Tubeless Tires, Unmarked Alloy Wheels and Tire Sealers

[Pete Logan]

I've done a search on this and come up with one thread from a couple years ago, in which a number of different experiences were related.

Some people advised against deviating from the factory setup, while others reported running tubeless tires on unmarked alloys for yonks with no problems.

There appear to be two issues:

1. Whether the alloy rim might be slightly porous, leading to a slow loss of tire pressure, and

2. Something to do with a bead providing perimeter sealing for the tire, which I wasn't quite sure I understood.

I have a 1982 GS750E, with alloy wheels, that are the original Suzuki items, Not marked as suitable for tubeless tires. At the moment they have tubes fitted.

Ideally I would like to switch to tubeless tires, and use a tire sealer.

This one: http://www.ultrasealuk.biz

Does anyone have any experience doing this, or any other opinions on whether this is a feasible/good way to go.

The principle objective is to prevent the kind of explosive decompression that can happen with tubes, and to provide as much security in the tires as possible. I have had one experience of this, and do not want another

I can get photos of the rims if this helps.

Many thanks for any help anyone can give me on this.

Pete

[Anonymous]

Pete,

The major safety issue is the bead seat profile on older rims. Rims designed for tube tires often have a different bead profile than the correct tubeless rims. This can lead to the tire not being held correctly on the rim and a potential tire/rim separation while riding. I am sure you can imagine the consequences of this. The correct rims should be marked with a "WM-#" designation. The WM indicates the correct tubeless tire bead seat profile and the # matches to the width of the rim.

I know many vintage racers and supermoto racers who run tubeless tires (with tubes) on spoked rims that do not have the correct profile and experience no problems, but it is your call as your butt will be on the bike when it is moving...

Mark

[SqDancerLynn1]

I often wonder why they did it that way, My GS 850 has a tubeless rear rim and an unmarked Re tube type front rim and yet the rims look identical

[Pete Logan]

Thanks. I hadn't heard the WM marking before, just that rims for tubeless would be marked "For Tubeless", which these are not.

It's dark here now, but I'll go and look in the morning.

I don't need much imagination. I once had a rear tire go bang on me, so I pretty much know what happens there. It's that I am trying to see how best to protect against.

Thanks again.

Pete

[earlfor]

Re: Tubeless Tires, Unmarked Alloy Wheels and Tire Sealers

Pete, I have just been where you are. My 85 1150E has tubeless marked front and rear rims. My 79 750E has had the spoked wheels changed to 81 750E mags. 81 750E mags are tube type mags. It is my understanding that the difference is the porosity of the castings, and tube type rims, if used without a tube will leak down. I also this past week completed a rebuild/refurbishing project for a customer on his 78 GS 1000E. The 1000E has tube type stock rims. I measured the rim retaining lip dimensions on all three bikes. There is no difference I can detect with the use of a digital verneer caliper that measures to .001 in. There may be some differences in the rims of other GS models (I have not measured their rims) but, it is reasonably logical to assume Suzuki would have no reason for making rim retaining lip dimensions different for different models. Tire companies do not make their tube type and tubless type tires with a different bead. In fact, some tires (Metzler) are designated tube/tubeless. The retaining bead of the tire cannot be different than other tires. I measured it. It is not different. Now, as to the porosity question with the alloy of the mag wheel. My customer wanted to use tubless tires on his bike. (one of the reasons for all my measuring and checking) I took his rims, removed his old tires, and cleaned the inside with acetone to remove any residue. Then, I "sanded/scuffed" the inside of the rim with a scotch pad. (a nylon pad usually used for removing paint, available at hardware stores or paint stores) I then wiped the inside of the rim clean again with acetone. I masked the lip of the rim (the area where the tire's rubber bead would seat on the rim) with electrical tape because besides not allowing paint to bleed through, the electrical tape stretches and can be pulled neatly around a curve. I brushed two coats of
two part catalyzed epoxy barrier coat onto the inside of the rim. Epoxy barrier coat is a marine coating used to seal and provide a water barrier when refurbishing old fiberglass hulls that have an absorption problem.
Catalyzed epoxy coatings are almost 100% non porous. If a marine supply is not available to you, it would work equally well to use epoxy laminating resin as a barrier coat. Just brush a coat on, allow it to set enough that you can brush on the 2nd coat without disturbing the 1st and then allow it to harden for two days. As soon as you have brushed on the 2nd coat, go ahead and remove the masking/electrical tape. Mount and balance your tubeless tire. (you will have already installed valves for tubeless tires) I inflated the tires to 100 psi to be certain I had a good seat on the tire bead to rim. Then reduce the tire pressure to the normal 40 psi (or whatever you use) The tires have been on the 1000E a week now and have not leaked any air. They still show exactly 40 psi in each tire. My road test was 450 miles of cross country riding. The usage was aproximately 200 miles at 50 to 70 mph, 200 miles at 90 to 100 mph and 50 miles at 130-140 mph. The ride was a mixture of straight smooth road, rough roads, curves and some hills. Lean angles ranged from none to scraping the centerstand and brakes were applied at any angle and any speed during the ride. Maximum braking from high speed was also checked various times. The tires gave no problems and I am confident enough of the modification to put my butt on the seat at any speed and under any conditions.

