Powermeter choices

rozzer32

So I would like to start training with power again. I used to have a old powertap sl but had so many issues with it I ended up getting rid.

But now I would like to start using it again and would like some opinions please. My choices are either:

A new 2012 Sram Red Quarq - I currently run force and am slowly starting to upgrade to Red so this would fit in nicely although I know I'd have to run the new front mech with the new chainset. Looking about these are about £1500ish.

A powertap G3 built into IRD aero rims from wheelsmith. Now having had issues with my old powertap I'm a bit hesitant but are the new model powertaps a lot better than the old ones? A wheelset would cost about £1200.

I'd love to have an SRM but I can't afford one

I know there are second hand PM cheaper but would prefer to buy new so I have the warranty back up.

So just wondered what peoples thoughts were and if anyone has any experience of the new powertap hubs.

I am the god of hell fire

power2max?

napoleond

Power2max have apparently sorted their temp drift issues and look like a good option.

rozzer32

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

Anyone got a link to the info saying they have sorted it?

brettjmcc

Maybe give Rotor a call on their new power cranks coming soon?

danowat

I run a powertap SL+ for training, and a Quarq on my race bike, powertap has been faultless over a couple of thousand miles, the only issue I had with the Quarq was it went a bit haywire about 9hrs into a 12hr TT and showed reduced power for a while.

amaferanga

rozzer32 wrote:

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

Anyone got a link to the info saying they have sorted it?

I think it was announced at Eurobike. There's some relevant discussion on the Google Wattage list as well.

rozzer32

brettjmcc wrote:

Maybe give Rotor a call on their new power cranks coming soon?

Yes they do look interesting and I have done some reading on them, apparently they will be out at the end of the year.

rozzer32

amaferanga wrote:

rozzer32 wrote:

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

Anyone got a link to the info saying they have sorted it?

I think it was announced at Eurobike. There's some relevant discussion on the Google Wattage list as well.

Just found this. New units apparently should be sale sale in a couple of months and for the same price as current units

http://www.dcrainmaker.com/2012/08/power2max-announces-updates-to-power.html

amaferanga

I've ordered a P2max that's due for delivery in a couple of weeks and I think I'm getting one of the new ones.

rozzer32

amaferanga wrote:

I've ordered a P2max that's due for delivery in a couple of weeks and I think I'm getting one of the new ones.

There's no mention of the new model on their website. Did they tell you you were getting a new one?

twotyred

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

If you mean drift due to temperature changes then all power meters do this to a certain extent. The P2M does it more than most but the nifty auto zero takes care of it under normal riding conditions and it would only be an issue if, for example you, were doing a time trial up Alpe d'Huez. I've had a P2M for the last 9 months including a trip to the Alps and I'm quite happy with the quality of data from it so much so I'm in no hurry to send my unit back for the update.

Alex_Simmons/RST

twotyred wrote:

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

If you mean drift due to temperature changes then all power meters do this to a certain extent.

This difference in drift between different power meters however is more than an order of magnitude.

twotyred wrote:

The P2M does it more than most but the nifty auto zero takes care of it under normal riding conditions and it would only be an issue if, for example you, were doing a time trial up Alpe d'Huez.

or riding on a trainer, or doing time trials, or long intervals, or longer hillclimbs, or consistent efforts for 20+ minutes.
But apart from that, yeah, normal riding conditions.

BTW - there is no information on how this zero is actually triggered. that's a problem, as it really matters.

amaferanga

rozzer32 wrote:

amaferanga wrote:

I've ordered a P2max that's due for delivery in a couple of weeks and I think I'm getting one of the new ones.

There's no mention of the new model on their website. Did they tell you you were getting a new one?

It's not been confirmed, but the Canadian distributor posting on the Google Wattage group thinks I'll get the updated one. I'm not that bothered if I don't - I ordered it before the update was announced and now that my PowerTap is dead (I refuse to pay £425 to repair it) I just want a power meter again. It's only 50 Euro to get the update later anyway.

rozzer32

twotyred wrote:

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

If you mean drift due to temperature changes then all power meters do this to a certain extent. The P2M does it more than most but the nifty auto zero takes care of it under normal riding conditions and it would only be an issue if, for example you, were doing a time trial up Alpe d'Huez. I've had a P2M for the last 9 months including a trip to the Alps and I'm quite happy with the quality of data from it so much so I'm in no hurry to send my unit back for the update.

I can remember reading somewhere that people were experiencing drift in-between intervals which is never good. You don't want to be doing a set of intervals where the PM is reading 20 watts higher than when you first started.

danowat

I know someone who uses P2Max, and they say it's very repeatable, however, the figures don't bear much relation to "real world" figures.

rozzer32

Well surely if you're going to spend hundreds on a power meter you'd want one where the figures can be taken as real data.

I've joined the google wattage group and reading the Power2Max thread one poster said now there will be 2 slopes to go wrong with the new temperature drift model. What does this mean?

