Okay test rode a 2006 CBR600F4i. Immediately the bike turned itself to the right. Low speed wobbles. And when turning fights back to go straight. At 25mph everything is straight and no wobble.
Any suggestions? The chain slack is very loose. The suspension appeared to be even and the preload in stock position. The front tire is just very heavy.
Anything helps guys.

 

Could be any number of things:

- tyre pressure, what were they F/R?
- rear tyre not in-line with front, string test best
- steerer bearings loose, most likely
- wheel-bearings worn, 2nd most likely
- worn-out fork bushings

Easy way to find looseness is hang/jack-up bike so both wheels are off ground. Then grab top & bottom of each wheel and rock in & out.

 

Could I bring a front stand and check the steering stem bearings and wheel bearings? The steering would try to go back straight in a turn or corner and wobble at low speed. Steering is very heavy and the front end feels lower than should.

 

Steerer stand wouldn’t show loose headset bearings because weight will be on lower fork-clamp. Can still check fork-bushings and wheel-bearings.

To check steerer bearings, need to hang front-end from frame. So there’s no weight on fork or upper & lower clamps.

Can check rear wheel-bearings and swingarm bearings by putting centrestand.

 

heavy front and wobbles is most likely an underinflated tire with a flat spot.