Wildguzzi.com
General Category => General Discussion => Topic started by: rudyr on September 19, 2021, 04:33:58 PM
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Last week going to Cedar vale, at stop lite I did a shot gun start got the front wheel off the ground about a foot, ( loaded with camping gear about 120lb. Plus me175lb.) haven’t adjusted the shock off low poison because of my 8’9” height. Well today coming back from mo-can passing a car faster than I like, started getting a high speed wable. Pull back on the bars nothing( pushing against my back pack gear , so let off the gas that’s when it got really bad bad. How do you get out of a high speed wobble more power and more power pushing on the bars as hard as I could, got out of it but I was going really fast(I don’t think I changed lanes but all those car’s were about 1/4 mile behind now and not ant hurry to come any closer. What I think running over loaded with out spring tension on shock. You guy’s beware.It was bad I don’t think I went stop to stop but I have when I was 50 year’s younger.Rudy
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I'd say it was because of the way you loaded your bike. Were you using proper pannier bag arrangement, or was the load piled high on the seat behind you?
I've never had any issue with my V85.
I guess the other reason might be your 8' 9" in height!
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120 lbs of camping gear? I carry 2 person tent, cot, air mattress, sleeping bag, folding chair, clothing, food, Jet Boil, tools and necessary miscellaneous and I top out around 65 lbs. I ditched the aluminum panniers and rear case and use Nelson Rigg soft luggage panniers and Moose Racing 40 liter tail bag. Switching to soft luggage saves about 28 lbs. You must carry a lot of gear and if it truly is 120 lbs, your rear end heavy front end light.
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Is the gear on a rear rack or strapped to the pillion seat? 120 lbs. on a rear rack would explain the wheelie and the wobble. 120 lbs on the pillion seat should not be a problem. How's your tire pressures and wear? Glad you pulled out of it before things got really weird!
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I moved the top box 150mm forward on mine, but I doubt the issue is related to centre of mass.
If that was an issue, everyone who took a pillion would crash.
Tyre pressure ok ?
Rim straight ?
Road irregularity?
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Last week going to Cedar vale, at stop lite I did a shot gun start got the front wheel off the ground about a foot, ( loaded with camping gear about 120lb. Plus me175lb.) haven’t adjusted the shock off low poison because of my 8’9” height. Well today coming back from mo-can passing a car faster than I like, started getting a high speed wable. Pull back on the bars nothing( pushing against my back pack gear , so let off the gas that’s when it got really bad bad. How do you get out of a high speed wobble more power and more power pushing on the bars as hard as I could, got out of it but I was going really fast(I don’t think I changed lanes but all those car’s were about 1/4 mile behind now and not ant hurry to come any closer. What I think running over loaded with out spring tension on shock. You guy’s beware.It was bad I don’t think I went stop to stop but I have when I was 50 year’s younger.Rudy
I don't think a warning to others is necessary. You, on the other hand, could learn a thing or two about suspension set up. One lesson would be that the preload setting is not for adjusting ride height. If you were carrying that much weight and with little to no preload applied to the rear shocks you caused this problem.
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I would just add that a load aft relative to the rear axle center is relative to the overall stability at speed. Add the wind load at high speed as well as a soft rear spring , things up front can get squirrely pretty quickly.
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Too much speed, heavy load in the bags and not enough preload will almost always produce what you experienced. Keep in mind that increasing the preload MAY increase ride height unladen, but with 120lbs of load plus your weight the bike will settle.
I haven't had much experience recently with a tank slapper or heavy front weave, but when I have had it, I was taught to stay on throttle loose arms on the bars and shift weight forward and down, basically laying over tank.
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I dunno... I regularly carry 120-ish lbs of camping gear. Its called my wife. She is the ultimate camping gear. And I think I'm the only guy she's ever done anything with that WASN'T around 8' 9"...
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I don't think a warning to others is necessary. You, on the other hand, could learn a thing or two about suspension set up. One lesson would be that the preload setting is not for adjusting ride height. If you were carrying that much weight and with little to no preload applied to the rear shocks you caused this problem.
I think he figured that out. That is some scary shit. BTDT
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You, on the other hand, could learn a thing or two about suspension set up. One lesson would be that the preload setting is not for adjusting ride height.
Oh ok then.
