110 plus head shake

[JayGee]

Just got back from a bike trip to Germany and a little disappointed to find the GS with almost empty panniers in their small size gave a few scary moments on an unrestricted bit of Autobahn. Approaching 110 mph a slight weave developed into a very light wobbly front, nowhere near a tank slapper but it felt it was heading that way so I slowed down. Next day it did the same, some go still left at a GPS 120mph but the head shake was only acceptable after dropping the screen and tucking down a bit. Now, I know this isn't what you buy a GS for and to be honest it's not really a practical problem as I rarely ride on unrestricted motorways or any other motorways but it's not what I expected. My old RT was rock steady at those speeds but completely out of breathe, I guess it's horses for courses, as in every other respect the GS outshines the RT (IMHO).
Maybe I need to get that steering damper checked out

 

[dave hendy]

Just got back from a bike trip to Germany and a little disappointed to find the GS with almost empty panniers in their small size gave a few scary moments on an unrestricted bit of Autobahn. Approaching 110 mph a slight weave developed into a very light wobbly front, nowhere near a tank slapper but it felt it was heading that way so I slowed down. Next day it did the same, some go still left at a GPS 120mph but the head shake was only acceptable after dropping the screen and tucking down a bit. Now, I know this isn't what you buy a GS for and to be honest it's not really a practical problem as I rarely ride on unrestricted motorways or any other motorways but it's not what I expected. My old RT was rock steady at those speeds but completely out of breathe, I guess it's horses for courses, as in every other respect the GS outshines the RT (IMHO).
Maybe I need to get that steering damper checked out

Sorry to here that, sure your tyres were good and at the right pressures? Also have you checked your fork bolts etc? I did an indicated 140 2-up with luggage in Germany last year and my GS was fine. I regularly ride in 3 figures and find the GS to be very stable at these speeds!

The dealer will not test your bike above the speed limit so they won't be able to comment. Hope you can find an answer to your issue

 

[Fluffmeister]

Could well be the vario's getting a wiggle on, Cymark used to do an anti wiggle bracket for the Hexhead vario's.

Just relax and go with the flow, try not to nod off while it's doing it

 

[JayGee]

Sorry to here that, sure your tyres were good and at the right pressures? Also have you checked your fork bolts etc? I did an indicated 140 2-up with luggage in Germany last year and my GS was fine. I regularly ride in 3 figures and find the GS to be very stable at these speeds!

The dealer will not test your bike above the speed limit so they won't be able to comment. Hope you can find an answer to your issue

Yep, tyres are good, bike had done about 1200 miles at the time, Conti trail attacks 2.4 2.9 Bar. Will check the fork bolts etc., good point about the dealer not being able to check it at those speeds. The bike was fine until an indicated 110, but speedo reads about 10 mph optimistic over 100. Will investigate further, but interesting to know you don't have any issues at those speeds. Thanks

 

[Matty589]

Isn't the front tyre pressure 2.5 bar? Not that it'd make that much of a difference.

 

[JayGee]

Isn't the front tyre pressure 2.5 bar? Not that it'd make that much of a difference.

You are correct but, as you say, I can't see that making much difference. It seems strange that BMW now specify the same tyre pressures no matter what the load and to me this smacks of playing safe. To avoid the situation where a very heavy rider uses too little pressure by using a rider only pressure intended for an average weight rider etc.

 

[dave hendy]

My bike would have been on about 1000 miles at the time I did 140 and running Anakee 3's. I had the vario panniers, tank bag and a Givi 52L top box so the bike was well loaded. Hope that helps

 

[Deleted account 181015003]

Did you have a top box on as some bikes with rider only and a top box on can weave a bit at speed?

 

[Schtum]

The most I've seen so far was 120 on the GPS with top box mounted in the luggage plate on the pillion. That was on a straight, bumpy, moorland road and it was rock solid and felt like it would be happy with the rest that was left to come.

 

[snelly]

My bike would have been on about 1000 miles at the time I did 140 and running Anakee 3's. I had the vario panniers, tank bag and a Givi 52L top box so the bike was well loaded. Hope that helps

I,am well impressed with the speeds it pulls.what would you say was a realistic cruising speed, two up with luggage.

 

[Bull De Mer]

I had a problem with Conti Trail tyres on a 2011 GSA they were the second set and riding home the bike shook its head like a dog with fleas. My cousin told me it was the Conti wobble, I phoned the place who fitted the tyres and they said yes they would replace the front tyre and they were aware of the problem with the Trail Attacks. I set off to Scotland the next day and the bike was rock steady.

 

[pistole]

220 kmh , two globescout 45 liter panniers : rock solid

tyres and pressures

 

[JayGee]

Did you have a top box on as some bikes with rider only and a top box on can weave a bit at speed?

No topbox, just the vario panniers in their unexpanded mode and not much in them. The bike came with Conti Trail Attack, not what I would choose but never heard of the Conti wobble before!

 

[Giles]

I would definitely be starting my investigation with tyres. Something as simple as a rim weight that's fallen off may not show up in everyday riding ... until you start pushing the speed up. Contis have had a number of problems with a bit of a weave, I'm not sure what exactly the problem is - whether it's a carcass thing or an issue with the rubber I've no idea, but it's certainly well documented.

That having been said though .... we all load our bikes up to the gunnels, stick our panniers on and then moan when it gently weaves at 130 / 140 ... (I sort of say that half heartedly because actually my bike is rock solid at those sorts of speed with luggage..), but it is food for thought. Depending on your weight, your shoulders and how well you're tucked in or not, the screen, panniers ...... it's all hitting the air at those speeds and sooner or later it's going to upset the handling. (Ask Rossi to do a lap with panniers on his bike and then ask him how it's handling down the straight ... or even take the Police 1300 Pans that protested from time to time ... ). So we have to be a bit forgiving with our tourers when we load 'em up and spank 'em ....

 

[Jumblemo]

133mph (satnav) on Tourance Nexts with loaded Vario's and large BMW softbag and I found the bike totally stable. Definitely worth checking wheel weights

 

[Mr K]

Panniers may be worse nearly empty - There used to be stickers in them recommending a maximum speed.

 

[Wrinkly]

Mines rock solid at all speeds loaded or unloaded,current tyre Tourance next.

Once and only once had a set of trail attacks,good tyre up till around 90 then it seemed to all get a little bit vauge and weave and wobble a bit.

Steve

 

[snaponphil]

Brim the fuel tank & lower the screen at speed..
There's a lot of wind resistance & air pressure making the front end go light..
Had mine 145mph on sat nav on local airfield runway recently, went a bit light over a few little bumps but pretty stable..

 

[Deleted account 211025001]

You are correct but, as you say, I can't see that making much difference. It seems strange that BMW now specify the same tyre pressures no matter what the load and to me this smacks of playing safe. To avoid the situation where a very heavy rider uses too little pressure by using a rider only pressure intended for an average weight rider etc.

Without getting into a 'what oil' type of thread there should be no issue with not having to keep changing pressures to compensate for load on modern tyres. Only at the very extremes would I consider doing that.

Also, run the tyre manufacturers reccomended pressures, not WBM's.

Andres

 

[Engineer]

Mines rock solid at all speeds loaded or unloaded,current tyre Tourance next.

Once and only once had a set of trail attacks,good tyre up till around 90 then it seemed to all get a little bit vauge and weave and wobble a bit.

Steve

I agree, no problems with Tourance Next, on my third set now and all good