High Speed Wobble

[Biker Dash]

I've heard of this happening, and well, on a burst up around 120mph, I felt it. Was nothing extreme, and it went away when I slowed back down to around 80 or so. It was just enough to let me know that Woona was not liking going that fast.

As I mentioned, I've heard that this is common with the 1st Gen Max. What would be the possible cause of this to occur?

I do have a windshield mounted. It is tilted back around a 40* angle or so. I had a decent tuck behind it, and my arms were loose on the bars. Bearings were recently checked, when I had the new Avon Venoms (120/90-18 + 170/80-15) mounted.

Here is the windshield, as mounted on the bike:

 

[[email protected]]

Could be a number of things.

Steering bearings.
Front tire
Rear tire
Windshield
Swingarm bearings
Wheel bearings

Id start by pulling the windshield and then a test ride. If it persists, check the steering bearings. While the front end is in the air check for play in the wheel bearings. Spin the front wheel and check for cupping, runout, bulging...replace tire if any abnormality is found.

Check the rear tire for abnormalities. Check swingarm for play.




Sent from my SCH-I405 using Tapatalk 2

 

[Matt427sohc]

Did you install the tire on your bike or a shop. If a shop did then they should have balanced the tire. Also on the tire is a direction arrow showing the way the tire should rotate. Also a small indicator dot should be on the tire for the location of the valve stem. Secondly most wobbles if not cause by tire not being balanced will be the head bearing in the triple tree not adjusted right. Sean Morley has video on U tube on how to check if the triple tree bearing are adjusted right. Hope this helps. Note why I know about the tires I had on the had a low speed wobble. Changed the tire problem solved. Finally with mine the tire had a bad spot.

 

[shawn]

used to have that problem when bike was new.Boxxenstopp changed the wimpy front fork springs problem solved.Now it don't matter if the tires are bald or loose (not lose) steering head bearings or other interesting theories.Had the bike for 17 years.It always cruises at a 100 plus with no problems everyday

 

[Biker Dash]

Of the issues listed so far, the only ones that would be questionable as of now are the windshield and the fork spring. By questionable, I mean that they might be the culprit. The tires are virtually brand new, and the shop in question makes certain things are balanced.

As of now, my best guess would be the windshield catching air enough to do this. I shall have to take her out for a run at speed without the windshield to test this.

Mind you, the max I normally see on my bike is 80 or so, and running at that speed, I have zero issues.

 

[alorio1]

If you did not have this problem before you changed the tires, then I would be looking at all aspects to the installation of the tires,IE, balance, maybe the tires were not lubricated well enough to allow the tire to seat right on the rim, red dot aligned with valve stem, rotate both wheels and check run out on rim and tire, check run out on outer diameter of tires for roundness, check for loose bearings and proper washer placement on back axel. Do Morley's bounce test on steering head brgs. As mentioned previously check swing arm for side play. If you look close, there is usually a line on the tire that's just above the rim. You can usually tell if the tire is seated correctly by rotating the tire and check this ring on the tire is even with the rim, on both sides of both rims. If you bought the tires from a shop and find run out side to side or on the outer diameter of the tire, they will try and convince you that the run out is within specs and leave you with what I consider a tire with a defect (blem tire).

 

[jfeagins]

I'm curious to know how a bad fork spring or two can cause a front end wobble? And if that is the case, how can we test them to determine a bad one?

 

[Itgoes]

Was it a wobble or a weave? Big difference IMO. A wobble is a much higher frequency an is usually related to something in the front, steering head, tire, wheel....etc.

A weave would most likely be the windshield, swing-arm , front wheel not straight in relationship to the triple tree and/or rear wheel, a cross wind, or you (how you sit on the bike).

If you push a Max real hard through some high speed sweepers you will feel a weave, that's mostly from the back end, the swingarm and mushy shocks........IMO.

All of my VMax's had a weave at some speed....the one that had an upgraded front and rear suspension and solid motor mounts, did it at a much higher speed.

