To help give you a 'real world' perspective of gearing, the supplied 42/20T gives a low gear of 30.1GI and a high of 92.1GI (and a whole lot of usable range in between) - the low gear being slightly smaller than the 34/30T combo we used on last years' CdF and the high limit ensuring you’ll not be spinning out and running out of gears too quickly. A true chameleon of a bike and amazingly versatile bike - light touring, commuting duties, heck, there's even clearances for CX knobblies!