Gain Ratios?

[katonk]

I need some help with the gear ratio on my single speed bike. As some of you know, I recently purchased a singlespeed commuter road bike to replace my “road duty” hardtail. The setup on my new bike isn’t working for me. My average speed has gone up by about 2 MPH, but my average heart rate has gone down significantly. At around 20 MHP I simply can’t maintain the needed cadence. It’s pretty much flat where I ride; only very short climbs.

The 26” bike had 2.35” tires at 42x15 and 175mm cranks. The 700c bike has 25c tires at 39x16 and 172.5mm cranks.

Whenever I need information on gears I go to Sheldon Brown’s (RIP) site. Using his Gain Ratio calculator my 26” bike had a gain ratio of 5.4, but the 700c bike has a gain ratio of 4.7. If I ran 44x16 on the road bike, I’d be at a gain ration or 5.3. Close enough.

My question’s are:

Is this “gain ratio” thing for real?

Was I running too high of a gear ratio on the hardtail?

Does 44x16 on the road bike seem reasonable?

Anyone have any other clues they’d like to loan me?

[bighit8]

If you can keep a cadence of 80rpm use what ever gear ratio that takes. If you are pushing a heard gear and doing 20mph and heart rate goes down, your cadence is slowing down.

[OffRoadie]

Don't over think it. If you're spinning out, put a larger gear on. 39x16 is on the low side. Most people recommend starting at around 42x16. 44x16 for a flat area would be great.