Replace the square taper BB like for like regardless of chain set (going on commuting hybrid so longevity and maintenance free) or do I get the recommended axle length for the chainset in the correct shell width?
I am thinking recommended axle length…

This is the one I am thinking of… Cheap and cheerful 🙂

So to clarify, you’re asking “Shall i buy the wrong one again, or get the correct size this time?”…

Edit: so you’re looking at replacing the chainset? I wouldn’t bother, personally. Get yourself a UN55 bottom bracket, and forget about it for another decade.

ST axle length determines your chainline, so yes get the correct BB for the chainset.

Duffer – Member
So to clarify, you’re asking “Shall i buy the wrong one again, or get the correct size this time?”…

No, I am replacing a chainset and BB that has lasted 11 years and I haven’t had to replace before, the original set has riveted rings that are well beyond their best so I can’t swap them, 14 quid for the lot seems OK. UN 55 is already on the list though, along with a chain and cassette.

As I suspected neilwheel, quick measure and get it ordered then 🙂

Ok, i understand now.

Unfortunately, it looks like you’ll need to replace the lot. Personally, i’d stick with Square Taper, but that’s a choice for you to make.

Something like this would suit, plus another tenner for the BB. It would mean you can replace the rings individually in the future.

I am sticking with square taper as it just goes on and on, and the one I linked to is 42 big ring and I want 48… Although it is hilly round these parts… and the kids are getting heavy in their trailer with their bikes on longer rides… but that FSA one would keep the 48 for commutes but drop two teeth for the trailer/granny ring…

Decisions decisions…

At the lower end, it’s actuallly chaper to replace the entre chanset, than replace just the rings. Those rings will be steel and last for ages. And for a commuting chainset, you’ll probably hardly use the granny ring, if ever.

Stoffel, the steepest parts of my commute are properly steep, second gear in the car jobs, it’ll get used even before a 2 and 4 year old need a lift on a road section, or need to bail into the trailer with their bikes at the end of a ride 🙂

£14 worth of solid steel crank paired with UN 55 bomb proofness wringing it’s way from Germany shortly. Just couldn’t justify anything more bling!