Lightest bb386 power meter? (measures both sides)

Discuss light weight issues concerning road bikes & parts.
alcatraz
Posts: 1234
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Hi WWs

What bb386 power meter is the lightest without choosing small niche brands?

What happens with the chainline when installing a bb386 crank (86mm) on a bb30 frame (68mm)?

Will a quarq spider found on a pf30/bb30 sram red crank fit a bb386 sram crank? Or are the spiders different?

Thanks /a

mrlobber
Posts: 767
Joined: Sat Oct 23, 2010 9:36 am
Location: Where the permanent autumn is

by mrlobber

1) Hard to tell because you haven't said whether you're talking about BB386 crank or BB386-compatible crank. If both, then, for instance, also Shimano 9100-P comes into play, which in turn factors in chainring choice on other spider based PM's. Or, depending on your current pedal choice, you might even be able to go lighter overall with Vector 3 and simply choose the lightest standard crank out there. So narrow down the choices first slightly ;)

2) Nothing wrong with that, if the crank had a, say, Q factor similar to Shimano DuraAce (which a pretty standard crank to install in a BB30 frame, with appropriate bearings and spacers, of course), chainline would also be
Retired bikes: Cervelo S5 2015 / Felt AR FRD 2014 / Cannondale SS HM 2014 / Scott Addict SL 2014 / Scott Plasma Premium 2014 / Orbea Orca 2008 / Look 596 /

by Weenie


alcatraz
Posts: 1234
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

You're right.. but considering a compatible crank is heavier because of the larger BB and the heavier axle, that would defeat the purpose of the question, no?

But since it's been mentioned. How heavy is a 9100P crank 50/34 170?

Quarq/p2m/etc.. do they weight about the same?

I'm running xpresso 12 pedals @160gr. How much are vector 3's?

/a

Jian81
Posts: 36
Joined: Mon Jun 15, 2015 1:29 pm

by Jian81

I can answer your third question.
AFAIK, most important thing it is to check if the Spider is NHB or HB, 110BCD or 130BCD. Your chainrings must match your Spider in both ways.
Regarding frame compatibility, i have emailed SRAM directly regarding this as well. However, i am currently on a bb86 frame and wanting to swap to a BB30 frame. I have both the regular BB30(Alloy silver spindle) Sram Red crankset and the BB386 BB30(Black spindle) Sram Red crankset. Bear in mind that i have not yet tried it but will be doing so soon as im changing frames.

Here's my question and their response,

Me:
Hi
I recently purchased a BB386 Sram Red 2018 Crankset 30mm Spindle diameter with an installed Quarq Dzero Spider NHB. Both of which are currently installed on a BB86 frame.
I also own a regular BB30 Sram Red Crankset HB.
My question is, if in the future i decide to shift to a BB30 frameset(currently on a BB86 frame). Can i simply swap out the BB386 LEFT crankarm for the BB30 LEFT crankarm while still continuing to use my RIGHT Sram Red crankarm with Quarq Dzero Spider?
My visual observation seems to me that they are the same other than the different spindle length.
Thanks

SRAM USA:

Hello,

Yes, this swap is possible. The spindle length is the difference between these cranksets.
Regards,
SRAM USA
www.sram.com
Service and Technical Documents:
www.sram.com/service
Learn more about The Power of Bicycles: www.worldbicyclerelief.org

alcatraz
Posts: 1234
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

NHB or HB. Are these model numbers? Have you observed any difference in design?

About the swapping of the left arm between a bb30 and bb386 crank would not be very wise since the bb30 arm usually arches outward from the frame. A bb386 arm would be comparatively flat. Isn't the spindle stuck to the left arm on sram 30mm cranks?

I imagine that apart from the right arm being closer to the frame than it should be, you might get chainrings touching the frame.

Thanks for writing!
/a

mrlobber
Posts: 767
Joined: Sat Oct 23, 2010 9:36 am
Location: Where the permanent autumn is

by mrlobber

Vector 3's are 320g. If you're running Time Xpressos, obviously, the pedal based PM penalty is higher than average for you.

From P2M, the lightest BB386 setup is FSA KForce Light Compact, ~570...580g. Quarq DZero Compact is ~540..550g (chainrings excluded).
Retired bikes: Cervelo S5 2015 / Felt AR FRD 2014 / Cannondale SS HM 2014 / Scott Addict SL 2014 / Scott Plasma Premium 2014 / Orbea Orca 2008 / Look 596 /

Jian81
Posts: 36
Joined: Mon Jun 15, 2015 1:29 pm

by Jian81

alcatraz wrote:
Wed Jan 24, 2018 11:26 am
NHB or HB. Are these model numbers? Have you observed any difference in design?

About the swapping of the left arm between a bb30 and bb386 crank would not be very wise since the bb30 arm usually arches outward from the frame. A bb386 arm would be comparatively flat. Isn't the spindle stuck to the left arm on sram 30mm cranks?

I imagine that apart from the right arm being closer to the frame than it should be, you might get chainrings touching the frame.

