| Author | Message | ||
     Phelan |
Over the last few days of commuting 70 miles a day round trip, I've noticed a wobble that starts around 75-78 mph and gets worse as speed increases. I have to back down to about 70 before it stops. Any ideas on what could be causing this? It was a 525 mile trip to get here in Colorado last week and I don't remember having the issue at all on the trip, though I had it a little the day before, in which sparked me to check and correct the tire pressures from 41 PSI (where they had dropped to) to 45 PSI (correct for the tires and I believe correct for the bike as well). Today I checked them when I got to the shop (41 PSI) and aired them back to 45, but still had the wobble when I left for home. Isolators look good, with 3K mi on the front, and the tires have maybe 1000 miles on them (Conti Trail Attacks) | ||
| Deanh8 |
Check all your motor mount rubbers then bearings (wheel, steering head etc) | ||
| Imadog |
Wheel Bearings, Swing arm pivot and steering head bearings come to mind. | ||
| Buellistic |
"TOO TIGHT" on the head cone bearing cause the "WOBBLE" with all other thing good !!! CHECK the FACTORY SERVICE MANUAL for the HOW TO CHECK !!! | ||
| Buell_bert |
I have also seen rims that have thrown a weight cause "wobble" on bikes OR cars at or above certain speeds. If the neck bearings are loose you usually FEEL a clunk on firm accel and deccel and sloppy/flop over, cornering back and forth. Also check the rim in case you hit a pot hole and damaged it or a tire that may be failing (bulging/distorted) . Good luck and keep us informed. | ||
| Dannybuell |
a 96 needs the Banke frame brace or a clone. The front of the bike is vibrating like a tuning fork. The frame brace eliminates this. At speed wind resistance will lift the bike a bit, adding pre-load to the rear shock will resist this effect. my 96S1 was bought with 7,000 miles in 1997. My S1 now has 104,000 miles. I experienced wobble many years ago, the Banke frame brace took care of that. ass be damned the rear shock pre-load is more of a tuning move to keep the front end down. | ||
| Damnut |
I had the the same problem until I replaced my tires. | ||
| Buellistic |
If your Front tire is CUPPED, it will cause a drive ability problem in handling !!! | ||
| Phelan |
I welded in a frame brace in my S2T, so that's not the issue. Neck bearing aren't too tight because I've never touched them and this is a recent issue, but they could possibly be loose, though I doubt it. I do remember hitting a pothole, maybe that had an effect, though I'm leaning towards wheel bearings, since I remember my rear bearings being a little stiff when I changed the tires. I will be replacing the wheel bearings this week. The other possibility could just be a combination of things and bad roads; most of the commute from Fort Collins to Longmont is grooved roads. Anyway today it was raining this morning but cleared up halfway through my morning commute, and the bike didn't wobble at all, not did it wobble on my way home. | ||
| Phelan |
Like I said, the front and rear tires are like new, maybe 1,000 miles on them, and never below 41 PSI, most of the time at 45. | ||
| Two_seasons |
Thrown weight like Buell_bert said? | ||
| Phelan |
Ah didn't see the thrown weight part. I have tire a tire balancer and tons of spare weights; I'll check that out when I change the bearings. | ||
| Buell_bert |
I have seen tires or usually a tire that has thrown a weight where the steering is fine slower but as the speed increases the shake will increase with speed and may smooth out or just get steadily get worse. It has everything to do with harmonics and resonant frequencies. Most of the shaking was at 45-65 mph. Good luck and let us all know what you find out. | ||
| Rocket_in_uk |
It might not be at all relevant but my S1W will always wobble if I 'lay down' and place my feet OVER the rear pegs with them hanging behind. Before you wonder how I know this, lol. When on long runs I sometimes put my feet on the rear pegs. The comfort relief is welcome and causes no difference to the handling. Not so if I move my feet back that bit more as described. A weave will occur which wants to turn into a 'tank slapper'. Could you have had a weight carrying issue? Love to hear of you riding those roads, Brings back great memories. Rocket in England | ||
| Phelan |
Rocket, you may be onto something there... I do move my feet often and sometimes in non-standard positions along with laying forward, crouching my chin under the windshield. I'll try a few positions on my way this morning as that could be the issue itself. | ||
| Essmjay |
I think you are running the tire pressure too high. Not necessarily related to the wobble, but it will affect handling and tire life. | ||
| Essmjay |
per my owners manual- front ....30 w/solo rider, 38 at GVWR rear......36 w/solo rider, 40 at GVWR | ||
| Essmjay |
Load capacity is 400 lbs, so unless you have put on a lot of weight there is no way you are hitting GVWR unless you are touring or riding two up with a heavy gal.. | ||
| 46champ |
I have found that running the tire pressure up to the max allowed on the tire effects gas millage, tire millage and handling. The gas millage goes up a little very little. The tire millage goes up a noticeable amount. But the handling degrades that is why the the manual recommendations are what they are. They (the factory) are sacrificing a very little gas a noticeable amount of tire life 10 to 20% for better handling. And yes I pump my tires up because I am cheap. | ||
| Rocket_in_uk |
Rocket, you may be onto something there... I do move my feet often and sometimes in non-standard positions along with laying forward, crouching my chin under the windshield. I'll try a few positions on my way this morning as that could be the issue itself. I have no explanation I can offer other than to say carrying a pillion does not cause an issue. In doubt it's a weight issue in the regular sense of how the load is carried. It might be that the weight of my booted feet upsets the balance when this slight amount of weight is shifted behind the rear pegs. Or is it an aero issue? I will offer this though. I've always been of the opinion my S1W is as stable as can be. I've never weighed less than 190lbs, but when a rider of less weight than myself has ridden it, some have reported back it waggled its head. More so when I lent it to a bloke who weighed about 100lbs. He reported back he thought my Buell was dangerous and nearly got him into a serious tank slapper at 80mph. I've never had the slightest hint of a tank slapper ever. I have been thrown off a Suzuki many years ago when I got into a tank slapper I just couldn't hold despite fighting hard to. I ended up in an ambulance for a trip to the hospital that time. So I do know what a tank slapper is, lol. I suppose light riders need steering dampers. I've never needed one for myself. Rocket in England | ||
| Skntpig |
Check the torque on the rear isolators. If they are loose the whole motor/frame connection can create a wobble. Check with your tire manufacturer. A bunch of tires now work better and recommend lower pressures than just a few years ago. Some are as low as 26F and 30R cold before a spirited ride or Trackday. The change in fuel and tire wear mileage wouldn't be worth the horrible handling over inflation would create for me. I don't commute on my bike or ride it as cheap A to B transportation. Rear compression setting could be too high or front redound too low. Just don't change too much at once so you can understand what helps and what didn't. Good luck. |
