Rear tire wobble quandry -- SS brake lines

[buggrin]

The new K491s are finally mounted with tubes and bead locks in place. I had to finally give up on mounting the rear myself cause them rim locks are near impossible. Now there is some wobble in the rear tire -- looks to be about .075" TIR (total runout). The rim is dead true but you can see the tire moving from side to side when running on the center stand.

I ran it up to 85 mph and could not feel anything, but I'm wondering if there is going to be a problem from this. I never noticed any wobble before, but this is the first time trying to mount a rear tire so I was paying more attention. I noticed it when checking the balance, but put the wheel back in anyway to test ride it. Now I don't really want to take it back apart if that isn't necessary.

Anybody with any thoughts or experience with this?

Also, rebuilt all MCs and calipers and replaced original lines with Speigler ss ones. A lot of work, but man does it feel better. Much more controllable modulation and less lever movement. Shoulda done that years ago...........

[MartyA]

If your rim is true, the tire is either not seated or the tire is a second. Did you check it after your run? It might have seated itself.

[2fast]

rear wobble

Did you inflate fully before tightening the rim locks? If not, try loosening the rim locks and running the inflation up as high as you dare to be sure the beads are seated and then back off and retighten the rim locks. It should be able to take 80 lbs pretty easily. I would recommend having a shop mount them when possible. It is not expensive and if they pinch your tube, they fix it. Also, there is no substitute for spin balancing. A good shop will be able to do that for you. The static balance method is better than nothing, but pretty crude by comparison. I would recommend bringing it to a shop to spin balance prior to remounting. We run on 2 wheels, which one is not important?

[Geezer]

I'm a little surprised anybody still uses the rim locks. That’s the first thing I toss and I’ve never had a rear tire slip.

Geezer

[2fast]

Rim locks

Of course having a tire slip will depend on how hard you brake, or accelerate. Kind of like not wearing a seat belt or a helmet cause you have never needed one in the past. Of course, your mileage may vary.... I can't see getting rid of them for any good reason. If you do remove them, you then need to fill the hole to prevent a tube aneurism. Never mind the rim was designed to include it.

[Renegade]

Re: Rim locks

Originally posted by 2fast
Of course having a tire slip will depend on how hard you brake, or accelerate. Kind of like not wearing a seat belt or a helmet cause you have never needed one in the past. Of course, your mileage may vary.... I can't see getting rid of them for any good reason. If you do remove them, you then need to fill the hole to prevent a tube aneurism. Never mind the rim was designed to include it.

On dirt bikes, rim locks were intended to stop slippage when running with less air pressure than what is usually required.
With the XS, I am more inclined to believe that Yamaha added rim locks as a safety device so that the tire does not come loose from the rim in the event of a flat at speed.
I have experienced that with my Sportster at about 75mph. Something cut the valve, making it deflate almost instantly. By the time I could get pulled over to the shoulder the rear tire was halfway off the rim.

[mitch]

Renagade

Now i know your lying a Sportster wont go that fast ..............MITCH

[Jerry]

Older XS 11s used 2 bead lock devices on the rear wheel, along with tube-type tires. As Renegage suggested, these were to help keep the tire on the rin in case of a flat.

Tube-type tires tend to come off the rim faster/easier in the case of a flat than tubeless tires.

The stock tube-type rim ends up with 3 holes in it, 1 for the tube stem, 2 for the bead locks. The bead area for a tube-type tire (rim and tire) is different than a tube-type rim and tire, so not only is it a hassle to convert the tube-type rim to tubeless, it is unsafe as well. It may be possilbe to remove the locks, fill the holes, and continue to run tube-type tires, but upgrading to tubeless rims is probably the better way to go overall.

Many people simply swap in the later tubeless rim from other XS 11s or the XJ. If you stay with the same size, 16 inch, this is a bolt-in swap. If you have the early 17 inch rear, swapping to the 16 takes some work, or you just have to live with the tube-type tire. There was no Yamaha production 17 inch tubeless rim for the XS. (Front whels are also a bolt-in swap.)

