Hey! I have two bicycles. This post is about my first one: A 1985 ST400 touring bike by Cannondale. My other is a 2012 Cannondale, but this post is not about that one.
My crank length is 172.5mm, the tire is a 27 x 1 1/4" (32-630), and my chainring is 50/45. The freewheel gears are 13/16/19/23/28/34. The weight of the bike is 24 lbs. Components are all Shimano 600.
I'm generally on the small ring, second-smallest freewheel ring. That means for me to maintain 20mph, I have to do 87 rpm's. If I kept it on the same freewheel ring and just put the chainring on the 50 tooth one, I could maintain 20mph with a cadence of 78.
Using my present bike:
Goal:
22mph - 45/13 @ 78 rpm
50/16 @ 86
23mph - 50/16 @ 90
45/13 @ 81
24mph - 45/13 @ 85
50/13 @ 76
25mph - 45/13 @ 88
50/13 @ 79
26mph - 45/13 @ 92
50/13 @ 83
27mph - 50/13 @ 86
28mph - 50/13 @ 89
29mph - 50/13 @ 92
30mph - 50/13 @ 95 (hi)
Quickly obvious from the chart above is that my ideal gear for 22 mph is either 50/16 or 45/13. Also obvious is that for anything higher than 23 mph that the big has to be used up front with the smallest freewheel in back.
My method of execution suggests I should just keep the chain ring on the 50 gear and the freewheel ring on the 16 and work on cadence. If I'm going 78 my cadence is too slow anyway. So, if I work on the 50/16 cadence at 80+, I can stay there in a wide window until my cadence hits about 90 rpm. At that point (or going downhill), I can switch the freewheel gear to the 13. At 90 rpm on the 50/16 I'll be going 23 mph, so I've got a good year of riding until I should think about the 50/13. Once I do, I'll have to make sure my cadence starts at a minimum of 79 rpm. This will get me to 25 mph.
Note:
At 17-19 mph, my best gear is 50/19.
At 20-22 mph, my best gear is 50/16.
At 23-25 mph, my best gear is 45/13.
Anything over 25 has to be 50/13, though.
My crank length is 172.5mm, the tire is a 27 x 1 1/4" (32-630), and my chainring is 50/45. The freewheel gears are 13/16/19/23/28/34. The weight of the bike is 24 lbs. Components are all Shimano 600.
I'm generally on the small ring, second-smallest freewheel ring. That means for me to maintain 20mph, I have to do 87 rpm's. If I kept it on the same freewheel ring and just put the chainring on the 50 tooth one, I could maintain 20mph with a cadence of 78.
Using my present bike:
Goal:
22mph - 45/13 @ 78 rpm
50/16 @ 86
23mph - 50/16 @ 90
45/13 @ 81
24mph - 45/13 @ 85
50/13 @ 76
25mph - 45/13 @ 88
50/13 @ 79
26mph - 45/13 @ 92
50/13 @ 83
27mph - 50/13 @ 86
28mph - 50/13 @ 89
29mph - 50/13 @ 92
30mph - 50/13 @ 95 (hi)
Quickly obvious from the chart above is that my ideal gear for 22 mph is either 50/16 or 45/13. Also obvious is that for anything higher than 23 mph that the big has to be used up front with the smallest freewheel in back.
My method of execution suggests I should just keep the chain ring on the 50 gear and the freewheel ring on the 16 and work on cadence. If I'm going 78 my cadence is too slow anyway. So, if I work on the 50/16 cadence at 80+, I can stay there in a wide window until my cadence hits about 90 rpm. At that point (or going downhill), I can switch the freewheel gear to the 13. At 90 rpm on the 50/16 I'll be going 23 mph, so I've got a good year of riding until I should think about the 50/13. Once I do, I'll have to make sure my cadence starts at a minimum of 79 rpm. This will get me to 25 mph.
Note:
At 17-19 mph, my best gear is 50/19.
At 20-22 mph, my best gear is 50/16.
At 23-25 mph, my best gear is 45/13.
Anything over 25 has to be 50/13, though.
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