Stages power meter
stoobydale
Posts: 535
I have the chance to buy a Stages power meter but it means changing from Campagnolo to, probably Shimano. If I was to buy it and then decide to sell it, which one would be the best to buy?
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What an open question that is.
Quite interested in these myself. Can you get back once you have tried to comment further...
Good luck.faitduvelo.wordpress.com0 -
PM sent.0
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Do you have the matching crank??
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Assume you already know this, but at present they are only selling and supporting their pm in the US, which means buying it in the US and if there is a problem it will be unsupported in the UK (assume you would need a US postal address for any returns if required)
Interested in how these compare to some of the more established pm products and may pick one up next time I am in the US. Probably will just get the non-drive arm to match the chainset I already have as the cheapest option.0 -
They are available in the uk now.
I know www.cadencesport.co.uk are doing them (they aren't strictly am online retailer but will do mail order.)
Don't know what the lead times are though.Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
Yes, available in the UK now with full back up.0
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Interesting - thanks for that. Makes life simpler0
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Just buy a Power2Max instead. Proven and almost as cheap.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0
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Stueys wrote:Grill wrote:Just buy a Power2Max instead. Proven and almost as cheap.
But not quite as portable
Errrr ¿que?Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
No as it would require that your bikes have identical chainsets. With Power2Max all you have to do is swap the whole chainset. This does depend on bottom brackets, but I can swap mine (Rotor 3d) between 3 of my bikes in just a few minutes. Also as the PM is in the spider for my Rotor P2M I can swap crank arm length, which is nice as I use shorter ones on my TT bike.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0
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Grill wrote:No as it would require that your bikes have identical chainsets. With Power2Max all you have to do is swap the whole chainset. This does depend on bottom brackets, but I can swap mine (Rotor 3d) between 3 of my bikes in just a few minutes. Also as the PM is in the spider for my Rotor P2M I can swap crank arm length, which is nice as I use shorter ones on my TT bike.
Ah, now I understand why I was being dense. So a question, between my two bikes ('12 Canyon ultimate cf slx (ultra torque) and a 2010 Spesh Allez (think 68 mm bb) ) can I easily swap a p2m between the two?0 -
You'd need the same chainset on both bikes either way so both need same BB.
Stages doesn't support Campag which I assume is in your canyon...Insta: ATEnduranceCoaching
ABCC Cycling Coach0 -
I believe you'd have to swap out the BB. AFAIK Ultra Torque uses a 25mm spindle. If your Allez is BSA then you could get the Rotor 3d cranks (not the +) and you'll just need the appropriate BB for the Canyon (BSA I think) and then you should have no problem.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0
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Thanks both, that helps. I'll have a chat with my LBS around the options to get both bikes on the same BB0
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Better to get a power meter that measures power output from both legs instead of one that does half a job, but is only about 15% cheaper.25% off your first MyProtein order: sign up via https://www.myprotein.com/referrals.lis ... EE-R29Y&li or use my referral code LEE-R29Y0
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Buckles wrote:Better to get a power meter that measures power output from both legs instead of one that does half a job, but is only about 15% cheaper.
Disagree as this only leaves Rotor Power and pedal based systems as options. Quark, P2M, and even the mighty SRM only measure the drive side with no issue.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0 -
Disagree with that, SRM and similar systems are able to measure through the whole pedal stroke, as both cranks affect the spider, where's stages just measures on a single crank and doubles it.0
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JackPozzi wrote:Disagree with that, SRM and similar systems are able to measure through the whole pedal stroke, as both cranks affect the spider, where's stages just measures on a single crank and doubles it.
My point is that only Rotor Power has non-drive side strain gauges.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0 -
Disagree with that, SRM and similar systems are able to measure through the whole pedal stroke, as both cranks affect the spider, where's stages just measures on a single crank and doubles it.
Could be wrong, but I don't think they actually measure. They might iterpolate. As has been said, you need strain gauges on both sides to measure.0 -
You have been misinformed.Grill wrote:Quark, P2M, and even the mighty SRM only measure the drive side with no issue.
The strain gauges are in the spider which is locate between the coupled cranks and chainrings, and hence are downstream of the cranks and so they measure the combined contribution from both cranks quite well.