[Renegade]

Re: Renagade

Originally posted by mitch
Now i know your lying a Sportster wont go that fast ..............MITCH

Good one, Mitch. I should have said was a cast iron Sportster and not an Evo. And a far cry from being stock. It just takes understanding the engine design to get that speed.

First, you change the factory final gearing from 19/50 to 24/48 (which is as far as you can go with a cast iron Sporty, and even then it requires some grinding of the transmission case for chain clearance), regrind the cams, and up the displacement from 61 to 77 cubic inches. Then you get to learn all about high octane fuel and additives, heavy duty clutches, exhaust pipes blowing off at the head, and brakes that were never intended to stop a bike that is that quick. But it was a blast to ride. Kind of like an XS but doesn't accelerate quite as quick.

[eltoroloco]

I'm all for having a bike shop doing it. It saves me the head ache and for only 15 dollars mounted and ballanced.

[KurtG]

I think you are mistaken about the lack of 17" rear tubeless wheels. I purchased a set of wheels last year from a '81 1100, 19" front/17" rear clearly stamped "suitable for tubeless tires". The info I got at that time was that tubeless wheels appeared late in the '79 model year for the standard bike. They were a direct swap to my XS1100F.

[i]Originally posted by Jerry [/i

Many people simply swap in the later tubeless rim from other XS 11s or the XJ. If you stay with the same size, 16 inch, this is a bolt-in swap. If you have the early 17 inch rear, swapping to the 16 takes some work, or you just have to live with the tube-type tire. There was no Yamaha production 17 inch tubeless rim for the XS. (Front whels are also a bolt-in swap.) [/B]

[Geezer]

Originally posted by KurtG
I think you are mistaken about the lack of 17" rear tubeless wheels. I purchased a set of wheels last year from a '81 1100, 19" front/17" rear clearly stamped "suitable for tubeless tires". The info I got at that time was that tubeless wheels appeared late in the '79 model year for the standard bike. They were a direct swap to my XS1100F.

The fitting of rim locks was the out come of a lawsuit against Kawasaki. As I recall in 1974 Kawasaki paid out over 2 million dollars because some schmuck ran too little pressure in his rear tireon a Z1 and was running WFO. It wasn’t until the market demanded tubeless tires that this insanity came to an end.

A properly inflated rear tire won’t slip. Also newer tires require more pressure than the stock tires of 1978~79. In the early~mid 1980s the tire companies went to a shallower angle on the bias plies so the ties would run cooler (sort of a semi-radial design.)

After tossing the rim locks, I seal the hole from the inside with duct tape and fill it with silicone sealer on the outside. I’ve been doing this to all my rim lock equipped road bikes for the last 20 plus years and I’ve never had a tire slip on the rim (YMMV.)

Geezer

[Bikeboy]

Tubeless !!!!!!!!!!!!!!!!!!!!!!!!

Your right KurtG, they did make tubeless rims for XS11 in 1979, I have one. An 1979 XS11f or standard as some people call them. And stamped on the side of the rims is the words ( Suitable For Tubeless Tires). I put Avon Venom-X Radials on my bike this past summer, and I love them. Grips the road real good. Sorry Jerry your wrong just this one time.

[Geezer]

Originally posted by KurtG
I think you are mistaken about the lack of 17" rear tubeless wheels. I purchased a set of wheels last year from a '81 1100, 19" front/17" rear clearly stamped "suitable for tubeless tires". The info I got at that time was that tubeless wheels appeared late in the '79 model year for the standard bike. They were a direct swap to my XS1100F.

All 16" rears on the specials were tubeless and the 1980 on standard 17" rears were tubeless. I'm still hoping to find an tubeless 17" for the rear of my Mongrel.

Geezer

[Jerry]

I stand corrected!