dave66
03-20-2007, 07:24 AM
it is time to replace the chainring on my fixie. what i used to do is bring the dead ring into my LBS and pick one with same bolt pattern but i will be ordering on line this time so i want to be sure i get the right size.
how do i measure to verify i get the correct xBCD?
wat are the satandards? i assume theire is a
mtn standard
road [shimano] standard
road [campy] standard
compact [which i do not want] standard
it is to replace the stock ring that came on my fuji track rig - would i be pretty safe just ordering a 48T SS ring?
Dave Hickey
03-20-2007, 07:33 AM
it is time to replace the chainring on my fixie. what i used to do is bring the dead ring into my LBS and pick one with same bolt pattern but i will be ordering on line this time so i want to be sure i get the right size.
how do i measure to verify i get the correct xBCD?
wat are the satandards? i assume theire is a
mtn standard
road [shimano] standard
road [campy] standard
compact [which i do not want] standard
it is to replace the stock ring that came on my fuji track rig - would i be pretty safe just ordering a 48T SS ring?
BCD
MTN 110mm
shimano 130
Campy 135
compact 110?
Track 144
Track(old) 151
What is the crankset on your bike now? Your Fuji has either a 130 or 144 bcd. It also might have a 1/8" chainring instead of a 3/32"
FatTireFred
03-20-2007, 07:35 AM
it's easy... BCD = bolt circle diameter. On a 4-bolt, measure between 2 non-adjacent bolts, center-to-center. On a mounted 5-bolt, you can measure BB bolt to a chainring bolt, again center-to-center, and multiply by 2. If not mounted measure between 2 bolts and go to a table like those on SheldonBrown/HarrisCyclery.
FatTireFred
03-20-2007, 07:37 AM
BCD
MTN 110mm
shimano 130
Campy 135
compact 110?
Track 144
Track(old) 151
What is the crankset on your bike now?
there are others, don't forget triples like 110/74, 94/58, 104/64, etc.
dave66
03-20-2007, 08:13 AM
i knew i came to the right place!
Tytelynes
03-21-2007, 07:56 PM
If you have access to a digital caliper (just get one! They're just too handy NOT to own!) put the inside jaws in one bolt hole, zero the caliper, then measure two holes, furthest radius to furthest radius. That is the centerline to centerline distance.
Easy huh? :thumbsup: