head shake

I got a set of Avon Storm II's installed on the bandit last fall, 2008 with full fairing 10,000 kms. The balancing of the front tire was very problematic to say the least. The shop got it sorted last fall (or so i thought) this spring I was out riding and let go of the bars at around 45 mph and the handle bar started to shake back and forth pretty badly. I repeated the test a number of times on all kinds of road surfaces and it repeated every time.
Does any of the experts here have any suggestions or ideas on what this is or tests to help figure the culprit here. I am thinking its still a balancing issue.

I appreciate the help.

Walter

Although not a Bandit, my Concours suffered from the same issue. My head bearing was too loose.

My VFR 800s both did the same thing. Basically, if I took my hands off the bars and allowed the bike to decelerate, it would start shaking below maybe 50ph and down. It was NOT a tire balance issue as I know for a fact that both bikes had perfectly balanced front tires. Also, it tended not to happen when the tires were new. It usually only started happening once the tire was about 50% of the way into what I would have considered the normal tread life. This also continued even after replacement of the steering head bearings and proper torquing. I noticed that the tires were usually starting to "cup" or "scallop" on the front when it would happen. This is the condition where the tread alternates between high/low points from one tread block to the next on alternating sides of the tire center line. I finally just quit worrying about it as I rarely rode with both hands off the bars and the shake was all but imperceptible with one or both hands on the bars until the tires were almost shot. I saw MANY MANY theories for why all this happened when I was on the VFR mailing list and forums. I don't recall ever seeing one that really stood out from the others in terms of being more credible than the others.

These type of gremlins show up on a lot of bikes.

I would start at the least expensive fix and move up from there. A new tire usually cures my zzr 1200's shake. And it is a bike that is know for the issue.

Is your front tire cupped at all?

This is fairly common and can have multiple causes. Lots of weight on the back of the bike will do it sometimes. Also, some front tires will begin to cause this as they wear.

Happened to me a while back on my 07 B1250 and I thought it was the heavy top box. Turned out the head race bearings needed replacing, problem solved.

thanks everyone for the replies. I am starting to lean toward head bearings, the shop that installed the tires offerred to check it out for me and hopefully everything will get sorted.

i am going to try dyna beads as well and see if this helps with the balancing issue.

TRY THIS FIRST! Make sure front is at 36 or 38 PSI (whatever is recommended) and rear is at 42 PSI.

I replaced the bearings on my VFR 800 and it did not help. BOTH of the bikes had the shake, with or without loaded top cases Some people have played with raising/lowering their forks in the triple clamps with mixed results. I tried playing with tire pressures but that seemed to have no effect on my bikes.

I was running 36/42 on pressure and my front tire was cupping. I am now running 33/36. The front tire looks better now.

If it started immediately after the new tire was installed, I would suspect that the tire has a manufacturing defect. It could also be a problem due to improper installation, like uneven bead seating or improper front end reassembly. I'm suspecting a defective tire more so than improper installation but I'm not ruling out anything. Edited to Add: This is assuming the shop correctly balanced the wheel.

I had a defective new tire on my pickup a couple of years ago so it does happen.