Shuriken
Well-Known Member
Tire pressure is definitely something I can try. Mine are higher PSI than that.
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Tire pressure is definitely something I can try. Mine are higher PSI than that.
Redbone
Well-Known Member
COPRUNNER runs that air pressure because it gives him better traction on dirt roads!:rofl_200:
Shuriken
Well-Known Member
The steering head is definitely more stable if I push forward on the bars. Even just tinkering down the road at like 60mph, if I push firmly forward on the bars and induce a headshake, the bike returns to normal much faster.
I'm NOT suggesting to push forward on the bars to prevent speed wobble or anything like that - I am just continuing to experiment while trying to solve a few problems.
If pushing forward on the bars alone makes that much difference, I am just going to swap the head bearings and readjust. Suspension may contribute (lack of damping from the rears?) but the suspension is already loaded up to a degree because I am sitting on the bike. So pushing forward on the bars seems to me to probably tighten the steering head rather than to preload the rear springs or whatever, so I think the steering head is a major contributor to my problem.
It may take me awhile to get to the bearings, since it is now riding season, but I intend to change them and let you guys know.
I'm NOT suggesting to push forward on the bars to prevent speed wobble or anything like that - I am just continuing to experiment while trying to solve a few problems.
If pushing forward on the bars alone makes that much difference, I am just going to swap the head bearings and readjust. Suspension may contribute (lack of damping from the rears?) but the suspension is already loaded up to a degree because I am sitting on the bike. So pushing forward on the bars seems to me to probably tighten the steering head rather than to preload the rear springs or whatever, so I think the steering head is a major contributor to my problem.
It may take me awhile to get to the bearings, since it is now riding season, but I intend to change them and let you guys know.
I've had a mid sized sport windshield on my 94 since the first few days I had it, 4 years now. With the original forks in good shape and air in them, I had the bike to 130 and had no wobble. When the forks started leaking the low speed wobble intensified drastically. Uneven fluid levels, I'd imagine.
I recently changed the front forks out with some that Sean had rebuilt from a 97. Springs, Gold Emulators and BG Fluid. After doing that, I had a moderate low speed wobble, even at 10 mph with one hand off the bars. The wobble was there at most speeds to 55 when using one hand on the bars. We adjusted the steering bearings at the last tech day that CaptainKyle had at his house, here in Fl..
After that adjustment, I noticed a weave at certain speeds and with a certain load. I backed the adjustment off about 1/16 of a turn and that cleared up. It only slightly shows up with both hands off the bars.
I had the bike to 120 mph the other day and no hint of wobble. I dropped the throttle at the peak and it was still steady. I believe the windshield helps to keep the front end stable by placing an increasing down force on the front forks with increased speed. Kind of like a spoiler. I've run this type of windshield on other bikes to nearly 150 mph and they were rock solid as long as the windshield is 4 point mounted.
Just my thoughts.
I've heard so many cures for the high speed wobble that it's really muddied the issue. Everything from rear tire pressure, Front tire design, wheel design of the stock VMax wheels, shocks, springs, bearing tension and on and on and on. There may not be 1 set cure for every VMax, just gotta find out what cures the one you ride.:biglaugh:
Note, I started using this type of windshield because I was hit in the chest by a moderate sized bird that got into my flight path. It was on an XJ-1100 Yamaha. I was accelerating hard, at about 80 mph when the bird hit me. I nearly went off the back of the bike. The sissy bar stopped me in time to regain my composure and a death grip on the bars.
I recently changed the front forks out with some that Sean had rebuilt from a 97. Springs, Gold Emulators and BG Fluid. After doing that, I had a moderate low speed wobble, even at 10 mph with one hand off the bars. The wobble was there at most speeds to 55 when using one hand on the bars. We adjusted the steering bearings at the last tech day that CaptainKyle had at his house, here in Fl..
After that adjustment, I noticed a weave at certain speeds and with a certain load. I backed the adjustment off about 1/16 of a turn and that cleared up. It only slightly shows up with both hands off the bars.
I had the bike to 120 mph the other day and no hint of wobble. I dropped the throttle at the peak and it was still steady. I believe the windshield helps to keep the front end stable by placing an increasing down force on the front forks with increased speed. Kind of like a spoiler. I've run this type of windshield on other bikes to nearly 150 mph and they were rock solid as long as the windshield is 4 point mounted.
Just my thoughts.
