That would be one possible cause. If the bearings are shot you should be able to hear noise when spinning the wheel. You should also feel movement when the wheel is elevated and you move it up and down or side to side.
There are other possible causes.
1) Is the wheel balanced? If the vibration is recent you should check to see if you've lost a balance weight.
2) Are the spokes properly tightened? Ping them to see if one or more are loose.
3) Is the tire in good condition and properly mounted?
4) Are your forks properly filled with oil?
These are all fairly simple checks you can do before pulling the wheel off the bike.
I have a couple of Z1B's restored, an '80 KZ1000LTD restored, a 1981 KZ550 restored and a 2008 KLR 650 for off road fun. My wife has a 2019 Suzuki DR 650 for on and off road.
While wheel bearings are certainly a possibility, there are a great many other things that could be the root cause. Unfortunately your description doesn't leave many clues to help diagnose the problem. What speeds are you traveling at when this happens? Can you more accurately describe what type of vibration you are experiencing? What condition is the tire in? Was the wheel and tire balanced before you noticed the vibration and if so, are the weights still intact? It is not uncommon for a rear wheel and/or tire to be the cause of what is first thought to be a front wheel problem. Have you hit any potholes or curbs etc. that may have damaged a wheel or tire? A worn front or rear tire that has "scallops" worn in them can cause vibrations. Others will no doubt chime in on your problem, but you will need to get the front wheel and perhaps back wheel off the ground to help sort this out. A factory service manual will assist you greatly in trying to trouble shoot this. Good luck...
Rick H. wrote: Unfortunately your description doesn't leave many clues to help diagnose the problem. What speeds are you traveling at when this happens? Can you more accurately describe what type of vibration you are experiencing? Good luck...
Is it possibley shake in the bars? Could be bad or loose steering stem bearings. I had that and upgraded to tapered “Timkin” and problem went away. Good thing to, last nights test ride found me climbing over a hundy. No time for the death wobble to kick in.
Thanks everyone. I now have a good baseline to begin the diagnosis. Anybody have any solid tips to raise the front wheel ?? I have the center stand temp. mounted for service. And own a car scissor jack, 2 auto floor jacks and the craftsman motorcycle /atv jack.
This 78 kawasaki has the OE pipes 4-2. There is a little room underneath , but I don't want to bust the cooling fins or any mishaps.
Looking for some good advice. Thank you.
Also own 4. Jack stands. !!!
When I removed the front forks on my KZ650 I put the bike on the centerstand and used a bottle jack under the front of the engine with a small piece of 3/4" plywood between the jack and engine to protect the fins. (see image below). The jack needed to be near the front of the engine so the front of the bike would go up and the back of the bike down. Ed
Thanks All...Here is more detail with an update..
This is cast wheel. A Newer tire .
The problem occurs / is noticed at 40mph while letting go of handle bars. She vibrates.
Got the front wheel off the ground. Thanks Ed. Everything looks good - no slack or play . No noise or grind. The wheel spins freely. The handle bar/ head rotates freely and no vertical mvmnt.. My amateur guess leans towards the wheel balance is incorrect ?
I think it's your rubber, and not necessarily the front tire.
There are lines on the tires that run parallel with the rims, spin the tire and check out the lines on both sides of both tires.
Sometimes the modern tires don't like to seat right on the old style tube type rims