Stages Or P2M Power Meters?

crossed

I'm looking at getting a power meter as I'm wanting to start taking my winter training a bit more seriously and I'm in two minds about what to go for.

The 2 units I can't decide between are the Stages 105 or spending a bit more and getting the Power2Max unit.

I can get the Stages 105 for £475.
The FSA Gossamer P2M is £570

I Thought about jumping up to the Rotor 3D F P2M but it means a new BB as well and it bumps the price up to £740 or so.

Is the P2M worth the extra money over the Stages?

Everything I've read so far on various forums seems to be people recommending whatever power meter they've got which isn't really helpful so I'm trying to get opinions from people who've used both and can give a good recommendation either way.

Bar Shaker

Wait for the 4iiii to be released.

slowbike

What tipped me over the edge on Stages was the ability to swap between cranks with different rings - I use 53/39 on the TT bike and 50/34 on the road bike - whilst this would be possible with the P2M it would be more of a ballsache. Also the Stages was cheaper.
It is easy to skew the power readings by putting more or less effort in on the left leg, but for my use I think it is ample.
Had I seen the 4iiii before I bought stages I would've been tempted to wait for that.

paul2718

I've had a P2M for a few years now, and recently borrowed a Stages that had been replaced under warranty due to the well-known battery issue. So it works but occasionally after having seen a wet road it is dead the next day. I'm assuming they've fixed this now.

The P2M is a much higher quality piece of equipment, there's much more to it, the battery compartment is robust and properly sealed, it just works, and keeps on working. The Stages seems to produce reasonable numbers, and they are comparable, but I cannot comment on the reliability. I cannot run both together since the P2M is on a Rotor and the Stages is Shimano. The P2M limits me to 53/39 rings, because clearance couldn't be guaranteed with the 110mm version. The Stages, as well as being crank size agnostic is much lighter and more discreet

I was considering a new Stages to go with my Shimano crank, but it is now starting to look expensive and the 4iiii is very appealing. We shall see over the winter.

Paul

crossed

The 4iii looks quite interesting but having just read the DC Rainmaker write up about it, I'm not sure whether or not the Q4 2014 delivery will be accurate!

Part of me is just thinking 'sod it, just blow the extra on the Rotor P2M' but I'm really undecided at the moment :shock:

slowbike

paul2718 wrote:

recently borrowed a Stages that had been replaced under warranty due to the well-known battery issue. So it works but occasionally after having seen a wet road it is dead the next day. I'm assuming they've fixed this now.

Mine has not yet been used in the pouring rain, but have washed it (on the bike) and had no problems - it has a red seal around the battery compartment.

shockedsoshocked

I recently finished my dissertation comparing power meters, and Power2Max were extremely helpful in all aspects when I was asking them about their products. They actually passed around my original enquiry between departments till they found someone who spoke sufficient English (eventually a guy called Nicolas who was the Power2Max France support guy). They're keen on making a product of similar standard to that of the SRM, and test and calibrate their devices using DIN/ISO certified devices. Stages on the other hand didn't respond to any of my emails. I know it doesn't necessarily reflect their products, but from that experience i'd personally choose the Power2Max everytime.

Grill

Had my Rotor 3D P2M for about 18 months now and it's been faultless.

Alex_Simmons/RST

There will always be a new product on the horizon to wait for. Problem is, it's on the horizon and one can never really know how it will perform until it's been through the ringer of actual use.

I recently updated my "Which Power Meter?" blog post. It goes through a whole host of factors to consider when making your choice, as well as introducing all the various options.

http://alex-cycle.blogspot.com.au/2013/ ... meter.html

RChung

Alex_Simmons/RST wrote:

There will always be a new product on the horizon to wait for. Problem is, it's on the horizon and one can never really know how it will perform until it's been through the ringer of actual use.

Every power meter currently on the market (and all those that are no longer) have had problems with version 1.0. Sometimes those problems were quickly fixed, sometimes not. That's why the #1 rule of power meters is: No low serial numbers. A special case of rule #1 is rule #2: don't base a decision on vaporware. They don't yet even have a serial number.

I recently updated my "Which Power Meter?" blog post. It goes through a whole host of factors to consider when making your choice, as well as introducing all the various options.

http://alex-cycle.blogspot.com.au/2013/ ... meter.html

Nice.

charlie_potatoes

Bar Shaker wrote:

Wait for the 4iiii to be released.

Disagree. It does look interesting but.....

Carpe diem

RChung

ShockedSoShocked wrote:

I recently finished my dissertation comparing power meters

Interesting. Where did you do this, for which degree? How did you do the comparison?

shockedsoshocked

RChung wrote:

ShockedSoShocked wrote:

I recently finished my dissertation comparing power meters

Interesting. Where did you do this, for which degree? How did you do the comparison?