This is all getting very technical. I just want a PM I can bolt on and go training with haha.

amaferanga

danowat wrote:

I know someone who uses P2Max, and they say it's very repeatable, however, the figures don't bear much relation to "real world" figures.

Not heard that one before. What's he comparing the figures with to come to that conclusion? The only issue I've heard with the P2max is the drift problem, but this is (was?) only an issue until the unit warms up and if there are big temperature changes during which you don't stop pedalling at all.

To say the numbers are offset from reality (again, what does that mean though?) suggests that that particular unit may be faulty and should be returned to P2max for repair or replacement.

rabk

I bought a Powertap Pro December 2011, and decided I wanted a crank based meter for the TT bike

I bought a Power2max, received and fitted end of July 2012, Had fairly significant issues with Zero offset moving substantially - took a long time to stabilise.

I Contacted P2M, they said unit was faulty - I returned it, they replaced with a new unit (received within 10 days), which seems much better - limited drift in Zero offset (settles after 10-12 minutes)

Based on my data from the Powertap, the P2M seems to be spot on.

Doobz

amaferanga wrote:

rozzer32 wrote:

Yea I have looked at Power2max but when I read up about them the big problem was the amount of drift they suffered from. But if they have sorted it then it looks a good option.

Anyone got a link to the info saying they have sorted it?

I think it was announced at Eurobike. There's some relevant discussion on the Google Wattage list as well.

I had been looking at the P2M units for a while but always been put off a bit by the temp drift. Now that it has been confirmed "resolved" I decided to to check a few things with them. I was so pleased with the feedback I got from them and from some research I had done that I placed an order pretty much right away.

I would be careful of some of the stuff you read on the wattage group. some real "tinfoil hat" type freaks.

Email summary and .pdf from them below..

https://docs.google.com/open?id=0B3XLon ... jlXd2dYV2c

Hi there,

I am currently looking at buying a crank based power meter. I have been
training with power using a Powertap SL+ for 12 months but because of the
weight I am limited to just training and not racing as the weight of the SL+
wheel is a bit high.

Ideally I would like to race with Power as this is the most valuable data. A
crank based meter is the only way I can achieve this without having two
Powertap wheels which would not be financially sensible.

I have been doing some research on the Power2Max and have some questions
regarding reliability over the cold winter months.

Are there any limiting factors I need to know about using the Power2Max in
the winter time. As most the time in the winter I train 6 days a week in any
weather (snow/rain/sun/ice) will the Power2Max be able to cope in these
conditions without any huge drifts in my power data?

Hopefully if you can confirm of this and any new features I should be aware
of before making the purchase then I would greatly appreciate it..

Many thanks,
Steve

Hello Steve,

Thanks for your interest in power2max.

We attached you the new Flyer with all the new features. One of our new
feature are "Compensation of temperature dependent drift".
So, where ever you are training your power2max power meter works accuracy.

Best regards

Your power2max Team

Wow this is great. I have been following the Eurobike coverage and I noticed this new feature too.

Can you let me know when the new version of the meter will be available..

many thanks,
Steve

NOW!
If you order now we will send out the new version. We starts in week 36

twotyred

or riding on a trainer, or doing time trials, or long intervals, or longer hillclimbs, or consistent efforts for 20+ minutes.
But apart from that, yeah, normal riding conditions.

Riding on a trainer in a room with a reasonably constant temperature will not affect the unit and unless your time trial, long interval and hill climb involve going up the side of a mountain with significant temperature changes then it won't be an issue. So yeah normal riding conditions. And if P2M are to be believed the temp drift issue has now gone away with the upgrade.

This P2M hate is getting a bit tired now Alex. I can't help noticing from your sig you sell SRM power meters so you're not exactly unbiased.

amaferanga

I was also really impressed with the customer service and the information I got form P2max. Answered all my questions promptly (even replying on a Sunday once) and were just generally helpful. Quite the opposite to my experience with Saris/Paligap.

P2max are offering a crash replacement policy as well which looks good. Not a free replacement, but reasonably priced.

Doobz

amaferanga wrote:

I was also really impressed with the customer service and the information I got form P2max. Answered all my questions promptly (even replying on a Sunday once) and were just generally helpful. Quite the opposite to my experience with Saris/Paligap.

P2max are offering a crash replacement policy as well which looks good. Not a free replacement, but reasonably priced.

Plus. 2 Year Warranty, User Replaceable battery, No need to recalibrate when changing chainrings, L+R Power Balance etc.. Would be daft not to..

rozzer32

Well I wasn't looking to get the power meter until around Christmas time anyway. So hopefully by this time people will have some feedback on the new Power2Max. But it's looking like a good option so far.

Does anyone know if the Rotor 3D+ would fit BB86 BB that I run on my Scott Addict?

