I discovered yesterday riding out in Shawnee Mission, KS that even in my granny up front, the 25 cog in back was quickly reached, and I was really struggling on the surprisingly large hills (our first ride out that way) in my very lowest gear on my new-to-me Trek Pilot. I'm used to riding my Bike Friday, which was built for touring with mountain gearing (12-34) in back plus the smaller wheels, giving a tiny low gear that can get me up just about anything other than straight vertical.

The Terry Isis I rode back in 2003 had 12-27 in back, so I am wondering if I could have the 25-tooth cog changed to a 27t on the Pilot with no derailleur change, anyone know? I know that only gives me one more gear, but that's exactly what I needed yesterday!

Also, at the same time, I'd like to have the "cheater brakes" (don't know what they're officially called) removed from the handlebars. I never use them, and the bars are narrow enough (36cm) that I really can't ride on the top at all with those brakes installed.

Is this an easy DIY or something I should have the LBS do?

Thanks!