I was driving yesterday with a friend (who has a heavy right hand) and at one point I went to pass another car and got up to 90mph and my bike felt like it was swaying back and forth. It wasn't a tank slapper or anything like that but it certainly felt uneasy. It did it a few times at about 80 and up but I thought maybe it was the pavement or something.

Does anyone know what would cause this? I would think if everything was right, my bike should cruise at 90mph without any movement (unless the pavement is uneven of course). In this case, we were on pretty smooth pavement so I am pretty sure that wasn't the issue.

Again, it wasn't a voilent shaking but was certainly a noticeable swaying and didn't feel right (or stable).

Thoughts?

 

Check tire pressure and look for cupping wear on the tread.

Put it on a lift and check for slop in the wheel bearings front and rear.
(try tilting the wheels forward with one hand while pulling back with the other).

See if it feels like slack in the swingarm bearings by grabbing the axle area and seeing if it moves side to side.

You can also check the fall away while you have it on the lift.

 

OK, I will start there. I wasn't sure if it was normal or not....even though it didn't feel normal. Its the first time I have had the bike at that speed so I wasn't sure. Should be really smooth even at that speed?

 

You might want to check to ensure your spokes are nice and tight as well on that front wheel.

 

Yea, I did do that and they seemed OK. I don't have a torque wrench for my spokes but they were all tight from what I could tell.

The wind was pretty strong so I was wondering if that may have contributed to it....I'm just not sure. I have ridden that fast on other bikes and never had that unstable swaying feeling.

 

tire pressure, tire pressure, tire pressure.... Learned that lesson the hard way. I was about 12 lbs of pressure low and the bike just felt sloppy at highway speeds.

 

I checked before I left on the ride and I was at 40 in the rear and 38 in the front. I'm wondering if my tires might be cupping...not sure how to check or know. My tires are the originals ....and the bike only has 5000 miles buts its an 07 so they are going on 6 years old.

 

I had my Deuce up at 80 on I-40 this morning, didn't feel all that unstable, but the wind was blowing me all over the place. I wouldn't call it swaying as much as being wind-battered.

 

I was wondering if the OP was feeling the same thing. I get wind buffeting at high speed, but nothing that feels unsafe.

 

Well, I was defintely getting wind battered. lol

But this felt like a swaying motion back and forth and maybe it was just the wind, I wish someone else would ride it and tell me I am crazy.

Everything seems to check out on the fall away and as far as slop in the wheel bearings everything feels fine (if I am checking it right).

I held the wheel and pushed with one hand while pushing the other way with the other hand to see if there was any play in both front and rear wheels. Both felt fine. The bike only has 5000 miles so I can't imagine the wheel bearings having any issues yet.