So in your own words, if pre load is not used to adjust ride height by reducing static sag, what is it’s function ?
Please stay on point... :popcorn:
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Too much speed, heavy load in the bags and not enough preload will almost always produce what you experienced. Keep in mind that increasing the preload MAY increase ride height unladen, but with 120lbs of load plus your weight the bike will settle.
Yes the bike will settle, but the alteration of pre load will NOT alter the LENGTH that the spring settles TO.
It will only reduce the static sag.
If your unpreloaded spring is 200 mm long when FULLY LADEN, it will still be 200 mm long FULLY LADEN, when you add preload.
So you see that the SPRING is in the same condition compression wise, but it has not allowed as much static sag, so therefore the damping rod is not as compressed, therefore the ride height is higher.
Just consider this...
You have loaded your bike ready to go with rider aboard and a glamorous assistant holds it level on it’s wheels.
The damper rod is compressed 100 mm, so it’s 100 mm away from it’s top stop, it is NOT topped out.
You then have someone wind on 50 mm of pre load while you are on board.
As the bottom adjuster is being wound up, what stops the top collar retreating away from the compressing spring ?
NOTHING...!
After you have added 50 mm of pre load (and the spring is holding the same weight as before), the compressed length of the spring will be the same as before you added the pre load, it’ll just result in the damper rod being 50 mm more extended, giving increased ride height but not an alteration to the performance of the spring.
Please if you’re going to respond, don’t tell me “My mate used to have a Norton.........and. ..Ummm....”
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Optimal pre load is only as good as a given spring rating. Ride height means little if you have to exceed the optimal range of a spring to achieve a given ride height.
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Optimal pre load is only as good as a given spring rating. Ride height means little if you have to exceed the optimal range of a spring to achieve a given ride height.
Do you not agree Lucian, that the spring “range” (rating would be better), is independent of pre load.
The spring does not know what ride height you have.
If you stand on the 3rd rung of a ladder and use a slinky, you can stand on the 5th rung and the slinky will perform the same, it’s just further up the ladder..... :grin:
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Probably a combination of things caused this .
TS
I’d say that’s somewhat certain mate.
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My top case is Give 30 L about 10 lb. of cargo. Tire pressure though came after the wild ride plus stem torque plus high front fender, 8500 miles on bike And by pushing hard forward I did put weight on the front. TheGive planners had about 20 lbs. evenly. I pack wide and tight not over the top of the case except my coat. I my have been going fast when I got control and started slowing down I was at 92 mph I don’t know how fast I had to go to get out of the warble it didn’t go away easily. I think when I pasted the car I my have doing 90 + mph I wasn’t looking and then when it started I didn’t look had to much on my mind. Speed ca kill.Rudy
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My top case is Give 30 L about 10 lb. of cargo. Tire pressure though came after the wild ride plus stem torque plus high front fender, 8500 miles on bike And by pushing hard forward I did put weight on the front. TheGive planners had about 20 lbs. evenly. I pack wide and tight not over the top of the case except my coat. I my have been going fast when I got control and started slowing down I was at 92 mph I don’t know how fast I had to go to get out of the warble it didn’t go away easily. I think when I pasted the car I my have doing 90 + mph I wasn’t looking and then when it started I didn’t look had to much on my mind. Speed ca kill.Rudy
Well that clears things up.
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My top case is Give 30 L about 10 lb. of cargo. Tire pressure though came after the wild ride plus stem torque plus high front fender, 8500 miles on bike And by pushing hard forward I did put weight on the front. TheGive planners had about 20 lbs. evenly. I pack wide and tight not over the top of the case except my coat. I my have been going fast when I got control and started slowing down I was at 92 mph I don’t know how fast I had to go to get out of the warble it didn’t go away easily. I think when I pasted the car I my have doing 90 + mph I wasn’t looking and then when it started I didn’t look had to much on my mind. Speed ca kill.Rudy
Yep, I reckon I got most of that.
Your bike should not be so close to disaster that such a thing could cause trouble. With a pillion and no luggage, your centre of mass would still be further back than your situation.
Check..
Headstem bearings Adjust/grease or replace.
Handlebar attachment bolts.
Every fastener that holds the forks in.
Wheel bearings.
Axle pinch bolts.
Front wheel true
Front wheel balance...(not the same thing)
Front tyre condition.
Front tyre pressure.
