Originally Posted by
susanrm
Could you please clarify why a mountain bike derailleur would help so much? I know my friends on mountain bikes climb hills much easier...
It's the gear ratio. The bigger rear cog you have, the easier it is to pedal up hills. You just won't go quite so fast.
The mountain bike rear derailleur is necessary to shift onto a 32 or 34 tooth rear cog. A road derailleur will rub on a rear cog that size.