low speed wheel wobble (Solved)

So after all the work I've put into the bike it decides to develope a low speed wheel wobble (starts and 20mph). I was riding into work today and coasting to a stop light. I took my hands off the wheel to adjust my postioning and the front end started to shake. I've done this countless times before and never came across this issue. I went on my way and tested it several other times. I was too close to work to see what high speeds did.

Where should i start? I'm guessing its one of the bearings in the headset? Possibly the wheel not being aligned? Maybe loosen the pinch bolts and bounce the front end a few times?

I'm hoping for a "quick fix" as I have a 200 mile trip, my longest yet, planned on the 20th and a buget thats been spent already on the bike.

What is the best grease to repack bearings??

 

Re: low speed wheel wobble

headset or wheel bearings? have you done any work that required pulling the forks?

 

Re: low speed wheel wobble

I found some high temp wheel bearing grease at work on clearance.. Its made my mag1. Its a "specially formulated with premium, state-of-the-art lithium complex grease."

Sounds good for the front wheel bearing but what about the bearings in triple tree/headset area?

 

Re: low speed wheel wobble

I've yet to pull the forks, only tire when I changed out the tires. That was 2 years ago. Only put on 500 miles since then. So I'm doubtful the tire is cupping

 

Re: low speed wheel wobble

You can't "repack" the wheel bearings. They have to be removed to do so, and there's no way to remove them without rendering them unserviceable.

CHECK the steering head, by all means.

Then check your tire pressures, and rear wheel alignment (since it's a chain driven bike.)

How many miles on the bike? (Add that to your sig too, please.) It may be time for rear shocks. Have you serviced the forks yet (changed the oil if nothing else?)

 

Re: low speed wheel wobble

Bike has 12700 miles on it. Front has not been serviced besides brakes.. Tire Pressures are all good. The rear shocks seem fine, they have a nice bounce and recover. Nothing great, but norhing that should be throwing the geomtry of the bike off. I'll pull apart the forks and see what's going on in there. Are those bearing able to be repacked or are they unserviceable as well.

If they can be serviced, what's the best grease for the job? Will the high temp wheel bearing grease work or should I use a multipurpose grease?

 

Re: low speed wheel wobble

You need rear shocks. The originals, crap to begin with, had a lifespan of about 6K ~ maybe 8K miles.

Change the fork oil. Go up to 15W from the recommended 10W.

The steering head bearings are a collection of loose balls trapped between their races; if they're not loose and don't have an obvious "detent" in the centered postion, then you can push that down the list.

To check the steering head for looseness:

Put the bike on the centerstand, and have an assistant sit on the rear of the seat to raise the front end off the ground. Kneel in front of the front wheel, and reach forward and grab a lower fork tube in each hand. PUSH rearward/forward; and see if there is any discernable "rocking" play in the steering head bearings. If there is, it can be tightened a tad by adjusting the collar at the top of the steering head.

With the front end still in the air, center the forks. Then push on first one handlebar, then the other. The forks should "fall" smoothly to each side, with no "detent" in the center. If they're smooth, then the bearings are "OK" (for now anyway) and you can leave them until you're ready to upgrade to tapered rollers.

However, unless there is a steering head issue, I suspect your handling issues will go away with functional forks and new rear shocks.

Oh, and that grease will be fine for any bearings you need to grease, greasing the axle(s) or the speedo drive, etc. Just don't use it as a brake lube.

 

Re: low speed wheel wobble

Great. Will dig into it tomorrow after work.

As for driving; I took it out on a break and got it up to 70. The wobbles there with hands of bars, not as bad though.. A finger can stop the wobble.

How bad would it be to continue driving with the wobble . obviously it only happens with hands off the bar.

 

Re: low speed wheel wobble

you had a wobble at 20 with no hands so you tried 70 with no hands, wow,
don't do dat no more.

 

Re: low speed wheel wobble

Yeah.. Well had to find out how bad it was.. Not the best idea but I was in a controlled area and knew the risk; regardless how stupid it may have been.


Back to the problem at hand.. I got the bike home and put the bike on the center stand. put some weight on the back so the front was floating.

From lock to lock it was smooth with hands on the bars, then I was able to push with a finger from lock to lock with no hands on.

Shook the hell out of it and found no free play.

Went to spin the front wheel and it rolled about 6 inches. I think i found the problem... Brakes are dragging, since it's a 550 and only has brakes on one side I'm sure that playing a factor into the wobble.

I assume the wheel should rotate freely?

