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I have an old 2001 Schwinn Homegrown Pro that I want to upgrade to a 10-speed drivetrain. I'd like to do it myself as a learning exercise, but I'm not sure what kind of tool I need to remove the old bottom bracket (or to install the new one, for that matter). The crank is a Deore XT Hollowtech FC-M751, but I am not sure what the bottom bracket is. The original specs of the bike are at this page

http://www.bikepedia.com/quickbike/BikeSpecs.aspx?year=2001&brand=Schwinn&model=Homegrown+Pro#.Upj1FMRDspU

But it lists the bottom bracket as "unspecifed." It's dark in color and has inside-facing splines, but there are no obvious markings on it.

So, what do I need in order to remove this?

Bottom bracket

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For this kind of thing your best resource is usually the Park Tools web site. They have guides for most bike maintenance procedures, including details on what tools you need for what brands, etc. –  Daniel R Hicks Nov 29 '13 at 21:30
    
You could also buy any one of a number of bicycle repair manuals (Zinn and Park Tools are two of my favorites.) –  WTHarper Nov 30 '13 at 14:53
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1 Answer

up vote 5 down vote accepted

As this is an older octalink crankset/BB you will require a:

  • Crank Extractor like this to remove the cranks.
  • Bottom Bracket tool like this to remove the bottom bracket.
  • Dust cap removal tool (if it has these) like this
  • 8 or 10mm hex wrench for crank bolts.

This is likely to require a lot of effort to free up after 12 years so I'd recommend a repair stand.

For fitting a new 10 speed crankset (at Deore, SLX, XT etc level) it's likely you'll need to move to a threaded external bearing BB such as Shimano BB70 which will probably come with the crank set you purchase. This requires:

  • External bottom bearing tool like this to install the bottom bracket and no other tools.

I was on the Park Tools site so used their tools as examples, many brands make similar tools. They also have a good reference section to learn how to work on a bike here.

Personally I would recommend trying to borrow the tools to remove the BB from your LBS rather than purchasing new as the standard for mountain bikes has changed to (many different) external bearings systems. It may end up you purchase them for this job and never use again....

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Or join a bike co-op if you have one in your area. –  Batman Nov 29 '13 at 22:00
    
I would just turn the bike up-down for this procedure (no need of a repair stand). It gives you pretty nice access to serve BB. –  Alexander Dec 1 '13 at 5:23
    
I think you'll struggle with getting leverage to undo a BB that's been in place for 12 years outside of a stand. The plastic cup will be easy but the cartridge may well be fused. –  DWGKNZ Dec 1 '13 at 7:05
    
Standing the bike upside down is also a violation of rule #49. velominati.com/the-rules/#49 –  DWGKNZ Dec 1 '13 at 7:09
    
In my experience, a really fast BB is best removed with a long lever while the bike is standing on its wheels. This way, you could even consider using you bodyweight for leverage. –  arne Dec 3 '13 at 9:26
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