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Discussion Starter · #1 ·
I just bought a used 2003 Epic frame, and the Brain shock can wiggle 1/4" at the vertical blowoff valve. I haven't ridden it yet, but it looks like the vertical part of the shock will knock against the left seatstay.
Is this "play" normal for the brain shock?

I dismantled the rear end to check it out, and the the asymmetrical link there are 3 thin washers. From left-to-right, here are the order of components:
Top shock mount -- washer -- asymmetrical link -- washer -- frame -- washer -- asymmetrical link.
Is this sequence correct? I don't feel like this end of the shock is the culprit.

The bottom end of the shock is attached with a 4mm allen fitting that I can't for the life of me figure out how to undo; the allen wrench can pass all the way through and it looks like it's made out of one piece. If I had to guess, I'd say that this end of the shock is where all of the looseness is based.

So, Epic owners: Is it normal to be able to grab the brain and shake it 1/4" from side to side? Does this create noise on the trails? Does anyone put some form of padded in between the Brain and the left seatstay?

Thanks!
 

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Discussion Starter · #4 ·
How much resistance should I feel?

OK, I just took another look at the shock...

When I wiggle the shock, the tip of the brain moves through a range of exactly 1/4".

Regarding resistance, I feel essentially none as I wiggle the brain. I can very easily make a rattling sound.

I was in a bike shop today and checked out an 06 Epic. The bottom shock mount is different from my 03. Anyway, the 06 Brain probably moves through a range of 1/8"-3/16", and feels like there's much more damping/resistance than mine.

Is my behavior typical of the earlier models, or does it sound like there's something wrong? I may have to pay my LBS to check it out...
 

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Sounds normal...

as Damion days. I just did the maintenance rebuild of the rear end of my 2003 Epic (bearing repacking etc.) and there was less play at the shock after I put everything back together. There should be some play, don't worry much about it, unless it seems excessive.

Enjoy the bike.

Cheers,
Cristian
 

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There should be a small foam pad stuck (about a cm or so in diameter) on the side of the brain to keep it from knocking against the seatstay. It is not thick (1mm) and does not prevent the shock from wiggling, but it does damp the "knock" onto the seatstay.
 
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