30mm bearings in bb86 frame

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hambini
Posts: 580
Joined: Tue Nov 15, 2016 8:13 am
Location: Cologne, Germany

by hambini

TheKaiser wrote:
Fri Nov 09, 2018 11:20 pm
hambini wrote:
Fri Nov 09, 2018 10:22 pm
The load rating for a 4130 bottom bracket is ~25% of that of a bottom bracket that uses 6806 bearings (BB30/PF30/BB386)


Hambini
Good to see you back! Always appreciated your sharing of tech data like your 25% figure above.
:D
Hambini Aeronautical Engineer, Polluting YouTube since 2016 - views expressed are my own...

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lewolive
Posts: 160
Joined: Tue Dec 04, 2012 4:10 pm
Location: Gien, France
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by lewolive

hambini wrote:
Fri Nov 09, 2018 10:22 pm
Even if your bottom bracket doesn't creak. You will get significantly reduced bearing life and stiffness. The load rating for a 4130 bottom bracket is ~25% of that of a bottom bracket that uses 6806 bearings (BB30/PF30/BB386)

If you have the option, I would consider a different crankset. Shimano deliberately designed BB86 to stop people using 30mm cranksets

Hambini
Maybe... But I have the chance to have 2 bikes with BB86:
-One Canyon Ultimate CF SLX with 41/30 CyclingCeramic bearings and Rotor 2Inpower
-One Aeroad with first the original Shimano BB86 and a Dura Ace 9000 crank. I have upgraded to BB86 41/24 CyclingCeramic

The 1st generation of 41/30 had 2 ranges of balls and it was lightly less smooth than the 41/24 Cyclingceramic. But the 41/30 CyclingCeramic was a lot smoother than the original 41/24 Steel Dura Ace.
On the next generation of 41/30 CyclingCeramic, there is one range of balls and I cannot say if 41/30 Ceramic is better than 41/24 Ceramic. Overall I prefer 41/30 because I have better feelings with a 30mm Rotor crank at 1600W than with a Dura Ace.
But 30mm cranks are not only more rigid, there are a few of them competing for lightness first. So, I think 41/30 is not a marginal product.

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