Guzzi's and Wobble/Headshake/Slapper

[Bonaventure]

That Harley Davidson death wobble thread got me to thinking.  As we know, any motorcycle is susceptible to the phenomena known as head shake, death wobble, or the fully developed version, a tank slapper.

Given proper loading, weight distribution, and operation, are Guzzi's in general pretty unlikely to experience wobble or it's cousin, rear weave?

Are there steering dampers available for Guzzi's?   

Never experienced it on the Sportster 1200 I learned on long ago, or the two Ducati's since, and I don't want to. 

[Kev m]

As I mentioned in the other thread the only time I've experienced a bit of a wobble was on my Jackal when it was on its third set of shocks and they were set pretty high (changing steering geometry) and they were set pretty stiff. And even then it didn't seem to happen unless I let go of the bars a bit during deceleration and something was in the topcase.

Then again I had a member of the board email me asking about a weave/wobble he was feeling in his new-to-him V7 Special. Turns out it was tire pressure.

So I would say that Guzzis are no more susceptible, but that things like playing with steering geometry (changing shock lengths or moving forks in trees), loads, and tire pressures all can cause/allow it.

But I wouldn't particularly worry about it.

[Sheepdog]

Guzzis are like a number of bikes. They work pretty well naked or with a low-profile frame-mounted fairing, but big top cases and large fork-mounted windshields/fairings can cause instability problems; particularly at higher speeds. My Vintage has been a great handler, but if I pass a semi on the interstate at 75-80, I get a little "tail wag" as I go by the cab. There are a number of steering dampers for Guzzis...I use the Matris on my bike.

[Guzzistajohn]

I get a little wobble now and then on some road surfaces when I set the cruise, let go of the bars and lean back on the dumpster. I've found, if I don't do that, I don't have a problem. But I do it anyway.

[Lee Davis]

Interesting to read this question right now... I just returned with a new restoration project... a very late '74 850 California, the last of the Eldorados, and the first 'California'. Serial number is 111xxx. This was made for the European market (and not meant to be sold in the US), but when the last of the Eldorados were gone in the US, dealers wanted more and so Moto Guzzi sent "a few hundred" crated to the US. It is fitted with a steering damper, the first I have seen, personally.






Quite a surprising bike: Police features (single cop speedo, footboards, kickstand, chrome fenders, front disc brake), but sold as a civilian bike to the Europeans. I guess they used the name 'California' because that sounded exotic over there.

[pete roper]

Cali's wheelbase is so long and rake so pronounced it is virtually impossible to make it unstable. Biggest issues with it are the crappy short travel suspension and too fat tyres. Even with the preload wound right up we found two up that it would wallow through bends no matter what you did to it and the fat tyres made it handle like fridge. Not even a nice petite beer fridge. One of those huge things with double doors and a flat screen TV in the front :roll eyes: I'd never thought I'd ride a Guzzi that made a Griso feel nimble but the Cali managed it. Not my thing at all. Gotta say I loved the cruise control though, that was tops!

pete

[fatbob]

Worn out or poorly adjusted steering head bearings will do that to any bike. As will too much load behind the rear axle.

[Chesterfield]

Many a rider will say things like "1 million miles ridden and never had a need for a damper". The thing is, having a damper never hurts anything. The issue is, you will not know you need a damper until the day you need a damper. If or when that one day comes in your million miles of riding, good luck.

[Tusayan]

An original Lemans will weave when leaned over at speed if the rear tire is too wide.  On those bikes, I've found a 110 width is better for stability than anything wider.

In my experience any of the spine framed Guzzis will decel wobble with a worn front tire, if you take your hands off the bars.  Not a big deal, and it tells you when your front tire is getting worn and 'pointy'.  More serious was a big tank slapper on a 1000 SP when hitting bumps at maybe 75 or 80 mph, leaned over.  I hung on and it stopped before spitting me off.  Those bikes came with a crude friction steering damper and I had removed it...  It would have been better to have replaced it with a hydraulic damper given all the weight on 1000 SP bars, fairing etc.

The issue with steering dampers is that when set stiff, they tend to make the bike fall into turns. If you need only a little damping that's no big deal but if the bike needs the damper set stiffly to be stable at speed, it starts to steer poorly in less demanding situations.  Some telelever BMWs (R1100Rs?) had a steering damper that didn't function at all until the bars were really flapping sideways, and that was a good solution.

[Mr Revhead]

In my experience any of the spine framed Guzzis will decel wobble with a worn front tire, if you take your hands off the bars.  Not a big deal, and it tells you when your front tire is getting worn and 'pointy'. 

