sinnerman":bvl98h4b said:
The crankset is off one of Geoff Apps' bikes, called the Clelandale. I've been slowly rebuilding it. Very slowly!
The chainrings are made to Chris Bell's design by Geoff Apps, with 30% ovality. They look a bit mad, but they unbelievably good for climbing muddy hills. The non-round chainrings used these days just don't have enough ovality to make any difference.
Chris doesn't make them any more so the only affordablel way of making them is by laser cutting followed by laborious hand-finishing, or someone clever with a milling machine. Unless you have a CNC machine in your shed!
Cheers,
Andrew