I've heard so many cures for the high speed wobble that it's really muddied the issue. Everything from rear tire pressure, Front tire design, wheel design of the stock VMax wheels, shocks, springs, bearing tension and on and on and on. There may not be 1 set cure for every VMax, just gotta find out what cures the one you ride.:biglaugh:
Note, I started using this type of windshield because I was hit in the chest by a moderate sized bird that got into my flight path. It was on an XJ-1100 Yamaha. I was accelerating hard, at about 80 mph when the bird hit me. I nearly went off the back of the bike. The sissy bar stopped me in time to regain my composure and a death grip on the bars.
RaWarrior
Well-Known Member
I've found that if I really smash myself down on the airbox cover behind the factory flyscreen, I can usually avoid wobble. I mean as flat as you can possibly go, I'm staring right at the speedo and actually looking through the flyscreen. I was at 125 in a quasi-crouch and the weave started, I dropped right onto the cover and it quickly faded, took it to about 135 and it was steady.
BothaBoeta
Active Member
I'm a newbie,I have a speed wobble,at 70 or so.when you lads mention bearings and checking them,which bearings are you speaking about?Also,mines an old 97 and the front tire is about to get balanced,anything else I can have cheked on the cheap?
woodsman30
Well-Known Member
Alright I have never felt this wobble at all any speed one hard or no hands :ummm:
So i guess my question is why are people not checking their bike over before purchase and or after every summer ??? The bike needs to be checked top to bottom front to back . I dont mean just looking you need to break out the wrenches and torque bar. I have no idea why anyone would ride a used bike and bring it past 100mph and hope the last owner was good with maintenance:confused2:
Same as tires why are these not checked before each ride?? forks should be check as well I mean really how long does it take to check pressure on tires and forks maybe 5 minutes if you drink a beer too.
I may be anal about maintenance but why I do not understand why dont people look at their bike and not just ride them :ummm::ummm::bang head:
So i guess my question is why are people not checking their bike over before purchase and or after every summer ??? The bike needs to be checked top to bottom front to back . I dont mean just looking you need to break out the wrenches and torque bar. I have no idea why anyone would ride a used bike and bring it past 100mph and hope the last owner was good with maintenance:confused2:
Same as tires why are these not checked before each ride?? forks should be check as well I mean really how long does it take to check pressure on tires and forks maybe 5 minutes if you drink a beer too.
I may be anal about maintenance but why I do not understand why dont people look at their bike and not just ride them :ummm::ummm::bang head:
for what its worth, i got rid of my wobble. i got the wobble when i took my front end off and back on, i slid my tubes an inch up and when i filled the air in my shock tubes i used a bicycle shops pump with a gauge on it. it was wrong, i had 21-22 lbs in each shock! used a progressive air gauge to take it down to 10psi and it fixed me right up!
RaWarrior
Well-Known Member
The wobble on mine is really starting to annoy me enough to do something about it. I really don't go 110+ very often, but I feel like I'm losing out of the top 1/3 of the Max's potential because of this damn weave.
I did the bounce test without adjusting anything. By that, they were too tight. Had to push the handlebars the whole way down, wouldn't fall on their own. Loosened the nut and re-set it to fall but not bounce and went for a ride. Weave came on earlier(90 or 100 instead of 110-120) and was definitely more pronounced. Still fine at all other speeds(was before also), no weave on decel or no-hands. So I tightened the first nut as much as I could with a screwdriver and mini-sledge. Tried again. Maybe the same as when I started, maybe a bit better but the weave appeared at about 130. Definetly better than at the "bounce test" setting. Bike's a 97 with a bit over 20k miles(8500 are mine). The p/o was an older guy and I really don't see him riding wheelies, he *told* me the fastest he ever went was a tad over 100. I've never wheelied it, but I suppose the head bearings still could be no good, even though I didn't feel any roughness when the front wheel was off.
Checked the swingarm.....they're all good. Tires are new ME880's, though the high-speed weave doesn't seem any better or worse than with the old mis-matched set. Though corner stability and overall handling is MUCH better....no more wiggle when hitting a bump in a corner. Tried various fork pressures, no difference noticed so I put them back to 0 psi(progressive springs).
I'll deal with it until winter, and maybe do the head bearings then. Except for the 110+ range, it's rock steady. Can coast with no hands totally straight, hard braking is fine, highway is perfect. The head nut tightness had no effect on low and mid speed ride, but looser made the high speed worse.