A simple static test of the strain gauge torque readings by applying a known torque to either crank arm will quickly demonstrate this.0 -
Well that's not strictly true either, although you may not be aware of the variety of power meters that exist (there are over 20 brands). e.g. MEP and Axis cranks also have independent crank arm strain gauge measurement.Grill wrote:JackPozzi wrote:Disagree with that, SRM and similar systems are able to measure through the whole pedal stroke, as both cranks affect the spider, where's stages just measures on a single crank and doubles it.
My point is that only Rotor Power has non-drive side strain gauges.0 -
Alex_Simmons/RST wrote:
You have been misinformed.Grill wrote:Quark, P2M, and even the mighty SRM only measure the drive side with no issue.
The strain gauges are in the spider which is locate between the coupled cranks and chainrings, and hence are downstream of the cranks and so they measure the combined contribution from both cranks quite well.
A simple static test of the strain gauge torque readings by applying a known torque to either crank arm will quickly demonstrate this.
Thanks for clarifying. So where exactly are the strain gauges located in the Rotor Power cranks?English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0 -
Stages measures the torque applied to the left crank with a strain gauge on the left crank arm, and the rotational velocity (once per revolution) of the left crank arm using accelerometer. This is used to calculate a left side crank power value.stoobydale wrote:Disagree with that, SRM and similar systems are able to measure through the whole pedal stroke, as both cranks affect the spider, where's stages just measures on a single crank and doubles it.
Could be wrong, but I don't think they actually measure. They might iterpolate. As has been said, you need strain gauges on both sides to measure.
Stages then assumes the total power = 2 x the left side measured power.0 -
Each crank arm had 4 strain gauge sensors.Grill wrote:Alex_Simmons/RST wrote:
You have been misinformed.Grill wrote:Quark, P2M, and even the mighty SRM only measure the drive side with no issue.
The strain gauges are in the spider which is locate between the coupled cranks and chainrings, and hence are downstream of the cranks and so they measure the combined contribution from both cranks quite well.
A simple static test of the strain gauge torque readings by applying a known torque to either crank arm will quickly demonstrate this.
Thanks for clarifying. So where exactly are the strain gauges located in the Rotor Power cranks?
I also forgot the Factor power cranks also have independent crank arm measurement, so that's four power meters I'm aware of that do this.0 -
Stages measures the torque applied to the left crank with a strain gauge on the left crank arm, and the rotational velocity (once per revolution) of the left crank arm using accelerometer. This is used to calculate a left side crank power value.
Stages then assumes the total power = 2 x the left side measured power
My answer was not worded very well. I was more referring to the spider based power meters not actually measuring the left hand side power but interpolating the torque applied to the right hand gauges via the bottom bracket and left hand side crank arm. But from your previous answer, I stand corrected.
I was aware of the Stages assumption of doubling the LHS to give a total output. But from initial reviews it seems that this is not really an issue as the figures are repeatable. Wich surely is the main thing at this price point. In your opinion, how much would you rate as a feature, L/R balance? Of the very few people I know with a power meter with this ability (3 people) they do not rate it at all. But we are just everyday blokes that enjoy some sociol riding and a bit of racing in the summer.0 -
Just to show how confusing this issue can be. Here's a quote from DCRainmakers website,Estimated Left/Right Power: This became all the rage over the last 18 months or so, starting with the SRAM/Quarq RED unit offering left/right power. That platform works by essentially splitting your crank in half and assuming that any power recorded while pulling up is actually coming from the left side, whereas pushing down is from the right side. Thus, an estimation. It’s good, but not perfect. Note that even with true left/right power (below), there’s actually very little in the scientific community around what to do with the data. While you may think that perfect balance would be ideal – that hasn’t been established. And some that have looked into it have found that trying to achieve balance actually lowers your overall output. The only thing folks agree on is that measuring left/right power can be useful for those recovering from single-leg injury.
Actual or True Left/Right Power: This is limited to units that can measure your power in more than one location. Thus why we see it on pedals, as well as the more expensive crank-arm based power meters. You can’t measure it directly at the spider, instead you have to measure it upstream of that.0
