Hi All,
New to this so bear with me. Riding a CB sportXC (yeah, I've never seen another one !}. I've looked on the shimano website to check up on all the bits fitted but whats confusing me are the specs. Yeah I understand largest rear sprocket (34t)/smallest rear sprocket (11t/ max. differential on front chain ring (20t).But how do you work out the "total capacity"(43t). I'm thinking when I need to, to go bigger on the front (52-42-34)plus mega range rear cassette(34-11).

Plus as an aside, Are Shimano moving away from 7 (21) speed bikes ? 'Cos everything seems to be 8/9/10 speed rears 'n I've got 7 speed controls

Total capacity is worked out by-

Take the smallest ring at the fron from the biggest ring

Take the smallest sprocket at the rear from the biggest

Add these two numbers together.

So I would imagine you have a 42 big and 20 small on the front and 34 big and 11 small on the rear?

(42-20) + (34-11) = 45

thanks for that h.r.p..
I know the the bike was built "down" to a price but I like it 'n it fits me. Now to find some calliper brake pads that hit the rim of 700c wheels without dragging on tyres or missing rims on bottom edge :.((

P.S. have 48/38/28 front and 28-11 on rear, but yeah I now understand the maths so my derailleur will cope with going up a step.

P.P.S. Can you still get derailleur protection cages (I fall off a lot, especially when white van man attacks me !!!)