Doobz

rozzer32 wrote:

Well I wasn't looking to get the power meter until around Christmas time anyway. So hopefully by this time people will have some feedback on the new Power2Max. But it's looking like a good option so far.

Does anyone know if the Rotor 3D+ would fit BB86 BB that I run on my Scott Addict?

Should do with no problems..

http://www.power2max.com/techdetails_ko ... litaet.php

neeb

rozzer32 wrote:

A powertap G3 built into IRD aero rims from wheelsmith. Now having had issues with my old powertap I'm a bit hesitant but are the new model powertaps a lot better than the old ones? A wheelset would cost about £1200.

I've been using a G3 for a couple of months now and it's been faultless. My first power meter so nothing to compare it with, but very happy so far. Got it built into a very light Reynolds Thirty Two clincher, plenty stiff and the total rear wheel weight is under 890g. What issues did you have with the old powertap?

rozzer32

neeb wrote:

rozzer32 wrote:

A powertap G3 built into IRD aero rims from wheelsmith. Now having had issues with my old powertap I'm a bit hesitant but are the new model powertaps a lot better than the old ones? A wheelset would cost about £1200.

I've been using a G3 for a couple of months now and it's been faultless. My first power meter so nothing to compare it with, but very happy so far. Got it built into a very light Reynolds Thirty Two clincher, plenty stiff and the total rear wheel weight is under 890g. What issues did you have with the old powertap?

The data would drop so some rides you'd have no data, some rides it would work fine. Then the reading would be way off, like read 80 watts when you're sprinting ( I know I'm bad but I'm not that bad). Then the problem sorted itself, then re-appeared and then sorted itself again. I think the torque tube was going and I have read a lot of threads about people having to have torque tubes replaced and it's about £300 to do so. But I don't know if these issues have been solved with the G3.

However I would prefer a crank based system. I'm leaning towards the Power2max now but like I've said I will see what these new models are like first.

bigpikle

I've been looking at the P2M since they were launched and keep swinging back and forth about them.

There seem to be a couple of issues:

1. different units seem to vary massively in how they are affected by temp drift, in terms of how MUCH they drift and how LONG it takes to settle. This begs the question about how the new 'fix' will work as clearly different units will need different levels of correction?

2. P2M have never given any details on how the units auto zero, so people are wondering about what is happening to their numbers and what may, or may not, actually be changing in the recorded data. How they zero is a critical element in the reliability of the data, and many people place higher levels of importance on data reliability thatn others.

I'm watching keenly as the units potentially have many advantages. My PT has performed perfectly for 2 years but limits my wheel options so a crank system is ideal. You cant ignore the P2M because of cost, but I'm still not toally convinced just yet and will watch the feedback on the claimed fix very closely

rozzer32

Bigpikle wrote:

2. P2M have never given any details on how the units auto zero, so people are wondering about what is happening to their numbers and what may, or may not, actually be changing in the recorded data. How they zero is a critical element in the reliability of the data, and many people place higher levels of importance on data reliability thatn others.

Why is this important?

Alex_Simmons/RST

twotyred wrote:

This P2M hate is getting a bit tired now Alex. I can't help noticing from your sig you sell SRM power meters so you're not exactly unbiased.

1. I don't hate them. I call it like I see it, and with the benefit of a decade of experience with on bike power measurement tools covering half a dozen power meter brands, many tens of thousands of power meter files and personal interaction with many hundreds (thousands?) of power meter users, I have a pretty fair idea of what a power meter should/shouldn't do.

If you've ever seen my long history of comment on power meters, you'll know that I praise and criticise fairly (and Quarq, SRM, Powertap, ergomo and Polar have seen such criticisms from me in the past on other matters).

I have on many occasions wished P2M well in their endeavours and still do. Any company worth its salt will listen to such feedback and use it to improve their product. I hope P2M is doing this and not being head in the sand about it.

2. Yes I sell SRM. At least I am disclosing that interest. I have confidence in their product.

As for the P2M drift, there are many reported cases of large drift occurring when no or very little temp change is going on. To be frank, anything that drifts *at all* when environmental conditions don't change has a serious problem. The P2M is way over sensitive to temp changes.

For example, there are things I wouldn't trust this device for, such as aerodynamic field testing.


Pithy Power Proverb: "The most important consideration when choosing a power meter is the quality of data. Everything else is a feature."

Alex_Simmons/RST

rozzer32 wrote:

Bigpikle wrote:

2. P2M have never given any details on how the units auto zero, so people are wondering about what is happening to their numbers and what may, or may not, actually be changing in the recorded data. How they zero is a critical element in the reliability of the data, and many people place higher levels of importance on data reliability thatn others.

Why is this important?

There are several reasons, but here's a couple of questions for you to consider:

Would you trust a torque zero measurement made on any crank based power meter while still clipped into the pedals?

Let alone one that you don't know the circumstances of when it is applied?

Can the auto torque zero be disabled, so the user can check and control how and when this occurs?