My Venture would weave real good over 95.....kinda like wagging it's ass end. Not really dangerously, but it definitely felt unsettling. :surprise:

 

[[email protected]]

Was it a wobble or a weave? Big difference IMO. A wobble is a much higher frequency an is usually related to something in the front, steering head, tire, wheel....etc.

A weave would most likely be the windshield, swing-arm , front wheel not straight in relationship to the triple tree and/or rear wheel, a cross wind, or you (how you sit on the bike).

If you push a Max real hard through some high speed sweepers you will feel a weave, that's mostly from the back end, the swingarm and mushy shocks........IMO.

All of my VMax's had a weave at some speed....the one that had an upgraded front and rear suspension and solid motor mounts, did it at a much higher speed.

My Venture would weave real good over 95.....kinda like wagging it's ass end. Not really dangerously, but it definitely felt unsettling. :surprise:

Good explanation of the weave. Definitely an unsettling feeling while leaned over and pushing hard thru a turn. I tried new shocks and solid mounts but it never went away. Next step was a braced swingarm from Sean. It made a huge difference.

 

[Matt427sohc]

Tires due cause problems along with head bearing & one day if you don't check from time to time it will happen. Note going 100 is nothing like going 155 that much difference in speed will if everything is not right will cause high speed wobble aftermarket springs or not. Be careful what you say as a blanket statement.

 

[sdt354]

I have a very similar windshield, mine is a Memphis Shades. It's a sail after 100mph.

 

[Rusty McNeil]

Every single aftermarket windshield of the "clip on" type that attaches to the handle bars and forks that I have ever had caused some type of weave or wobble if taken to high enough speed.
I've had one on several different bikes too. Never a matter of if just "how fast before it happens?"

They give the wind a bigger lever on the from forks that helps amplifies any less than perfectly symmetrical aerodynamics.

 

[Biker Dash]

Every single aftermarket windshield of the "clip on" type that attaches to the handle bars and forks that I have ever had caused some type of weave or wobble if taken to high enough speed.
I've had one on several different bikes too. Never a matter of if just "how fast before it happens?"

They give the wind a bigger lever on the from forks that helps amplifies any less than perfectly symmetrical aerodynamics.

THAT sounds like a very likely culpurate!

Y'all mentioned a difference between wobble and weave? The oscillations seemed to be about 3-4 a second or so, and the bar ends would move maybe an inch max distance when this occurred.

 

[johnblaid]

This may make no difference but the windshield appears to be mounted on the handle bars. Would it be more stable if they were mounted on the forks like Rifle does?

 

[rebeltaz83]

i have a windshield similar to that one. was on it when i bought it. i have the "shake" up around 85 to 95. i don't think it's the shield, because 1 i just put new tires on it and it didn't do it at all, but now that i got some miles on them, it is back to doing it again. and 2 it only does it in 5th gear at wot. if i drop to fourth and go wot to redline, and shift to 5th it won't wobble at all it'll, go straight as an arrow. but if your getting a "weave" or wobble" then it could be the sheild.

 

[brad bruggeman]

Mine did this when I first got it.I replaced the stock fork springs with progressive springs and it solve my problem.Also,my windshield is bigger than yours so I don't think that is the problem.I had an 88 venture that had the same problem and same cure.

 

[adambweird]

I dont have a windshield but i get a scary ass wobble in the front from 128-131mph then its smooth as glass.

 

[sdt354]

used to have that problem when bike was new.Boxxenstopp changed the wimpy front fork springs problem solved.Now it don't matter if the tires are bald or loose (not lose) steering head bearings or other interesting theories.Had the bike for 17 years.It always cruises at a 100 plus with no problems everyday

I'm glad that works for you, but new guys, and anyone else. DON'T LISTEN TO THIS, IT'S THE WORST INFORMATION I'VE EVER READ. Loose steering bearings, bald tires will get you hurt or worse.

 

[jfeagins]

i'm glad that works for you, but new guys, and anyone else. Don't listen to this, it's the worst information i've ever read. Loose steering bearings, bald tires will get you hurt or worse.

ok.