82 xs400r seca rear wheel wobble

DR45701

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Went for a ride yesterday and noticed that the rear of the bike felt a little wonky. Once I got back I out the bike on the center stand and proceeded to spin the back tire with the engine off. I noticed that the tire didn't rotate uniformly and would wobble back and forth( maybe slightly up and down?) Everything seems tight and the wheel won't give if I try to push side to side. So, with that being said, everything I've searched has pointed to:

1. A warped rear sprocket
2. A bent axle
3. Improperly seated bead
4. Possible wheel bearing

Not exactly sure where to start with this diagnosis, any help is greatly appreciated. The wheels are the original cast and I cannot completely determine if the wobble is at the rim too or solely at the tire.

As an added bonus, when I went into the garage today I noticed a strong gas smell and a puddle on the floor under the center stand. Closer inspection revealed fuel dripping from the clamp between carb and air filter. Stuck float? Should I drain the bowl and clean the carbs?

I'm new to tinkering on these things and don't have the most experience but am more than willing to try, just looking for some guidance in the right direction!
 
Here's a link to a video of it running. May just end up taking to the shop and pay for my education

 
I would say the tire is off. It's hard to mess up a mag wheel. But it wouldn't be a bad idea to have that checked also.
 
On your tire is a thin ridge just out from the rim. This ridge should be the same distance from the rim all the way around. If not then the bead is not seated right.
While up on the stand set something along side the tire. This something should be able to hold a piece of heavy wire, A coat hanger will work. With this something and the piece of wire sticking out set it so the end of the wire almost touches the rim.
Spin the tire. watch how close the rim runs from the wire. If it stays the same distance away from the wire all the way around your wheel is straight.
A loose axle and you may not be able to wiggle the rear wheel by hand, but the load of riding can cause a wobble. Check the axle tightness.
If your axle is tight and you can't feel any movement while trying to wiggle the tire left/right and don't make funny noises are feel catchy your bearings are ok.
A loose swing arm pivot bolt can cause your wobble while riding. I bought a bike once that had the threaded end of the pivot bolt broke off. A PO had drilled and tapped the broken bolt for a 5/16 inch bolt. It could not hold securely. This made the bike feel like the swing arm swung sideways as well as up and down. I had a spare pivot bolt.
Check these things before you pay a shop $75 + per hour to do these things.
Leo
 
Rim seems straight.. The tire seated improperly. Youll have to let the air out and slowly fill it again and use a rubber/deadblow hammer to straighten it as you fill.

The tightness of the chain can hide things like worn swingarm bushings and wheel bearings.
 
Thanks for all the replies. Tire was definitely mounted un
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evenly. I tried to re seat on my own a few times with plenty of lube but to no avail. Took it to the shop. They didn't seat it much better. He balanced it out but considering it was new year's Eve he probably couldn't have cared less(that the bead wasn't even)...might go ahead with a new tire if after I hit it with a hair dryer and some more air it doesn't pop. Tire is an '18 and has a decent bit of tread left but if it's not seating then ‍♂️. It's a Metzeler, new to this so unsure if that's a quality brand.
Anyway have rear tire off now, cleaned and greased chain and driven sprocket bearings seem okay? No noticeable grinding but shouldni replace these since these are most likely the originals? Will update as I learn, until then thanks again.
 
You might try around at highway speeds. This will allow the sidewalls to flex more. This extra flexing heats the tire uomore than at standard pressure. The heat lets the tire soften up and stretch a bit.
You will know when it seats, The ride will smooth out. It may take a few minutes.
Once it does reset the pressure to normal.
This has worked for me several times. It can be a bit scary the first time or two you do this
Metzler is a good brand. A lot of them out there.
Leo
 
Make sure to break the bead loose all the way around before you add the tire lube.

Bouncing it on the floor can help set it. I agree taking it for a ride can help by warming it up. A hot water bath followed by tire lube can warm it up. Beating the bead area with a rubber mallet. I've had some stubborn ones too but now that you know what to look for you'll get there.
 
Thanks Sandman, going to give it another go here shortly. Been swamped with work/ holiday activities. When you bounce the tire on the floor do you generally do at a lower pressure in tire or higher? I tried to do so but didn't have a whole lot of luck this far.

