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Getting your (Shimano) bearings …
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Getting your (Shimano) bearings …

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Getting your (Shimano) bearings …

Page Type: Article

Activities: Cross Country, Downhill, Mountain

 

Page By: BeDrinkable

Created/Edited: Apr 2, 2011 / Apr 2, 2011

Object ID: 280382

Hits: 3969 

Page Score: 75.81%  - 6 Votes 

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Intro and stuff.

So, say you (like me) have a Shimano external bottom bracket. And say you (like me) have noticed a little grinding recently. And say you (like me) hate to spend money on what should be maintainable equipment. Out of luck, right? Au contraire mon frere! (In US English that translates to, “I don’t think so, chump!”) With a little creativity and some patience these are just as serviceable as any other bottom bracket.

Procedure

Step 1: remove the cranks. Whatever issues I may have with Shimano, I have to admit that they try to make things as user friendly as possible. Removing these cranks is no exception. A tip here: if you don’t feel like buying a special tool to remove the end cap from the crank, you can wedge a pair of needle nose pliers in there and get it out. If you ruin the thing, replacements are only a couple dollars.
Crank, removed!
Removing the crank arms


Step 2: remove the plastic shim / dust cap. This is the trickiest step. The easiest that I have found is to use a long, narrow screwdriver. Wedge the end in from behind and gently tap around the back of the cap until you can get a grip on the front. From there just pull it out with your fingers. Take care! These are not designed to be removed and so are a little brittle. 
Dust seal removal
Popping off the dust cap
 
Dust seal
Plastic dust seal, off













Step 3: Remove the rubber seal from the bearing. It works best to use a small, narrow tool. I used a small eyeglass screwdriver. A paper clip might also work.
Bearing seal removal
Removing the bearing seal


Step 4: pack the bearing with your choice of grease! A synthetic works best. If you have the urge, Phil Wood and (I think) Hope both make well regarded bottom bracket grease. They run you a little more, but may be worth it to you. I like Pedro’s, but Park is probably just as good.

Reassembly

Pretty straightforward. Just reverse the steps! As with disassembly, use caution when inserting the plastic shim / dust cap. If you press it in crookedly, it could crack. A flat piece of wood could be handy.
Bearing, repacked with grease.
Bearing, regreased

So go out and give it a try! Even if you mess it up, what have you lost? 20 minutes and a piece that you were going to throw away anyway. Also, you can use these steps to get at the bearings themselves, if you decide you want to keep the BB and slap in some Enduro bearings.

Images

Bearing seal removalBearing, repacked with grease.Crank, removed!Dust seal removalDust sealCrank removal

Comments


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Viewing: 1-5 of 5

WasatchvoyageGreat article.

Voted 10/10

This one will come in very handy, I've got a Deore XT BB on the Giant right now which will need an overhaul probably within the year. Thanks for putting this one up!
Posted Apr 3, 2011 12:50 am

BeDrinkableRe: Great article.

BeDrinkable

Hasn't voted

Glad it might help. It sure is nice to be able to resurrect equipment rather than tossing it.
Posted Apr 4, 2011 9:55 am

Andy LivoEveryone

Andy Livo

Voted 10/10

has the spring bug. Bike maintenance!!! I find that Bullshot is the best grease I have used. Think they still make it? I bought a huge tub about 8 years ago and its still half full!
Posted Apr 3, 2011 9:39 am

RayMondoBullshot

RayMondo

Voted 10/10

If you've 1/2 a tub left, then you can't be riding enough!

Though I can say the same for myself, and my tub is even smaller, and that's no Bullsh*t !
Posted Apr 10, 2011 1:11 pm

Andy LivoRe: Bullshot

Andy Livo

Voted 10/10

Well with the Chris King headset and Hope bearings I rarely use the stuff these days!!!
Posted Apr 10, 2011 2:59 pm

Viewing: 1-5 of 5