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Do you not agree Lucian, that the spring “range” (rating would be better), is independent of pre load.
The spring does not know what ride height you have.
If you stand on the 3rd rung of a ladder and use a slinky, you can stand on the 5th rung and the slinky will perform the same, it’s just further up the ladder..... :grin:
I don't understand the slinky analogy, From rung to rung the slinky would perform the same , but dropped to the floor off rung three vs. rung five the Slinky's spring rate would diminish greatly , It's important to consider static sag and spring rate relative to rider sag when determining preload. Ride height is only relevant when the spring rate and rider sag are within the acceptable range.
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Yes the bike will settle, but the alteration of pre load will NOT alter the LENGTH that the spring settles TO.
It will only reduce the static sag.
If your unpreloaded spring is 200 mm long when FULLY LADEN, it will still be 200 mm long FULLY LADEN, when you add preload.
So you see that the SPRING is in the same condition compression wise, but it has not allowed as much static sag, so therefore the damping rod is not as compressed, therefore the ride height is higher.
Just consider this...
You have loaded your bike ready to go with rider aboard and a glamorous assistant holds it level on it’s wheels.
The damper rod is compressed 100 mm, so it’s 100 mm away from it’s top stop, it is NOT topped out.
You then have someone wind on 50 mm of pre load while you are on board.
As the bottom adjuster is being wound up, what stops the top collar retreating away from the compressing spring ?
NOTHING...!
After you have added 50 mm of pre load (and the spring is holding the same weight as before), the compressed length of the spring will be the same as before you added the pre load, it’ll just be 50 mm more extended, giving increased ride height but not an alteration to the performance of the spring.
Please if you’re going to respond, don’t tell me “My mate used to have a Norton.........and. ..Ummm....”
Youre talking in circles my friend ;-)
Cranking up the preload will result in an increase of static (unladen) ride height, and reduce sag. Never mentioned or implied increasing spring length. It is all about resistance to load and resulting height. My point was he said he had the preload on lowest setting to keep the static height lower due to his 8'9" height. I'm assuming he meant 5'9" All I was pointing out was that his increased load would have likely brought the ride height down to where it was on the lowest setting unladen, and remove his concern about reaching.
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I don't understand the slinky analogy, From rung to rung the slinky would perform the same , but dropped to the floor off rung three vs. rung five the Slinky's spring rate would diminish greatly , It's important to consider static sag and spring rate relative to rider sag when determining preload. Ride height is only relevant when the spring rate and rider sag are within the acceptable range.
The spring RATE would not alter however high you drop it from. The RATE is the amount the spring deflects (squashes), under a GIVEN load...(Check the definition).
Your example is varying the load by dropping it from higher.
My tongue in cheek analogy was for two reasons, one is to demonstrate that the spring does not have a different RATE if it is operating at a different part of the shock’s limits, that is in between zero and full pre load.
The RATE is a function of wire diameter, number of turns (angle) and if everyone has their say, spring material.
The spring in Rudy’s bike has the same wire diameter and number of turns no matter how it is pre loaded.
The other reason I tried to introduce some levity, was to hopefully stop a fight breaking out...(again).
It’s usually best to imagine the shock out on the bench with a load to compress it and imagine (or measure), the state of the spring before and after you root around with the pre load. If all else fails, ask Isaac Newton.
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Fat finger my height 5’9”. I’m not basket ball player. My speed limit in this state on free ways 75 mph. I normally run about 3 mph over. Now passing can be something else. I have painted as clear a picture of what happened today. I’m thinking I took the bike pasted it’s limit for the shock set up. This week end I did look at a v85 with a 1” shorter mono shock and front tubes moved up 3/4” they said it worked good. I do have very small Give tank bag, coup of maps and gloves.Rudy
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Youre talking in circles my friend ;-)
Cranking up the preload will result in an increase of static (unladen) ride height, and reduce sag. Never mentioned or implied increasing spring length. It is all about resistance to load and resulting height. My point was he said he had the preload on lowest setting to keep the static height lower due to his 8'9" height. I'm assuming he meant 5'9" All I was pointing out was that his increased load would have likely brought the ride height down to where it was on the lowest setting unladen, and remove his concern about reaching.
If you’ll agree that altering pre load will not change the ride quality, then we are on the same page.
