# Bushnell vs Co-Motion Eccentric BB?



## ptfmb71 (Mar 22, 2004)

I posted this on the Singlespeed forum, but thought your guys may know also

I'm going to buy one of the EBB above and would like to know if anyone has one they like better? From what I understand the Bushnell is lighter and has a good reputation, but the Co-Motions says theirs is easier to adjust.

thx


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## [email protected] (Feb 24, 2007)

*Eccentric Shootout...*

I'm using each of those eccentrics. I have the Bushnell in my off-road tandem and the Co-Motion on my road tandem.

When the Bushnell gets dirty it doesn't like to release when I loosen it. But, the way it expands as a whole - it doesn't seem like it would wear on the inside of the bottom bracket shell in any one spot. And it only has one bolt to loosen - even though I often have to whack on it several times to get it to let go (sort of like releasing the wedge in an old quill stem). Sometimes tightening it or loosening it requires a heavy hand, which I don't like.

The Co-Motion eccentric requires easily loosening 4 bolts (2 on each side) - but once they are loose the eccentric easily rotates. It doesn't seem to care if it gets dirty. It has two skinny wedges in it - and while it hasn't made any marks inside the bb shell in the year I've been using it, I could imagine it making marks in the long run, since the eccentric itself doesn't expand - just the two little wedges. And you don't have to overtighten it - it doesn't take much to make it stay put.

I'd say it's a draw - but I like the Co-Motion one better because of its simplicity.


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## TandemNut (Mar 12, 2004)

Henry,
Are you greasing up the Bushnell between the shell halves and the wedges? I haven't had one need banging on to loosen before. 
I don't think either one wears on the front bb shell enough to be an issue before many other age-related issues would end the serviceable life of a tandem frame (the same could be said for me as well...)


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## [email protected] (Feb 24, 2007)

*Got grease?*

Alex,

Hey there!

Yeah, taking the Bushnell apart and cleaning it - then greasing the wedges helps for sure. But - and maybe it's the Bend, Oregon moons dust that gets in everything and my habit of washing my bike too much - it still seems to need more TLC than the Co-Motion.

My wish list includes trying a Co-Motion eccentric on my Ellsworth Witness to see if it stays maintenance free once I'm riding it off road. I like it better for the road tandem - but that tandem doesn't see much dirt riding! : )

So my experiences might not be a fair comparison for these two eccentrics...

Henry


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## itsdoable (Jan 6, 2004)

BigNut said:


> Henry,
> Are you greasing up the Bushnell between the shell halves and the wedges? I haven't had one need banging on to loosen before...


Likewise. Unless the c-clip on the bolt is broken/missing, you should not have to bang a bushnell eBB loose.


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## TandemNut (Mar 12, 2004)

[email protected] said:


> Alex,
> 
> Hey there!
> 
> ...


Well, I gotta admit, I have no experience with moon dust contamination, Oregonion or otherwise...
Just out of curiosity, what chain lube are you using in these sort of conditions?
Thanks


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## [email protected] (Feb 24, 2007)

*Moon Dust...*

I'm using a local favorite, which is DuMonde Tech Green (the thicker stuff). A little goes a very long way. And it keeps my chain from being dried out by the Martian Death Rays!


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