Speed is relative term. The big chain ring will increase the distance per revolution, it will also decrease the torque. If you turn high RPM's in the smaller chain-ring you can achieve similar speeds.
Let's do an example:
1. Front Chain-ring = 39, rear cog = 14, RPM 105, Speed will be 22.35298295 mph at the roll out (2050 or 80.7") I programmed into my Excel spreadsheet.
2. Front Chain-ring = 53, rear cog = 19, RPM 105, Speed will be Speed will be 22.38314892
mph at the roll out (2050 or 80.7") I programmed into my Excel spreadsheet.
That's pretty darn close. Study your math and gearing. There is nothing to fear.
I try to avoid the big chain ring early in the season and work on keeping my RPM's higher (85 to 110). I'm old and have always allowed my knees and legs time to adapt, (4 to 6 weeks indoors or outdoors). Then I gradually add gears and my body is ready for the added stress.
| current weight: 192.0