Death wobble question
- Thread starter R_W_B
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TRIPPSTER
Member
I have a bro that has had a wobble start in the front wheel. We went through his bike several times to try to find out what was going on. At first the front tire seemed to almost bounce right before the wobble. It came down to tire pressure. his front called for 40 I believe. he was a couple pounds over, then dropped it to 39 and since then, he pulling 90 + with ease.
Just my opinion: I notice that the death wobble only appears in Harleys with rubber-mounted engines, that is, the Road King and Dyna series. You don't hear of Fatboys with that problem. I think the frames as originally designed used the bolted engine to add rigidity. It is lack of rigidity (among other things, like trail) which causes the wobble. I believe when Harley started using rubber-mounted engines to compete with the Jap bike's smoothness, they did not redisign the frame to increase its rigidity independent of the engine assembly. When you add to that the factors of loading, wheel and tire problems, wind buffeting on windshields and fairings, maladjusted frames, worn bearings, bushings, etc., you increase the likelihood of high-speed or cornering wobble.
ggadwa
Member
For what its worth, my 09 FXDC had Wobble issues right from the start. I was NOT IMPRESSED....
I started with Rubber Mount Shims, then Tire Pressure adjustments, then removed windshield, then installed fork brace....still wobble persisted.
Then I did many comparisons between Sputhe Stabilizer and True-Track lateral stiffness solutions, opted to install Sputhe.... not as tough a job as some folks proclaim, amazingly it did nicely stiffen the frame and removed the feeling of lateral movement. However, the Wobble was still there but diminished. I decided my tires especially rear was getting thin at 7,000 miles and I preparing for the long trip to Sturgis so I had a pair of Metzlers installed and ask the Shop to adjust "front fork fallout" when he had the rig on the stand. Shop said the fallout was loose and he put the front fork fallout slightly stiffer than specs.
3000 miles later and absolutely no sign of wobble at any speed or any road condition. Maybe it was related to the Dunlops vs the Metzlers, but my bet is the Front Fork Fallout stiffed up did the trick. Never the less I really do like the results of installing the Sputhe Stabilizer front and rear!!!
Riding lots and smilin' more.
GARY
I started with Rubber Mount Shims, then Tire Pressure adjustments, then removed windshield, then installed fork brace....still wobble persisted.
Then I did many comparisons between Sputhe Stabilizer and True-Track lateral stiffness solutions, opted to install Sputhe.... not as tough a job as some folks proclaim, amazingly it did nicely stiffen the frame and removed the feeling of lateral movement. However, the Wobble was still there but diminished. I decided my tires especially rear was getting thin at 7,000 miles and I preparing for the long trip to Sturgis so I had a pair of Metzlers installed and ask the Shop to adjust "front fork fallout" when he had the rig on the stand. Shop said the fallout was loose and he put the front fork fallout slightly stiffer than specs.
3000 miles later and absolutely no sign of wobble at any speed or any road condition. Maybe it was related to the Dunlops vs the Metzlers, but my bet is the Front Fork Fallout stiffed up did the trick. Never the less I really do like the results of installing the Sputhe Stabilizer front and rear!!!
Riding lots and smilin' more.
GARY
wideglider
New Member
I have had experienced the wobble, it was kind of scary so I did some reading and talked to alot of mechanics. It was suggested that I adjust my spokes I did and the problem was solved. I adjusted them twice a summer since and alls good.
I've had 'tank slappers' on a Triumph, Norton, and a Kawasaki 1000R. The one on the Kaw was so bad the handlebars severely dented the tank on both sides… When I took it in to get another tank, the boys there were a bit wide eyed….
I am 59 and been around a bit, but when I first started riding I was given some great advice: when in doubt: gas it. You are basically in control of a gyroscope (your rear wheel) and it is only stable under power. If you start getting a little 'squirrelly' DO NOT back off the throttle…. stabilize it by keeping the gas ON. This does not mean you have to accelerate, but giving it a bit more juice will settle it down. It wobbles because 'it' does not know what to do…. (in a manner of speaking), so you give it a 'new' command which creates stability. This is also true with crossing rail-road tracks; pavement irregularities; rain grooves.
My front end starts to wiggle when I 'jump on it' just enough to take the weight off the front tire, but not doing a wheelie; quickly, I give it a bit more juice then shift.
On a motorcycle you have 3 strengths, so take advantage of them: great vision; front brake; and acceleration. Use them to stay 'out' of trouble. If you don't master these three; you WILL get into trouble you can't get out of.
I am 59 and been around a bit, but when I first started riding I was given some great advice: when in doubt: gas it. You are basically in control of a gyroscope (your rear wheel) and it is only stable under power. If you start getting a little 'squirrelly' DO NOT back off the throttle…. stabilize it by keeping the gas ON. This does not mean you have to accelerate, but giving it a bit more juice will settle it down. It wobbles because 'it' does not know what to do…. (in a manner of speaking), so you give it a 'new' command which creates stability. This is also true with crossing rail-road tracks; pavement irregularities; rain grooves.
My front end starts to wiggle when I 'jump on it' just enough to take the weight off the front tire, but not doing a wheelie; quickly, I give it a bit more juice then shift.
On a motorcycle you have 3 strengths, so take advantage of them: great vision; front brake; and acceleration. Use them to stay 'out' of trouble. If you don't master these three; you WILL get into trouble you can't get out of.