Generally when I read a description of a situation on these pages, you don’t have to go far to find an ambiguity in a sentence. But if I have said something wrong, edit it down and serve it up...I’ve been wrong before... :clock: :clock: :clock:
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Youre talking in circles my friend ;-)
Cranking up the preload will result in an increase of static (unladen) ride height, and reduce sag. Never mentioned or implied increasing spring length. It is all about resistance to load
Yes and there is no real argument there, the bike will settle less when you roll it off the centrestand and the weight of the unladen bike hits the wheels, but the spring will be in the same condition (length) after you jump on, as it would have been if you’d added no pre load.
It’s just that the eye to eye length of the shock is greater (longer) so ride height is increased.
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You beat the dreaded front end wobble by loading the front wheel, not by trying to get away from it. Get your weight up on those bars.
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Yes and there is no real argument there, the bike will settle less when you roll it off the centrestand and the weight of the unladen bike hits the wheels, but the spring will be in the same condition (length) after you jump on, as it would have been if you’d added no pre load.
It’s just that the eye to eye length of the shock is greater (longer) so ride height is increased.
Yup, on the same page. :bow:
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Yup, on the same page. :bow:
Good stuff.. :thumb:
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"Your example is varying the load by dropping it from higher."
Exactly! Just as loading the rear and not increasing the preload. Adding preload in the slinky example would amount to lowering the rung as the slinky works in tension not compression as a rear shock.
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120 lbs. of kit , wow I thought I carried everything but the kitchen sink . I’ve scaled my load @ 80 lbs. or so . Did ya get the cast iron camping sink? Just kidding I’m glad to hear it ended well & may educate others
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So would it do it with a 120 lb passenger? In my mind your load isn't the issue if properly balanced. I'd for sure do some checking if it were me. Doesn't sound right. But it could have been an anomaly too like a wind gust, road imperfection, etc if it was a singular issue.
+1 on Huzo's comment.
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I find the whole spring rate/pre load/ ride height conundrum most frustrating
Just as I think I have my head around it it drifts off - just out of reach again :cry: :cry:
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I had a weave on my V11 Sport when I had saddlebags on it. Unlike yours, my bike would straighten up when I backed off the gas. The bottomline to all this, I needed a stiffer rear and softer front. I got the shock re-sprung with a stiffer spring and rebuilt the adjuster, also run the front softer when I carry a load. The stiffer spring helps because it can be adjusted in the "sweet spot" for heavier loads.
Since your bike wheelied, I'd guess you're still loaded too far back. But you might try to stiffen the rear substantially and soften the front to some degree. Actually, for my Sport, I got more benefit from softening the front than stiffening the rear- not with preload but with the adjusters, just to make the fork more compliant.
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Don't worry , just remember the forces are directed downward . Einstein kinda proved that :grin:
TS
Are you thinking of Newton?
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Men I have looked bike over can’t finder anything. I just was west of a town with fresh asphalt (2 wk.) flat slightly down grade, wind? My is reg.Cot, 4 man tent, sleeping bag, chair 3 legged stole, & one change of clothes exter socks & sweater,coat. Est. Weight passed back of axel is half seat load, 20 lbs. from saddle baggies. Told it was a Give top case but it’s Hepco/Becker I think it’s 33L I really don’t think over 10 lbs. l Am load the spring a little tighter and take the little rubber bumper off the under side of the seat3/16” lower and go a little slower(the hard part) that ride yesterday was for real young men not old men.amen Rudy
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I hate to admit I'm 240# but I've had all 3 bags fully loaded and hit 90 maybe once with no issues. I do have the front dropped 3 lines on the fork tubes (about 1/2") so you might do that.
how did you do a wheelie without the TC kicking in and shutting it down?
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I find the whole spring rate/pre load/ ride height conundrum most frustrating
Just as I think I have my head around it it drifts off - just out of reach again :cry: :cry:
It’s because people muddy the waters with poor analogies and repeating back what was said to them innacurately.
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Don't worry , just remember the forces are directed downward . Einstein kinda proved that :grin:
TS
And Newton said there was an equal one in the opposite direction. :grin:
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Actually, for my Sport, I got more benefit from softening the front than stiffening the rear- not with preload but with the adjusters, just to make the fork more compliant.
