Front End Wobble or Shimmy

I have an 81 750 Seca that I recently purchased with about 20k miles on it. I have noticed that at speeds above about 5 - 10 mph I start to get a wobble or shimmy in the front end. The wobble is bad enough that you would not be able to ride with anything less than 2 hands firmly gripping the bar. I am currently away from my bike and am unable to check anything, but I wanted to get it "fixed" as soon as I am home with it so I am trying to compile a good "list" of items to check and or repair. The tires are both in good shape and seem to be balanced well. The front forks do leak a little bit of oil, it passed our state inspection so it's not a bad leak.
A friend of mine told me the frame is likely bent, which would mean a major fix to get rid of it.
I am currently in the process of doing some restoration to the rest fo the bike, but if there is a possibiliy of a bent or damaged frame, I want to know that before I put anymore money into it.
Thanks
8)

 

All you have to do is LOOK for damage. A frame that's bent or damaged LOOKS like it.

My money is on Front Wheel Bearings, something loose or not right up front ... or, The Number One Cause for a Wobbly Front End.

Driving While Intoxicated!

No. You'd never do that!

Test and Adjust or replace without even bothering to check ... those Old, Probably Pitted and Worn-out Headset Bearings!!!

 

Would an alignment problem cause this?

 

Possibly, but Rick is spot on for the most likely and least expensive culprits. I'd start hunting there. New fork seals and head bearings would be where I would start (the former because they leak, the latter because they are never looked after, I'll guarantee it).
I'm curious, how can you can tell that the balance is ok on your rims? Have you had them checked?
Additionally what have you seen that would suggest that you have an alignment problem?
I guess this list of questions will do for the moment. Let's hear back from you when you get a chance to look over the machine with a critical eye.

 

The tires can still be bad and cause a wobble even if they "look" good and are balanced and they go bad after 4 years so if there's any doubt replace them.
The rear shocks too but I would check the wheel bearings and head bearings like already mentioned. If the frame is out of alignment or forks bent you could probably see it because the wheels would not line up.

 

Trust me when I agree with these guys. I too just went throug the same problem. Everything "looked" good from the start but didn't end that way. A lot of little problems can lead to just one (seemingly) problem. Do yourself some big favors that will pay off in the long run: Replace your head bearings with tappered barings; replace your wheel bearing and if your tires are more than a couple of years old, change them. My front and rear tire looked great until it got up to about 65 mph then the bike would would shake and shutter in the FRONTEND, not the back. So I changed the front tire, the worse of the two but still had the same problem. I went through a month of hell till I finally got it straighened out buy making all these changes and each one of these changes made some improvement but the biggist was the "great" tire on the rear.
It hurts the wallet if you have someone else do the work but get your hands dirty and take pride in knowing it was you that made this bike an awsome ride.
Good luck
the Buff

 

To answer the question, No, I'd never drive intoxicated, lol.

As far as the balancing, you are right, I don't know the tires are balanced or not I just know there are no missing weights, so I'll have to keep that in mind.

I jut recently purchased this bike and have only put a couple hundred miles on it. The guy I bought it from, is a friend, and had the bike for 13 yrs. Although not a bike mechanic, he is an auto/aircraft mechanic. He has taken very good care of the bike and when i asked him about the wobble he said he never noticed it. I think that may be tied to either because it sat for 6 months to a yr before I bought it or he chalked the wobble up to poor road conditions.

I will ask him about the wheel bearings, when the last time it was that he changed them. Also I am already planning on getting a new set of tires.

Besides all the great info I'll get for possible solutions, my other main reason for the post is to comfortably rule out the possibility of a bent frame or front end before I sunk "too" much money into everything else.

Are the front bearing something that I could tackle myself or should I just let the shop do it when they put my new tires on? What is a decent/average price to pay to have them replaced?

What are the Head Bearings? Were are they? What do they do?

I have to admit, I may be a fairly capable shade tree mechanic when it comes to cars, but in 18 yrs of riding I have never been much of a bike mechanic.