I did the bounce test without adjusting anything. By that, they were too tight. Had to push the handlebars the whole way down, wouldn't fall on their own. Loosened the nut and re-set it to fall but not bounce and went for a ride. Weave came on earlier(90 or 100 instead of 110-120) and was definitely more pronounced. Still fine at all other speeds(was before also), no weave on decel or no-hands. So I tightened the first nut as much as I could with a screwdriver and mini-sledge. Tried again. Maybe the same as when I started, maybe a bit better but the weave appeared at about 130. Definetly better than at the "bounce test" setting. Bike's a 97 with a bit over 20k miles(8500 are mine). The p/o was an older guy and I really don't see him riding wheelies, he *told* me the fastest he ever went was a tad over 100. I've never wheelied it, but I suppose the head bearings still could be no good, even though I didn't feel any roughness when the front wheel was off.
Checked the swingarm.....they're all good. Tires are new ME880's, though the high-speed weave doesn't seem any better or worse than with the old mis-matched set. Though corner stability and overall handling is MUCH better....no more wiggle when hitting a bump in a corner. Tried various fork pressures, no difference noticed so I put them back to 0 psi(progressive springs).
I'll deal with it until winter, and maybe do the head bearings then. Except for the 110+ range, it's rock steady. Can coast with no hands totally straight, hard braking is fine, highway is perfect. The head nut tightness had no effect on low and mid speed ride, but looser made the high speed worse.
naughtyG
Well-Known Member
TBH, I reckon your head bearings may be shot. Do yourself a favor: remove the front wheel and handlebars (remove faux-tank and rest bars there), maybe even loosen the triple-trees and remove the fork tubes; and then once all the weight is off, have a feel at moving the triple-trees from end to end.
If you feel any roughness at all (which you can't with all the weight - I speak from experience) then you'll know the bearings need replacing. It's very apparent this way. Good luck..
If you feel any roughness at all (which you can't with all the weight - I speak from experience) then you'll know the bearings need replacing. It's very apparent this way. Good luck..
RaWarrior
Well-Known Member
Front is a stock size Metz ME880. Rear is a 170.
It's pouring rain now, but I checked tire pressure(doh!) since I hadn't even thought about it since getting the new tires mounted. Both were at 29-30....for sure a bit on the low side. Aired them up to the 33/36 sticker spec, and I'll try again later. Remember when I first got the bike the tires were low and airing them up definitely helped. Found a research paper online in my school's online archive about motorcycle wobble. It got pretty in-depth, but a common cause for high-speed weave was determined to be flexing in the tire itself, from insufficient sidewall stiffness(why radials are better here), and that ensuring proper pressure and possibly slightly over-inflating can prevent this flexing that induces weave.
In researching this a bit, the Vmax is not alone in the high speed wobble. In searching for the problem, every Harley site is absolutely littered with this issue, one even had a dedicated forum for "stability issues". Reading a bit, I feel a bit better. They complain of severe, tank-slapper butt-pucker moments pushing it much past 90, where I get a gentle weave at 130. Apparently HD has been sued multiple times from injuries/deaths from severe wobble that put the bike over.
It's pouring rain now, but I checked tire pressure(doh!) since I hadn't even thought about it since getting the new tires mounted. Both were at 29-30....for sure a bit on the low side. Aired them up to the 33/36 sticker spec, and I'll try again later. Remember when I first got the bike the tires were low and airing them up definitely helped. Found a research paper online in my school's online archive about motorcycle wobble. It got pretty in-depth, but a common cause for high-speed weave was determined to be flexing in the tire itself, from insufficient sidewall stiffness(why radials are better here), and that ensuring proper pressure and possibly slightly over-inflating can prevent this flexing that induces weave.
In researching this a bit, the Vmax is not alone in the high speed wobble. In searching for the problem, every Harley site is absolutely littered with this issue, one even had a dedicated forum for "stability issues". Reading a bit, I feel a bit better. They complain of severe, tank-slapper butt-pucker moments pushing it much past 90, where I get a gentle weave at 130. Apparently HD has been sued multiple times from injuries/deaths from severe wobble that put the bike over.
Shuriken
Well-Known Member
Wife and I took a a 100+ mile ride yesterday. With her and I both on the bike, the front end is planted and quite solid. She is a petite gal but I guess having a passenger makes a huge difference. Wonder how many of us have the speed wobble with aftermarket front and rear springs/shocks....
naughtyG
Well-Known Member
My bike came with Progressive springs in the front forks, and aftermarket 12.5" rear shocks (which I believed to be older Progs too), as well as very shit Dunlop Qualifiers and completely shot head bearings.
