Edco Competition Triple inner chainring BCD?

[daddyduca]

I have an Edco Competition Triple chainring set from the late 80s. Slowly the innermost, granny chainring is wearing out and it's time to replace it. Friends have told me the BCD of this is non-standard, i.e., not 74mm. Does anyone know the BCD, and who else might have made one that size (unfortunately Edco died years ago).

 

[one-eyed_jim]

Edco are still in business:

http://www.edcoengineering.nl/

I'm not sure why their web site is now .nl, but edco.ch redirects there too.

There was an edco-SAPIM connection a few years ago, and I've got a pair of very nice edco hubs that are Rigida branded, so maybe there's been some corporate to-ing and fro-ing.

In any case, if you have access to the cranks, it would help if you could measure the bcd yourself. Measure between the centres of two adjacent bolt holes and multiply by 1.7

The only edco cranks I've seen were more recent than yours (mid nineties), doubles, and used 130mm bcd.

 

[daddyduca]

Edco Competition Triple inner chainring BCD

Dear Jim, Thanks a lot! I'm going to contact Edco about a replacement ring. Using your formula, the inner chainring BCD turns out to be 85mm.
Cheers, DD

 

[one-eyed_jim]

Re: Edco Competition Triple inner chainring BCD

Using your formula, the inner chainring BCD turns out to be 85mm.

Could that be 86mm? - that used to be quite a common bcd in the eighties. Stronglight rings are still around in that fitting:

http://www.spacycles.co.uk/products.php?plid=m2b0s149p0

 

[daddyduca]

Dear Jim,

You must be right about 86mm. Thanks a lot for the link!

 

[Tommi74]

I might have some NOS EDCO Chainrings lying around at home. They are dark grey anodized. I also have a left crankarm, black with red inscription. I can check when I´m back from my holiday. But posting from the netherlands is a bit more expensive.