I did the DIY thing with my Marin San Rafael bike. I purchased the bionx 250 from nycewheels (don't recommend them for their patchy customer service - missed mo

I did the DIY thing with my Marin San Rafael bike. I purchased the bionx 250 from nycewheels (don't recommend them for their patchy customer service - missed most of last year's riding season thanks to them). My commute is about 12 miles each way with some big hills. Getting the kit allows me to easily do the commute both ways in a day. It left me pretty dead before. Was it worth it? To me, yes. Riding the bike is FUN. If you miss the strenuous workouts do what I did Saturday, and turn the motor off for all or part of your ride. The bionx 250 maxes out at about 17 mph for me. It really makes a huge difference on the hills. With my battery enclosed in one of those nylon 'trunks' you can't even really tell it is an electric bike without looking closely. But this thing is a couple years old now and I'm sure isn't state of the art anymore. If I was buying today I'd definitely look at the non-kit, pre-built options. I spent hours getting everything the way I wanted it--enjoyable hours for me, at least.