Which adjusters...? :popcorn:
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Well , one of those guys :laugh:
Was actually thinking of the theory of relativity , which as explained by a physicist bud states that "gravity pushes down" :grin:
When thinking of a spring it helps to see them as a lever over a fulcrum , pushing down on one end causes the other end to go up , right ?
Dusty
Einstein was referring to that concept when he stated..
“Give me a place to set my foot and I will move the Earth...”
If you release a basketball from 2 metres, the Earth attracts the ball and the ball also moves the Earth “upwards”, by an incomprehensibly tiny, but calculable amount.
Also your physicist bud might be better to say gravity “pulls down”, because the two masses are “drawn towards” each other.
Just sayin’.
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Which adjusters...? :popcorn:
meaning compression and rebound. For the V11 Sport, I soften both fork adjusters when I load the saddle bags on. I usually leave the rear shock alone I got it dialed with a heavier rear spring.
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I'll let you argue that with him .
TS
Ok Dusty.
My # is +61437 070946
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The only thing that makes sense here is the part about passing the car. The wake can upset and impart some sort of steering input through the wind force and the arms and torso or maybe the high front fender. The steering geometry’s influence from having excessive rear sag is debatable as is the effect of the rider’s steering inputs.
I researched this last year after a friend gave up riding when his KLR did the Hong Kong Wobble and landed him in the hospital for 9 days. He passed a tractor trailer on a two lane 55 mph highway. I also previously watched him remove a lowering link for the rear. The fork tubes were slid up to compensate, and I told him he should change that back too, but he blew it off….. Made sense that the steeper steering head and the truck’s wake caused this. There’s a-lot of good videos on this topic and it will always be as clear as mud….
Another friend related his story of his Guzzi that he crashed from a wobble. His Telefix fork brace snapped and must’ve had energy stored in it. He said it slid and caught on fire.
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Trust me on this , Brandon can and will tie your mind in knots W/O even breaking a sweat , having a PHD in physics means he actually knows of which he speaks . Then there was his GF who worked in a field of theoretical physics so esoteric she could tie his mind in knots . Once looked at the math she was generating , that was years ago and I still get a headache thinking about it . Him and Kirby both responded with the same answer as to what the ToR really means , gravity pushes down . An oversimplification , well yeah , but in real world terms it is close enough .
TS
Doubtless your Physics mate could tie my brain in knots.
But I was happy with it the way it was and yes we should all listen to Kirby because he’s clever...
Now that we’ve paid our dues.
As for your Physics mate regarding wiping the floor with me, I’m reminded of the words of the great man A Einstein..
He did a little bit of Physics too..
“If you can’t explain something simply, you don’t understand it well enough..”
(https://i.ibb.co/Vmv9xtY/29-EF775-C-9900-4150-90-BF-A4-F0643-F3873.png) (https://ibb.co/Vmv9xtY)
Couldn’t agree more Frankenstein.
BTW..
I’d love to talk to what’s his name...
Not to try to match him, but to have my misunderstandings put to rights. But for now I’m stuck down here on the ground with the average bloke.
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I hate to admit I'm 240# e .
In my circle of friends 240# is called puny. Come to Texas and I'll buy you a chicken fried steak. :grin:
Tex
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Peter , no one was arguing with you , most of us understand how preload actually works , no idea why you are worked up over this mate . What we were doing was infecting some humor , Rudy is a real world friend , he knows that .
TS
Actually you were injecting humour, although you were sort of correct ... :wink:
The new thread I posted is to try convey some stuff to Tris and to the others that are not in the “most of us” bracket.
If you took a poll two years ago and asked the membership what preload does, you would have gotten a different average response to what you’d get today.
PM sent..
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Maybe , although I doubt that . Most of figured that out 30 years back , buncha old guys here , remember .
Dusty
Anyway, I’m glad Rudy’s bike didn’t get too out of control so as to hurt him.
Will be interested to see if the probable cause raises it’s head.
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I know absolutely nothings about the Physics involving the forks or rear shocks but I did have an incident when I got my 02 Stone last year, that I will share.
The guy I got it from was a big guy, 300lb.
He told me that he had cranked the shock preload down quite a bit to keep it from bottoming out on bumps.
Therefore when I got it home the first thing I was to turn the adjustment nut up towards the top to release the spring pressure, thus getting a softer ride.
