Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the February Giveaway for a Reflective Backpack & Spine Protector from RiderBag


Parts and tools for changing a bottom bracket
#1
How difficult is it, and what tools are needed, to change out a bottom bracket?
Dave

  Reply
#2
Hi Dave,
There are 3 common bottom brackets shown here:<br />
http://www.sheldonbrown.com/gloss_bo-z.html#bottom
Which one do you have?

  Reply
#3
I have to go look at the bike when I get home. It's a fairly new specialized tarmac, and suspect it is the cartridge type set up. I sure appreciate your assistance!
Dave

  Reply
#4
To remove your crank arms you'll need this tool:<br />
http://harriscyclery.net/itemdetails.cfm?ID=542
To remove the bottom bracket you'll need this:<br />
http://harriscyclery.net/itemdetails.cfm?ID=518
Once removed, you'll have to replace the entire bottom bracket. Unlike traditional bearing/cup units, the cartridge BBs are sealed, and meant to be replaced rather than serviced. Any good bike shop can match up your old BB and sell you a replacement. I'm hoping to do a video tutorial on this soon. Let me know how it works out for you.

  Reply
#5
Thank you! What a great resource!
Dave

  Reply
#6
Hi Alex. I'm replacing a sealed bottom bracket also. Do you know what the torque specs would be on a Shimano UN54? There's nothing in the box telling me how tight to install it.

  Reply
#7
Tighten it with about 360 inch pounds, which equates to 30 foot pounds, or 40 Newton Meters (Nm).

  Reply
#8
Thanks Alex. Both sides? The left side is a plastic piece.

  Reply
#9
Sorry... yes only the metal end. The plastic side just needs to be snug.

  Reply
#10
Excellent. Thanks very much.

  Reply
#11
Hi there

Can I revive this thread please - apols!

I ask, as there appears to be two different tools required to remove both cups of a standard Shimano cartridge bottom bracket....

I've just picked up an old Orange Prestige which I'm about to restore, and I was able to remove the non-drive side (I believe the bb had been installed back to front) using a Shimano UN74 tool and a 32mm spanner. However, there is a plastic cup left in the bb in the drive side, and the same UN74 tool is too big to fit into the splines on this cup - what model of Shimano tool do I need to remove the cup that remains?

It was a cheapo CS-21 sealed cart bottom bracket for identification.
  Reply
#12
It should be the same tool for each side.

Am I correct that you've removed the cartridge and now just have the old plastic cup stuck in the frame?

As it's a plastic part, you coould probably cut it and break it to get it out.
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Do you wave to other cyclists?
Yesterday 10:32 PM
need help
Yesterday 06:42 AM
PROPER HYDRATION WARNING!!!!
03-07-2021 11:22 PM
How to stay safe while biking?
03-07-2021 09:10 AM
Is Presta valve lock nut useful?
03-07-2021 01:11 AM
What size bike should I get?
03-05-2021 03:44 PM
Fausto Coppi Gilco frameset
03-04-2021 10:23 PM
Freehub body change compatibility
03-04-2021 12:17 PM
What kind of frame do I have here?
03-03-2021 01:07 PM
Sensah Empire road groupset
03-03-2021 08:47 AM

[-]
Top 5 Posters This Month
no avatar 1. Jesper
17 posts
no avatar 2. Painkiller
10 posts
no avatar 3. ILv2MTB
7 posts
no avatar 4. Criminal
7 posts
no avatar 5. JoJoJo
4 posts