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

You don't need a torque wrench for any part of a Power2Max, even if you disassemble the spider. I've tested it extensively, even with missing bolts it still reads fine, it's a very good piece of kit.

I have one that goes on the CX bike and is then swapped across to the road bike (inc. changing chainrings from 38/44 to 38/53) when I want to use posh carbon wheels (the road bike normally has a Powertap on it). Takes very little time to change chainrings and move it across, it's hardly a faff at all.

Stages powermeters are bunk and will give you bingo data, they're far too expensive for what they are. I used to have Ergomos which work on the same concept (left leg x 2), they were nice for the track bikes I used them on but only because they cost me £50 each rather than £500, it's utter madness and I can't understand why people want to use the Stages PMs over something like a Power2Max or Powertap.

Xav

Thanks everyone for the comments and advice. I already have a Rotor crankset so the price of a P2M now is a lot closer to the price of a Stages and, for the time being at least, the former is at least available sometime soon.

I'll order the P2M tonight, once I've had confirmation that my Stages order is cancelled and I'm getting a refund.

if anyone with 6800 is after one: http://www.bikeradar.com/forums/viewtopic.php?f=40091&t=12958401

Which one did you go for Ed?

There is a 172.5 5700 Stages in Cadence I noticed this afternoon, whilst waiting 2 hours for a flat white to be made.

Garmin Vector, based upon being able to get a bit of a discount on them and swap ability between my campag and shimano bikes with different crank lengths...

I can never login to Bike Radar as I've forgotten my username- Amey, what is that link to?

Stages Power Meter on Shimano Ultegra 6800 crank arm 172.5mm long.
2 weeks old. Some minor rubbing on the arm from overshoes. Works Perfect no issues, impulse buy but not ready to commit to power training. So wasted on me.
£699 new. Reciept to prove, manufacturers warranty. Im after £550.

Pictures:

https://www.dropbox.com/sh/ud6b97a3t7ielks/GehpAccd7i

Email/text or phone me if interested. Located in Codsall, Wolverhampton.

07964604135
mrrewire@gmail.com

.

Cheers, wrong length for me- and not cheap enough given the condition.

In other news, it's impossible to contact Bikeradar if you can't log in, it would seem.

Thanks everyone for the comments and advice. I already have a Rotor crankset so the price of a P2M now is a lot closer to the price of a Stages and, for the time being at least, the former is at least available sometime soon.

I'll order the P2M tonight, once I've had confirmation that my Stages order is cancelled and I'm getting a refund.

How'd this go Andy?

if anyone with 6800 is after one: http://www.bikeradar.com/forums/viewtopic.php?f=40091&t=12958401

Would've been ideal for me, but it's been sold. Oh well, better get my arse in gear and get that order in.

Ordered the P2M on Tuesday, paid for it last night. They've said it'll be with me by the end of the month.

No news regarding my S-type as of yet :(

Ordered my new chainrings though. Gone for 52/38, as the 34 frankly irritates me. Should have kept to 50 for the big ring really. But I cant really see 2 teeth there making a massive difference, and this was cheaper.

As a lover of all things geeky and gimmicky. I've gone with O.Symetrics, as I got a decent deal on the new refined 2014 rings.

Considering P2M measures both cadence and torque, and presumably does this per second. And that both pedal speed and torque will now vary with a min-max time difference of say 0.2 seconds. I struggle to see this working out well.

But a quick google says its a combo thats been used a fair bit before. So what do I know.....

*Guten *Tag Smallfurry,

*ihre bestellte Ware wurde versandt. In einer separaten *
*E-Mail erhalten Sie die Sendungsnummer von UPS mit der Sie Ihre Sendung *
*verfolgen können. Sendungen von Kleinteilen erfolgen per Post ohne *
Sendungsnummer.

:)

Considering P2M measures both cadence and torque, and presumably does this per second. And that both pedal speed and torque will now vary with a min-max time difference of say 0.2 seconds. I struggle to see this working out well.

Power2Max samples torque AND cadence (using accelerometers) at 50Hz (50 times per second), compared with something like an SRM or Quarq which measure torque at >50Hz, but cadence only once per revolution, so a range of ~0.5-3Hz. Means that using non circular chainrings isn't so much of an issue with P2Ms (just over 2% inflation with Osymetrics) but results in much greater inflation of power numbers (ie. >5%) with an SRM or Quarq. Everyone has to transmit at 4Hz as per the ANT+ protocol, but they're 4 identical data packets so it's effectively 1Hz that goes to the head unit, all the calculations are done in the cranks

Xav

SRM can record at 0.5 second intervals, if I had to hazard a guess I'd say that this was ANT rather than ANT+?

Not sure what happened to these- I was watching them and I think the auction was cancelled and restarted.

Anyway, they seem very cheap to me?

http://www.ebay.co.uk/itm/281261369514?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

SRM can record at 0.5 second intervals, if I had to hazard a guess I'd say that this was ANT rather than ANT+?

The wired ones can go down to 10Hz/0.1sec - but yeah I think they dual broadcast on their own private ANT channel as well as ANT+. The SRM PCVII is certainly wired differently from normal ANT+ head units, but you can pick up something like a Quarq on a PCVII with a bit of fiddling

Xav

You need to set the Quarq to "German" mode and it can then be picked up by a PC-6 or 7, from what I have read- using Qalvin.

^^^ Two and a half days to go, mind. But at the price they're at now, yes, they're a bargain.

Must resist. Too many wheels, not enough bikes. And yes, I know there's a simple way to solve this...

You need to set the Quarq to "German" mode and it can then be picked up by a PC-6 or 7, from what I have read- using Qalvin.

That's right, drains the battery though

Xav

Power2Max samples torque AND cadence (using accelerometers) at 50Hz (50 times per second), compared with something like an SRM or Quarq which measure torque at >50Hz, but cadence only once per revolution, so a range of ~0.5-3Hz. Means that using non circular chainrings isn't so much of an issue with P2Ms (just over 2% inflation with Osymetrics) but results in much greater inflation of power numbers (ie. >5%) with an SRM or Quarq. Everyone has to transmit at 4Hz as per the ANT+ protocol, but they're 4 identical data packets so it's effectively 1Hz that goes to the head unit, all the calculations are done in the cranks

Xav

Great informative post. Cheers and repped!

I did do a little research before buying the rings. One of the distributers in the far east sells both O.Symmetrics, and P2Ms, and has a whole racing team on them. So I figured it wasnt a massive problem.

NIce to read a concise technical explanation though.

Cheers - don't train on the OSymetrics though, they will mess up your pedal stroke. Save them for races/hard rides on Strava ;)

Xav

Right, pre-ordered an Ultegra 6800 Stages for the Fred bike. Let the waiting begin.

Yeah, about those marginal gains.

Remarkably, at the age of 29, this winter marked the first time that Haussler has trained diligently with a power meter. "With Garmin, we had to use it as part of the team, but this is the first time I’ve actually worked with someone and done interval training, motor pacing, sprints and proper weight training," he said. "All this kind of stuff is new and it’s something I’m getting a big advantage from."[QUOTE]
[/QUOTE]

Powermeters In The Pro Cycling Peloton - YouTube

team sky in Stages are more shit than we anticipated but we think/hope they'll improve shocker

Whats that Skippy? Shimano has patents for a crank based powermeter system measuring force in multiple planes?