I took it on a test ride and around 75-80 mph the the bike started going into a wobble. Experience told me that if I didn’t back off at that point that things would get serious.
I went home and called a buddy, that’s actually involved in this conversation now, and gave him the scenario which had taken place.
He advised me to tighten the spring back down, making the spring stiffer, about mid way between the setting it was and the setting I had moved it to.
I took the Stone back down the same 4 lane highway and after letting the traffic get ahead and out of sight, ran the bike up to 90+ mph and it was totally stable.
The Stone is equipped with the large shield and Givi large bags, empty.
I admit I have no idea as the the Physics behind the shock spring changes but the difference was made.
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On my EVT there is a sticker on the tank recommending I not exceed 130kph (80mph) due to aerodynamic wind loads. In addition, there is a crude friction type steering damper between the lower triple clamp and the frame. Perhaps an aftermarket steering damper would help.
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An Oldie but a goodie..... https://www.youtube.com/watch?v=z3OQTU-kE2s
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I was to turn the adjustment nut up towards the top to release the spring pressure, thus getting a softer ride.
He advised me to tighten the spring back down, making the spring stiffer,
:popcorn:
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An Oldie but a goodie..... https://www.youtube.com/watch?v=z3OQTU-kE2s
Here's another one https://www.youtube.com/watch?v=fvsDIq3WwVA (https://www.youtube.com/watch?v=fvsDIq3WwVA) Wobble & weave starts at the 4:30 mark. Emphasis was given to weight distribution AND tire condition/pressure.
Also mentions that wide loads (panniers) can contribute. Perhaps it's not the amount of weight so much as how it's distributed AND what profile it presents to the oncoming air. If the load it particularly wide OR if it's uneven it could create a high level or uneven drag that could unweight the front end or introduce a weave/wobble.
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Preload is your friend when adding any weight to the bike. The further back, the bigger effect it has on the front end. 30lbs behind and above the rear wheel has a similar effect as 100lbs on the pillion seat.
Keep top boxes as small as you can and distribute additional weight as low and centrally as possible.
Remember the 30% sag rule, it works. Adjust preload to give the correct amount of sag with rider and luggage every time. This ensures that rake and trail remain constant.
Your arse sliding down the road, your choice.
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Here's another one https://www.youtube.com/watch?v=fvsDIq3WwVA (https://www.youtube.com/watch?v=fvsDIq3WwVA) Wobble & weave starts at the 4:30 mark. Emphasis was given to weight distribution AND tire condition/pressure.
Also mentions that wide loads (panniers) can contribute. Perhaps it's not the amount of weight so much as how it's distributed AND what profile it presents to the oncoming air. If the load it particularly wide OR if it's uneven it could create a high level or uneven drag that could unweight the front end or introduce a weave/wobble.
That is true for my V11 Sport. I usually got the weave on the loaded bike in semi wake at about 80mph.
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In my circle of friends 240# is called puny. Come to Texas and I'll buy you a chicken fried steak. :grin:
Tex
That's one of the reasons I got this way! Pass the gravy.
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Don't worry , just remember the forces are directed downward . Einstein kinda proved that :grin:
TS
And Newton said there was an equal one in the opposite direction. :grin:
Gravity is NOT a force, no matter what Newton said. General relativity shows us this.
https://youtu.be/XRr1kaXKBsU
:grin:
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And Newton said there was an equal one in the opposite direction. :grin:
Gravity is NOT a force, no matter what Newton said. General relativity shows us this.
https://youtu.be/XRr1kaXKBsU
:grin:
Well said Bulwnkl.
That’s intrinsically true. F=m.a
But can you imagine the rabbit hole that we’d end up going down before we got back on point if we thrashed that one out...(assuming we could).
The thread would be more contaminated than the Nile and would be nuked mid stream.
But I love that stuff on the video.
Physics does not lie or become confused.
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Sure it does , witness the spin 1/2 and spin 2 particles , or string cheese theory , even Albert himself couldn't explain the latter .
TS
The truth is being told by the Physics, but Alby couldn’t speak the language.
How d’you reckon he’d go with today’s super computers and electron microscopy techniques ?
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The real thinking and problem solving at the edge of theoretical physics is still done by the human brain , so Albert would likely still be at the cutting edge . Remember , he did his best work before he became famous , and now all these years later there are hundreds of physicists around the planet trying to disprove a lot of what he theorized , and failing mightily . W/O Einstein we might still be stuck with Newtonian physics .