 

My bet is it's the steering head bearings. Put the bike on the centerstand and jack up the front of the bike with a jack under the frame rail or the engine. You want to get the front wheel in the air where you can rotate the handlebars left and right. What you are looking for is to see of the bearings are self centering. If they are then your steering head bearings are trash and you need to replace them with the tapered roller bearings. What usually happens is that the steering bearings dimple the races a tiny amount. Its actually hard to see or feel. I just replaced mine and now I can ride the bike without my hands on the handlebars.

Sean

 

Out here in the heat what happens is the grease dries out and hardens and the bearings and races rust so the bars get hard to turn. Either way it's bad.
If they are in poor shape be sure and replace them with the new tapered roller bearings, they look just like car wheel bearings but cost a lot more, about $35 usually.

 

Start with easy and cheap; check your tire pressure. Under-inflated tires could give you a wobble. It's probably something more serious, as mentioned above, but you never know.

 

The fact that the bike did a good deal of sitting would light a big neon arrow pointing at the headset bearings. Since it a bit of work and involves taking down the front end ... you might as well get all you ducks in a row and do the hole front. Wheel bearings, fork seals and headset bearings.

The good news is that the bearings for the wheel and headset are a Universal size used in many, many applications. The tapered rollers you'll get from a bearing supplier are rated much higher in load and turning ... same holds true for the front wheel bearings.

The bearings from suppliers are rated for much higher load and rpm's than the stock ones.

You'll be very happy to have new bearings in there and have a "Day One" newness happening ... rather than riding around on bearings that have sat and developed a hitch in them.

 

Another possiblility if the bike sat for an extended time, flat spots on the tires. These will cause a mad vibration at speed.

 

ok, thanks for all that. I will move ahead with the front end rebuild then. So, how do I find the right bearings if I don't order them from a bike shop?
I went on bike bandit, great site for OEM parts btw, and found "All Balls" for $40, but no wheel bearings. Old Bike Barn had Wheel bearings for $14.

I will update after I am abel to get back to my bike and do the fixes.

Thansk to all

 

Forget the balls for 40-Bucks. They're standard 1/4-Inch Balls. 40-Bucks worth of those at a Bearing Supply Store should be a few hundred ... easy!

 

When I did my front end I got the tapered bearings from the Old bike Barn.
I had never done this job before but I've turned a wrench or two over the years. The word on the street was that you should spend a good day on this job. I had it all tore apart and back together in 2 hours. The whole job took closer to 4 hours because I had a heck of a time putting the front wheel back on. I felt like a complete moron as I contemplated heaving the wheel over my 6 foot fence into the street on the other side. Talk about DUH! It's much easier to remove the brake caliper then put the wheel on then replace the caliper. Don't look like an idiot like did.
Good Luck its not really that bad of a task.
The Buff

 

Actually if it's all balls racing then its tapered bearings from china. Had I known I would have bought a set of bearings that were made someplace else beside's china. Probably has something to do with me being a machinist and seeing chinese made crap that was supposed to be made to a certain standard but wasnt............ Hmm anyone want some lead in there paint????......... Next time I will demand that the bearings be made either in Japan, or the USA or someplace that actually stands by the standards that are demanded. Right now I am wondering if the AllBalls racing steering head bearings that I purchased from Dennis Kirk is going to last me more than a few years or should I just go to the local bearing shop and demand quality bearings. OK sorry rant off for the walmart mentality for parts. When was the last time that we bought something from there that lasted more than a few years but we have some old antique that was made before we were born that is doing the job that was asked from it. OK I am ranting wayy to much.... Want more proof?? check out the latest chinese bike... All of our XJ's will outlast that crap.
OK Chinese rant off I promise............... wait have you heard about the..................

Great Buffalo, the job should only take at the most three hours to do. It helps if you have all of the tools or can use stuff laying around the shop that will work to tap out the races and tap in the new ones. BTW hopefully you do not freeze too much this winter... I used to live in Mobridge SD as a kid ............. I know what F'in cold is


Sean

 

A cheap trick for getting the wheel back on without removing the caliper is:

Drive a small hardwood wedge between the brake pads and open the bleed nipple. Drive the wedge in separating the pads. Close the bleed nipple.

