I'd like to ride 100 miles on my FG bicycle. I have run several marathons (26.2 miles) and a couple of ultramarathons as well (50km). I haven't run that far though since October 2011.

Any advice as far as training? I'd like to do it this Fall if possible, but I can wait until next year if need be.

My longest rides right now are only about 15 miles max. I don't stop because I can't continue though. I just stop because I went where I needed/wanted to go, and back.

I'm familiar with hydration and nutrition and electrolytes - from my ultrarunning experience. I probably need to figure out how not to get chafed on a bike though. Do I need to do a couple 50's before embarking on a hundo? What's the best way to prepare? I don't want to set any speed records, just cover the distance in a reasonable amount of time.