Front end Shimmy

I have been riding a lot, but now I am noticing a front end shimmy. At first I thought it was just from crappy roads, but the other day I was on fresh pavement and I let go of the handlebars. It started out a a slight wobble, and quickly got worse. The handle bars were shaking to the point where it got scary.

I checked the tire inflation, bearings, and made sure the brakes weren't dragging. What else could it be

 

I have the same exact problem with mine if I let go of it at anything above 20. Its almost like it needs a steering dampener...

 

1,tire wear.
2,fork oil needs changing. level low one one side.
3,pinch bolts,fork brace,fender bolts have loosened, a diff in fork
height can cause shimmy.
4,steering head nuts require adj- bearings may be fine.
5,air assist checked if applicable.

I greased by steeringhead bearings not long back and did not get
the nuts quite perfect. Now I have a very slight shim between 30-40 mph.
Since I'm aware of it and prepared I have put off a re-adj since I'll
be doing a fork seal change soon.

 

I reckon you ought to hang on.

 

I have noticed that the left fork had a ring around it from the dust cap and oil residue, but it is very rare that this happens and it hasn't amounted to any quantity that would cause a difference between the two. I will check the steering head when I get a chance, thanks.

 

Possible that the tire is out of balance (lost the weights)

 

replacing the steering head bearing and a front fork service (new springs, seals, and oil) did away with my shimmy.

Sorry can't tell you which one was the source of the problem performed both at the same time.

Before I did the job neither seemed "bad." But it sure did ride nicer after

 

I replaced the oil and seals about 2000 miles ago, can't remember if I even checked the steering head.

 

check the steering head. Steering head bearings, especially ball bearings, will develop "detents" over time which seem to notch the steering in a particular direction. With your front wheel up, you should be able to turn your handle bars from lock to lock, without any notchiness or binding.

The loss of control comes from the fact that when they fall into the notch, it takes more force to get them out, and you over correct you steering with the extra force when they pass the detent. This can happen without you noticing in a feedback loop until it is too late. Steering dampers can hide the problem, but do not fix it.

 

Worn or loose swing arm bearings can be th problem as well. Maybe they need to be tightened. Have had this problem in th past and thats what fixed it.

 

The three things that I would suspect right away:

1. steering stem bearings
2. steering stem bearings
3. steering stem bearings

Get a complete set of tapered roller bearings and do both the top and the bottom bearings of the steering stem. It's a straight-forward job. Just take your time taking things apart, and label all the electrical connections in the headlight bucket.

Quick suggestion: jack the bike up high enough so that once everything is off the front, the whole front assembly can be lowered out w/o taking all the forks apart. Also, put a couple hooks and stuff in the ceiling so you can hang the handlebar assembly after you disconnect the few cables and wires.

Disconnect the cables, wires, etc....

suspend the handlebars high enough to be out of the way

take the front wheel off and get it out of the way

disconnect all wires in the headlight bucket

remove triple top clamp

lower fork ass'y

remove/replace bearings, races, and seals. Take your time driving the races into place, go slow, don't forget to pack the bearings with a high quality grease



re-assemble in reverse order

I did my first one myself w/o help, other than asking some questions. Seriously, it's not a major job.

take your time, don't rush or get frustrated. It may take you several hours over a couple of days to do, but go slow. it's not difficult.

if you have trouble, we'll talk you through it.

Dave Fox

 

a lot of those wobbles don't have a good ending, it takes a expert rider like this guy

 

I agree with hogfiddles except for two points.

Take the tank off and lay down a thick towel to rest the bars
on. then just tie the bar ends to ft pegs or hwy pegs.
A hanging anything would make a nice dent if it came down.
Plus ;it's alot less stressful when your not constantly worried
about scratching your paint job.

Unless someone has chopped up your wire loom, labling is un-
nessasary as all plugs are diff in shape and will not go together.
If you can (time wise) clean the plug ends as you put them back
together and don't forget the Di-electiric grease.
spot.

 

Thanks guys. I will look into this ASAP.
Polock, that video was hilarious, thats about what it feels like.

 

I had screwed a good hook into the ceiling and tied the bars up with a wire. Wasn't worried about anything falling. Was not worried about paint cuz I had already taken the tank off anyway.

Yes, the wire connectors are all different sizes, shapes and colors, but I labelled anyway, and some of the grounds and turnsignal wires are just bullet connectors that can fit a few different conceivable ways. So, I played it safe, just like your towel-on-the-tank technique.

........you have a purple toothbrush!?!?!?!?!?! BWAAAHAAAAAHHAAAAA!!!!!

 

I took the tank off as well.the towel was threr to protect the frame and bars :wink:

 

I messed up my tank last time I fueled up (overflow and rattle can clear coat don't mix).

And the toothbrush came in a 2 pack, I travel a lot. But I leave the purple one at home in the cup with the rest of the fam. Nobody will ever know..