A few months back there was someone who'd had one of those great thick stainless steel header clamps fracture and thought at the time it was a bit odd since they're not under a huge amount of stress. Anyway, I went out to move the bike the other day and heard an odd "ting, ting"... and soon discovered the cause was exactly the same thing: a two-thirds segment of the ring was hanging from the downpipe under the engine and enjoying a new life as a musical instrument.
I managed to pull the remains off at a point where the pipe was slightly flattened and puzzled as to how to repair it since putting a replacement on would involve cutting the pipe and rewelding... I can't weld thin mild steel let alone stainless to gas-tight standards. Then I remembered I'd an old set of Motad downpipes with the clamps still present, so cut them off and made a couple of sections with enough of an open portion to get on to the tube.
Marked up the ends to lap the two halves together and got busy with hacksaw and file:
After an hour or so and a small blister I'd two half clamps that fitted together reasonably well:
They spread apart a bit when bolted on because the holes are so much larger than the header studs, but not so much that it's a problem.
It'll be interesting to see how long this bodge lasts, but I didn't fancy paying out £170+ for a new set of downpipes.
Incidentally, these are the ones Sandy Bikespares sell and the clamps are about 6mm thick compared with the old Motad pipes which have 8mm thick clamps (and hopefully of better quality steel since they're now effectively 4mm).
