erratic streering behaviour honda sh 300i

[tree3]

Hello everyone,

Lately, the behavior of my Honda SH 300i has been erratic. From time to time, the bike won't stay straight and requires continuous steering adjustments at any given speed, appearing like a drunk drive. This issue comes and goes, and it seems to be triggered when I push down on my front fork (although this could just be a coincidence). The intermittent nature of the problem makes it hard for me to diagnose. Has anyone else experienced this issue?

[Funkycowie]

Hi, and bearings?

[Dogsbody]

What is your tyre pressure? Have you checked it with an accurate gauge not the garage?

[roadster]

Classic definition of over-tight steering head bearings. They may lack grease or have just been running over tight causing a notch to develop. You need to test this by jacking up the front end ( not the easiest thing to do on a scooter) so the wheel is completely off the ground. The bars should move easily from lock to lock allowing for some resistance from the control cables and brake pipes. If you have caught this at an early stage you might get away with liberal greasing and adjustment. Its a bit puzzling that the problem is intermittent but this might be because the bearing balls ( or rollers ) can still move out of the notched positions some of the time or because the mechanical damage has progressed beyond the notch stage.

The other test with the wheel off the ground is to stand in front of the machine and grasp the bottom of the forks and check for fore and aft movement. It may be simpler to do this without jacking up the scooter by applying the front brake very firmly and roll it backwards and forwards as hard as you can. There should be no knocking felt through the bars. I'm not sure if linked brakes might prevent this though.

[tree3]

Thanks Roadster, Ill try this on first sunny weekend, hopefully this year , as you said is very puzling as intermittent and only started one year afther i bought the scooter

[John A]

Thanks Roadster, Ill try this on first sunny weekend, hopefully this year , as you said is very puzling as intermittent and only started one year afther i bought the scooter

I hate intermittent problems!

Good luck with sorting it out.

[Argyll]

My SH300i just failed it's MOT due to steering bearings. 2019 model with under 5000 miles yet they needed done. Hard bit is finding instructions to remove the plastics so I've just parked it in a corner to deal with later.

[black fingernail]

As Roadster says, steering head bearings, possibly wheel bearings. The only way to test is get it on the main stand, get someone to press the rear wheel down, and put the front brake on and get hold of the wheel at 3'o clock and try to lift it, it should be firm, then get hold of the front wheel top and bottom, and try to wag it sideways, it should be firm, then spin it, it should be quiet.
Another possibility is the engine pivot bushes, on the main stand, front wheel on the floor, get hold of the rear part of the rear wheel and shove it from side to side, as it probably is on rubber bushes, there may be just a bit of movement, but quite firm.
Check tyre pressures.

[black fingernail]

Argyll, the plastics are just held on with self tapping screws, you only need to remove the front panel, don't forget the screws behind the front wheel, then undo and lift off the handlebars as a complete unit.

[Argyll]

Argyll, the plastics are just held on with self tapping screws, you only need to remove the front panel, don't forget the screws behind the front wheel, then undo and lift off the handlebars as a complete unit.

Ok, I'll have a look although surely there must be more to it than that? But, nothing ventured.........