Earl



[quote="Pete Logan"]
Some people advised against deviating from the factory setup, while others reported running tubeless tires on unmarked alloys for yonks with no problems.

[Pete Logan]

Thanks, Earl, that's great. That's the way I'll go. I'm not so much concerned about rim porosity, 'cos I have no real difficulty with just checking the pressures often, but it's good to know how to take care of that, too. I had been worrying that the tire sealer wouldn't do anything about the rim, because it relies on the rubber.

I was concerned about the suggestion that the rim/bead interface might be different, and potentially allow a sudden 'let-go'. As I said, I know from experience that when this happens one 'proceeds directly to the scene of the accident'.

Tomorrow I'll go and take a real hard look at the rims and post any markings I can find just in case anything rings any bells - positive or negative.

In the meantime, thanks everyone.

YOU GUYS ARE GREAT

Pete

[Anonymous]

Aren't the valve stem holes different? I thought you needed to put a collar around the valve stem of a tube put in a tubeless tire.

It's very interesting to hear that the rims are cast on the same inside pattern, I may have to seal my 1100s rims now...

Steve

[Pete Logan]

Aren't the valve stem holes different? I thought you needed to put a collar around the valve stem of a tube put in a tubeless tire.

It's very interesting to hear that the rims are cast on the same inside pattern, I may have to seal my 1100s rims now...

Steve

Ah - good point - as I have the tube type, I guess if this is so the holes are smaller than they need to be to take a tubeless valve ???????????????

On the other hand, I've slung tubes into car tires to fix a puncture and not worried about sleeving or anything - Hmmmmmmmmmmmmmmm

Another thing to look at in the morning.

Thanks Steve.

Pete

[earlfor]

The valve stems on the tubes that I have used have all been steel. The valve stems I used when changing over to a tubless tire were also steel and identical to the steel stems in a tube with the only difference being a steel retaining base and rubber grommet that seats against the interior side of the rim. I used stainless stems and they were $25 each, but worth it. I doubt they can be broken and will not crack and age. If a rubber "pull through" type stem were to be used, its possible the hole in the rim would need to be enlarged, but I doubt it. (I dont know........havent tried one, and dont intend to)

Earl

Aren't the valve stem holes different? I thought you needed to put a collar around the valve stem of a tube put in a tubeless tire.

It's very interesting to hear that the rims are cast on the same inside pattern, I may have to seal my 1100s rims now...

Steve

[Anonymous]

Earlfor,
Where did you get the valve stems?

[earlfor]

I bought the valve stems at the local suzuki/Honda/Yammie/ and everything else dealer. Its just a standard diameter tubeless rim/tire valve stem.

Earl

Earlfor,
Where did you get the valve stems?

[Anonymous]

Tim: I've used them on heavy equipment before, anybody that services bobcat tires will have them.

Earl: Did the GS1000 you worked on have the star spoked mags on it like the 81/82 E bikes have?

Thanks, Steve

[earlfor]

The star spoked rim on the 78 1000E looked exactly like the star spoked 81 750E rim. I believe all the star spoked rims are the same. (with the exception of width)

Earl

Tim: I've used them on heavy equipment before, anybody that services bobcat tires will have them.

Earl: Did the GS1000 you worked on have the star spoked mags on it like the 81/82 E bikes have?

Thanks, Steve

[Joe Nardy]

Pete,

I have run tubeless tires on my '83 1100E for many years with no problems whatsoever. My wheels are not marked MW or tubeless. I had to enlarge the valve stem holes and use a rubber pull through stem. I know of at least two other GS's doing the same thing with no problems. I will say that there is a difference when changing tires on tube type rims versus tubeless rims. The tubeless rims are much harder to break the bead. Also, you don't get the 'POP' on tube type wheels when the new tires are inflated and seat on the beads. That being said, I can't see why tube type wheels would have a problem with the tires detaching. There isn't much (if any) difference between 30 PSI pushing a tube against a tire against a rim and 30 PSI pushing a tire against a rim. Like Earl, I feel confident to ride this bike as hard as I like with no concern about tire problems.

Thanks,
Joe

[dpep]

Re: Tubeless Tires, Unmarked Alloy Wheels and Tire Sealers

The tires gave no problems and I am confident enough of the modification to put my butt on the seat at any speed and under any conditions.

Earl

Earl, thank you very much for this post. This has been a running confusion for me for 20+ years. I have always suspected what you determined, but never had what I would call a definitive answer until now. If you have taken the measurements and done the testing, I will consider that case closed.

It is still a problem for those of us who don't change our own tires. I haven't found anybody in a shop willing to mount tubeless on a wheel that doesn't say it. I can understand that they have to cover their ass. Still, I'm going to get an extra rim (tubeless) for my front (back already is) and coat my current tube type rim according to your description.