Not you can remove the wedge and have room to slip the brake disc between the opened pads without removing the caliper and wiggling it on.

The wood won't hurt or score the pads. It just opens them enough to allow you to position the brake rotor between the pads without the energy consuming fight and the marring you can do to the pads with a pry bar, screwdriver or anything else you might try before heaving the wheel over the neighbors fence!

 

If your races are in good shape, Rick is right. If the balls are worn, chances are that the races have taken a beating as well. Inspect them carefully. Any blemishes and you should get the new bearing set.

 

just an update. I replaced the wheel bearings the other day with an All Balls front bearing kit. It seems to have helped with the wobble some. I think I have narrowed it down to the fron tire though. I noticed my pressure was low, like 26 psi. So I aired the tire back up to the 41 recommended on the tire. The wobble diminished. It didn't go away thought. So it looks like I am/was chasing a problem with 2 causes. After I replaced the bearings I was able to go "no hands" until around 30 mph. Then the wobble came back. After some close inspections on the front tire I notice cracking inbetween the treads. So, off to get a new tire. Since the back is showing a lot of wear I am going to get a new set. I am trying to decide between the Metzeler Lasertecs and the Battlax B-45's. They are about the same price the only thing I noticed is the B-45's don't come in a 110/90-19 for the front all they offer is a 100/90-19.
I don' think it will make much of a difference. Anyone have any opinions on those tire choices?
I will update again when I can get the wife to allow the $300 purchase for the new tires. :mrgreen:

 

Do you have a 110/90-19 on there now? If you do that could cause the
wobble just from having a tire that's too big.

 

I'm running the LaserTec's on my Maxim.

I really like the way they feel and corner. I especially appreciate their high-speed rating. When the Summer traffic is moving along good, heading North into New Hampshire and Maine ... traffic will be cruising along at 80 to 85 mph.

Nice to have tires that can handle that kind of riding all afternoon.

 

Anyone have any opinions on those tire choices?
:[/quote]

I have been using the Dunlop D404f 110/90/19 on both front and rear for about 2 years. I like them because they aren't to expensive, they warm up quickly in cold weather and even as a daily driver, I have yet to see any major wear after about 9k miles. As for using them on front and rear, its hard to find the 100/90/19 for the front and it barley changes the handling (if at all). Plus I just like Dunlop's performance tires.

 

I wouldn't spend $300 for tires! Dunlops are widely available in 100/90/19 size for the front. I just got a new one on ebay for $50!

 

yeah when my front blew out it was gonna take 2 weeks to get it in, the only parts dept. here really sucks. and they are really inexpensive. i didnt think about ebay when it happened b/c my xj is my only mode of transportation. so they had 110/90/19 and it fit so it worked, and ive never had any wobble b/c of it.

 

no matter what you do, you'll still have wobble until you replace the steering stem bearings. After you do that, you'll wonder why you didn't do that FIRST, but then you'll think of all the other stuff you otherwise wouldn't have fixed, so either way, you'll be ahead and running a straight wobble-free line. Been there, done that.

dave
83 XJ650K Maxim
81,85,87 Viragos
67 Honda 305 Dream

 

