Bottom Bracket Bafflement

leehutch

Hi Guys,

I have been given a Giant ATC with a snapped bottom bracket. I have taken it out and now I am just wondering do I need to get the same one to go back in or can I get a different type as long as it is the same size?

Sorry for the amateurness of this post.

As well I will be getting a new crankset so old one doesn't need to go on new bottom bracket

It has AXEC 113/JIS engraved on it.

JBA

That's a standard square taper bottom bracket. You can replace it with anything the same size.

If you are going to get a new chain set as well then it's worth changing to an external, threaded bb such as Shimano HollowTech II.

leehutch

JBA wrote:

That's a standard square taper bottom bracket. You can replace it with anything the same size.

If you are going to get a new chain set as well then it's worth changing to an external, threaded bb such as Shimano HollowTech II.

Thank you for the reply, so is it an English thread?

And is 113 the size?

keef66

Yes, it'll be standard BS thread. And 113 is the length of the spindle. Which is only important if you're wanting to replace it with the same thing and a similar square taper chainset.

If you switch to something like a Shimano Hollowtech II the spindle is part of the chainset and the BB is a pair of outboard bearings / cups which screw in so you don't have to worry about size

billycool

As above, something like this:

https://www.wiggle.co.uk/shimano-deore- ... m-bracket/

or this if you want something higher spec:

https://www.wiggle.co.uk/shimano-saint- ... cket-cups/

You will need a BB removal tool as well like this:

https://www.wiggle.co.uk/park-tool-bott ... ool-bbt-9/

You can then fit some nice new cranks.

leehutch

BillyCool wrote:

As above, something like this:

https://www.wiggle.co.uk/shimano-deore- ... m-bracket/

or this if you want something higher spec:

https://www.wiggle.co.uk/shimano-saint- ... cket-cups/

You will need a BB removal tool as well like this:

https://www.wiggle.co.uk/park-tool-bott ... ool-bbt-9/

You can then fit some nice new cranks.

That’s brilliant thank you, are they all a standard size? will any English thread fit my bike?

I am thinking a 1x crankset, what would you recommend?

billycool

A 68-72mm crank should fit just fine as they are the standard size.

In terms of cranks - I personally stick with Shimano and SLX or XT are pretty good.

Something like this for 1x11:

https://www.chainreactioncycles.com/shi ... prod148289

It might be influenced by how many gears you run at the back as chainwidths vary.

What gears you got?

leehutch

BillyCool wrote:

A 68-72mm crank should fit just fine as they are the standard size.

In terms of cranks - I personally stick with Shimano and SLX or XT are pretty good.

Something like this for 1x11:

https://www.chainreactioncycles.com/shi ... prod148289

It might be influenced by how many gears you run at the back as chainwidths vary.

What gears you got?

Really sorry for the naive response it there are 8 cogs

Thanks for your response it was really useful!!

leehutch

I have just gone for a straight replacement to get the bike back on the road.

I have bought this from Halfords https://www.halfords.com/cycling/bike-parts/gears-drivetrain-cables/vp-bc73-68-x-113-square-taper-cartridge-bottom-bracket

Daft question but should the left side threaded part just pull off?

The Rookie

Yes it should, you screw in the right side (most of it) fully and tight, then the left side.collar which just locates that side and stops 'float'.