Bicycle Mechanics - Campy chainrings on Shimano Crank?

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krems81
04-29-08, 06:10 PM
Hi,

I have a 135bcd shimano dura ace crankset, and since campy's chainrings are all 135bcd, I'm wondering if its normal and kosher to put campy chainrings on this crank? Would there be any compatibility issues?

Thanks,
Brian


HillRider
04-29-08, 06:37 PM
I have a 135bcd shimano dura ace crankset....
Thanks,
Brian
Are you very sure about the BCD on those Dura Ace chainrings? Every Shimano outer and middle road chainring and crank I've ever seen has a bcd of 130mm except the compact rings which are 110 mm. I've never seen any Shimano cranks with a 135 mm bcd.

LWaB
04-29-08, 09:19 PM
Shimano has never produced a 135 BCD crank.


krems81
04-29-08, 10:07 PM
Interesting. I will have to remeasure. Thanks.

urbanknight
04-29-08, 10:23 PM
Interesting. I will have to remeasure. Thanks.
Or if you have chainrings on the crankset right now, see if the BCD is stamped like it usually is.

Peter Jon White
04-30-08, 06:52 AM
Since their introduction in the early 1970s Dura Ace cranks have had 130mm bolt circle chainrings. There is not now nor has there ever been any 135mm Shimano chainring.

HillRider
04-30-08, 07:18 AM
Or if you have chainrings on the crankset right now, see if the BCD is stamped like it usually is.
I'm not sure about every maker but I know neither Campy nor Shimano stamp the bcd on their chainrings. The rings are engraved with the maker's name, the tooth count and, more recently, whether for 9 or 10-speed but no bcd value.

If you are not sure, you have to measure the distance between bolt holes carefully and look up or calculate the bcd from that.

forensicchemist
04-30-08, 08:41 AM
and if I recall, Campy 130 BCD is not the same as Shimano 130 BCD: 1 bolt is slightly offset on the Campy making you use only campy chainrings.....

HillRider
04-30-08, 09:02 AM
and if I recall, Campy 130 BCD is not the same as Shimano 130 BCD: 1 bolt is slightly offset on the Campy making you use only campy chainrings.....
Right idea but the wrong details. Campy does not, and AFAIK has never has made 130 mm bcd chainrings.

What you are thinking of is Campy's compact cranks with a nominal 110 mm bcd. Campy made the bolt circle 110 mm like everyone else BUT offset one bolt a bit so their rings wouldn't fit on any other 110 mm crank and no other 110 mm chainrings would fit on a Campy compact crank. Cute huh?

Again, IIRC, they only did this for the Record and Chorus compact cranks. Centaur, etc. did use a standard 110 mm bcd and would accept other makers rings.

K6-III
04-30-08, 09:17 AM
The only other manufacturer that commonly uses 135mm BCD is Miche.

forensicchemist
04-30-08, 10:11 AM
Right idea but the wrong details. Campy does not, and AFAIK has never has made 130 mm bcd chainrings.

What you are thinking of is Campy's compact cranks with a nominal 110 mm bcd. Campy made the bolt circle 110 mm like everyone else BUT offset one bolt a bit so their rings wouldn't fit on any other 110 mm crank and no other 110 mm chainrings would fit on a Campy compact crank. Cute huh?

Again, IIRC, they only did this for the Record and Chorus compact cranks. Centaur, etc. did use a standard 110 mm bcd and would accept other makers rings.

Yea, thats what it is.....thanks HillRider....I knew there was something there, just not positive what it was. Thanks for clearing it up...

spin-n-grin
04-30-08, 12:16 PM
and if I recall, Campy 130 BCD is not the same as Shimano 130 BCD: 1 bolt is slightly offset on the Campy making you use only campy chainrings.....

Heard the same, but don't remember from where. One of the holes is millimeters shy of a perfect bolt circle.

forensicchemist
04-30-08, 01:04 PM
Heard the same, but don't remember from where. One of the holes is millimeters shy of a perfect bolt circle.

Re-read Hillriders post...he's got it right.