I have seen some good ideas on here. There is more to being a "Good" tire than having good tread. I can't say that I would change a tire for just being two years old, but typically there is a "tire life" to go by, many disagree on what this is. Visually inspect the tires with the tire in the air where you can spin it and look it over carefully before you spend a fortune on it. You can tear it down and do a complete rebuild and never know what the actual problem was.
Were it me, first I would check the tires for flat spots, cracks, broken belts and air pressure. You can give a quick check on the wheel bearings by removing the brake caliper so that you don't have drag, check the wheel for any signs of side movement, free spinning or other noise. There is a DOT code on the tire that will tell you the age (Mfg date) of the tire. You will have to do a search to find the code dates. Some will argue to change the tires every 4 - 5 years, myself, if the tires are not cracking and kept inside (or off the ground), I will go by tire wear and visual inspection for cracks and defects. You will have to use your own judgment on this. Depends on how deep your pockets are.
If you buy tires, a good place to look is American Motorcycle tire. Even though they charge for shipping, the bottom line is better. Buy a couple of tire irons and change them your self. It is not that bad. Should you decide to do this you can PM me and I will explain how to balance them, or I can post it here so that others can know. It is not that difficult, I do it quite often. It will cost you at least $50 per wheel to mount and balance if they will balance them at all. A lot of shops believe it is not necessary to balance them.
Check for loose bolts on your tripple tree or fork brace if you have one. After checking these you can begin to look farther. I hate to go though everything like this at one time because you really don't know what the problem was if it took care of it. Check the obvious and easiest first.
I can appreciate the idea of pulling and checking the stem bearings, but that is not the first thing I would do. Like I said, it all depends on how deep your pockets are.
See if your aircraft mechanic friend will give you some assistance. A certified aircraft mechanic has much higher standards to adhere to than an automotive mechanic. You can't just pull over if there is a problem with an aircraft.

Ed

 

at least in a plane you have time to think about it, sometimes on a bike you don't

"it's better to be down here wishing you were up there, than to be up there wishing you were down here"
i always liked that one

 

You should do exactly what they would do if you were to bring this Bike in to a Dealership for this problem.

"The bearings are 20-years old ... I recommend you replace the Front Wheel Bearings and the Headset Bearings and tighten them to Specs"

If you still have a Wobble after replacing the Bearings you have another issue to look for:
Bent Fork
Loose Axle or Pinch
Loose Pinches at the tree.
Dry Forks
Dead Springs
Missing pre-load.
Bad tire, tube or Out of balance front wheel.

 

I am not saying that he should not replace the bearings as you suggest, I replaced mine (wheel bearings) before I put it on the road, but if he replaces everything at once he will have absolutely no way of knowing exactly what the fix was. His discoveries could help out someone else some day.
On the other hand, if someone is on a very tight budget as I was when I put my V65 Magna on the road and can't afford to change everything at once :?:
I had just retired due to disability and had absolutely nothing extra to spend. Rather than have the bike sitting for who knows how long, it would be nice to know what would be the least expensive repair until some funds come along.
Actually, I didn't replace my wheel bearings. I am an industrial Machinist and an Aircraft Machinist with the U.S Air Force by trade. I have built and rebuilt machinery and aircraft parts for quite a few years now with no failures. I cleaned and repacked my bearings and replaced the seals with new ones. Like I said, it depends on how deep your pockets are and mine are shallow, so I get the job done with the least amount of expense possible or leave it sit.
She's a running strong. I am not trying to step on anyone's toes here. From the posts that I have seen on this forum that you have replied to, I see that you are a very knowledgable person. It is great if a person can change all of this at once but some just can't afford too, and depend on these posts to help determine exactly what the cause of a problem is. They can't use this information if everything is changed at once and they still don't know exactly what the cure was.

Ed

 

"So I aired the tire back up to the 41 recommended on the tire."
this sounds a little excessive to me, might be why your seeing cracks in the rubber. older rubber doesn't stretch that well
head bearings will cause real bad handling on steel grating bridges or a road with pronounced rain groves
you want to check the swingarm too
i'd say check or replace everything all at once, you don't want a wobble at
80mph, makes you find religion real quick
ain't no fun cleaning out your pants thinking about what to change next

 

41 psi is what is listed on both tires, the front is an IRC Durotour and the rear is a Spitfire 11?? anyway, the max cold psi is 41 on both.

I have checked the front tire, did it while I had it off to replace the wheel bearings. that is why I started looking at tires. I found cracks in between the treads and on the sidewall lettering.

I did check the main stem bearings, by lifting the front off the ground and checking for slop or movement of the fork assy. I didn't find any, not that this means they are good I guess.

