decel wobble

[Indyventure]

Hey all...I noticed something for the first time during a ride yesterday. I've had my 89 VR for about 6 months now and I'm really enjoying it.

 

Yesterday I was riding with a small group of guys so I was driving a bit less agressively than usual. So I was doing more one handed driving than I ever do. So I noticed when the bike is in decel, throttle rolled back all the way, as the bike hits about 40 mph with one hand on the bars the front wheel starts to go into a pretty strong wobble. It is not a full tank slapper but it shakes pretty hard and I want to get both hands on the bars asap and this straightens it out quickly. When I do it with both hands on the bars I only feel a slight wobble coming through my hands. The wobble tends to disappear after my mph drops to around 35.

 

one note: yesterday before the ride I did adjust my CLAS setting moving the front end from from a pretty low setting up to 18 lbs if memory serves me right.

 

Anyone have any ideas on what might be causing this? The front steering head bearing was repacked about 5000 miles ago. the tires are elite 2s I believe.

 

thanks everyone!

 

Bob

[Marcarl]

Take a look at this post, it's for a 2nd gen but the procedure is the same and the results are the same.

http://www.venturerider.org/forum/showthread.php?t=511

Your steering head acts as a damper to prevent the wobble you experienced. Something else may be causing it but the steering head is the first thing to check out. That you had it replaced just recently makes sense that it is now loose. The seals will compress and the bearings will seat better with some riding. Tighten them once more and you should be good to go.

[muffinman]

I find that on my 83 when the front tire is at the end of its life (almost worn out) that I get a shake at 35 to 40 mph.Hows the tire look?

Jeff

[Indyventure]

thanks guys...I'll check both of those leads out tonight. Yesterday was the first day I took the VR through some real tight twisties and I was shocked how well it handled. I could lean her right over nicely.

 

Bob

[KingSizer]

My 84 does the same thing. The front tire is just about done, but I won't be replacing it until next spring. I'm hoping that a new tire will get rid of the wobble. For now I just keep both hands on the bars (most of the time).

[Guest KitCarson]

My 84 does the same thing. The front tire is just about done, but I won't be replacing it until next spring. I'm hoping that a new tire will get rid of the wobble. For now I just keep both hands on the bars (most of the time).

Whew......you are living dangerously.....I have a friend who had an old sportster sitting in a shed.....we got it out and dusted it off. and got it to running again.....the tires are how old?????? Had dry rot cracks in the sidewalls.....he was going to fill them up with silly cone.......I bought him some new tires........tires are the only thing between you and the road.......you have my permission to hit my ignore button :rotf:, but please go get a new tire......do not wait till spring....and take that last ride to the corner store. Respectfully Kit And like Carl has said...get the front end off the ground and check out that front end......and the bearing....all that stuff.

[yamahamer]

MY 06 RSV does the same thing mine was front tire pressure.

[CrazyHorse]

Mine does the same only at 40mph I think its inherent in these bikes. My steering bearings were fine I have superbrace,solid engine mounts, progresive springs, new tires. Still have it right around 40mph.

[muffinman]

Mine does the same only at 40mph I think its inherent in these bikes. My steering bearings were fine I have superbrace,solid engine mounts, progresive springs, new tires. Still have it right around 40mph.

Jim this in not inherent in the venture I had the same thing happen after getting a new tire and had to have it rebalanced to get the wobble out.Tell the place that ballances your tire that you ride in excess of 100mph and it is wobbling.1/4 ounce out and my 83 does all kinds of weird things from a wobble to tire hopping at 90+ mph

If a reballance does not help check the wheel for warpage also check the wheel bearings while it is off.

Jeff

[CrazyHorse]

Jim this in not inherent in the venture I had the same thing happen after getting a new tire and had to have it rebalanced to get the wobble out.Tell the place that ballances your tire that you ride in excess of 100mph and it is wobbling.1/4 ounce out and my 83 does all kinds of weird things from a wobble to tire hopping at 90+ mph

If a reballance does not help check the wheel for warpage also check the wheel bearings while it is off.

 

Jeff

Thanks Muffin but why does everyone say around 40mph? Mine is stable above and below that 0-100+ except 40mph. It almost seems like some sort of harmonic issue with the bike itself, but you would know better then me. I'll look into those things this winter. I also have Ride-On installed in the tire probably have to clean this out for rebalancing. Thanks for the help.

[muffinman]

No problem JimBob I have not figured it out if it is actually a harmonics problem ot just the weight of the bike

Let us know if you have any more questions

Jeff

[CrazyHorse]

No problem JimBob I have not figured it out if it is actually a harmonics problem ot just the weight of the bike

Let us know if you have any more questions

Jeff

 

I remember reading another post I believe by gearhead about a 40 mph wobble. I will feel the wobble accelerating and decelerating but you need a light touch to feel it accelerating. Bike is stable as can be 100+ in sweepers etc (except if big truck near then you get the buffeting) rides great nothing scary happening but that darn 40 mph range with a light touch or no hands or one hand you feel it and its gets strong quick but stops if you hold the bars. Thats why I was thinking its some sort of harmonic issue. Now 83-85 are different weight bikes and weights are slighty different front to back. I wondering if this is more of 86-93 issue? You change the harmonic frequency with weight or just differences in bike. But like I said there are much more knowledgeable people like yourself then I am about these bikes. I would think if was just wheel weights people would have different speeds at which you get the wobble but I'm not a sceintist.

