<p>I don't know, but if I were you, what I would do is put the big ring in the 53 and the rear at about 25 or 24. Have a cadence sensor and spin at 90rpms until the effort feels equivalent, at that gearing, as it does on the road. If its too hard to spin at 90, loosen up the torque, too easy, tighten a bit. Wait a bit for the tire to warm up. The key would be using the same setup each time , same gearing and rpms to produce a similar result. Once you are dialed in, then you can put it in a harder gear for the workout. That's what I did, until I got my computrainer.</p>