I was wanting to get new tires as the back has more wear than I like and am comfortable with. someting about leaning into a turn with that flat of a rear tire bothers me. I like the nice round shape it should be. :lol:

 

That's interesting. Why would having a slightly larger tire cause a wobble?

 

the book for my xj750j says 26/28 front and 28/32 rear, i run 30 front and 32
rear and i go about 220
have any idea how old those tires are ? if their a few years old and have never had that much air in them, thats why they cracked
new tires are never a bad thing
to check the head bearings ,raise the front wheel and slowly move the bars back and forth, right at center if you feel a little bump the bearings are shot
it's like a detent and the bars want to stop there, doesn't seem to happen anywhere else but right in the center
while the wheel is up check if it's true

 

Unless you KNOW that the Headset Ball Bearings and Races have been cleaned and repacked a couple of time over the course of the last 20-Years or so ... I'd be willing to bet the Headset Bearings are BAD.

Dried-out and rusting.
Not smooth and causing your handling issue.

Recommendation:

Replace the Bearings and Races with Tapered Roller Bearings.
They come Sealed.
They don't cost much if you deal with a Bearing Supply Company.

They are eyeyballs and kidneys at the Dealership.

The ones you get at the Bearing Supply Co, are better and come with a Lifetime Warranty.
The ones you get at Yamaha are the same ones in a Plastic Bag with a Logo and a Barcode and 40-Bucks mark-up!

 

snoopt1,

The tire pressure you should go by is on the sticker on the bike, usually located somewhere on the left side of the bike on the swingarm near the rear wheel. The markings on the tire are the maximum recommended pressure for that particular tire, depending on application, not necessarily yours. The tire is made for multiple applications. Either go by the MOM (Motorcycle Owners Manual), vehicle repair manusl or the sticker on the swingarm. It could even be somewhere else on the bike, not familiar with yamaha that much, but am familiar with tire inspection procedures at a Government level.
If the tires have cracks, or have been sitting for a long period of time extremely low or flat, you need to change them. The only way an older tire would still be good is if it was sitting indoors, fully inflated and off the ground or floor, even then it would be iffy. Bias ply tires are especially notorious for going bad after a long periods of time.
I just changed a set of tires on a 89 model bike that had only 3000 miles on them and looked like new, but were cracked. They were dangerous to ride on. I am all about saving money when you can, but if there is any cracking in the tires at all they should be replaced REGARDLESS of tread depth. Get down eyeball level with them and look very closely with a flashlight if necessary.

Ed

 

Nice Post, Ed.

You summed it up nicely.
Don't run on dangerous tires.

 

Ok, sorry ti took so long to repost. It has been a busy last year. I replaced the tires. Problem solved.

Thanks to all for the advice/help.

 

i am experiencing the same problems. I would like to swap out the front wheel bearings and the steering head bearings. I own a '82 xj750 and would like to know the specs of these bearings so that I can order them. does anyone know the sizes for them?
thanks,
Mark

 

The sizes of all the Rotational Bearings are Laser cut into the Race.

The MOST important factor you need to know about finding replacements is this:
Yamaha does not manufacture Bearings.
Yamaha makes little plastic bags with Bar Codes on them.
If you buy a Yamaha Bearing ... that little Bag with the Bar Code on it is going to cost you upwards of $35.00 ... for a Bag you throw away.

Go to a Bearing Supply Store -or- Shop online.
You'll save 30-Bucks a Bearing.
You'll get Bearings rated for loads and RPM's made by Turbines in Jet Aircrafts.
They'll be so reasonably priced you'll want to ALL your Bearings.

 

but i would still need the sizes right? i assume i would have to provide them with outer diameter, inner diameter and thickness of the whole bearing housing?

 

I would take the bearings to a store and have them match them to the correst size roller bearings/races and you should be in business. Bearings are cheap in most cases, unless you go to the dealer. They think they are gold plated I guess.

 

The point is:

They are a STANDARD Bearing. Multiple Applications. A World Std size!

