Originally Posted by
bicycleflyer
Sheldon Brown's website has a universal calibration chart of sorts. I am assuming you need the circumference in millimeters. So if you go to that chart you see there is no 700X47. You need to split the difference between 700X44 (2224) and 700X50 (2293). That will get you (2259)
The answer ... 2259
http://sheldonbrown.com/cyclecomputers/index.html
It's interesting to compare the
Sheldon Brown's table to the table in the
Sigma's 1606L manual
-- there are
significant differences in the numbers (circumference in millimeters) for the same wheel sizes.
Sheldon Brown's table:
700x18C 2102
700x
20C
2114
700x
23C
2133
700x
25C
2146
700x
28C
2149
700x
32C
2174
700x
35C
2205
700x40C 2224
Sigma's table:
Tire Size Miles Km
700 X 44 1382 2224
700 X 38 1355 2180
700 X
35 1347
2168
700 X
32 1339
2155
700 X
28 1327
2136
700 X
25 1308
2105
700 X
23 1302
2097
700 X
20 1296
2086
Why?