Bonneville America Forums Forums Technical Forums General Tech shimmy between 50 and 60

I have a 04 speedmaster. decel from 60 to 50 mph with hands off of bars the front shimmys a little bit. dealer says everything is tight and balanced. dealers say it could be just the way bike is. Anybody else with this problem?

Air pressure OK?

Whats the state of your tires and front suspension? If the tires aren't pretty new i'd start looking at them. if the are i'd probably consider when the fork oil was last changed and whether new springs might be in order. Are the springs stock? What about the spacers? Anyways, assuming the head is good those are the 2 things i would consider. Oh, and make sure the rear wheel alignment is on, plus as Phil said, pressures.

A few possibilities:
Tire balance.
Bent rim.
Tire condition and pressures.
Chain.
Headset bearings.
It is not "just the way the bike is". This is an indication of something out of whack. Maybe you want to fix it, maybe not. But you should know what it is in order to make that decision. For example, my front rim is slightly bent and I have a very slight shimmy around 45 on decel. I chose to just balance it out as best it could be for now.

I've had the same problem several times only I noticed it at 40mph or less. The cause was always either tire pressure or tire wear. If you have made any panic stops where you've skidded either tire (more than likely the rear, skidding the front could get hairy...!) you may have a flat spot in the tread.
Unless you've run over a railroad tie or hit a moose recently, I'd check the tires first.

Thanks for all the replys.Bike has 2500 miles on it. front tire wear and pressure good.head bearing is tight and all hardware checked for tightness. bigbill mentioned the chain, how can that effect the front end? I can live with it but would like not to

I would try aligning the rear wheel using the swingarm pivot points as reference. If that doesn't do it, take the wheel in and have it rebalanced. In that order just because the alignment is easiest and free, tho balancing would be the more likely of the 2. If you are sure the tire and pressure are ok those are what i'd look at next before going on to more tedious, costly and less likely things. remember.....the second you hop on the bike after a tire balance it begins to gradually lose balance over time as the tire wears. And that combined with the possibility the mechanic didn't do a great balancing job in the 1st place could easily lead to a tire well out of balance in short order. Before you take it in for rebalancing tho, try removing the balancing weights and see if that affects it at all.

Look at the amount of weight it took to balance your front tire. If you have a big hunk of lead up there to balance it there's a good chance that at some speed point there will be a slight out of balance condition.