next week if i get home in time. What time did you do?

Mark

mac_220

i've also found that i can maintain a higher power output with a higher candence of around 100 to 105.

Looking at the wheels i wanted to get some clinchers so i can use my powertap all the time. Looked at some Zipp 505 rims (used on the 404 wheels, work that one out!!) They're are really nice and i've found a place selling them for $450 so not too expensive. Problem is they weigh 600g, my current rims are 440g, that seems a lot of extra weight, the tub 505 zipp rims are on 330g, but i really don't want tubs. Still working it out.

thanks for the info, i'll have a look at the HED ones as well.

Regards,

Mark

fastcat

My time was about 41 minutes 46 seconds, based off the WKO+ analysis, but I think the official time was about 42 minutes (not sure how that worked out!).

ric_stern/RST

If you'd like some Zipps on a Power Tap hub or system, please give me a shout. We're doing 10% off during the TdF!

As regards the price you're quoting above, which you'd presumably be importing from the States, don't forget you have to add on import duties, and VAT.

Ric

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rayhuang

I recently completed a short TT (8 mile) with the watts covered on my PT cpu. I did this to pace myself on PE to see how it compared to pacing on power and I was suprisingly close to what I would have done had I used Power to pace. I analyzed my data post race and I ended up 102% of threshold. It was a combined flat and uphill course with 5 miles of flat and 3 miles of rolling and flase flat up. I equalled or bettered all my best power figures form 5 to almost 20 minutes. didnt blow them away, but beat them by 3 to 4 watts.

My conclusion of this experiment is that once youve done enough time trials and power training I think its possible to go faster than if you paced on power alone.

This may not always be the case for example in a flat 40k time trial, putting it on a power number and forgetting the rest can be very effective. But on a shorter or hillier course where you need to go pretty hard, but not hard enough to blow up and varying power requirements, going without power can allow you to get every last drop of energy out of your body.

I will experiment more in local short TT's and hope to do a very competitive (170+ entry) 20k TT in September without power as well.

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peterpen

What would your target power(s) been if you had been pacing with power?

I think I would aim for an AP something higher than 102% of FTP, particularly for the uphill portions. (Note that this FTP would be the one specific to my TT position, which is lower than my road position. If I did 102% of my road FTP for ~20min. on my TT bike, I'd be pleased.)