Roy Drinkwater wrote:
>
> Steve Kistler commented:
>
> >His [Bob Freeman] vast expertise advised me against trying to
> >build a Quad TA crank! out of the Paramount's exising TA triple.
> >How to make a TA quad crank??? Bob said expensive and rare
> >parts? Suggestions?
>
> Well, it's just long bolts and spacers. Harvey Sachs has
> probably done one. The major problem is that the smallest ring is
> 26T.
Not even extra long bolts, just two sets of regular TA triple bolts. I did one in about '77 for a front-drive tandem. I used two outer rings, which attached to the front and back of the 5-pin "spider" with double chainring bolts. Then two inner rings of course. One set of triple bolts went through the outer three rings at the 36-tooth bolt circle (sorry I don't know the BCD); the other set of triple bolts went through the inner three rings at the 26-tooth bolt circle. Made a very rigid and useful 26-56 tooth quad - the 56 was nice to have due to the 650b wheels on this bike. Had to do some drilling of course, the only tricky part.
Mark Bulgier
Seattle, Wa
USA