112mm chainring

[mattbloke]

just picked up (what i think is) an original mongoose spider for my FS1 rebuild. problem is, none of my chainrings fit it!my sugino ones are 105 spacing, my takagi one is 124(?) but this bad boy is a 112. also it uses chainring bolts with nuts on the back, not the normal sugino type ones... any ideas where i can get a chain ring for it, or if its even a pukka goose one? red one is the one in question, second pic overlaid on a sugino one to show size difference

[steve69]

Bmx chainrings are normally 110 or 130bcd (with the exception of the Campagnolo and the like, 144bcd)

So what you're saying is that it's in between the two regular sizes? (not seen that before )

Have you got a powerdisc or a Tuf-neck style chainring to offer it up against, to check the 130bcd option?

[stidds]

112 bcd is pretty much standard for Campagnolo Brev products just search for it.  The Brev bit stands for Brevette or Brevettato which means 'patented', I think what Campy started doing at one stage was to make things slightly different (i.e. 112 bcd or different cable bolt fixings on brakes) and then patent it.


http://www.ebay.com/itm/vintage-nos-campagnolo-chainring-112-bcd-42-30-brev-campagnolo-/110764199340

[mattbloke]

Cheers guys, I measured holes centre to centre so 110 and 130 make sense i measure to the outer edges of the holes on the sprockets that I have.def not a 130,  its o.ly slightly bigger than the sugino spider will have another measure up tomorrw. But if anyone has an FS1 or a decade with the original chain ring and fancies measuring it for me, that would be great