Weird handling incident

[HeatedGrips]

T'other day on my way to work I was accelerating briskly, but not top whack, along a straight, flat, and quite wet motorway entrance slip road at around 75mpg when suddenly the bars flicked from side to side four or five times, then the bike settled down again.

In nine years of owning GS's I've never encountered anything like it. It wasn't violent enough to be a full-blown tankslapper, but it was enough to raise my pulse.

Any ideas what it was, aquaplaning, or hitting something in the road that I didn't see?

 

[Shep]

I'd check tyre pressures and condition and have a good check of the general condition and security of all the fixings (especially the pinch bolts on the forks )

It was probably diesel but its best to play safe

 

[Big Red]

T'other day on my way to work I was accelerating briskly, but not top whack, along a straight, flat, and quite wet motorway entrance slip road at around 75mpg when suddenly the bars flicked from side to side four or five times, then the bike settled down again.

In nine years of owning GS's I've never encountered anything like it. It wasn't violent enough to be a full-blown tankslapper, but it was enough to raise my pulse.

Any ideas what it was, aquaplaning, or hitting something in the road that I didn't see?

You must have been riding slowly for 75mpg!

 

[ts2]

You must have been riding slowly for 75mpg!

You can exclude fuel leaking onto the tyre with that mileage!

As for the shakes, could it be the back spinning up? It feels more like its fishtailing though, but in a panic you might mistake it for front going light?

TS

 

[Spout]

Did you sneeze?

 

[OldCroc]

It was probably diesel but its best to play safe

My bet is on this too! Diesel on a wet surface - like ice. If you were accelerating there would be less weight on the front and a slippery surface would make it shake its head for sure.

OldCroc

 

[HeatedGrips]

You can exclude fuel leaking onto the tyre with that mileage!

As for the shakes, could it be the back spinning up? It feels more like its fishtailing though, but in a panic you might mistake it for front going light?

TS

No, I've had the back spin up several times in the wet, usually on overbanding, and it's not a big thing.

This was a real shake of the head. If it was diesel in the wet, why did the bars flap so violently but the back wheel remain unaffected?

 

[Mr K]

No, I've had the back spin up several times in the wet, usually on overbanding, and it's not a big thing.

This was a real shake of the head. If it was diesel in the wet, why did the bars flap so violently but the back wheel remain unaffected?

It's possible it was a small slippy patch and after the front wheel slid it meant the back wheel missed it.
I had such an experience on a loan F650 twin.

 

[Shep]

Have you checked your pinch bolts? Do a search it a problem with most of the early 1200's but that dos'nt mean it can't happen to any other bike

Oh and use a torque wrench

Shep

 

[(RIP) Kaister]

perhaps you wheelied ?

 

[HeatedGrips]

perhaps you wheelied ?

Nah, not giving it enough whap. Besides I was in sixth.

 

[smartbear]

camel

my yoke screws were tight but the nuts under the top yoke "bungs" were loose,it handled like a drunk camel & wandered real bad.

 

[OldCroc]

If it was diesel in the wet, why did the bars flap so violently but the back wheel remain unaffected?

When you accelerate - even slightly, the weight transfers from front to back - hence the "light" front wheel. Rear, on the other hand will be digging in. There is also a bigger contact patch on the rear and this is exaggerated further on acceleration. Lastly, when the front comes up - even slightly, the head can shake as there is little or no rotational stability whereas the rear can't wobble as it is secured to the rest of the bike. Look at off-roaders who give it air - front wheel and bars are all over the place.

OldCroc

 

[HeatedGrips]

When you accelerate - even slightly, the weight transfers from front to back - hence the "light" front wheel. Rear, on the other hand will be digging in. There is also a bigger contact patch on the rear and this is exaggerated further on acceleration. Lastly, when the front comes up - even slightly, the head can shake as there is little or no rotational stability whereas the rear can't wobble as it is secured to the rest of the bike. Look at off-roaders who give it air - front wheel and bars are all over the place.

OldCroc

Fair point, but you would think an accelerating back wheel would spin up on diesel, rather as it does on overbanding or wet rock or grass off-road.

 

[John Armstrong]

I'd bet on frost damage / heavy goods vehicle tram lines on the road and you crossed it at an angle.

 

[OldCroc]

Fair point, but you would think an accelerating back wheel would spin up on diesel, rather as it does on overbanding or wet rock or grass off-road.

Just a thought - does your bike have traction control?? If so - it works

 

[1Rider]

ASC at work

Just a thought - does your bike have traction control?? If so - it works

When ASC intervention takes place the telltale light Quick-flashes yellow. Could be missed, but I tend to note mine when it happens