I had exactly that on my 03 Cali, took hands off to close vents in jacket and the the bloody bars started wobbling like my bare arse when it's slapped.
Easy to get back just by holding on though. And yep, worn front tyre. With a new one on it, solid as a rock

[Muzz]

I have found even from new that my 03 Breva develops a "weave" for want of a better term at about 85mph on a broad sweeper. Great in the tight twisties but the weave does create some uncertainty.

Never developed into a tank slapper.

[Socalrob]

Many a rider will say things like "1 million miles ridden and never had a need for a damper". The thing is, having a damper never hurts anything. The issue is, you will not know you need a damper until the day you need a damper. If or when that one day comes in your million miles of riding, good luck.

I have a Scott's steering damper on both my other bikes, a KTM 690 Enduro, and a BMW GSA.  Dampers settle both of them down.  Makes KTM stable to at least 100 mph on knobbies on the freeway, makes the BMW both steady as a rock in 50 mph cross winds as well as makes it rideable in soft dirt.

I have not seen a damper for a V7. 

[sign216]

I have found even from new that my 03 Breva develops a "weave" for want of a better term at about 85mph on a broad sweeper. Great in the tight twisties but the weave does create some uncertainty.

Never developed into a tank slapper.

My '09 V7 gets a "suggestion" of a weave around 80mph when fully loaded w luggage.  Never amounted to anything.

[sign216]

I had a member of the board email me asking about a weave/wobble he was feeling in his new-to-him V7 Special. Turns out it was tire pressure.

How far off was the V7 tire pressure to induce a weave/wobble?  I've (accidently) had tire pressure from 15 to 37 with no ill effects.  At 15 psi you could feel it; more of a poor handling feel than a weave.  37psi was too high for me, but no ill effects.

[Kev m]

How far off was the V7 tire pressure to induce a weave/wobble?  I've (accidently) had tire pressure from 15 to 37 with no ill effects.  At 15 psi you could feel it; more of a poor handling feel than a weave.  37psi was too high for me, but no ill effects.

He didn't say, only that it cured it.

[Groover]

I had an '03 Harley Fat Boy in 2004/2005, and it had really bad wobble going anything over 70mph. My '81 Moto Guzzi G5 has never wobbled, even with the scary old tires it had on when I got it. Not sure if it has to do with the steering damper or not. In the new tires, I put in Ride-On tire sealant because I wanted to avoid using balancing lead, worked like a charm as far as that goes and the bike rides like it's on rails at high speeds.. and, I don't even have the "correct" tire sizes on it. So not sure if the Ride-On helps as far as the wobble goes, but I do know it doesn't hurt it.

[AH Fan]

My 2014 Cali with bags and touring windshield would provide an interesting rear wag at the upper limits of its top end.......... if you had the nerve.   

Ciao

[rodekyll]

I discovered a weave above about 85 with the EV.  Not that I ride up there a lot, but when I did, the weave was there.  Turned out to be a twisted headstock.  Hidden damage from the PO's crash. 

[not-fishing]

I had a 76 Honda that had a nasty wobble and it ended up being loose spokes.

I've found this film informative:

https://www.youtube.com/watch?v=fvsDIq3WwVA

[Muzz]

My '09 V7 gets a "suggestion" of a weave around 80mph when fully loaded w luggage.  Never amounted to anything.

The funny thing is that mine is better laden than solo, and two up it appears dead stable. Springs on the rears are backed off as far as they can go, and sag is then about right two-up.

I have always thought that the the springs are too strong, the compression damping too harsh and the rebound too soft. Sadly, descent shocks are a bit out of reach.

[normzone]

How does one source a proper dampener for a '99 Bassa ? Is there a preferred model amongst the tractor motor brotherhood ?

My Eldo had one I was content with when I got it, but it had been splashed by the P.O. who blamed the crash on a wobble on a radius overpass.

Funny enough, I only ever got one wobble out of the bike - on a radius overpass.

