Power2Max HUGE Price Drop!

Discuss light weight issues concerning road bikes & parts.
jever98
Posts: 811
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

Hi silver,

the MTB Type S is still a way off, first the road models will start :-). It's too early to comment on the versions, but the first ones will very likely be the Rotor ones, because they are so versatile and a great combination of weight, stiffness, and value.

The Hollowgram is a nice crank, but I can't comment yet if there will be a model or not. On the downside stands that it's a very expensive crank and only fits BB30 or PF30, limiting its utilization.

Cheers
NIcolas
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DMF
Posts: 1062
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Location: Sweden

by DMF

The non-P2M FSA Gossamer cranks fits with a Shimano HT2 bottom bracket (as far as I know...), would that be true for the P2M FSA Gossamer too? I would really like one, but MegaExo bottom.brackets are just a total deal breaker (would be using it with a Hope BB), and would be reason enough to go with Stages instead.

Also, what is the accuracy like on max efforts, i.e 1700w? Not for repeatability but for actual numbers? Would it still be +/-2% of an SRM or a WattBike or similar, or close enough to get something one might claim is close to the truth?

by Weenie


jever98
Posts: 811
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

@DMF: You can fit a FSA Gossamer in a Shimano BB, but it's a bit of a tight fit, since the Megaexo standard is marginally different. The power2max and not power2max FSA Gossamer don't differ in terms of axle standard.

The accuracy doesn't differ on max efforts or non-max efforts. The only things that change are the torque and cadence.

Hope that helps!

Cheers
Nicolas

PS: Side note - if you are concerned about accuracy, a single leg system will always be less accurate, unless the power contribution from both legs is always exactly the same. For me personally it varies up to 3% depending on the type of riding and bike - probably due to marginal differences in pedaling style and position. A power meter that measures one side with 2% accuracy would then drop to 5% accuracy because of this variation.
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DMF
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Location: Sweden

by DMF

Thank you Nicolas, very informative! Just wanted to make sure there wouldn't be some spider interference or equal, not that I know why there would be. But best to be sure before dropping the cash.

I realize there may be a left/right leg difference not acknowledged by a single sided PM, just as long as the power spikes doesn't throw off the numbers unreasonably, like say 15% off :)

Will certainly opt for a Gossamer P2M for next season. The Stages is similar price for just Rival NDS crank arm with PM, but as I already have a RED chainset, I will get that one left over for another bike when going with P2M. Seems more beneficial.

mentok
Posts: 509
Joined: Sun Jan 01, 2012 9:58 am

by mentok

@jever98: can the road rotor 3d+ spider be installed on a mtb rotor 3d+ crankarm?

thanks :)

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

by g32ecs

Can I fit the Rotor3D in a Shimano HT2 BB86?

I'm not sure if there's anything that P2M did to hinder this combination.

dha
Posts: 163
Joined: Tue Jun 12, 2012 4:40 pm

by dha

I think that will fit having looked into it. There is the newer "shimano" version coming out early next year (?) with the ability to fit the 4 bolt rings so you would assume it will fit shimano BB standards too.

jever98
Posts: 811
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

@mentok: unfortunately that won't work, because MTB cranks have a longer axle, so the geometry will be off.

@g32ecs: BB86 frames need to be checked for compatibility - the outer diameter of the bottom bracket bore mustn't exceed 53mm - which is very rarely the case. For the new Type S this figure will increase to 57mm (except on SRAM crank models).

Best
Nicolas
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KWalker
Posts: 5845
Joined: Mon Dec 28, 2009 8:30 pm
Location: Bay Area

by KWalker

DMF wrote:The non-P2M FSA Gossamer cranks fits with a Shimano HT2 bottom bracket (as far as I know...), would that be true for the P2M FSA Gossamer too? I would really like one, but MegaExo bottom.brackets are just a total deal breaker (would be using it with a Hope BB), and would be reason enough to go with Stages instead.

Also, what is the accuracy like on max efforts, i.e 1700w? Not for repeatability but for actual numbers? Would it still be +/-2% of an SRM or a WattBike or similar, or close enough to get something one might claim is close to the truth?


To chime in here I've been on one for around 4 months now with about 350hrs on the unit. I've used multiple Quarqs, SRMs, and PTs and its almost identical across the board vis-a-vis the other crank based meters with 1 important caveat- its much more stable in terms of temp/elevation drift.
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kode54
Posts: 1162
Joined: Tue May 23, 2006 9:39 pm

by kode54

will there be a version of p2m for the THM M3? which has a removable spider.
- AX Lightness Vial EVO D + DA9150 + Enve SES 3.4 carbon hubs
- Parlee Altum + DA9150 + Enve SES 4.5 carbon hubs
- Parlee ESX + DA9150 + THM SRM PM + Enve SES 6.7 CK hubs
- Independent Fabrication Ti FLW + DA9100 + Enve 3.4 CK hubs

jever98
Posts: 811
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

@kode54: unfortunately not. It doesn't fit because of the little star-shaped structures that protrude from the crank arm.
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Sabella
Posts: 26
Joined: Sun Aug 08, 2010 2:55 am

by Sabella

Hi , i´m from Brasil and i want to buy a power2 max, where can i buy one?

mentok
Posts: 509
Joined: Sun Jan 01, 2012 9:58 am

by mentok

jever98 wrote:@mentok: unfortunately that won't work, because MTB cranks have a longer axle, so the geometry will be off.



@jever98: by this do you mean that: 1) the spiders don't match, 2) the power2max won't report accurate data, 3) the chainline will be poor, 4) the bottom bracket is not compatible.

this is for a singlespeed mtb application so #1 and #2 are my only concerns - so long as the spider splines can fit any rotor crank (mtb or road) and that the spider reports correct data regardless of the crankarms it is attached to, i'm cool with it.

thanks

jever98
Posts: 811
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

@mentok: the road spider can be mounted on the MTB fork, the interface is the same, but the geometry will be off. Accuracy will not be affected. What kind of single speed application do you have in mind? The BCD might be challenging.
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by Weenie


mentok
Posts: 509
Joined: Sun Jan 01, 2012 9:58 am

by mentok

@jever98: I'm currently running an old wired mtb SRM professional on my singlespeed which is essentially just one of their old road compact spiders (5 bolt 110bcd) with an adaptor plate on the inside to support a middle and small ring (74 and 56bdc i believe). because the cranks carry a "road" offset, you need a very wide bb to get enough Q to clear the stays (my bb is 126 octalink which is near to impossible to replace). so yeah, all my nice SS rings are 110bcd 5-bolt. also, i run a 130bcd on my road bike and I really like the idea of having a 2nd, compact spider that i can swap onto my road bike for hilly rides as required.

thanks for your help, you've told me everything i need to know. I'm confident enough at this point to take the risk and give it a go. I'll report back when i eventually get it done (probably closer to xmas) to confirm whether or not it actually works. Thanks :D

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