XSLeo- The PO installed the tire and I rode it around for a quite a bit as it was before I really noticed the wobble ( first bike so no real metric of what a proerly seated tire feels like). I had hit speeds around 70 with the tire seated as it is and rode quite a few miles around 55-60 but didn't sustain speeds for more than probably 7ish minutes. Not sure if that's long enough at highway speeds?

Thanks again all, going to do some shopping from the couch today as well for new tires. The front is a '15 and the rear is an '18. I've read in Lee Parks' Total Control that the rubber compounds start to deteriorate and become more rigid over time. He then suggested that sport bike tires be replaced every 2-3 years and cruisers within 5 years. This seems like sound logic to me, what do you guys(gals?) think?
 
Old tires can be dangerous tires. They do get hard which reduces grip. They also are more prone to blowouts.
On a sport bike if you ride it much I think the tires will wear out before they get old. A lot of those tires are very soft to improve grip but this soft a tire wears out quickly. Some as quick as 2500 miles with aggressive riding.
On cruisers tires are harder and last longer. On my HD FXDX with Dunlop D401's I get around 15000 on a set.
I have heard most manufactures recommend not running a tire over 5 years old. I believe it, When I bought the 81 it had old tires on it. Looked very good. Even had the mold tits on the tread still. The bike had a bad wobble at around 35-40 mph. Scary bad. At times it felt like it wanted to throw me off. Swapped the front wheel and tire off the 75. Smoothed right out. Bought new tires before I rode it more.
Your rear at 2 years old should be ok. The front is about maxed out. New tires won't hurt.
As you were riding the bike did you try running the tire a bit soft? This makes the sidewalls more flexible and this helps the bead seat.
Leo
 
Thanks Leo! No I didn't run it soft, recommended PSI is in the 28-36 range ( depending on load) for the rear, I've kept it at about 30. How low is it safe to drop it?
 
Pulled the tire from the rim and there was all sorts of dried goo (mm+ thick clumps of this crap). With a Dremel and brass brush I was able to get the worst of it before the brush disintegrated. I used some #0000 steel wool, cleaner and a pick to get the worst of what was left. I feel like this was the main problem with the bead seating as the side that wouldn't seat correctly had a lot of build up. I'm going to try to pick up a new brush or two tomorrow and get most (hopefully all) of what's left before installing tire. I'm also checking the bearings per a recommendation in another forum. I went ahead and got the Metzeler s that I posted a link to and may just wait until those arrive to install (if I can wait that long :) )
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Make sure your tire is a tubeless tire. Look like someone has run a tube on that rim at some point or used a sealant.
 
Thanks Chris, the tire is tubeless. Rim also says suitable for tubeless. I cleaned it up and reinstalled the old tire. It still had a bit of wobble in it and Ithe bead line still wasn't 100% perfect. I checked the rim and bearings, they both seemed okay. I noticed that the tire looked a little misshapen. Had the previous owner let it sit for a while (about a year) would that cause any deformation in the tire?


I got a new tire, installed it yesterday and went for a ride. The new tire felt 100x smoother although I didn't take it above 60ish. About 10 minutes into the ride it started raining steadily. Which brings me to my next question, what do you folks put on your face shields to keep the rain off? Seems like a waxy compound or a little rainx fluid would she'd it right off. Visibility didn't suffer until the rain turned to a fine mist.

I've got a new front I'm going to spoon on here in the next day or two. I just got the garage back to a much more cohesive state twenty minutes ago.

Thanks everyone for all of the invaluable input!
 
Bias ply tires will get a flat spot from sitting and it takes time to "roll" the flat spot out, basically just a heat cycle.

I dont ride in the rain, but I swear by Rain X. Ive always used it on my cars and if you apply it correctly the application will last a while. I dont even use my wipers because Rain X is that good. Everyone should be using this stuff.

BEWARE, sometimes the Rain X could have negative effects on acrylic and plastic lenses. I used it on an old pair of ski goggles once and it made the lenses cloudy. Ski goggles are made of different/sensitive materials so I dont think youll have issues. Test it first.
 
I dont even use my wipers because Rain X is that good. Everyone should be using this stuff.

I started using their washer fluid a few years back and it was the same way. I did notice that they have one for plastics now and not sure if anyone's used it. Haven't read up yet to see if it is okay to use on lexan (sp?) Or polycarbonate.
 
So the rainx plastic looks like the ticket. Safe on most forms of plastic. I'm going to try to pick some up/ order and let you know how it fares.
 
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