New powermeter rumours

Discuss light weight issues concerning road bikes & parts.
kulivontot
Posts: 1170
Joined: Sun May 16, 2010 7:28 pm

by kulivontot

kthx.

Peterson
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Joined: Sun Jan 04, 2009 7:33 am
Location: Denver, CO

by Peterson

I use a powertap and I am considering a stages.

I'm sure everyone has some leg power asymmetry, but who trains to even their leg power?

As a former competitive powerlifter, or perhaps anyone that seriously lifts weights, there is some strength asymmetry but this lessens with training and not something I have seen any competitive lifter need to address.

Who with a srm/quarq/vector trains to fix their leg asymmetry - probably not too many.

glepore
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Location: Pa USA

by glepore

I've had PT, SRM, and now stages. If you're training with the PM and not doing rehab, and if you're not doing under 1 min intervals, I see no reason not to use the Stages. It is consistent, and that is what you really need; it may have some issues with very short sprint intervals, but since these are usually performed all out, I don't consider this a practical limitation. The ability to use any wheelset at a low cost, temp compensation, and easy swap are all significant pluses. The only minuses I can see is the cost of changing crankarm length, and for the impatient, the 4 week delivery time.
Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

g32ecs
Posts: 143
Joined: Thu Apr 11, 2013 2:50 am

by g32ecs

Has anyone seen any deals on Stages (for less than their retail price)?

I'm interested in a Ultegra crank.

Nebby
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Joined: Tue Aug 20, 2013 12:53 am

by Nebby

g32ecs wrote:Has anyone seen any deals on Stages (for less than their retail price)?

I'm interested in a Ultegra crank.


I think your only chance to find them for less than retail would be ebay and/or used. With how new the PM's are along with the fact that most if not all of the cranks are still on backlog, it's highly unlikely they'll start marking them down anytime soon.

glepore
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Location: Pa USA

by glepore

Yeah, ebay is the key. I almost bought a SK01 to part out to get a used Ultegra 170 stages and the Di2 but decided it wasn't worth the trouble. Stages has a backlog, because, I believe, they build to order. If you need a 172.5 contact me, I might want to go back to 170, Mine's a DA, but one side of yor bike would look cooler :)

I think Stages might ultimately have to drop their price a bit, as pressures are downward. I'm interested to see if Garmin comes out with a single sided vector at around a grand, that would really change the market.
Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

g32ecs
Posts: 143
Joined: Thu Apr 11, 2013 2:50 am

by g32ecs

ahh, I'm going to try my chances during Christmas. I think I'm going to need it 1st week of Feb for an 8 week training block.

the Shimano arms are interchangeable correct? now that I think of it I don't really mind a mismatch.

unfortunately I need a 165 which is hard to find. they do list that size though.

glepore
Posts: 1090
Joined: Thu Mar 28, 2013 4:42 pm
Location: Pa USA

by glepore

The road arms are interchangeable, the xtr not.
Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

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Rob81
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Joined: Fri Nov 07, 2008 1:54 pm
Location: Northern Italy close to Gavia and Mortirolo
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by Rob81

Garmin (Italy) gave me the chance to test Vectors pedals,
here's my rides/test and comparisons so far in a sort of daily "diary": http://goo.gl/cXoCWA

bricky21
Posts: 1405
Joined: Tue Sep 14, 2010 3:28 pm

by bricky21

Peterson wrote:I'm sure everyone has some leg power asymmetry, but who trains to even their leg power?

As a former competitive powerlifter, or perhaps anyone that seriously lifts weights, there is some strength asymmetry but this lessens with training and not something I have seen any competitive lifter need to address.

Who with a srm/quarq/vector trains to fix their leg asymmetry - probably not too many.


The trouble with single leg measuring has nothing to do with training asymmetry. It has to do with accuracy. Especially if asymmetry varies over the course of a ride, different intensities, and or day to day.

maquisard
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Joined: Thu May 01, 2008 8:51 pm
Location: France

by maquisard

bricky21 wrote:... Especially if asymmetry varies over the course of a ride, different intensities, and or day to day.


Which studies indicate it does! Well said.

bricky21
Posts: 1405
Joined: Tue Sep 14, 2010 3:28 pm

by bricky21

There is info out there about pedaling asymmetry. It's the whole basis for things like spin scan, and independent leg power meters such as Garmin Vector. These questions are not just dreamed up. Perhaps someone with better resources could provide some links.

From our testing we have found that there is not a large variation from a riders left to right leg while riding. We make the assumption that your right and left leg’s are doing the same amount of work and double the left leg’s power.


For some that is good enough. For others, me included it isn't since it goes against everything I've ever understood about pedaling symmetry limited as it may be.

In my eyes a better question is were are the studies to show that asymmetry doesn't have a significant effect on power analysis as Stages claims?

glepore
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Location: Pa USA

by glepore

Well, you can look at the DC rainmaker review, where he ran PT, Quarq, Stages and then Vector side by side and logged the data. The only significant difference seemed to be for very short intense bursts. For doing 1 min, 4 min 20 min intervals, it would seem to be perfectly acceptable.
Cysco Ti custom Campy SR mechanical (6.9);Cannondale SS Evo Di2 7970 (5.79); Willier Cento Uno Air Di2 9070 (7.0); C40 Mk2 DA 7800 ; Anvil Custom steel Etap;1996 Colnago Technos Record

eric
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Location: Santa Cruz, California, USA
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by eric

Apparently DCRainmaker doesn't have significant asymmetry. If I knew that for sure about myself, Stages would be a reasonable alternative for me. If I didn't know it, then I'd be guessing. If for example you had a consistent 48/52% split you'd already be outside the typical 1.5% accuracy range.

Does that matter? If your asymmetry is consistent then you would have power data that is precise but not accurate. Depending on what you do with it, that may be ok. But you'd have to know that your asymmetry was consistent and did not change with power output, position changes, training, etc. Everything we know about asymmetry says it does change with at least power output and position changes, and I'd expect it to change if you spend time working on your pedalling form. If your asymmetry changes significantly your power data is neither precise nor accurate.

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Mario Jr.
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by Mario Jr.

Exactly. My Rotor Power showed that I have a 45/55% L/R balance. This is confirmed by a Garmin Vector I tried. But this will explain why my former P2M powermeter showed 6-8% more power than the Rotor, as that would have assumed that my left leg was doing the same work as the right.

For the record, my balance evens out when I all out.

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