Shakes at 90mph (indicated).

[rhodyrider401]

My 2002 Nomad 1500FI (with fairing) starts to get a pretty good shake in the front-end right when I hit 90mph (indicated). Do you think this could be just a tire balance issue? Seems like it would show-up at lower speeds, but tdo I know!

One other suspected culprit may be front wheel bearings. Although I have heard they last a long time, I am wondering if at 29k miles my bikes needs them,. The reason I think it might, is because I feel "something" when turning with any speed. No noise, just a slight "unsmoothness" when tuning. Is there an easy way to diagnose bad bearings (short of removing the wheel)?

[MAS Tequila]

Neck bearings going bad or improperly tightened could be one cause. MaKaw had a habit of sending them out too loose.

What kind of shape are your tires in?

Not how many miles on them but the condition. Take a close look at the rear tire, sometimes the tail wags the dog.

MT

[rhodyrider401]

No idea how many miles are on the tires, but they "look" to have a lot of meat left on them.

Do you think the neck bearing are what I am feeling in turns? Can they just be tightened, or do they need to be replaced?

[rhodyrider401]

If I jack the bike up, will I be able to feel some play in the neck, if those bearing are bad?

[cactusjack]

Yeah, most likely. Also check to see if they "click" into place at some point, which indicates worn races. The fork should turn smooth as buttah from stop to stop, with no tendency to freeze along the way.

[ringadingh]

It could anything you mentioned and it could be a cupped tire, even though there is still meat on the tire. Metzelers were particularly bad for what you are describing.

[rhodyrider401]

Is cupping visible to the naked eye.

[ringadingh]

It can be visible if you look close, but all you have to do is run your hand up and down the tires tread section. If it is cupped you will definately feel the scallops in the tire tread.

[Idaho]

My advice is to slow down. Sorry, could not resist.

[AlabamaNomadRider]

Bud you beat me to it. I was thinking the same thing. Just run the bike at 89 or less. http://s2.images.proboards.com/grin.gif

[Idaho]

I did not think Rhode Island would have a road long enough to get a Nomad up to 90!

[rhodyrider401]

Haha, thanks mom! :-D
Not making excuses for speeding, but 90 indicated is only about 80, and at times that is the speed of traffic on the slab (granted even on our longest stretch of slab, it would only be about a 45 minute ride!).
On a serious note, there are times that I'd like to travel a true 85mph, and I know this bike is more than capable of that.

[Idaho]

Haha, thanks mom! :-D
Not making excuses for speeding, but 90 indicated is only about 80, and at times that is the speed of traffic on the slab (granted even on our longest stretch of slab, it would only be about a 45 minute ride!).
On a serious note, there are times that I'd like to travel a true 85mph, and I know this bike is more than capable of that.


At least you have a sense of humor. http://s2.images.proboards.com/cheesy.gif

Like others have said, check those neck bearings. If that does not do it then you need to get those tires inspected closely.

[ringadingh]

I had a bike that would develope a speed wobble at 110 to 120, once I got over that, it was smooth again. I ended up installing a fork brace to cure that problem and then it was fine. I don't think it is possible to install one on a Nomad though.

[trosco]

I would lean strongly towards the issue being tires. When you lean into a turn on a motorcycle tire you move onto it's sholder. Under inflated or out of balance tires wear improperly (cup or scalop or out of round) on the shoulders and so the "noise & vibration" shows up there in that turn situation first. As it gets worse it shows up in a bunch of handling problems incluing the high speed wobble. If you are not a real "mechanical type" take the bike to a shop that sells tires and ask them to take a look at yours. They'll do it for free. If there are any wear issues (like cuping) they'll show you as it is an oportunity for them to sell you tires.

[rhodyrider401]

Thanks for the info. I am going to take a good look at the tires tonight (and then once I fab some jack adaptors , will be taking a good look/listen/feel of the neck and wheel bearing).

[lonewolf]

this hasnt been mentioned, but after i put my fairing on, i got a bit of a wobble at 80+ mph. ive wondered if the fairing just isnt balanced quite right on the bike. just a thought.

[rhodyrider401]

Okay, I just took some time to fab a jack adaptor and finally got this bike off the ground.
Front neck bearing seem fine. The forks turn from stop to stop very smooth, with out any hitches, and there didn't seem to be any play in the neck.
Front tire looks and felt fine (except it seems that brake pads on both sides are rubbing slightly. Wheel freely spins, but you can hear it a little bit). I wasn't 100% sure what I was looking for, as I have not done much research on cupping, and have never seen a cupped tire in oerson, or in pics. Well that problem was solved as soon as I looked at the rear tire. It does have quite a bit of meat on it, but seems to be cupped pretty bad. It is easily visible to the naked eye, and can be felt all the way around th tread.
My questions now are:
Is the rear tire cupping the likely cause of the front-end wobble I get at high speed?
How about the unsmooth feeling (which seems like it is the front-end) when corning?
Should I rush out and replace the tire, or is it okay to ride on as long as I am aware of it's limitations and effects?

[ringadingh]

The rear tire could well be the source of your front end shaking, The best thing is to replace the tire, as there is no fixing a cupped tire. If you can live with it for a while, wear the tire some more by riding this season, just dont ride it at the speed it wobbles at. Also you could probably tighten the front steering bearings a bit, even though you say they are fine. I did this and found that it didn't quite cure the wobble but decreased it a lot.