I'm starting to build up my mileage (saddle time) and I'll be using the rollers with some outside time plus weights.
The bike I'll be using on the rollers doesn't have a computer so no mph or cadence. I can normally keep a cadence above 90 rpm. How can I do intervals on the bike? Please no suggestions of counting my rpm for 10 seconds and multiplying as I can't do it (I've tried). Also it will be a while before I get the computer back on the bike.