View Full Version : Cycle front end wobble
10-02-2009, 02:18 PM
Strange thing happened a few days ago. My 89 Yamaha Venture Royale motorcycle with 50k mileage was running great last time I rode it. Started driving to work doing about 25 mph and took my hands of the handlebars to zip up the jacket further when all of a sudden the front end started to wobble back and forth quickly, causing me to quickly grab the bars to keep it in control. That has never happened before. Visually checked the tires and air pressure and both were good.
Any ideas what to look at next?
Twin Cities, MN
maybe a cord seperated in the tire
10-02-2009, 02:55 PM
Cord, or wheel wheight, stone in the tire.
10-02-2009, 03:04 PM
Head bearing adjustment when the last time you done that service they do come loose.
10-02-2009, 03:06 PM
Outside of the ideas above, with the miles that you have on the bike, it can be the bearings and races in the triple tree. Put the bike on the center stand, if it has one, put weight on the back of the bike so that the front tire is off the ground. Kneel in front of the bike and move the wheel post to post. If you notice it very easy in the middle and a little tension beyond center position this may be the problem. The bearings wear after a while. Without any tension the wheel will do the shakes.
10-02-2009, 03:09 PM
also I do not know if the venture had weights in the end of the handlebars. If did make sure you did not have one fall out. But I am still going to bet that the head bearings are loose
10-02-2009, 03:59 PM
sledhd1 i agree, sounds like a head bearings if tire is good.
sledhd1 you going to make the poker run in leaf river??
10-02-2009, 04:43 PM
I had a 1984 Venture Royale and now have a 2002 Midnight Venture. Definitely have the steering head bearings checked and serviced. That is without a doubt, causing your wobbling. I have had it happened to a certain degree on both bikes. The old one wobbled more and the new one just felt very vague in curves.
10-02-2009, 05:05 PM
Wow...I love this site. Thanks for all the input. Head bearings...where/what exactly are they and is it something that a "semi-good sled wrench except when it gets too complicated" like me can do myself? Thanks again
10-02-2009, 05:10 PM
ANOTHER VOTE FOR LOOSE STEERING HEAD BEARINGS
10-03-2009, 02:05 PM
I did most of it myself, with the exception of the removing the race at the bottom of the post. The cycle shop had the correct press, etc... for that.
It is a quite in depth job, as you will more than likely have the whole front end of the Venture apart, and then some. It is your call. Just remember the importance of what you are working on, and if you will feel save with your work. There is an outside chance the bearings just need to be snugged up, though I doubt it. Let a qualified tech at least take a gander at it.
10-03-2009, 07:14 PM
If you visualize the steering post rides on a bearing surface in both the top and bottom of the bike frame. These bearings go bad, particularly if the bearing have never been lubed (some you can't) and they will go bad because they require the right torque and to keep smooth turning of the wheel, right and left these things need attention...as most have pointed out this is most likely your problem.
Get a good garage manual on this procedure specific to your bike and go ahead and do it. It isn't hard....just time consuming to take off brake, rotor, wheel, and drop the triple tree down to get to bottom bearing and then replace the top putting it all back together again.
If you have a friend that has done it, that surely will help.
10-03-2009, 11:01 PM
I had the same problem with My Heritage Springer. I had the front tire replaced after it was worn out. New tire doe's not wobble. The only thing I can figure was that the old tire lost a weight and was out of balance. Springers are notourious for steering yoke bearings. I am asuming that is what you guys are refering to as Steering head bearings?
10-04-2009, 01:25 AM
Would also be a good time to check the rear swing arm bearings or bushings and both front and rear wheel bearings.
10-05-2009, 11:41 AM
you may also check your front tire for cupping and wear as this can also cause a slow speed wobble.
10-07-2009, 10:27 AM
After owning several bikes (6 to be exact) over the years, I have run across your situation a few times. If you eliminate the tire as a probable cause, it could be a few things.
