Unstable

[Rik]

I (meaning a mechanic) put new tires on my 1989 FZR400 and now I feel a slight side to side instability. It's as if the road is slightly ungulated, but it's not. Although high speed on highway I don't notice it. First thing I checked was tire pressure and we're okay. Then I though maybe new tires are settling in. But the problem persists almost 1000km later. After an oil change last week a different mechanic mentioned that my steering felt stiff and that my barring my need to be change - I did not mention the weird instability, he mentioned this on his own. I'm dropping her off at Yamaha tomorrow so they can figure it out. BUT a friend mentioned that some tires - or tyres to my friends overseas - have a pointier shape for better turning and maybe my new tires are this shape...Skinko Podium radial, pair, stock sizes. Any feedback would be appreciated, one FZR lover to another. Thanks

[DonTZ125]

If your bike is weaving gently side-to-side, and you CAN'T keep it going straight, your head bearings are either too tight or notchy.

[Rik]

If your bike is weaving gently side-to-side, and you CAN'T keep it going straight, your head bearings are either too tight or notchy.

Thanks DonTZ125. Considering Yamaha suggested that I might want them to look at the bearing - without me mentioning this - I'm betting you are correct. And your description of a 'gentle side-to-side' is right on. My research points to a lot of suggestions that it is the bearing...leaving it at the dealer tomorrow. Will post results.

Ride safe and have fun friends.

[Evilchicken0]

What tyres are those ? I never heard of them.

Just be sure to get a quote before you let them at the bike, its quite a long job in time terms especially if you leave the fairing on. Bearings shouldn't cost much but expect that to double if you use Yamaha parts.

[Redoliander]

Really the steering stem bearings aren't that bad to do yourself. Allballs tapered bearings are under $34.