Looking at getting a 2nd hand powertap to try instead of using hr for training for triathlon and tt’s. Not got masses of training time so will prob use the time crunched program again. Anyone gone from hr to power meter and did it improve ur training and then times as a result of that?

Cheers

Yes and no. I was at my fastest when I trained on HR, but that was because I had lots of time to ride. Training on power does mean you can make the most out of less time. Good for turbo sessions.

Powertaps are heavy though, if you have ‘nice’ wheels on your road bike consider it will add a chunk of weight.

How good are the power meters that are in the pedals or attached to the cranks? They seem to add minimal weight…

Its a more accurate way of training, when you use it with a training programme such as training peaks the results (and gains) are more ‘obvious’ so you can be more specific about what you do and focus your training better.

How good are the power meters that are in the pedals or attached to the cranks? They seem to add minimal weight…

There are quite an array of power meters that are pedal/crank based (basically everything bar Powertap!).

Some are heavy, some aren’t.

– SRM are the gold standard, big money, fairly light

– Power2Max look very interesting and sensibly priced, adds a reasonable chunk of weight

– Quarq are owned by SRAM, lighter than Power2Max, you have to glue a magnet to your frame for the cadence reed switch, in between P2M and SRM price

– Pioneer are messing around with a new system which is hideously expensive, bit of an unknown

– Polar/Look do some pedals, not ANT+, so you have to use the Polar head unit

– Garmin Vector pedals are very light, pretty expensive, reliant on accurate set up of ‘pods’ on the cranks

– Stages do a LH only crank unit, cheapest solution, works on assuming your power is 50:50 distribution and doubling the output from the LH side, perfectly good for most, lightest solution – only adds 20g

– Xpedo have just announced some Keo compatible pedals with all the gubbins in the pedal. Looks a little heath robinson, but they’re meant to be pretty good value.

Personally if I was starting out now I’d get either P2M or Stages. Neither require any hardware on the bike, other than the unit itself, so you can move it around if you want.

I read the title as a powernap over HR training, personally I would go for a powernap every time. I could take on the world after a good nap 😆

Looked at stages just need to get one from states nearly £200 cheaper

There have been lots of issues with Stages since they came out, the v2 ones aren’t perfect either. So be careful with getting one from the US as you may need backup at some point.

Reliability seems a bit suspect with stages, I’d probably buy anything as complicaed as a power meter from a shop I could take it back to. I do like the idea though, and it’s probably the one most likely to drop in cost in the future. We prototyped something similar for hockey sticks but found the same problems they did (namely they don’t work on carbon fibre and are a PITA to calibrate).

Bear in mind a powertap G3 used to cost almost as much as SRM, Quark, etc, they’re good VFM now. And while not light, ~500g hub is about 300g more than a superlight hub and 200g over anything normal, that’s the kind of weight you could save spending the money saved elsewhere.

Looked at stages just need to get one from states nearly £200 cheaper

Until it drops off and you need it warrantied…

My decision came down between Stages and P2M, couldn’t have lived with not knowing whether my doubled left leg was a true reflection of my actual output and went for a P2M. Generally my output is 50/50 but if I’m spending a long time at or above FTP it’s 52/48-L/R.

Recently rode my P2M through the worst conditions imaginable in a recent reliability ride, rained all day and there was a 5 mile section that was basically riding through huge puddles with water flowing down the road between ’em, at one point the water was deeper than my BB. Still working thank ****!

Thanks for the comments above…I’m ‘considering’ a power meter at the moment. I’m off to the states in September for work so tempted to buy out there.

What sort of price ranges are the options – ‘big’ money I presume is like £1k?

Anything in the £200-300 range?

Anything in the £200-300 range?

Not unless you go for one of these devices that doesn’t utilise a stress gauge and calculates estimated power through some complex and inaccurate equation.

I’m tempted to invest in a stages, but considering hiring one first to see if this whole power thing is for me. I suspect all I really want to know is what my outputs are for 5/20 min, and how it compares to the readings on my VR trainer.

big money is 1400 quid or so for the garmin pedals or srm

What sort of price ranges are the options – ‘big’ money I presume is like £1k?

big money is 1400 quid or so for the garmin pedals or srm

Keep trying: £3300 for SRM Dura Ace

Anything in the £200-300 range?

New, no. Wired Powertap second hand.

tpbiker, you can hire power meters for not very much money per month (I hired a powertap from my lbs for about a fiver a month, I had it so long that that the hire cost was about the price of the wheel, luckily they said they’d waive the rental if I brought one!) If all you want to do is use it to get some turbo baselines and compare to virtual power then hire may be a good way to go.

Quite fancy a stages here. Use a powertap at the moment but it’s pretty much permanently on the turbo bike. Stages is tempting for the TT bike.

My decision came down between Stages and P2M, couldn’t have lived with not knowing whether my doubled left leg was a true reflection of my actual output and went for a P2M. Generally my output is 50/50 but if I’m spending a long time at or above FTP it’s 52/48-L/R.

I think even the more complex systems have to ‘guess’ at L/R ballance.

For example a powertap might read 100W.

A Sages meter might read 51W, and it might require 2W to lift the deadweight of your back leg, 51×2=102W. So they disagree.

A P2M measuring torque between an isolated spider and crank axle only sees the net power, and averages it twice per revolution to get a L/R reading (imagine 2 stages meters, the readout being 1 minus the other). So as with the stages you can trick it, a stronger pull-up will register on the wrong side. So in trying to correct an indicated imbalance you might just overcompensate for it by pushing down harder.

I think even the more complex systems have to ‘guess’ at L/R ballance.

Not many of them. Powertap has the disadvantage that it’s measuring power through the transmission, so drivetrain losses will affect it. Everything else has a ‘real’ measurement of left and right.

So as with the stages you can trick it, a stronger pull-up will register on the wrong side

I see what you’re getting at, but I think that’s a red herring.

Stages Warranty and customer service for my US bought power meter has been outstanding. Might buy another when I am over there later this month.

For TT, where you are trying to maintain constant effort, I’d suggest a Powercal HR based monitor. The NP readings for my Powercal have been very consistent with my Stages crank. Peak and variation are miles away, mind. I use the Powercal on 30sec averaging. It’s not really that different to basic HR zones though, so don’t kid yourself.

I think the point was that any crank based system can only measure the net effect of both legs in each part of the stroke rather than actually measuring forces exerted at the pedal.

So on a crank based system you can could be getting unmatched numbers from a lazy upward leg rather than a weak downward leg.

Stump the extra and get yourself a power2max or quarq. Pretty much everyone I know, including myself bought a powertap, got annoyed at only being able to use one rear wheel(and get power data), sold it and bought a quarq/p2m. If you don’t think this will happen, don’t worry and by a powertap, they’re very good at what they do.

NB – get the 2nd gen Powertap/Quarq Riken or elsa/grey powertaps – reliability is vastly improved.

Also, on L/R balance, read this: http://alex-cycle.blogspot.co.uk/2013/11/left-right-out-of-balance.html

I personally won’t touch stages yet, everyone I know who’s had one has had to warranty it, and that’s not cool. Even with the new battery cover.

I definitely improved after getting a powermeter, but I also got bigger and stronger. Initially I didn’t really understand the thing and it was more of a hindrance, but now that I get it better, it definitely is a very useful tool.

[Hi I hav a powertap for sale mtb at 450 if ya interested