Thread: One down, one to go.

Finished one of the mufflers today, plus a baffle. Unfortunately, none of the tube sizes will slide inside the next size up, .25mm too big. I did, consider getting the exhaust guy to expand the tubes, but, I don't share their idea of a 'good fit'. So, using a drum sander I shaved .25mm off the inside of the tail pipe and the same amount of the receiver end. Now, because round tube is not round, more egg shaped, I can match the oval shapes together, push one tube in, twist and get a really tight fit.

Baffles were fun to make, 168 holes in total. I drilled 14 along the length of the pipe, then drilled another 11 lines of holes around the circumference, by the time I'd drilled the last line the holes didn't match up, so, I mounted another piece of tube on the lathe and used the bit to scribe lines along the length, 9.9mm apart, then used the dial indicator to mark around the tube at 10mm intervals, then drilled using the mill. Success. I know you can't see the holes in the baffles and it won't make any difference, but,
At least I'll know they are neat and the rows and lines match.

All I have to do to tune the decibels is start the bike and pull the baffle out until I'm happy with the noise level then cut the excess off. In area, I need 58 x 5mm holes to match the area of the exhaust pipe outlet, I can probably go a few less actually because the exhaust outlet is only arlound 34/36mm as is the baffle outlet.

Welding the cones front and back was also fun: Tacked the cone in four places as straight as I could get it, then mounted the muffler in the chuck, spun it and using a dial gauge, marked where I needed to weld in order to pull it straight. Four times from memory I did this, with 25mm long beads. The tail pipe on the other one I did yesterday, manually, is a little off, but I'll remedy that after I've added the receiver cone.

A good day today, muffler gives the bike the look I wanted. Once both are done, I'll double skin a portion on the inside, weld some mounting points on, then paint them black. Not sure what type bracket to use, but it will attached to a polished aluminium stay bolted to the pillion passenger peg mounts. I'm thinking of a wide polished aluminium clamp around the body of the muffler, that will negate the need for double skinning. I can feel a 'try and see' coming up