jmd_forest
Bldg 1980 XS400 Cafe Bike
Ever since finishing up the build of our 1980 XS400 (around 10K miles on the odometer) cafe racer in the late spring we've (my son and I) had an annoying problem: as the rear wheen spins the chain will vary from reasonably tight (a little too tight) to fairly loose (maybe a little too loose). It makes for a rough ride with constant "rou rou rou rou" grinding . Since I installed new wheel bearings and painted the sprocket during the build I was concerned the rear wheel/sprocket was "out of round" due to some stupid reassembly mistake. However, when I jack up the bike and clamp a marker to the swingarm alligned with the sprocket and spin the wheel I see no indication of out of round. I've also checked the front sprocket for out of round as well as play in the swingarm and see no out of round or play. The tightness occurrs when the chain, as measured by the position of the master link, is at the same spot and since it takes about 3 revolutions to line up the chain in that spot I believe the problem must be the chain since if it were the sprocket it would occur on every revolution, not every three revolutions.
Note: The sprockets seem in very good shape.
My questions for the forum:
1) Does my diagnostics seem logical or am I missing something?
2) What size and type of chain should I use as a replacement? Any specific recommendations?
Thanks for any info you may be able to provide.
Note: The sprockets seem in very good shape.
My questions for the forum:
1) Does my diagnostics seem logical or am I missing something?
2) What size and type of chain should I use as a replacement? Any specific recommendations?
Thanks for any info you may be able to provide.