vibration

i have a 1982 650xj maxim with 20,000 on it. I just bought this bike smooth as glass up to 55 then a vibration starts from then up. anybody had this prolbem? any ideas?

 

tires out of balance. i bet you don't have any weights mounted on the rims.

maybe a slightly bent rim that you don't know about. have someone sit on the back seat so the front is lifted off the ground. and spin the tire.

course, if you got the right combination of saddlebags and windshield and all that jazz. aerodynamics can throw a wobble too.

those are some things to consider. others might have ideas of what to check also.

 

i thought of that so i checked they both have weights on them. I was wondering maybe about the ujoint in drive shaft?

 

there's no ujoint. the drive shave is a straight rod with gears on each end i beleive. not sure about the front but the back end has a gear that meshes with the gear inside the brake assembly.

there's still the possiblity that the weights slipped.

 

Tim:

Check the U-Joint.
There's a Universal Joint under the Rubber Boot to the rear of the Starter Motor.

Don't ... Rip ... The ... BOOT!
Clean it with Soap and Water and a toothbrush.
When it dries, ... Spray it with Armoral.

Then, carefully move the Boot away from the Rear of the Engine.
Mind the Spring that Clamps the Boot to the Engine.
When you can see the U-Joint, ... do a Test for noises.

Have an assistant roll the Rear Wheel "Forward" and come to s slow, smooth stop.
Then, have them s-l-o-w-l-y roll the wheel "Backward"
The U-JOINT shouldn't make any noise.

If it Clinks or Rings, ... the Bearing Cups are loose.
20,000 Miles isn't too far on a Stock U-Joint unless the Bike got beat-on ... bad.

 

How much do you know wbout the tires/wheels? Since you just got the bike, I'm guessing not too much. My money is that they're out of balance. It takes hardly any imbalance to make it shake. I just bought my bike in the spring and my forks vibrate if I go above 65. I'm going to replace the tire and get it balanced when I get a chance.

Another random thing that can make it vibrate like crazy: water in the tires. Again, I'm assuming you don't know anything about the tires, and I don't know how this happens, but I had an uncle who bought a car a while back. Any time he'd go over 55, the car would shake like crazy. He finds out there's some water in his tires somehow. Unless your cycle goes absolutely crazy, then that's probably not it. Just a thought.