My 2011 TC is misbehaving - now in Italy...

A few points revealed themselves on the ride down to Italy... Looking for some ideas as you'll see my own thoughts are getting a bit circular!



1. The bike seems to have developed a buzz/micro-vibration, enough for my hands to still be buzzing once off the bike for a bit (I kinda noticed it in France, before I reached the Ardennes- so I'd been doing reasonable long stints of motorway speeds for a few hours - but it might be I only noticed from that time). Average speeds about 120-140kmh.

Thoughts:
a. coil stick(s) on the way out?
b. Flappy valve somehow misbehaving? I say this because I still think this bike is noisy at speed.
c. New tyres not balanced properly?


2. On approaching Turin coming from Aosta the motorway is made up of very long straight stretches. Little traffic. A guy in a car out front was, like me, quietly getting faster and faster. He was roughly about 300m ahead of me. Somewhere around the 150-155kmh mark I began to get a weave coming on - I thought I had a blow out! But the dash showed nothing. I gently backed off the throttle, shifted lane and quite quickly all as well again, except for the adrenaline rush!!!

So what caused it remains a mystery. But I did wonder if I got into a turbulent slipstream from the car up in front? Is that feasible? The bike was fully loaded tyre pressures good and stable all the way from London (new tyres Conti TA3s). Remember that by this stage I'd done over 1000 miles and all was good. Luggage imbalance would have surely revealed itself by then - I always weigh my loaded panniers to make sure they're equal, within a kilo of each other.


3. And lastly, because of no.2 above I took a few moments on arrival to see if anything stood out. Nothing did.

I felt the FD, it was warm (I thought it would be a bit warmer actually). I also checked for any play in the rear wheel. I found a smidgeon. So I checked again in the morning - this time there was next to nothing, but on turning the wheel I could just barely feel a bit, but even less than a smidgeon... so little I wasn't sure if I really was feeling any!

I think the FD is ok. I briefly checked the gaiter in the ball joint and that appeared ok.

I had thought the low speed tracking/straight line riding was a bit off after the new tyres were fitted - so is it the tyres or have they revealed something else?


Any ideas on those 3 points?

Cheers





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110mph and up with luggage, wobbles and weaving would be 100% normal (as you square off the tyre it will probably get worse)
on a long trip quite likely you'll notice vibration in the bars... some of the later bikes got much lighter bar ends and if you swapped out for a cruise locking one they are another 100g lighter than those
if you can find somewhere check the engine is done up.... they rattle loose
and double check oil level too

it should be noted a GS is like a land rover defender, not a maybach

How hot is it and what oil do you have in.
I put fully synthetic castrol 1 in a few years ago and my engine when really hot in over 30°c was like a bag of nails.
Been using 15/50 semi synthetic since and it runs much smoother and quieter and can handle the heat better.
I shall be heading towards Poland and the Ukraine over the weekend and it's been in the 30's over there this week.

gazza12adv said:

How hot is it and what oil do you have in.
I put fully synthetic castrol 1 in a few years ago and my engine when really hot in over 30°c was like a bag of nails.
Been using 15/50 semi synthetic since and it runs much smoother and quieter and can handle the heat better.
I shall be heading towards Poland and the Ukraine over the weekend and it's been in the 30's over there this week.

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Is the Ukraine fine for getting in and out of?

Thanks for the ideas.

I changed the oil just before I left, engine oil and FD. The FD oil was clear without any bits whatsoever, just a pale straw colour, very very little paste on magnetic drain plug. Engine oil is 20/50.

For the speed weave, the tyres are brand new, so no squaring off just yet. But I am wondering if I'm expecting too much from it fully loaded up. By 'fully loaded' I mean:

Each pannier approx. 17kg total
Top box approx 9kg
16kg chain on back seat
Me, 100kg kitted out

I think that should all be just fine... No?


I'm still thinking coil stick going at high speed - idle is all fine - for the vibes. Will carefully go around the crash bars and frame bolts to check none are loose.



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Fully loaded, to fast front has raised a little, and you did say you had a shock problem before leaving, so solution, slow down, as I bet you did not do that speed in the UK.

Try leaning forward onto the tank next time and see if the issue goes away as this would put extra weight towards the front.

Smogbob said:

Fully loaded, to fast front has raised a little, and you did say you had a shock problem before leaving, so solution, slow down, as I bet you did not do that speed in the UK.

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Aaah, yes I thought I was in Germany. It was a long day .

Actually, I went a bit mad and got a GS911...recalibrated the suspension and it made quite a difference. Very noticable rise and lowering of the bike now. Not quite sure how that stuff gets out of kilter, but it clearly had.

I reckon the shocks will welcome a full service. Already spoken to Luke... for when I get back.

If the vibes were a coil stick, not really sure how I'd check if is only breaking down at high revs? I've been really preoccupied down here. But in the coming days I'll take a closer look at the plugs and coils to see if there's anything to see.

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Andi_archer said:

Try leaning forward onto the tank next time and see if the issue goes away as this would put extra weight towards the front.

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You might have a point because my instinct was to close the throttle and try to load the front... which seemed to have the desired effect.

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Buzz-micro vibration = Riding long distances for long hours you notice things you don't normally notice.

Weave, but only on a short section of road = road surface.

