compact chainset

radiation man

at the moment my bike has a triple chainset 50 39 30 and rear cassette 26- 12 im thinking of buying a new carbon bike with compact chain set 50 34, sometimes on long sportives i end up using my 30 26 up the last steep hills, so to match this with a compact will i need a 34 28 .

ju5t1n

You can compare gear ratios here… http://www.bikecalc.com/gear_ratios

keef66

With a 34t chainring a 29t rear sprocket would get you virtually the same gearing as your current 30 x 26.

28t should be close enough though.