Power Meter Brand Reliability

[pcrispey]

Power2Max all the way
I have 2 units both with Rotor cranqs.
On my training bike a Rotor 3D 110mm. This one is used during all season in and outdoor so in all kind of conditions during and not one time a had a problem with it. It's only not working when the battery is empty but replacing it is easy and quiclky done I keep a spare battery at work and in my car.
I also had 3 powertaps alway's problems with them I needed 3 units because one of them was at service all the time. Torque hub replacement each time last time they gave me a new wheel. This one is only used for indoor rides now.

[bigfatty]

haha, seems like P2M is the way to go. one could only surmise that the SRM engineers are inept at what they do if they cannot bring a similar product to market at a competitive price. surely it wouldn't be greed that drives the price

[Tinea Pedis]

That wouldn't be the correct conclusion, as SRM have made some great products. As mentioned, their PV6 stuff (drift aside) were very dependable. Only they do now seem to be playing catch-up. Which when they are at the price point they are, makes for a tricky time ahead.

[rijndael]

It's interesting to see so many people recommend brand X, usually not an SRM, and talk about their great customer service. It's because so many folks have needed it.

The best customer service is the one you'll never/rarely need.

[MarkTwain]

Why not just name the brand you're referring to?

Rather than make a blanket statement that isn't specific to any (other than SRM).

[rijndael]

I don't have one brand in mind. I was serious when I said it's all of the above, excluding SRM.

Vector's durability, specifically their pods, is mediocre

Stages hands out battery doors like candy on Halloween

Quarq's record, prior to their current series that takes 2032 batteries, is ho-hum. Their current units are better, but far from perfect

Powertaps have had bearing issues, and some water sealing issues

[KWalker]

When a pro team ditches their sponsor's PM and buys their own, it says a lot about who they choose. Without being super specific, that team chose Power2Max and it wasn't because of budgetary reasons or anything of the sort.

[rijndael]

Unless they're willing to share why they picked P2M, I wouldn't let that sway my decisions in any way. It could be for some non PM (technical) reason like they wanted to run Campy rings, which greatly limits their choices.

If I was going with P2M, I'm make sure my unit didn't read low. I know of a few units which suffer from long interval drift.

[Tinea Pedis]

You're misinterpreting what is being said. It reads 'lower than my SRM'. That does not mean 'reads low'. Simply lower than what my SRM's would say. In some cases it was less than 2%, in some more. But rough average was 2% less. Which given SRM's have real and measurable temperature drift, is about what I expected.

So I'm more inclined to believe my P2M is closer to my real power (especially as my numbers match between my two P2M units), but that is just my take.

[rijndael]

You're misinterpreting what is being said.

No, I'm not. I didn't base that on anything that's been said in this thread, I'm basing it on experience comparing a P2M to a PT, which previously tracked well with a Quarq and an SRM.

[Tinea Pedis]

You standardise them all? I did, with a LeMond and a speed sensor.

Interestingly, when DC Rainmaker compared it to a PowerTap he found they were spot-on indoors - but there was drift within one of the units outside...

http://www.dcrainmaker.com/2013/01/powe ... eview.html

Given P2M has temperature compensation built in and the PT didn't, it's your call on which you prefer and if you can live with a unit that 'reads low'.

[rijndael]

I didn't.

I had a lot of data showing it tracked well with 2 other known units. It was pretty clear based on the other data (cadence, speed, and power from the other units) the P2M was the culprit - not the PT. On long intervals the power read low.

[Tinea Pedis]

I can only point out what one guy (who does it for a living) found. I know that's an appeal to authority, but Ray is damn thorough. And is why I now try to use a method to standardise the power data.

I'm guessing you updated the P2M firmware? If so, that's a comparison against units that drift with temp. As mentioned in the link.

P2M does read lower than my SRM, no doubt. No much - and looking back over my notes there were times it was equal. It's only my ego that's really suffered though. As for Quarq's accuracy...well, I've seen some incredible figures from my team mates off theirs. Two of them died on me. Drift was an issue. In no rush to try one again.

[rijndael]

I'm aware of quarq issues too, it's my 3rd one.

[rijndael]

And FWIW, I have a lot of respect for Ray's approach and data. Some of the people helping him on the backside (data correlation) are very clueful.

Part of the problem is we're dealing with sample sizes of one, there are certainly going to be outliers.