BB386 power meter options

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MarginalChains
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Joined: Thu May 05, 2016 10:08 am

by MarginalChains

Hi everyone,

I am building an AX Lightness Vial Evo Ultra set up, and am looking for a lightweight power meter solution. I have a stages at the moment and would like to keep to something crank rather than pedal based as I want to keep using speedplays. I love the look of the THM Clavicula SE crankset but it doesn't seem to have any power meter compatibility unless you go for the SRM M3 version which adds a huge chunk of weight.

The lightest option I have found so far would be to use an FSA k force light with a stages carbon arm (around 580g as far as I can tell for 50/34 with 172.5 cranks).

Does anyone have any other ideas or suggestions?

Thanks!

Nefarious86
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by Nefarious86

How heavy is the p2m option?
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MarginalChains
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Joined: Thu May 05, 2016 10:08 am

by MarginalChains

Nefarious86 wrote:How heavy is the p2m option?


About the same (576g) but without chainrings. So significantly heavier for the whole package it seems.

mlipfeld
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Joined: Mon May 09, 2016 2:53 am

by mlipfeld

What about the powertap chainring? But it's only for a compact setup

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MarginalChains
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by MarginalChains

mlipfeld wrote:What about the powertap chainring? But it's only for a compact setup

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Thanks for the recommendation. I did see this but ruled it out because it's a 150g weight penalty, and only available in 50/36 rather than 50/34 which I would really want.

I'm currently trying to establish if using a different (probably aluminium) stages left crank with the Clavicula right side would be feasible.

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zappafile123
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by zappafile123

The powertap chainrings will not fit an FSA K-force BB386 crank. Really they only fit lower tier, older model cranks - a totally redundant power meter release.

I have an FSA K-force BB386 p2m - its perfect as power meter, but it is heavy (cant remember how much it weighs exactly)... probably as heavy as the Ultra frame! I strongly encourage using a BB386 crankset for the 386 platform. Unless you use one, you're not going to get the full benefit of the system i.e. it wont be as stiff. I say, who cares about an extra 150g, get the right crank-set for your frame and a good power meter. Its still going to be an ultra-weenie bike.

If you have your heart set on a light crank based power meter, then your best bet is the THM SRM. But I hear SRM's dont work well with BB386 frames.
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Nefarious86
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by Nefarious86

P2M or SRM. Much cleaner than a hodge podge for a Stages.
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MarginalChains
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by MarginalChains

Thanks for the replies. Yes, I've discounted mixing and matching Stages, which at the moment leaves me deciding between the FSA/stages combination or the THM SRM. The THM has about a 80-100g weight penalty as far as I recall, but should be better as a PM and looks nicer IMO. But if (as Zappafile says) SRM with BB386 is unreliable, then that would negate the appeal of it for me. Does anyone else have any experience in that regard?

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pdlpsher1
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by pdlpsher1

IMHO when it comes to powermeters weight should be the lowest priority. Accuracy should drive the purchase decision. Currently I'm on the Quarq Red 22 PM and I have absolutely no issues with it. It's accurate and low maintenance. Battery life is extremely long which is a good thing since I ride a lot (10,000 mi. a year).

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zappafile123
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by zappafile123

Well, Quarqs 100% dont work with BB386 bottom brackets haha. You'll see a few BB386 bikes on here with SRMs. It works, I'm just under the impression that the tolerances are tight - they barely fit.
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Nefarious86
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by Nefarious86

https://www.power2max.com/northamerica/ ... nd-cranks/

Accurate, User friendly and without a sticker on the unit is almost indistinguishable from a normal spider IMO.
THM will be lighter but depending on location will mean down time for servicing etc.
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MarginalChains
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Joined: Thu May 05, 2016 10:08 am

by MarginalChains

I'm thinking now of possibly trying an AX morpheus with the K-force stages. It looks like it should fit. With chainrings this should come in around 480-490 grams I think. Does anyone know if the left arm fastening is the same on the Morpheus and the FSA style?

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