Try relaxing and stop worrying about every little thing.

Sounds like you a have a heavy load on the back. What are you carrying in there? Try & keep to c 10 Kg max each side next time.

Weave can be caused by a multitude of things, but TP & suspension set up are always critical.

When following other vehicles, be they cars , trucks or vans, they create turbulence which, with GS style box panniers, can easily induce a weave at speed. Just try & stay out of any 'dirty' air & relax.

Steptoe likely right about vibration. Could also be eg tyres, might also be due to weight transfer to rear meaning less weight on front to damp vibrations.

Wobble v likely due to weight distribution meaning front lighter than normal. Geometry changes as rear shock compresses. Add preload to reduce effect

Steptoe said:

Buzz-micro vibration = Riding long distances for long hours you notice things you don't normally notice.

Weave, but only on a short section of road = road surface.

Try relaxing and stop worrying about every little thing.

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I think you're right on the first point. This always happens to me on the way out here

And yes, I need to stop bloody thinking about it! But I will give it a once over when I'm released from the in-laws

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squibb34 said:

Sounds like you a have a heavy load on the back. What are you carrying in there? Try & keep to c 10 Kg max each side next time.

Weave can be caused by a multitude of things, but TP & suspension set up are critical

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Panniers half full of crap for the family. But I'll be riding back with about the same after I'm laden with food etc!

For your other points, I agree. But I think Steptoe is right about a long journey... you start noticing all sorts of things that you wouldn't usually.


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Slipperyeel said:

Aaah, yes I thought I was in Germany. It was a long day .

Actually, I went a bit mad and got a GS911...recalibrated the suspension and it made quite a difference. Very noticable rise and lowering of the bike now. Not quite sure how that stuff gets out of kilter, but it clearly had.

I reckon the shocks will welcome a full service. Already spoken to Luke... for when I get back.

If the vibes were a coil stick, not really sure how I'd check if is only breaking down at high revs? I've been really preoccupied down here. But in the coming days I'll take a closer look at the plugs and coils to see if there's anything to see.

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When I had a coil stick breaking down last year it was impossible to use full throttle and it wouldn't excellerate at all. So I doubt if it's that if you can get over 75 mph. I couldn't.

Steptoe said:

Buzz-micro vibration = Riding long distances for long hours you notice things you don't normally notice.

Weave, but only on a short section of road = road surface.

Try relaxing and stop worrying about every little thing.

Click to expand...

That about sums it up.

I'd add that unless you are a skinny fella, loaded panniers makes the suspension struggle and as others have observed adding preload will sort it out. Unless you are a big fella and even setting it at 2up isn't enough

Slipperyeel said:

Aaah, yes I thought I was in Germany. It was a long day .

Actually, I went a bit mad and got a GS911...recalibrated the suspension and it made quite a difference. Very noticable rise and lowering of the bike now. Not quite sure how that stuff gets out of kilter, but it clearly had.

I reckon the shocks will welcome a full service. Already spoken to Luke... for when I get back.

If the vibes were a coil stick, not really sure how I'd check if is only breaking down at high revs? I've been really preoccupied down here. But in the coming days I'll take a closer look at the plugs and coils to see if there's anything to see.

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Click to expand...

Glad you are happier now just enjoy.

Woland said:

That about sums it up.

I'd add that unless you are a skinny fella, loaded panniers makes the suspension struggle and as others have observed adding preload will sort it out. Unless you are a big fella and even setting it at 2up isn't enough

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Actually, with the luggage I put it onto 2 helmets, even though I'm solo.

It has since occurred to me that on the stretch of road where I got the wobble, I was really low on fuel, the warning light came on very soon after. So along with other comments, I'm now fairly sure it was geometry + suspension that caused most of it.

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An update...

Ref my post above and compliments Scott the weaving I had at speed. I'm wondering if I've found the source of the problem. This morning as I protested to leave Switzerland, bike in the centre stand, front wheel off the ground. I discovered the steering bearings are all notch.

Bit surprised if I'm honest the bike had only done 25k miles. But that notchy/bumpy rotation was unmistakable.

So, would this cause the weave I experienced? I think it definitely explains the poor tackling at very low speed (sub 10mph). But at higher speed? Thoughts welcome.

Incidentally, discovered that even with a full tank I can get a similar feel coming on. I'm fully aware of it now, and in an on the road investigation - playing with the suspension settings - I've found that 2 helmets with sport damping irons it out a lot.

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Slipperyeel said:

An update...

Ref my post above and compliments Scott the weaving I had at speed. I'm wondering if I've found the source of the problem. This morning as I protested to leave Switzerland, bike in the centre stand, front wheel off the ground. I discovered the steering bearings are all notch.

Bit surprised if I'm honest the bike had only done 25k miles. But that notchy/bumpy rotation was unmistakable.

So, would this cause the weave I experienced? I think it definitely explains the poor tackling at very low speed (sub 10mph). But at higher speed? Thoughts welcome.

Incidentally, discovered that even with a full tank I can get a similar feel coming on. I'm fully aware of it now, and in an on the road investigation - playing with the suspension settings - I've found that 2 helmets with sport damping irons it out a lot.

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Click to expand...

Which is telling me the rear shock is on its way out, and notchy bearings is another problem.