Thanks for writing!
/a
NHB=Non Hidden Bolt, HB=Hidden Bolt. Yes as the name suggests, the 5th bolt is the difference. NHB means 5th bolt hidden. Just make sure u get a compatible Chainring. For Sram theres a NHB and HB specific chainring. For other brands they are usually NHB. I own a Praxis Road Buzz which is both NHB and HB compatible. The crank arm is compatible with both NHB and HB so no worries(make sure its the one with the removable crank arm and spider)

As for the left crank arm, BB30 and BB386 are the same, both are arched outwards from my observation which got me thinking why couldnt i just swap them out and so i enquired SRAM which confirmed it was possible. Both have the spindle attached to the left crank arm. Only difference is the spindle length.

As for the right crank arm, ive placed them side by side, on top of one another and compared. They are the same in terms of the overall space of the right crank arm from the frame though the BB30 version arches from the spider more than the bb386 version but this is normal since the bb386 version has the removable Quarq Spider which takes up more space, which results in a crank arm with less arch compared to the bb30 version. The bb30 version is a one piece crank arm.

However, although theoretically and as confirmed by SRAM in my email exchange it would work, i would bring it to my LBS and see how it goes. If it doesnt, worse case i would just need a FSA bb386 spacer or some sort to fit my bb386 version.

glepore
Posts: 1156
Joined: Thu Mar 28, 2013 4:42 pm
Location: Virginia USA

by glepore

Recent Sram rings have both NHB and HB pin locations, and can be used either way. You put a plug in the unused hole. Dzero spiders are not interchangeable between Hb and NHB configurations, Quarq Red spiders are only usable with Red crankarms, but Elsa's and Rikens can be mounted either way using Force crankarms.
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

pdlpsher1
Posts: 1688
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

As a frame of reference, my newly acquired Quarq DFour BB30/BB386 170mm with 50/34 rings came in at 719 grams. It's not the lightest out there but reliability and accuracy has been solid. The numbers track my previous power meter which was a Quarq Red GXP. My GXP weighed 700 grams with rings.

dudemanppl
Posts: 764
Joined: Fri Feb 22, 2013 5:09 am

by dudemanppl

Just a heads up, SRAM gave you the incorrect information about the BB386 and BB30 cranks. They are NOT compatible with eachother.

Jian81
Posts: 36
Joined: Mon Jun 15, 2015 1:29 pm

by Jian81

pdlpsher1 wrote:
Wed Jan 24, 2018 6:58 pm
As a frame of reference, my newly acquired Quarq DFour BB30/BB386 170mm with 50/34 rings came in at 719 grams. It's not the lightest out there but reliability and accuracy has been solid. The numbers track my previous power meter which was a Quarq Red GXP. My GXP weighed 700 grams with rings.
Are you using it on a BB30 frame? Does it require any additional spacer to get it to fit? I bought my Quarq Dzero spider and Sram Red bb386 crankset separately. I dont think i saw any additional spacer.

alcatraz
Posts: 1234
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Bb386 cranks are compatible with bb30 frames but they don't come with spacers.

You have to get the spacers separately. They are usually provided with the bottom brackets but then in a type of bottom bracket designed to be used with bb30 frames and bb386 cranks. (not normal bb30 bottom brackets)

/a

pdlpsher1
Posts: 1688
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

I have a T47 BB which has the same dimensions as a PF30 I think. My DFour came with spacers and I used them. I think you just leave the spacers out when using it on a BB386 BB.


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SixThirteen
Posts: 37
Joined: Sat May 24, 2014 11:49 am

by SixThirteen

alcatraz wrote:
Wed Jan 24, 2018 6:19 am
Hi WWs

What bb386 power meter is the lightest without choosing small niche brands?

What happens with the chainline when installing a bb386 crank (86mm) on a bb30 frame (68mm)?

Will a quarq spider found on a pf30/bb30 sram red crank fit a bb386 sram crank? Or are the spiders different?

Thanks /a
You could consider the the ZPider from ZWatt which I have on my CAAD9. Its a BB386 native crankset and tries to measure both sides. No idea about lightest, with 52/36 rings and the adapter below came in around 900g

https://shop.teamzwatt.com/product/team ... wer-meter/

You buy your chosen rings in the same shop

It uses the BB386 to BB30 adapter https://shop.teamzwatt.com/product/fsa- ... o-adapter/. Just to note that the reducers says "BB30A" on them, when they are just plain BB30.

Easy to fit according to my mechanic, works well, chain line is OK etc.

Dual ANT+ / BT so you can capture data on both Garmin and Strava. Sends power and cadence.

HTH

Six13

by Weenie


Jian81
Posts: 36
Joined: Mon Jun 15, 2015 1:29 pm

by Jian81

Came back from my LBS, SRAM indeed gave wrong information, very disappointed. The left bb30 crank arm is not compatible, u will need to use the bb386 version spindle and a 13mm Drive Side spacer.

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