[redrider90]

My Mille is rock solid stable at all speeds but I rarely hit 90 MPH. It has never wobbled or weaved. But I had one experience caused by multiple riding mistakes on my part  that put the bike into a full severe wobble/end to end tank slapper at about 45/50 mph. I was fully loaded with camping gear and bags. I expected total weight was 850#s when I crossed going slightly up hill a steel railroad crossing in the rain. We were doing a 500 miler in an all day rain. I failed to cross at 90 degrees to the rails and instead I hit them at about a 60 degree angle (there was a slight curve in the road which I failed to adjust my approached to the RR crossing). Just as I came over the top I made another mistake and upshifted letting the clutch out with a slight increase in throttle. I am positive that as I crossed that wet steel crossing at the wrong angle going up hill and upshifted my rear tire slightly came up maybe not loosing contact with the ground but became somewhat unloaded. So as the back end came down, I upshifted at the wrong angle in the rain. The bike immediately went into a full end to end slapper. I really thought I was going down. All I did was hold onto the bars and back off the throttle and stayed OFF the brakes. As the front end went one way, the back end was going the other way. The forks hit the ends multiple times as my legs hit the jugs leaving bruise marks below my knees the next day. I went end to end 4 or 5 times. Then the last time it came around the bike shuddered and went straight and I was upright.
I pulled over shaken. Don, riding behind on his SPII  said how did you keep it upright and I said I do not know. I looked at my front tire and it had slid along the pavement leaving marks all the way to the outer edge of the tire on both sides tire perpendicular to the tread pattern which told me I was sliding across the pavement as it went end to end.
So for me I created the perfect storm, lost control in a fully loaded bike and the bike proved so stable that it stayed upright. I think if I had hit the brake or brakes I would have gone down. I remember it like it was yesterday and I still feel fortunate. My rear shocks were set to highest setting and my tire pressure was 34 front and 35/36 rear. I had nearly new tires.

[charlie b]

My T5 would weave in higher speed sweepers if the tires were squared off a bit.  Especially if I was loaded up for a trip.

Yes, it had the dreaded 16" wheels.  I liked them.  Steering was quick and precise.  But, there was a down side.

The quicker steering made itself known in corners with bumps.  If any of my weight was on my hands the bump would cause me to ever so slightly push on the bars and induce a small wobble in the corner.  For a long time I looked for other causes of this, such as bad head bearings, bad shocks, low tire pressures, etc.  In the end I just tried going through some corners without any pressure on the bars and the issue went away.

Last, loading.  If I had too much weight behind the rear axle I could get a weave started in the 80-90mph range.  Solution.  Don't load it behind the axle  :)

[sign216]

The funny thing is that mine is better laden than solo, and two up it appears dead stable. Springs on the rears are backed off as far as they can go, and sag is then about right two-up.

I have always thought that the the springs are too strong, the compression damping too harsh and the rebound too soft. Sadly, descent shocks are a bit out of reach.

Odd, as both our engines/frames should be the same.  Perhaps it's in how we load, and I've got a small sport windshield. 

[Muzz]

Odd, as both our engines/frames should be the same.  Perhaps it's in how we load, and I've got a small sport windshield.

I am about 166lb and 5' 7". I wonder if it is because I am a certain weight and being vertically challenged the front is being loaded up compared with the rear? Who knows? <shrug>

I have the original fly screen on. Not sure that would affect the bike in a high speed sweeper.

[sign216]

I am about 166lb and 5' 7". I wonder if it is because I am a certain weight and being vertically challenged the front is being loaded up compared with the rear? Who knows? <shrug>

I have the original fly screen on. Not sure that would affect the bike in a high speed sweeper.

I'm 5' 7.5" and 167 lbs, with the Guzzi sport screen.  I use a pair of soft bags, and am careful to keep vehicle weight low.  My rear shocks are set at the bottom, but everything else is stock (except the engine).  And to emphasize, at 80mph it's just a "suggestion" of weave.  Nothing real. 

[Chesterfield]

Guzzis seem to be the one of the least likely to have a headshake issue. Would I ride one without a damper yes. We all carry insurance for the unexpected. Believe me possible headshake is a good reason to carry insurance ( ala Damper ) for.

[balvenie]

Me and my '04 Cali seem to be the odd ones out here. The frame and steering head bearings have been checked but it was only after the stock fork  and rear springs were replaced, that the wobble in fast, bumpy bends was cured.

[Guzzidad]

     I had a serious tank slapper with my 96 Sport right after I bought it. It was my 3rd Guzzi and I knew that shouldn't have happened. I entered a nice high speed sweeper at maybe 80mph but hit a series of three minor bumps in the road and that set it off. The bike recovered after I rolled off the throttle. The previous owner of the bike was 40 pounds heavier than me and had the rear spring preload too tight for my weight. I backed it off and never had that problem again, in spite of riding way too fast for public roads. I don't ride that fast anymore. I still enjoy a spirited ride, but not stupid fast.

[Chesterfield]

Interesting, my '97 Sport came equipped with a damper from the factory. Did your '96 have one?