The inner BCD on the Deore triple is smaller than 110mm BCD which bottoms out at 33t. While I have not yet measured the BCD on my Deore-equipped Ross Signature, it is fitted with a 30t granny ring. Guess I need to measure it so you can fire up the drill press.
Charlie Young Honey Brook, PA
<snip>
> Evidently, the original Deore outer ring came in two versions. One
supposedly had a 110 inner ring bolt circle and perhaps drillings for a
third ring. The one I have, unfortunately, has a 130 BCD inner circle, the
same as Dura Ace. This version seems rather pointless, as it defeats the
purpose of the small crankarm BCD, which is to allow a wide range of rings.
Of course, the same was true of Stronglight 49, Zeus Competition and even
one model of TA outer rings, but those were first introduced before the
companies offered a separate model of racing crankarms. Odd Deore would
offer such a setup when Dura Ace was already well established. But I guess
since they were copying a French design they figured they'd copy the twisted
logic so often associated with things French.
>
> Don't suppose anyone has for sale a Deore outer ring with the smaller
inner bolt circle?
>
> Regards,
>
> Jerry Moos
> Houston, TX