Undergrad Applied Sports Science at Teesside University. Was intended to compare numerous power meters and stationary ergos against a Lode Excalibur Sport (as the Gold Standard device), but ended up being a bit limited due to lack of newer literature and the American manufacturers being pretty unhelpful, so I ended up going more down the root of comparing the transferability of lab (Lode + Monark Cycle) to road based devices (SRM, Powertap) due to calibration/sampling rate/where the power is sampled/inertias/Q-factors. Like I said unfortunately there isn't a lot of research comparing devices or about how they're calibrated which is a disappointment. My conclusion essentially was if it's German and expensive it will be accurate

Basically became a huge lit review, with a second section about how analysis of power during stage races can facilitate targeted dope testing. I think I may have referenced yourself on a couple of occasions (Alex pointed me in your direction!). Apologies for slight thread hijack.

aberdeenal

paul2718 wrote:

I've had a P2M for a few years now, and recently borrowed a Stages that had been replaced under warranty due to the well-known battery issue. So it works but occasionally after having seen a wet road it is dead the next day

I used my Stages Ultegra during Ride the North and it was lashing down for 2 hours plus lots of standing water on the road and I had no issues with at all

mulletmaster

I've owned both, found the stages to be inaccurate and unreliable. It was good enough to totally die so I got a quick warranty replacement and sold it. I know a lot of happy owners for for me the p2m is a vastly superior producrt.

iPete

They've come down in price, is the FSA Gossamer P2M 'only' £570, that's very tempting.
Is the stages price a mates rate?
I'm waiting on updates from 4iii, happy to wait as its a nice to have item.

jgarpotter

iPete wrote:

They've come down in price, is the FSA Gossamer P2M 'only' £570, that's very tempting.
Is the stages price a mates rate?
I'm waiting on updates from 4iii, happy to wait as its a nice to have item.

You can get a 105 for about £470 brand new from here (it does require you to wait for it to be shipped from Germany though!)

http://www.powermeter24.com/de/categori ... ting=price

iPete

That's very tempting. For some obscure reason I resent paying so much for something so small and light which massively contradicts being a roadie

Actually my real concern is the reputation and ordering from Germany presents a bit of a risk in terms of warranty(?). If it was a v2 product and the 4iii wasn't being a tease I would have got one a long time ago.

philbar72

Got 2 power2max rotor 3d cranks. Ones a rotor 3d, and ones a type s (lighter than my outgoing ultegra chainset). Easy to install, read right, and have confirmed what I feared, that I'm right side dominant, and put out up to 8% more power with my right leg!

A stages wouldn't be able to do that! They've also got a terrible rep for not liking water!

meanredspider

philbar72 wrote:

right side dominant, and put out up to 8% more power with my right leg!

That's great (well, it isn't of course). So what are you going to do about it?

DeVlaeminck

Just stop pressing down so hard with the right leg, problem solved.

frisbee

meanredspider wrote:

philbar72 wrote:

right side dominant, and put out up to 8% more power with my right leg!

That's great (well, it isn't of course). So what are you going to do about it?

Inject his right leg with botox?

meanredspider

And so the Stages will be telling you that you're putting out 200W when, in fact, you might be putting out as much as 208W (according to the P2M) - what difference will that make? What will you do differently?

RChung

meanredspider wrote:

And so the Stages will be telling you that you're putting out 200W when, in fact, you might be putting out as much as 208W (according to the P2M) - what difference will that make? What will you do differently?

Depends on what you're trying to do with the information. For some things, such as training FTP, probably not much. OTOH, testing CP or doing ramp tests or measuring drag, that much error can make if difficult to measure changes or improvements. For example, most ramp protocols require the step sizes to be equal and you ramp up until failure. For most people the degree of asymmetry isn't a constant percentage across all powers nor across all fatigue states so the failure point could depend on the test protocol. A similar thing can happen if you're trying to use your power meter to measure aerodynamic (or rolling) drag. Those are applications where you rely on linear response across the whole range of power.

Bottom line, training doesn't demand particularly high data quality so if that's all you intend to do a Stages is probably fine. If you do need high data quality (and not everyone does) then you'd probably be happier with something that provides it. Most importantly, people shouldn't think that everything you do with a power meter requires the same level of accuracy or precision. Whether a particular device is a good match for you depends on what you want or need to do.

meanredspider

I couldn't agree more. It's the 80:20 rule - most of us will get most of what we need with the simplest kit. Some of us (I suspect less than 20%) will want greater accuracy and precision for more sophisticated measurement. I'd imagine that precision is generally more important than accuracy though, never having needed to play about at the sophisticated end of bike training, I'm not qualified to comment. I know, for me, precision is most important and, even then, not critical. Most of my riding would fall into the category of "endurance" so my interest is just consistency of power output at a sustainable level. The Stages is more than adequate for that.

janesy

Not much to add to this but I have just got the P2M classic on a FSA K-force light. I couldn't get the stages as needed it for my Trek Madone and didn't have the necessary clearance.

It cost me 1000 euros with chainrings - £788.42
Sold my Duraace chainset for £220
= £568.42

I think that's a good deal.
Like I said nothing much to add other than P2M imo is superior.

slowbike

janesy wrote:

Like I said nothing much to add other than P2M imo is superior.

Without any reasoning given for that statement it's pretty useless ...

janesy

For my needs its superior. I dont have to give reasoning. Its all out there in the public domain.

slowbike

janesy wrote:

For my needs its superior. I dont have to give reasoning. Its all out there in the public domain.

You're correct - you don't have to give a reasoning - just makes your opinion practically worthless.
The only reason I can ascertain that the P2M power meter is better for you is that it fits your frame whereas the Stages PM doesn't - that doesn't make the P2M superior at all, just that the Stages PM isn't compatible. Exactly the same as for all those who have cranks that Stages hasn't created a compatible PM for yet.

janesy

I don't think my opinion is worthless. Its my opinion. Its not worthless to me. Aka my opinion.
Also I don't think the only reason people get a non stages because they have incompatible cranks.
Thats stupid.

I wanted the P2Max due to:
Good reviews
left/right balance
Accuracy.
Build quality etc
and of course fit. But then again I could of put a stages on my other bikes.

venster

Just out of interest, Janesy, how long did your P2M take to arrive from ordering?

Does it take the full 2 weeks the website claims ?