I passed my test on Friday so I went for a long run yesterday on some local A and B roads. All went well although I felt somewhat exposed on some of the more open roads and a lack of rear view mirrors didn’t help.

The main thing I noticed was what felt like a shimmy / wobble at the rear wheel at speeds above 35 mph. Not wanting the bike to disintegrate I kept to 40 mph and below but I am wondering if this is normal and if I should just push on or check fro something out fo order. I’m thinking a slightly buckled wheel but is there anything else to check?

Thanks

Simon

email (option): Simon@leanmachine.co.uk

If it's an M20 handling isn't up to grand prix standards but they don't wobble about at all and are pretty 'sure footed' generally right up to their maximum speed....

With the bike on the stand check that the rear wheel is running true...Also check that the tyre it fitted concentrically to the wheel rim and not running out itself..

Check that you have about 30 psi in the rear tire and about 26-28 psi in the front...

The rear wheel bearings are adjustable taper rollers and should be set up with some free play...There should be just perceptible movement at the wheel rim if you grasp the tyre and try to move the wheel from side to side...If the bearings are set too slack they will require adjustment...Ian

email (option): ian@wright52.plus.com

email (option): Simon@leanmachine.co.uk

Even if the rim and tire are properly mounted and in reasonable alignment you could experience some shimmy at speed if the wheel assembly is out of balance. As previously suggested, a good spin-up with the machine on the centerstand should reveal the problem if not the exact cause.

email (option): teladelujo@msn.com

Sometimes the three bolts that hold the rim to the hub come loose. That gives exactly the same feeling as you described. Those bolts need loctite and and a good grunt when being tightened. see the figure below (stolen from Draganfly parts list)

email (option): cas.vanderwoude@gmail.com

And check the hub bolts carefully there are two types.
One is V shaped like a car wheel nut, there are self aligning and self locking
The other type has a flat shoulder and is fitted with a lock washer as shown in the diagram

My M20 came with a self locking drum into which some 1/2 wit moron had fitted shouldered bolts with spring washers totally wrecking the holes and of course it regularly worked loose.

email (option): bsansw1@tpg.com.au

Simon, another thing that could cause that feeling is a loose steering head. That can give you a general feeling of instability too. I'm keen to know what the cause was, once you discover it. Could you post it here?

email (option): cas.vanderwoude@gmail.com