 

Anyone still tagged in here? I've recently purchased an '82 650J and it has the front end wobble. My friend has the same bike and his wobbles as well. He replaced his steering head bearings and has new tires etc but his still wobbles. We thought maybe it was just the XJ "thing" until I found this post.

I don't really notice it until I let go of the handlebars. However as I'm riding if I'm nice and relaxed on the handlebars I feel it. I have to hold her tightly. I'll start with the bearings but I wondered why that didnt' fix my buddies problem?

 

This thread never once mentioned swingarm bearings, or rear shocks.
When you say " steering bearings, new tires etc" what is the "etc"??

There's also weights inside the handlebars (or are there?)
For now, don't let go a 'dem bars !!
and 26/28 PSI on the front? That sounds low, I like 35.
Makes for a lighter feel to the bike.

 

Redwulf,

How is the balance of the tires on yours and your buddies bike. I ran across a shop last year that said they didn't feel the need to balance the new tires. Pure BS!

 

Hey Ed,
Yeppers they are balanced. I heard the same thing about balancing. I didn't buy that either.

I checked my steering head bearings yesterday by raising the bike up and they are smooth as a baby's "uh huh". No dead spots at all and I was amazed at how smooth they felt. I moved the forks fore and aft to see if someone replaced the bearings and didn't tighten them down enough. But there is no movement there either.

My buddy has been through two new front and rear tires and tires haven't made a different for him. He has used the same Kenda model both times though.

I need a new front tire. I think I'll change out the front tire re-balance and see what happens. If it still wobbles then I'm going to replace the front wheel bearings next.

When coming to tires I think I've narrowed my choice down to the Bridgestone Spitfire or the Dunlop DB 404. I just put a Kenda on the rear. I like it but I dont think it's going to last long. She sticks well in the turns and I really like it. My buddy has been using them and thinks he gets about 3-4K out of them. I'm not as aggressive in the mountains and in the turns. I've heard good things here on the Dunlops. Any other opinions?

Sean

 

I have Dunlop D404s on one XJ550R and Avon Roadriders on the other. Neither tire has a continuous center groove on the front so they don't follow freeway rain grooves, a major factor for me.

The Dunlop is an excellent all-around tire and does very well in the wet; I have about 3K on the set and they're only at about half-life I'd say.

The Avons are noticeably "stickier" but I only have about 430 miles on them so far so I can't offer much comment except to say they work VERY WELL in the twisties. Haven't had to ride in the rain with them yet.

You certainly won't go wrong with the Dunlops.

 

I have a set of the Avon Azaros on my V65 Magna. They are radial tires. They are a smaller size than my bike calls for, the proper size is not available. They handle very well on both wet and dry pavements. The ride is considerably rougher because of the smaller size. I would prefer a softer ride of a larger tire. I personally don't have a problem with Dunlops but I know others that really bad mouth them. I have bought them before and will again.
I sometimes think a lot of the bad mouthing is because they hear someone else complaining and just chime in. I am not that desperate to fit in with others.

Fitz, do you still need the part made that you asked me about?

 

Hey Guys,
My buddy fixed his front end wobble. When he put the new head bearings in he didn't tighten them down enough. When he put it up on the stand he didn't really feel any fore and aft movement. If any it wasn't recognizable. So he tightened them down a little more anyway and she's fixed. He claims it's a totally different bike!

So I raised mine up and checked. I had no dead spots (self centering) in the bearings. I had no movement fore - and - aft. But I went ahead and tightened them down a little. Then I started to notice the self centering spot. So it seams my bearings are out too.

My question is about replacement bearings. I've got a place close by that specializes in bearings. Will I need to remove these and take them over for a match? Or can someone tell me what I need to get? I'd like to get them before tearing the bike down. Just to save time. I really only have weekends to work and they aren't open on weekends.

Sean

 

Seen there was some talk about tires on this thread so I have a question about tires. I have seen some tires that are listed to be front tires for other bikes but are the same size as the rear tire for my maxim. Does it make a diffrence if use use it for my bike. Just want to make sure before I buy something that I can't use.
The question that Redwulf__34 had is one I would be interested in knowing also.