Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

Wearing the Fenix 3 on the drive side seems to solve the dropout problem.

I just did my first FTP test. It was going well (though during my first five mins I was too conservative) but after 12 mins the carcass of my rear tyre ripped. I had to get off, remove the carcass from the tyre then jumped back on and finished the test. Not ideal!
Just uploaded the file to trainingpeaks and its given me a 20 minue average of 15w higher than trainerroad - is this because it smooths out the spikes? It took me about 45 seconds to get off, remove the carcass and get riding again.

remove the carcass

Don't be so hard on yourself man. You've so much to offer the world.

Does anyone south have the powertap battery compartment tool? @dan @Dammit

I have one

is it one like this?

yes, I don't have it. but probably need to get one.

Awesome! will PM you when i find the right batteries.

@dimi3 that's apparently the one, annoying the batteries in mine have died so quickly

Just use an inner tube

Nothing could get mine off bar the tool

Not used Training Peaks, but sounds like the power calculation was made from the non-zero average, ie discounting the period of time when off the bike as opposed to TrainerRoad that included the zeros.

The only real way to know which figure is correct is to run the test again!

As for starting too conservatory, that's the best way to do the test IMHO.

As for starting too conservatory, that's the best way to do the test IMHO.

Dunno, maybe start in the garage and then move to the conservatory if it's too cold?

Though I agree with you, I wasn't totally ruined at the end, so j could go harder. First five mins I was holding around 285w, then after that I went up a gear and held 320-350w quite well.

Re-test next week.

Show off. ;0)

Difficult to know.

I'd add 10w to the starting power (295w) then see how much I can ramp. When you're close to your max 10 can make a massive difference over time.

My FTp is 280w. The other week I held 105% for 24 minutes. Which wasnt even during a hard test. This hints that I hould e able to hold more for 20 mins and thus set a Bigger FTP. But adding 5 or 10 watts to my 20 min climb power destroys me.

Be carful, the temperature in a conservatory can be at least 10 degrees warmer than a garage.

Aren't you supposed to try and hold a constant power throughout the test (as much as possible)?

My average power was 315w (from training peaks) so shouldn't I try holding at 320w from the beginning?

Pacing strategy is pretty personal, experiment with what works best for you.

A negative split (if you see what I mean) generally works best in my experience.

Bear in mind that the 20 test is not the real thing- for a 100% determination of FTP go and do a 40k TT/flat out for an hour.

So ride to the test, as it were.

Be carful, the temperature in a conservatory can be at least 10 degrees warmer than a garage.

But you have to ride in the conservatory if the garage is carful, or even just bikeful or junkful as most cyclist's garages are.

I'm certainly a negative split sort, but I guess I need to work out how low I start and then ramp up.

In that case I'd start at 315w.

You managed 315 having started at 285. So it's not a bad strategy.

As Dammit says. It's personal. But recovery from over doing it, is far harder than ramping after starting too easy.

Also, starting at 315w is going to hurt.

Sin of Sins #6 – 95% of a 20-min mean maximal power = FTP

Well, this method of establishing FTP isn’t one of the listed Seven Deadly Sins in the first place, but it has become such a commonly referred to/utilised method (mainly due to its publication in the excellent book, Training and Racing with a Power Meter) that it gets its own SOS number.

Firstly, the main issue with this common Sin of Sins is that the ratio between 20-min power (or other similar shorter TT duration power) and FTP is not the same for everybody, and neither does the ratio remain static for an individual. One should recognise that due to several factors, not least of which is the contribution of anaerobic capacity and the exact protocol used (e.g. performing a pre-ride blowout effort), that the ratio is likely to be within a range and where someone is within that range is anyone’s guess.

So, FTP might be anywhere in the range of, say 90% to 98% of 20-min max average power. Personally, my FTP has been at both 92% and 96% of my then 20-min max average power. So, by all means use 95% of 20-min max power as a starting point but remember it may well be out by some margin and it would be wise to use an additional or alternative method to validate your FTP estimate.

http://alex-cycle.blogspot.co.uk/2009/07/sins-of-sins-testing-ftp-2.html

Are you doing a blow-out effort beforehand? Anaerobic work capacity can contribute to an artificially high FTP when only doing 20min tests.

I'm doing the trainerroad workout which includes a 5 mins 'blow-out' hard effort before the FTP test, precisely for that reason.