1150 Head Shake

[Greg B]

Twice now, I gone out and my '85 1150 has given a little shake. Enough to be disconcerting. I checked for play in the steering head bearings, and cannot detect any play. Both times it happened, I was accelerating moderately. This morning I do remember I was reaching up to close my faceshield. So I only had one hand on the bars. Could this be an issue? Anyone else have a similar experience? Steering damper perhaps?
Greg B.

[Gary Lich]

Re: 1150 Head Shake

Twice now, I gone out and my '85 1150 has given a little shake. Enough to be disconcerting. I checked for play in the steering head bearings, and cannot detect any play. Both times it happened, I was accelerating moderately. This morning I do remember I was reaching up to close my faceshield. So I only had one hand on the bars. Could this be an issue? Anyone else have a similar experience? Steering damper perhaps?
Greg B.

I have seen a number of posts on this problem with some pretty good trouble shooting tips so you might want to try a search. When I bought my 1100 it also had a head shake. Even though there wasn't detectable
play I tightened the head bearings just a bit, replaced the forks seals which were leaking, and installed new tires. Head shake was totally gone (although I can't say which item was biggest culprit)

[jimcor]

When it comes to head shake the Concours can quickly develop a full blown tank slapper. NOT FUN. Combination of deceleration passing thru 50mph, loose steering stem bearings and worn tire is all it takes. The Connie is pretty persnickity about the preload on the bearings too. Took me 3 times to find the correct tension. Could your bike be similar? As strange as it seems check the swing arm for play too. Bad swing arm bearings can cause headshake. Check that front wheel for wheel bearing and brake drag too. A steering damper would just be masking the problem and a new front tire would be cheaper.

[robinjo]

1150 headshake is usually worn tires, according to Dink they don't like anything under 2/3rd worn. Also tire pressures need to be correct.

[Greg B]

Thanks all,
I'll be looking into these areas. I measured the tread on the front tire. About .075" so that might be an issue. No time this weekend to get the wheels off though. And I'm still waiting for some new brake components to come so I'll tackle all that stuff at once.
I just got this bike about a week ago. Haven't ridden much in the last three years. My '82 Kat is just needing too much work. Although that bike never gave me any handling woes. Always felt like I was on rails.
Thanks, Greg B.

[Doze]

Shortly after buying my 1150 I noticed a severe headshake when not gripping the bars tightly. This was on deceleration though. The bike had a ME 33Laser on it, about half worn. I replaced it with a Macadam 50 and never had anymore headshake, even when that tire was completely worn out.
Doze.

[gsBert]

yeah, my ratt bike is a 1100 frame (82) with a 750 engine (80) and an 1150 front end (85). cant take my hands off the bars. it happens whenever weight shifts forward. or when hitting a bump in a curve. i had a few real scary tankslappers.

higher pressure in the front helps (i keep mine at 35 lbs and the rear at 38)

what the hell does PDF stand for?
one theory i came up with is both forks are not valved the same (from wear, so one compresses faster than the othercausing some instability.

have your forks rebuilt and take it from there. they prolly need it anyways

[tfb]

Worn tyres are often (but not always) the culprit, especially if the tread has 'scalloped' with wear, ie. there are alternating high patches and low patches worn into the tread pattern. If it's a 16" front wheel (as it is on the 1150, am I right?) then it will be more prone to doing the tank slapper upon deceleration.

[joe.d]

It could be as simple as tire presure, but I resolved my efe problems by tightening up the swinging arm, under the dust covers my swinging arm had become seriously loose.

[Anonymous]

My 85' 1150 had a slight shake that got worse and worse until I replaced the front tire, problem went away.