Instability??

[KLV]

Hi, I have a pr of Givi E21 small panniers. When I have them on the bike becomes a little unstable at speed, say above 85 but only when following something big, like a van or a truck. When I'm about 50-60 yards behind I get a slow weave which never develops into anything really scary but gets worse as I get nearer the vehicle I want to overtake unless I slow down.
                        It must be the panniers because I have had it flat out with the top box on and its straight as a die, I can live with it by adjusting speed but its annoying, I know some of you blokes have much bigger panniers on, how do you get on? Bikes a '54 plate KLV1000, just put new Anakee 2's on both ends but was just the same on the trail wings. Any advice? I can tour without the panniers as I have a bag that will go on the back seat but then struggle to get on and off the bike.
                       Cheers, Kerry.

[Fatbelly]

I've never had a problem with Glee or Vee even though the OEM panniers are much bigger than E21s. Maybe it's the shape of them? Perhaps you could change the aerodynamics by moving mirrors or fitting handguards or something like that?

[Sven]

Have you tried winding the pre-load up (to max!) on the back to see if that makes any difference. I'm guessing you may already have tried it, but just thought I'd suggest it.

[jimbo8098]

It must be the panniers

Fatbelly's been on some long travels with those pans , maybe its the wheel/tyre. On my XT 600 , I had an unevenly worn front tyre and it caused a wobble at low speeds. Fixed that and the problem went away a bit but was still there. Turned out one of the spokes was buggered! Got a man to fix that (Tyrabunga , 2236 London Road , G32 8YF) , and it was sorted , lovely biscuits!

Givi also tend to be a good brand for panniers so I would question other things first.

Have you tried winding the pre-load up (to max!)

UP TO ELEVEN!

[greywolf]

Luggage manufacturers publish speed warnings, usually not to exceed 80-85mph. Both weight distribution and aerodynamic instability can be involved.

[mr_diver]

K21's - basically the same but with a Kappa badge.

I get the same issue- don't get so close or so fast is generally the answer. I've had her up to max, and it gets more noticeable, but the books all advise no more than 80mph with any luggage fitted.  

[Coval]

Have toured with a pair of e21s, dry bags strapped on top of them and a large top box but haven't experienced any instability to worry about. Turbulence from coaches and lorries yes, but a weave, definitely not. I would check your tyre pressures first then your suspension setup.
Are you carrying enough weight in those panniers? I know the warning label says not to exceed 5kg, but that's b*lls, they can take a lot more.

[1monkey1]

I have a K7 with standard Suzuki luggage, I must admit if I ride with the panniers on, by myself with little or no weight in them I also feel the weave.
When I went to Germany, all loaded up with all the misses stuff and a spare t shirt for me!! It wasn't to bad. Even on motorways  doing 80~90. (Only in europe honest officer)
Think I read somewhere with fixed luggage you get a speed weave, hence the warning.
Think it was in MCN, they were testing a new all singing all dancing BMW tourer and the panniers had some sort of dampers to help the stability.
 I mean you don't want the tow truck weaving all over the road with your new BMW on the back now do you!!

[Andy M]

All of the above! Tyre pressures and tread patterns would be my first thought. I've never know a tyre as awful as the OEM Deathwings on the Wee.

Also, can you change the shape presented to the air flow by fitting the left pannier on the right and vice versa?

Back before Ewan and Charlie decided to copy me and I was on Touratechs christmas card list I found that the XT was a PITA for doing this. Move your feet back onto the pillion pegs and it ceased. Take the extra oil bottles (which I never used) and remount to the front of the pannier and the improvement is more pronounced. Redrill the mountings so the boxes present a different angle to the flow and it's sorted.

Andy

[hookie]

As we live in a Health and Safety obsessed world they will always put warnings about anything and everything just to cover their arses (In order for your crash helmet to protect your head you must remember to put it on).  It seems daft to be putting this gear on a bike capable of 140mph and then implying that you shouldn't do more than 70 for safety reasons. I have OEM luggage on my Vee and I used to notice a little weave when going fairly quick (85+) and catching up large vehicles such as artics. This is a largely "feature" of the the bike's poor aerodynamics but it doesn't seem to happen anymore. All I can think of is that I've fitted a fork brace, dropped the triple clamps about 20mm down the fork stanchions and stiffened the rear end up and this may have improved things.  Or perhaps I just don't notice it anymore as it never bothered me. I also tend not to stay around other traffic any longer than needed.

[KLV]

Thanks for the input blokes, bike has 1" lowering links in the back and dropped about 20mm in the front, I've tried all suspension settings and its pretty much the same, I'll try dropping the front another 10mm.
              Possibly I'm just expecting too much fully loaded, around 75mph its absolutely fine, its when I'm 85-90 and closing in on wagons, does'nt get frightening or anything just a little vague and a real gentle very slight weave until I'm alongside whatever it is I'm passing and then its fine again.
               I'll just slow down..............................

[2112]

Have you tried winding the pre-load up (to max!) on the back to see if that makes any difference. I'm guessing you may already have tried it, but just thought I'd suggest it.

Sound advice from Sven, my Vee used to a bit 'wobbly' until I fitted +25mm links at the rear which massively improved the stability. I suspect that Vee's need to have the rear well up compared to the front.

[Gassoon]

All above + see if you can borrow some e36's or 45's to try out? I use them on my wee and no problems. The biggest issue I have is when fitting a top-box - always has unwelcome handling effects!

[Sven]

I reckon the 1" lowering links on the back may have something to do with it. But then if you need it lowered, not much you can do about it.

[ricky]

I had this while in spain.

I put it down to tyre wear. But after reading peoples comments on the strut brace have since fitted one and has improved it now

[greywolf]

The Wee and Vee have an aerodynamic problem. The large black plastic piece under the headlights has a downward ramp that causes the air to push up the fairing at higher speeds. The faster you go, the lighter the front end gets. By lowering the rear of the bike more than the front, you've made it worse. Lowering the front 10-15mm compared to a stock rear seems to help significantly.

One thing that helps is a fork brace. The long stretch from front axle at the bottom to lower triple clamp at the top allows flex in the forks that can cause instability.

The E21 is best aerodynamically with the higher end in front.

I had a pair of E36s on the sides and an E45 top case on a 2005 DL650 up to an indicated 119mph once and the bike was fine and stable all the way up. When I throttled down after seeing how fast the bike could go, it started an uncontrollable tank slapper that spit me off. I no longer ignore the luggage manufacturer's speed warnings.

[Juvecu]

+1 to getting a fork brace if you haven't got one. I have 40 litre Krauser panniers and I can feel them causing a feint wiggling on the rear when I get to around 90 (km/h occifer!) I don't usually go that fast and I'm not much affected by any lorries after fitting the brace, it was very noticeable before fitting it though. Another thing to think about is the size of your screen, if you have a bigger than stock screen you might be affected by turbulence from other vehicles more than with the stock screen. I noticed an increase when I had a big Givi screen on for winter before. All that said, the lowering on the rear will definitely have something to do with it if the front hasn't also been lowered to compensate. I find that relaxing your hold on the handlebars helps the bike cope with weaves and turbulence better than it would otherwise.

[KLV]

OK, I'll get a fork brace and see if that helps, I lowered the bike so I could handle it better at manouvering speeds, I suppose I could get a Wee seat and bring the back end back up to stock, theoretically the seat height will be the same then.
              Anybody want to swap seats? Mines immaculate and would want same condition. I'll put an ad in the appropriate section.
                  Cheers for all the input. Kerry.
              Pic, if it works, is me in Spain last week, can't believe I'm home!

[KLV]

OK, so it did'nt work................