My PHD buddy who found Mark Knopfler and Einstein at about the same time commented once that Einstein was the Mark Knopfler of physics , so brilliant some folks didn't appreciate how great a talent he was .
TS
I think I’ll enlarge that post and have it framed on my wall Dusty.
For once we totally agree..
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But back to the question about bike instability...
I had the occasion to strap a larger parcel on the back of the bike yesterday. Not heavy at 14 lbs (about 6 kg) but large presenting an area 34" x 8" to the wind. At 40 mph the V85 started to feel the effect with a vague feeling front end feel. Not a weave or tank slapper by any means, but it might have been worse at a higher speed.
To me this means that one need to be mindful of the load cross-section as much as the weight. Putting that large an item across the back seat certainly had an impact on the bike's handling. Could drag, especially away from the center line of the bike, be part of the cause of his wobble?
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Just got back off 140 mile exploring for primitive camp grounds (40+ miles gravel & steep mt. roads). found two good ones had to stop and get gas. Got on freeway coming home going 75 mph, truck got on my back end, I passed 3 truck trailer windy the front end stated to wable( 92mph) as I tuned back into lane it stops back to 75mph. A lot of wind from trucks, I think it was starting into a high speed wable but turning into the other lane just before it got started stoped it I think. Nothing but me and coat on back case. During my ride up Hy. 123 really curvy ( hairpin) going up the mt. stopped and picked up a guy with fun helmet and a skateboard no pads. 2miles or so let him off. He said he was going up and down the curve mt. road. with cars on road. Question is theirs some kind of skateboard raceing? I don’t know about.Rudy
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It sounds like you need to check your preload settings. You repeatedly encounter wobbles. You have one preload on front and one on rear. Rule of thumb is sag from rider and bike deadload should be 1/3 of the travel, which I think is 6.9” on the V85.
Manufacturers have test riders whose work is to tune the chassis design and suspension settings to avoid what you’re experiencing.
Something is wrong.
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I've done several passes in the mid 90' on my 2021 85tt with Dunlop trailsmart max tires, loaded side cases and large duffel on top. Bike has been rock solid in some pretty harsh side winds. Never any cause for concern.
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I forgot, check the spokes as well as the swingarm bearings.
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After I lost the front end on my V85 in strong side winds and a wet road, I decided that the Michelin Anakee Adventure tyres were not for me. Coupled with the fact that I don't ride off-road, and try to avoid gravel roads where possible.
They were replaced with Michelin Road 5 Trail, and the difference was chalk and cheese.
Incidentally, I found the same issue when I purchased and Indian FTR1200S. It too had off road tyres, I obviously hadn't learnt my lesson. These were replaced with Battlax Sport Touring T32, again a move I haven't regretted.
Finally to add my $0.02¢ to setting preload. I agree with Huzo, adjusting preload settings alters the ride height only (for non-progressive springs). Nothing more.
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Would checking the steering head bearings be of any value?
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Finally to add my $0.02¢ to setting preload. I agree with Huzo, adjusting preload settings alters the ride height only (for non-progressive springs). Nothing more.
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Ride height is an important issue, is related to chassis stability and is affected by preload regardless of if the spring is progressive. The OP could weigh alot and have the max setting on front preload and the min (which he already indicated because he had trouble reaching) on rear. Start in the middle on all the settings or as recommended in the manual….
Then get the front off the ground and shake the fork legs from front to back to check for steering head play. Then check that the front GLIDES smoothly through the steering range. It should require almost no force and no notchy feel. Then grab the rear tire when off the ground and check for swingarm play. Chassis pivot points should be okay an a bike so new…..
Something is wrong with the setup. It sounds like he may be heavy and has trouble reaching. The bike doesn’t care. Use the right spring and preload for the weight
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I agree with Huzo, adjusting preload settings alters the ride height only (for non-progressive springs). Nothing more.
Check out the “this might come as a shock” latest post Dave.
I’ll do it now.
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His thread is just muddying the water for him, unless a poster can actually look at his bike and eliminate the conjecture. He needs to figure it out or have someone do it before he gets killed.
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His thread is just muddying the water for him, unless a poster can actually look at his bike and eliminate the conjecture. He needs to figure it out or have someone do it before he gets killed.
