Bottom Bracket Service

[uclown2002]

I have a Cr-Mo axle 68mm x 118 mm BB on a Spesh Allez 2011 triple which has developed a little bit of play.
Is this the sort of thing that is serviced or replaced?
I think I have a crank extractor and a BB tool so looking to do myself educating myself in the process.
If I need to replace are there particular models you'd recommend?
Thanks guys.

 

[mrandmrspoves]

I think you almost certainly have a cartridge bottom bracket. They unscrew as a complete unit and are non serviceable. A basic Shimano replacement is only about £10 and in my opinion (I am sure some may offer a different view) quite acceptable. You may save an ounce by buying a Tiagra - but it will cost a lot more and probably not function better or last longer. Some recent bikes have gone over to press fit bottom brackets - for which you would need different tools - but I don't think your Spesh will be a problem.

 

[uclown2002]

Replace as above, they are cheapish and non serviceable. Two things:
The drive side undoes the wrong way.
If you use a bolt and big washer through the BB tool to stop it slipping, that can save a bit of grief.

Is this a square taper BB?
So a shimano UN55 be right one?

 

[Tim Hall]

Is this a square taper BB?
So a shimano UN55 be right one?

UN55 is a good choice. However you'll have to find out if you have a square taper one in there already. Take a crank off with your crank removal tool. If the axle is, umm, square in section, it's square taper.

Have a look at the Park Tools website for some good guides on how to do this.

 

[compo]

I have just fitted a UN55 BB on my Trek. One good thing is that it comes with a metal adapter ring rather than the usual plastic or nylon one. (I have had no problems with the plastic ones but still feel happier with a metal adapter.)

 

[uclown2002]

I got the cranks off with some difficulty but definitely a square tapered BB.

Ordered UN55 for £11.99 at CRC, so hopefully my BB tool in this kit http://www.chainreactioncycles.com/x-tools-bike-tool-kit-27-piece/rp-prod55964 will get the job done.

 

[mrandmrspoves]

Yes your kit comes with an ISIS (international splined interface standard) tool which can be used on a standard Shimano bottom bracket. Before you fit the replacement cartridge give the threads on your frame a really good clean and then grease well (or use anti seize) then screw the cartridge in by hand as far as you can - being careful not to cross thread it. Trying to remove a seized or cross threaded bottom bracket is a real pain - often involving chisels, scaffolding bars and grazed knuckles!

 

[uclown2002]

Yes your kit comes with an ISIS (international splined interface standard) tool which can be used on a standard Shimano bottom bracket. Before you fit the replacement cartridge give the threads on your frame a really good clean and then grease well (or use anti seize) then screw the cartridge in by hand as far as you can - being careful not to cross thread it. Trying to remove a seized or cross threaded bottom bracket is a real pain - often involving chisels, scaffolding bars and grazed knuckles!

Is there a knack to fitting the cartridge? Should I screw the drive side screw all the way in before fitting left side for example?

 

[mrandmrspoves]

No particular knack. Yes screw in from drive side (reverse thread so turn towards back of bike to tighten) When tight fit the left side which is not reverse thread so also tightens towards back of bike

This may help.....
.
View: http://www.youtube.com/watch?v=_Kf-V5iulaU