It did have the death wobble front 115 mph.
Furbur fix helped raising wobble to about 120.
Changing tires to Shinkos also helped a little, but still bad.
Changing rear shocks to OEM shocks made it big time worse.
Renewing the head bearings stopped it altogether, although as the Shinkos (rear especially) wore down it seemed to creep back a little (or I'm just really paranoid after almost dying too many times) at super high speeds (125mph+).
I did find that relaxing my grip on the handlebars always helped, and gripping hard made it worse.
As the Shinkos got older I also got the slow speed (30-40mph) wobble if I let go of the bars.
I've done solid motor mounts now but haven't had the chance to take it to high speeds since, and now I won't be riding it until next year (traveling the world).
I've definitely noticed that NO ONE has ever had it happen when 2-up, maybe it is a weight/geometry thing that is fixed by having a pillion.
It did have the death wobble front 115 mph.
Furbur fix helped raising wobble to about 120.
Changing tires to Shinkos also helped a little, but still bad.
Changing rear shocks to OEM shocks made it big time worse.
Renewing the head bearings stopped it altogether, although as the Shinkos (rear especially) wore down it seemed to creep back a little (or I'm just really paranoid after almost dying too many times) at super high speeds (125mph+).
I did find that relaxing my grip on the handlebars always helped, and gripping hard made it worse.
As the Shinkos got older I also got the slow speed (30-40mph) wobble if I let go of the bars.
I've done solid motor mounts now but haven't had the chance to take it to high speeds since, and now I won't be riding it until next year (traveling the world).
I've definitely noticed that NO ONE has ever had it happen when 2-up, maybe it is a weight/geometry thing that is fixed by having a pillion.
Hearing that, about not having a wobble with a passenger makes me wonder if guys that weigh 300 lbs and up are safe from the high speed wobble all together? I'm just to old to leave high speed blasts to possible crashes, especially when the wife's along. Since we adjusted my head bearings at the last Tech Day and I got the weive out afterwards everything seems to be alright at high speeds but I'm very leary and haven't pushed it past 130 with just me and 115 with 2 up.:ummm:
Shuriken
Well-Known Member
Agree with you about safety with a passenger. I didn't need to take it very fast to tell that the front end is solid with a passenger. We hit 95 once when passing some vehicles on the interstate and there is no hint of twitchiness at all in the front end.
Wife and I together with gear are less than 300 but there is definitely a serious clue about the bike being more safe and solid with a passenger. I'd like to hear from others who can test 60 vs 90mph with a passenger and if their bike is safer with more weight. If someone can observe what happens when two people mount the bike... such as... if there is a significant lowering of the bike, spring pre-load, etc....
I think with some new suspension and bearings I should be good to go. I have yet to determine positively which (bearings or suspension) is the bigger factor.
Shuriken
Well-Known Member
Just providing a link to another helpful post:
http://www.vmaxforum.net/showthread.php?t=13462
http://www.vmaxforum.net/showthread.php?t=13462
Shuriken
Well-Known Member
So... better late than never I guess.
Fork seals started leaking so I decided it's time to work on the front end. Brakes, master cylinders, fork seals, and steering head.
With the wheel and other stuff off, the steering head bearings felt overtight. Less resistance in the center and more as I turn it. Maybe some binding as well.
While waiting for bearings and fork seals, I have a chance to do other things and also inspect the bearings. So here we go...
I'll try to work on only one area at a time but hopefully some much needed TLC on this antique will be worth it. Fork springs and rear shocks are also a possibility but one thing at a time.
Posting here because my intention with the new bearings is hopefully a handling improvement.
Fork seals started leaking so I decided it's time to work on the front end. Brakes, master cylinders, fork seals, and steering head.
With the wheel and other stuff off, the steering head bearings felt overtight. Less resistance in the center and more as I turn it. Maybe some binding as well.
While waiting for bearings and fork seals, I have a chance to do other things and also inspect the bearings. So here we go...
I'll try to work on only one area at a time but hopefully some much needed TLC on this antique will be worth it. Fork springs and rear shocks are also a possibility but one thing at a time.
Posting here because my intention with the new bearings is hopefully a handling improvement.
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