 

Re: low speed wheel wobble

disk brakes do drag. how much is hard to describe. how about a mighty heave should get at least half a revolution.
have you ever done anything like this
http://www.yamahafz1oa.com/sportrydersw ... thod.shtml

 

Re: low speed wheel wobble

I've done it by eye sight but never with the string method. I will look into doing that.

Late last night I couldn't sleep so I snuck outside and pulled the cap off the master cylinder. Everything looked clean in there. I took my hemostats with a piece of high strength fishing line and cleaned out the small purge valve orfice. Buttoned everything back up and gave the front wheel another spin. Much smoother IMO.

Will try a few other things (check headset, wheel alignment, fork alignment) and report back

 

Re: low speed wheel wobble

The "string trick" is kind of hard to pull off with front and rear wheels/tires of greatly different width.

The easiest way to ensure the back wheel is aligned (after using the "tics" on the swingarm and axle pullers) is to spin it and watch the chain in relation to the sprocket when viewed from the rear.

If the wheel is properly aligned, the chain will stay centered on the sprocket (even spacing from the sprocket to the side plates of the chain on both sides.)

You really DO need to rebuild those brakes; the caliper will continue to drag and it will get worse the more you ride the bike. A properly-functioning caliper on a 550 should NOT DRAG AT ALL. I can spin the front wheel on both of mine and they spin freely until I touch the brake. Keep riding it like it is and you're going to overheat and warp your brake rotor.

Make sure the REAR wheel bearings exhibit no side-play whatsoever.

But if you want to completely get rid of the wobble, change the oil in your front forks. If they then leak, replace the seals. Replace the rear shocks.

The problem is most likely NOT coming from the front, believe it or not; unless something is horribly amiss.

 

Re: low speed wheel wobble

Great advice.. I already eyed up the wheel/chain and so forth and it looked good. I'm guessing the string trick won't work much more than that.

I've been in contact with Len to get the front brakes rebuilt, they need to be done regardless.

Fork oils on the list too. prayin the seals dont bust out with new oil.

Anyone got some good input on an affordable pair of shocks? I'm not looking for top of the line, I feel even the cheapest pair would be better than what i'm working with now. I don't do a lot of aggresive turns riding, more of a crusing attitude.

 

Re: low speed wheel wobble

Shocks are like tires and helmets; you pretty much get what you pay for.

However, like tires and helmets, there are reasonably priced alternatives that are far superior to their slightly cheaper counterparts.

I'm running Progressive Suspension's "12 Series" on both of my 550s. They're a steel-bodied version of their more expensive lines, and since the shocks and springs are sold separately you can choose between black or chrome springs and standard or heavy-duty spring rates. They come with cheesy plastic upper spring covers that I pitched, making them a basic, standard-looking, "naked" shock.

Or you can "eBay" some oriental aftermarket shocks; some of them are quite nice looking; but I can't swear to their longevity.


Progressive Suspension 12-Series, black springs:




Same shocks, chrome springs:

 

Re: low speed wheel wobble

The 12 series look nice. Anyone ever run emgo? They're 110 for shocks and springs. Jcwhitney carries them. I understand the whole you get what you pay for; I'm not trying to be cheap, I'm just married.

Needless to say the wife's not fond of the bike being a money pit. I've already sunk $400 into it this year. She doesn't understand restoration doesn't come cheap. Need to win the lotto or something.

 

Re: low speed wheel wobble

I forgot to mention I threw a trunk on the bike For the planned road trip. The more I read on wobbles the more I see trunks can contribute to it.

 

Re: low speed wheel wobble

http://www.youtube.com/watch?v=RBxK-OQ--fg
Fitz, we should pass your wisdom on to the rest of the world.

 

Re: low speed wheel wobble

The less weight behind the rear axle the better, I strap mine to the pillon seat or use saddle bags

 

Re: low speed wheel wobble

Problem solved. It was the pesky luggage rack/seat rest. I didn't really like it anyways.. It was 18 inches behind the rear wheel. I don't want to call it problem solved, probably more like problem temporarily avoided. I'd imagine there's something that was causing the wheel wobble?

Fitz probably hit it on the nose with the rear shocks though. The added behind the axle weight probably caused way to much stress on the outdated shocks.

This off season will hopefully be rewarded with front brakes rebuilt, wheel bearings, and tappered bearings in the headset along with a new pair of shocks...

 

Should springs be changed along with new shocks?
Or can one getaway with just changing the shocks?

 

i used the stock springs with the series 12 shocks, they fit just right

 

If they're original I'd say get the shocks and springs. If you're spending that much on shocks I'd get the springs. Old springs might cause the shocks to wear quicker.

Edit: Err.. Guess they're okay? I'd take polocks word over mine.

 

my bike budget said the springs were just fine.