Like many have already said, your head bearings are probably worn out. If I'm not mistaken, that bike weighs close to 800 pounds. It's not unusual to have the bearings wear out after that many miles, especially if the retaining nut was not torqued properly from the get go. Moreover, if you're a "heavy" front brake guy (like most are) this adds to the demise of the bearings.
On my Ducati SS, I encountered some high speed wobble on the track one afternoon and the culprit turned out to be a cracked weld where the top tube connects to the head tube. Check very carefully the same welds on yours and make SURE that has not happened. There is nothing, I mean nothing, more frightening than realizing you were just going 165 mph+ on a race track and your entire front end could have just completely fallen off the bike!
I had a "dad" moment on the track one day after someone tried to pass me on the inside of a corner. He caught a pinch of grass, slid the rear end out, hot tire "caught" the asphalt abruptly stopping his rear end from sliding, he "high sided" the bike, went over the bars into the trees and received a helicopter ride to the hospital.
I proceeded to sell my last bike.
My past "collection"-
-1974 Norton Commando
-1984 Yamaha FJ100
-1985 Yamaha FJ100 with a 1380cc big bore kit
-1985 Yamaha RZ350 Kenny Roberts Special 2- stroker
-1988 Honda Hurricane 600
-1998 Ducati 900 SS SP (one bad mo fo!)
I still ride when I get a chance to ride a friends for a day, but with all the extra-curricular crap people do while driving their cars now, I'll pass on owning another one.
Now, where's that snow at....My sled is looking at me. http://www.johndee.com/discuss/clipart/happy.gif
10-07-2009, 04:50 PM
Read all the posts. Thanks very much.
Doesn't appear any weights were missing, tread looks good. pressure good. Didn't dig into the head bearings. Took the bike out again expecting the same wobble...and nothing. Could not repeat the issue at any spead (kept it under 80...not the 165+ like Propjockey).
Maybe something was stuck to the treads of the tire for that short ride. i don't know. I'll just keep my hands on the grips a bit more in case it happens again.
It's suppose to be in the low 30's here in Mpls MN Friday morning. I'll ride it the 24 miles into work just to enjoy the cooler temps...sledding isn't too far away.
THANKS AGAIN ALL.
10-07-2009, 10:45 PM
After riding the 1st gen ventures (1988 and 1990) for many year and having experienced high and low speed wobbles and found there are several causes for them and many were mention above from such as the steering head bearing wear, needing grease and adjustment. Also the front tire wear, fork seals and, mono shock mount wear to name a few. The attached comments are from the Motorcycle Touring Assocation
( http://www.mtariders.com/v3/) Brench Wrench section is regarding the mon shock mount, some dealers will add grease fitting to support regular greasing to reduce wear. ALso the steering head bearing is recommend to be cleaned and lubed every 25K or 30K.
From the MTA web site and I also has this problem;
Want to fix that deceleration wobble? I'll tell you what worked for me on my 1984 Venture Royale.
After more than I 7K miles on my first set of Dunlop K491 's, they began to talk to me, vibrate and wobble when decelerating be*tween 45 and 35 mph. Time for a new set of skins, even though the wear bar was not showing.
The new tires were installed last fall and they were okay except — you guessed it the wobble was still there and worse than be*fore.
Back to the tire dealer who rebalanced and rebalanced until I gave up. Static balanc*ing and spin balancing helped but still there was a noticeable wobble. I figured what the heck, most gold Wings and Harleys I know wobble. I'll ride it out and switch brands next spring.
In the meantime, the bike went into the shop for a good going over and tune up. Among other things, they greased and rebushed the mono shock mounts. They did not touch the tires which had been purchased elsewhere.
Want to guess again? Well, that wobble is completely gone and the Venture handles better than new, even with 34K miles on it.
http://www.mtariders.com/v3/index.php?option=com_content&view=article&id=270:d ec eleration-wobble-aug-1989-pg-13&catid=79:tech-papers-class-suspension-frame&Item id=94 (http://www.mtariders.com/v3/index.php?option=com_content&view=article&id=270:d eceleration-wobble-aug-1989-pg-13&catid=79:tech-papers-class-suspension-frame&Itemid=94)
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