View Single Post
Old 09-15-07 | 05:33 AM
  #18  
piper_chuck's Avatar
piper_chuck
Senior Member
 
Joined: Aug 2007
Posts: 562
Likes: 0
From: Columbia, SC
Originally Posted by Jakeelserpiente
I'm not quite sure but my guess is around 90.

I know this is a pretty general question, but is the general consensus that when on a flat section of road one should be in the big chainring?
If you ride at 12 mph on the flats then the big ring is probably inappropriate. OTOH, if you're cruising at 22, then the big ring is probably necessary. It all depends on your speed. Have you used Sheldon Brown's Bicycle Gear Calculator? I've found it helpful to plug in my ring sizes, tires, and cassette and then select MPH at my target cadence in the "Gear units" selection box. This gives a chart that allows you to see what speed you would be at for each gear combination. I used this information to figure out that for the riding I do, and plan to do, a triple was more appropriate than a compact. Here is an example I ran for a compact crank, 700x23 tires, and 12x27 cassette.
HTML Code:
     50    34
27  13     8.9
24  14.7   10
21  16.8   11.4
19  18.5   12.6
17  20.7   14.1
16  22     15
15  23.5   15.9
14  25.1   17.1
13  27.1   18.4
12  29.3   19.9
piper_chuck is offline  
Reply