I have a bc500 bicycle

Hi jayster

Here are the configurations for your bc500 wheel size

Circumference in millimeters/1.6093;circumference in millimeters
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
27 X 1 3/8 1349 2169
27 X 1 1/4 1343 2161
27 X 1 1/8 1339 2155
27 X 1 1333 2145
26 X 2.125 1286 2070
26 X 1.9 1276 2055
26 X 1.5 1234 1985
26 X 1.25 1213 1953
26 X 1.0 (559 mm) 1189 1913
26 x 1 (650C) 1213 1952
Wide Tubular 1316 2117
Narrow Tubular 1308 2105
26 X 1 3/8 1288 2068
24 1191 1916
24 x 1 1089 1753
20 X 1.75 (406) 927 1491
20 X 1 1/4 (451) 1005 1618
17 x 1 1/4 838 1325
16 x 1 3/8 797 1282

For other configurations check this site out and plese let me know if it was helpful .
LInk Site : http://www.sheldonbrown.com/cyclecomputer-calibration.html