Cervelo R5ca crankset options & Build Specs

Discuss light weight issues concerning road bikes & parts.
rauce
Posts: 2
Joined: Fri Jun 15, 2018 10:44 pm

by rauce

Campag 46mm BBright cups have plenty of meat to them and could be turned down to fit the direct fit R5ca. If the THM cranks don't work out I could do the mod for you (I have a lathe at home) and I also have my own R5ca to test fit.

by Weenie


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wheelsONfire
Posts: 2987
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

Are you sure you're going to use LOCTITE 609????
Have you even read through diassembly method for this compound?

For Disassembly
1. Apply localized heat to the assembly to approximately
250 °C. Disassemble while hot.
For Cleanup
1. Cured product can be removed with a combination of
soaking in a Loctite solvent and mechanical abrasion
such as a wire brush.

I hope you see the problem here?
Anyway, i have never ever heard anyone recommend a locking compound or any chemical in conjunction with "direct press" bearings.
This should not be needed. The bearings should have such a tight fit that they sit fixed in place.

Cleaned BB, a good press and then bearings nothing else.
The "grease" mentioned by Cervelo was only if you have creaking sound.
The fit of bearings should be extremely precise.
Bikes:

Ax Lightness Vial EVO Race (2018.12.21)
viewtopic.php?f=10&t=156137
Paduano Racing Fidia (kind of shelved)
Open *UP* (2016.04.14)


Ex bike; Vial EVO D

Andres
Posts: 66
Joined: Mon Mar 09, 2009 10:10 am

by Andres

hambini wrote:
Sun Feb 03, 2019 10:39 pm
Andres wrote:
Sun Feb 03, 2019 1:44 am
wheelsONfire wrote:
Sun Feb 03, 2019 12:27 am
Francois_Viviers wrote:
Sat Feb 02, 2019 8:17 am
FSA 386 EVO require a specific spacer set for BBright that can be hard to find, but not impossible. the normal spacer set will just make the whole set up slightly too wide and turning crank will have some resistance. As a side note, Hambini BBright BB also does not work with 386evo cranks
First of all, the frame doesn't use, or rather, couldn't use a BB Right system as suggested.
It's just 2pcs 6806 bearings (30*42*7 bearings) you press directly into the frame.

But back to Hambini, why wouldn't his BBright work with 386evo cranks?
BBright is 79mm isn't it? BB 386 is 86.5mm... so what do i miss here?
They'll work, with the correct spacer configuration. The original 3D+ Rotor that was used on a lot of these frames is essentially a 386 crank. The rotor has the preload nut that takes up some room in the non-drive side, so if the crank doesn't have that, you need to make up for whatever space the 11mm spacer in the drive side doesn't take up.

This issue is the centreline.

My bottom brackets are designed for a spindle that is 90.5mm. True BB386 cranks are 86.5mm. So they will not go in.

Additionally, if you try and fit a BB386 (86.5mm) crank into a 79mm BBright Bottom bracket the chainline will need some adjustment as it has 45mm embedded in the non drive side of the frame.

The confusion arises because newer cranks are called "BB386" but have a much longer axle, the axle length is often 92+mm. It is in effect an extended BB30.


Hope that helps
Hambini
Sorry I meant to reply to the person talking about the FSA 386 crank... your 30mm bearings (42x30x7 or so) would press into the frame fine I would think...

Any BB386evo would work on a BBright frame with the correct spacers and PF30 BB, or a Kogel BBRight 386 type BB, it would not work with the BBRight specific BBs like yours unless it's a BB386/392 like the SRAM power ready cranks.

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