BB replacement help

[User]

 

[kyuss]

I reckon the spacer on your current one is just shimming the BB out to 118mm. If it's on a geared bike I wouldn't imagine the 0.5mm will make much difference anyway. Parker's have the UN54 in 118 for £9.

What chainset is it for? Sheldon has a good chart for what length axle you need for specific chainsets which might be worth checking out if you're unsure.