BB30 outboard?

Discuss light weight issues concerning road bikes & parts.
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visse89
Posts: 7
Joined: Sun Jan 07, 2018 11:17 pm

by visse89

Hi, i have a bike with bb30(68mm) and im using a quarq with 30mm spindle that is 105mm wide if im right, so its need allot of spacers and i think it looks awful.
Is there a bb that can take that up? im finding allot for 30 to 24 but not sure about 30. i regret buying the 30mm, would have been more versatile with 24

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IrrelevantD
Posts: 353
Joined: Sun Nov 29, 2015 5:47 pm
Location: Near DFW Airport

by IrrelevantD

External bearing Bb30 24mm spindle. I have a Wheels Mfg thread together one on my Allez Sprint and love it.

Edit: just read that you need 30mm spindle. They have those too. You’re crank is what’s referred to as BB386.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.

by Weenie


alcatraz
Posts: 1229
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Get a bb386 bottom bracket for bb30 frames. 42mm outer diameter.

Make sure it's the kind that uses cups/external bearings. Not spacers like you already do.

You can expect a little more stiffness after. Also I think those spindles don't expect the bearing race positions to be that narrow so you will help the spindle by widening the bearings.

dudemanppl
Posts: 761
Joined: Fri Feb 22, 2013 5:09 am

by dudemanppl

Literally just use the spacers. They're 60g lighter and nobody cares because you have a Quarq.

TobinHatesYou
Posts: 1758
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

I suppose if you really want that minor aesthetic, C-Bear makes a couple of wide BB30 conversion BBs.

This “Rotor” one is the compatible model:
https://www.c-bear.com/en/products/bott ... 30mm-rotor

visse89
Posts: 7
Joined: Sun Jan 07, 2018 11:17 pm

by visse89

It looks like this now, maybe i should just live with it. c-bear could be a option, and enduro had one to. they are 150-220 euro, its a gravelbike so having ceramic bearings feels a little overkill
Image
Image
I also have the BB that came with the bike but no tool for it, its a praxis bb30/m30 i made it 30mm in both ends now.
I measure it to 94mm with bearing covers, so question is if it will work? i dont want to take what i have apart before i think it will work and i have the tools

alcatraz
Posts: 1229
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Just take the crank off and put it into that BB off the bike and see.

It's probably exactly what you need. Make sure all the parts are pressed together properly. The hub shell width is 68mm and so should the distance between the cups be as well. You can measure it with a caliper so you aren't giving up on the idea prematurely if the crank doesn't fit.

If it came with the bike and is 30mm then 99% chance is you're ok. Obviously it's not a bbright/bba or something like that.

I guess you don't need any spacers. That crank has a preload mechanism that can be replaced by a wavy washer too if you need more space. (Probably not a bb386 crank, but as they say "compatible")

/a

visse89
Posts: 7
Joined: Sun Jan 07, 2018 11:17 pm

by visse89

Thanks alcatraz, i took it off and had a try.

Image
I measured the cup to 69mm inside with a rubber ring to take up the last 1mm on NDS to fit on the 68mm frame.
First i had to modify the cup a little, it had one side that was 28mm, just a normal 6806 bearing with a ring inside it, i could take the ring out with a bearing press into it.
The bearings wanst to smooth so i decided to replace them with some sram bearings that i filled with some thick grease.
First i used 2 fsa bearing shields and there was a little play so i was thinking wave washer but then i remembered that the original crank had thick shields, the one in the middle standing had a thick rubber side that i guess was suppose to be like preload on DS.

Image
And with that is wasnt any side play but the NDS the bearing shield was rubbing against a snap ring that i guess was suppose to keep the bearing safely inside the cup on that side.

The original NDS bearing shield was 28mm so i could not use that one but it was made to work with the snap ring.
Either i had to turn the bb around cause if i used the thick one on NDS it would change the chain line.
But still turning it around i had to move the small rubber spacer that was making the cup fit to the frame to again not change chain line, maybe 1-3mm would had been okey if on lower end but i didnt want that.
Or get rid of the snap ring, so thats what i decided to do, if it works with bb30 not having them secure with snap rings i hope this will to, i could have used loctite on the bearings to keep them more secure but decided not to for now.

Image
Im happy with the result, it looks allot better, maybe not better but(maybe) as good at least.
Should have gone down the route before but my LBS told me it would not work.

alcatraz
Posts: 1229
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Looks good. Does it feel stiffer?

The industry claims a shortcoming of a bb30 shell is stiffness.

For small people I don't think it matters much, but extra is always nice. :D

by Weenie


TobinHatesYou
Posts: 1758
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

alcatraz wrote:
Thu Sep 13, 2018 5:29 am
Looks good. Does it feel stiffer?

The industry claims a shortcoming of a bb30 shell is stiffness.

For small people I don't think it matters much, but extra is always nice. :D

Probably hard for most humans to feel, but the wider spacing probably does nominally extend bearing life.

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