[91nwl]

Most of the time the wobble is around 40 mph on decel. Most of the time it is tire related. It usually shows up when the tires are getting close to worn out, but sometimes it happens on new tires. It happens on all makes of bikes. People spend a fortune trying to fix it. You should see the attention this gets on the Goldwing boards. The most effective countermeasure is to keep both hands on the bars. If you think it is a safety problem when you have both hands on the bars, you probably have a significant tire issue...seperating tire, unbalanced tire, cupped tire, low pressure, etc. But most of the time it is barely perceptable if you keep both hands on the bars, so the wobble is not a safety issue in and of itself. If it wobbled at 100 mph, now that would be a problem.

[Gearhead]

I agree fully with 91 above. It's not just the Venture - it's happened on my last 3 bikes and new front tires always solve it; don't know if it's more related to wear pattern or the tire getting out of balance as it wears. Well, the new tire almost always gets rid of it. On the Venture, it is WAY better with the new tire, almost never happens, but it still will. It takes a bump from the road or (experimenting) a bump from my hand on the grip to start it, but light hand pressure on either grip stops it dead. I balanced the tire myself, but maybe it's still slightly out. Maybe the geometry of the Venture is more susceptible than others, dunno. I gave the head bearing the proper attention, and fully went thru both suspensions, by the way. At any rate, it's some harmonic that's common to most motorcycles at some level. Always worst at 30-40 mph, and worse on decel.

 

Jeremy

[GeorgeS]

I had the wobble around 40K, I regressed the head bearings, and added a little torque. It was too loose.

Anyway, adding torque fixed it. Never senced it again.

 

Since then I added the Superbrace, Progressive Springs, and Avon tire.

 

Its rock solid now at least up to 80 mph.

[Indyventure]

jsut to let everyone know what I found to close the loop..... My fronn tire although probably in it's last 30% of tire life looked "OK" however, I did find the my tire pressure was in the lower 30s so I inflated to 40 lbs and the wobble has signifiacntly been reduced.

 

I checked my steering head bearing first by pulling on the forks with the front wheel up and it felt ok, then I tried the test seeing if it fell easily to one side or the other. I found that mine wouldn't easily flop to one side with a nudge more because the wiring harness tend to hold it up about half way through the turn. They provide enoguh resistance in this test to stop the wheel turn. Anyway if I push it past this point the forks do bounce off the stops a little more then I think is proper. so I'm going to go ahead and tighten them up just a schosh.

 

I think a new tire is in my future too so between all three things I'm pretty optomistic this wobble will pretty much disappear.

 

Thanks again for all that helped!!!!

 

Bob

[Squeeze]

.... so I'm going to go ahead and tighten them up just a schosh.

 

I think a new tire is in my future too so between all three things I'm pretty optomistic this wobble will pretty much disappear.

 

Thanks again for all that helped!!!!

 

Bob

 

 

Dont forget to loosen the Pinch Bolts of teh Forklegs on the lower Forkbrace before tightening the Locknuts. And, of Course, tighten them back to the Specs afterwards.

[Indyventure]

"Dont forget to loosen the Pinch Bolts of teh Forklegs on the lower Forkbrace before tightening the Locknuts. And, of Course, tighten them back to the Specs afterwards"

 

 

I hadn't heard of that before...what's the thought behind that? thanks for the insight.

 

Bob

[Guest Popeye]

I replace my tires every other year...period. Dunlop 491 EIIs.

Had just a little of that wobble, but started upping the air pressure & keep them at 50 psi at all times. [tires wear evenly]

 

No wobble & scoot just handles better, whether 2up, dry, or wet pavement.

 

Also, I always keep CLASS at about 22 psi in front & 74 rear.

 

Book & techs always recommend different for each, but I just do what works...for my scoot, anyway.

[Squeeze]

"Dont forget to loosen the Pinch Bolts of teh Forklegs on the lower Forkbrace before tightening the Locknuts. And, of Course, tighten them back to the Specs afterwards"

 

 

I hadn't heard of that before...what's the thought behind that? thanks for the insight.

 

Bob

 

Hi,

 

i try to explain this by overdue the Facts.

 

Let's say, the Distance between upper and lower Forkbrace is 10 Inches before you open the Top Nut on the Tripple Tree. Now, you open the Topnut and tighten the Locknuts down to a Distance of 9 Inches. Now, you thighten the Top Nut down to Lock the Assembly. Now the Distance between the Stem is nine Inches, the Distance between the Forklegs is, locked and fixed by the Pinchbolts on both Forkbraces, 10 Inches. What happens to that one Inch ??

 

This Inch would add up in a massive Disformation of both Forkbraces. That's not what we want to have. We want NO Disformation or Tension on anything in the Suspension. Not to Mention that such a Distance would cause anything to break before the first test Ride is on Schedule.

 

In Fact there is a M25x1.25 Thread on the Stem. So, if you can turn the Locknut down by one Turn, the Distance between upper and lower Forkbrace is only reduced by 1.25 mm. Which is 1/20 of an Inch. Also a big Distance when we want to have NO Tension. One Turn is not uncommon, when this Area isn't maintained and repacked regularly.

 

Why to open the Pinchbolts on the lower Forkbrace? Beneath the upper Forkbrace the the Air Connector which cannot be raised or lifted, this Assembly has to stay in his exact Place. The Forklegs slip through the lower Forkbrace and can be tightend after adjusting the Locknut and tighten the Topnut.

 

Also, the complete Frontend needs to be off the Ground during the Process. This is for proper Adjustment and tensionfree Working on the front.

 

I hope you get my humble Explantion, if not ask again

[Gearhead]

" My fronn tire although probably in it's last 30% of tire life looked "OK" however, I did find the my tire pressure was in the lower 30s so I inflated to 40 lbs and the wobble has signifiacntly been reduced. "

 

 

I'd almost bet money that the front tire is the cause. I'm not saying it's unsafe, I'd use that front tire up because the wobble is not a problem with both hands on the bars. You could also try rebalancing. But they do start wobbling way before they're used up sometimes.

 

Jeremy