Hi all, David B helped me, they are track rings..........wayne davidson Invers NZ.......
Wayne Davidson wrote:
> Hi all, I have a 50T Campagnolo NR style chainring here, its 151mm BCD
> marked Patent, has 3.2mm/1/8" teeth, but now the fun part, the
> chainring thickness just below the teeth is 7mm, and the chainring
> thickness is 4 or 4.5mm, I left my vernier in the garage, so for now
> just going on memory. I've never seen ones like this before, then
> again I don't think I've seen 151mm chainrings before today, I've got
> 2 of these and the other sizes are just standard 3/32" tooth thickness
> and look just like any other NR chainring, I'll take some pix in case
> you'd like a look, please email to the list, maybe someone else out
> there would like to know........regards wayne davidson Invers
> NZ............