That’s why I started the one about pre load, it was rapidly submerging the intended topic.
However, whatever the root cause ends up to be, extraneous information cannot be a bad thing, as long as you don’t necessarily expect it to contain a solution.
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You speak truly ex great one...(a deep and knowing nod..)
You were indeed lost, but it seems you have now found your way....(deep bow accompanied by the crashing of a gong in unison..)
Follow me Sir, and I shall lead you towards the aura of enlightenment.
Fear not on your journey, the light you see before you is but a train coming the other way... :thumb:
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I'm wondering if removing the windshield would have an effect.
Sarah
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I'm wondering if removing the windshield would have an effect.
Sarah
I don’t think it would Sarah. From my experience most of the issues being discussed in this thread are rear shock related.
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I experienced much the same thing on a V7II while riding to California and back earlier this year. Pelican-style cases on HB racks and a Dart Marlin shield. I posted about it along the way and got lots of suggestions, tried everything to some benefit but nothing resolved the issue completely. If I had it to do over I'd remove that screen just to see.
Sarah
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That’s why I started the one about pre load, it was rapidly submerging the intended topic.
However, whatever the root cause ends up to be, extraneous information cannot be a bad thing, as long as you don’t necessarily expect it to contain a solution.
Reading and writing are having a limited effect. A simple adjustment and/or ruling out steering stem misadjustment would likely resolve…..
Extraneous information is a hindrance to getting a point across, maybe even to reading in the first place.
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Reading and writing are having a limited effect. A simple adjustment and/or ruling out steering stem misadjustment would likely resolve…..
Extraneous information is a hindrance to getting a point across, maybe even to reading in the first place.
If there is “a point to get across”, could you share it with us..?
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If there is “a point to get across”, could you share it with us..?
There may be a place for science projects/lessons but this didn't look like it, when the original poster had problems articulating. The diffuse, possibly erroneous nature of ensuing posts, and your separate thread made me feel the need to reply.
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There may be a place for science projects/lessons but this didn't look like it, when the original poster had problems articulating. The diffuse, possibly erroneous nature of ensuing posts, and your separate thread made me feel the need to reply.
Reply by all means, your input is as good as anyone’s.
But that’s why I took the conversation about pre load to another thread, it’s been going on for a few years. Rudy does not have to concern himself with it if he does not want to, indeed I can’t see why he would. But there are people who are interested, have you seen the number of views ?
Now maybe we can get out of Rudy’s thread.
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I adjusted the rear mono shock was on lowest setting. On front fork judgment, is screw & lock nut just for rebound? My windshield I’m going to adjust the angel. Rudy
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What tire pressures are you running Rudy?
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The 14MM nut on the fork is preload and the screw is for rebound. I'd start with 1 turn from no preload and the rebound mid way.
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I don’t know the cause but I read a tip that made sense as to what to do if this happens.The late Oak,bmw expert,suggests To loosen your grip on the left and centrifugal force will stop the wobble.Apparently the impulse to hang on tight is counterproductive and aggravates the problem.I think you do not abruptly release the throttle but gradually slow until the shaking stops.A very terrifying experience and a professional Guzzi test rider was killed in LA in the 60s trying to solve the problem on police bikes .This happened to him on a race track,I don’t know if they ever figured out th the cause or the fix.I had it happen to me on my Eldo back in 79 and solved it by removing the handlebar Wixom fairing.
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I had check the tire pressure the next day after I had the wable. But not since then. I have had a wable at the speed I was going, but it was not bad as I had this( test riding a KLR at sturgis)time. And had bad wable at lower speed but not like the one I had on the V85. I’m going to run slower on freeways. And stay on more gravel mt. roads exploring and camping,and mt. fishing. No camping next week taking my wife on a cruise ( going to the front line’s so to speak on the --19 war).Rudy
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Start by slowing down. Go from there.
I’m forced to ride the slab living in the northeast. NEVER have I had to do 90+ to pass anything.
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Start by slowing down. Go from there.
I’m forced to ride the slab living in the northeast. NEVER have I had to do 90+ to pass anything.
Oh, man- I-55 south out of Chicago is just crazy fast. I was doing 90 on my Ducati and was passed like I was standing still. Now, to be honest, there is no reason to drive slow in that landscape (no offense to anyone living there).