Tube to tubeless conversion

[argonsagas]

I beg to differ. The only time I have seen a tube deflate slowly is when the valve core is leaking. Any other time it has been rather dramatic.

If you stop for a moment and think about it, the whole reason you have a tube in the first place is because the tire can not hold the air on its own. Now that the tube is not holding air, how do you expect the tire to do it?

I have personally experienced a rather quick deflation (about 30 seconds) of a front tire on my KZ650 many, many years ago, with no bad concequences. On the other hand, I have also experienced a blowout of a rear tire on my KZ1300, which totalled the bike.

The fact that you have a tube-type or a tubeless tire and/or rim really does not have much to do with it. What causes the loss of air will have a much greater impact on the outcome of the situation.


.

I have experienced blow-outs and slow losses with tubes and tubeless tires. On the bike I have never had a blowout on the front, and only a slow loss on a tubeless tire.



I have been very lucky as most flats in my experience have occurred due to puncture, and the leak was unimportant as I discovered the problem while the bike was parked.

In the car I have had tube tires go slowly and RIGHT NOW. It is not the tire itself that retains pressure when the tube is punctured, but the remaining pressure within the tube that keeps it pressed against the inner walls of the tire that can slow the release. This usually happens in the case of a small puncture, and where the casing of the tire is not severely damaged. Severe damage to the tire casing leads to a like damage of the tube, which means an instantaneous and total loss of pressure.

 

[earlfor]

I beg to differ. The only time I have seen a tube deflate slowly is when the valve core is leaking. Any other time it has been rather dramatic.

.

I did say a tube MAY allow the tire to deflate slower. It depends on the size of the hole.

Earl

 

[Guest]

Tires loose air through several routes:
1) spoke holes! Cast rims are needed to hold air.
2) Between rim and bead - The rim and bead profiles must match each other quite closely. The rim must be smooth and free of rust. Bead wire is stiff, and it usually kinks when a tires is dismounted. Kinked beads seal poorly. Rubber around the bead must be soft enough to fill in mismatches between bead and rim, but mounting and dismounting damage the rubber easily.
3) Through the valve - Usually not a problem, but valves should be replaced with tires to be safe.
4) Through the tire itself - Most types of rubber are porous. Everyone knows that balloons lose air quickly. Thick rubber holds air better. But tire cords bleed air quickly. The thickness of the sidewall, the thinnest part, is what matters most, and the distance from the inside of the tire to the nearest cords.
Inner tubes are made from butyl rubber, which is much less permeable to air than normal rubber. Butyl rubber tears very easily. Tiny amounts of contamination can make a tube leak or tear. Lots of tube factories are too dirty, and contamination is common in them.
Tubeless tires have an innerliner on the inside of the tire. Innerliners ae made from chlorobutyl or bromobutyl rubber. Butyl rubber holds air better, but it won't stick to the rubber in the tire carcass. Chlorobutyl and bromobutyl rubbers will stick. The innerliner must surround the bead, to seal against the rim. Butyl rubbers are hard, so they don't seal well against the rim unless the rim is clean and undamaged, and the bead is molded exactly and undamaged.
The innerliner is made in several thin layers, so thin that you can almost see through them. The chance that one layer will have a small imperfection is relatively high, but the chance that two or three layers will have imperfections at exactly the same place is very low. Because the innerliner adheres to the tire carcass, it can't rip or tear if it is suddenly punctured. Usually. Damage to a sidewall can cause the sidewall to tear completely open. When a clean puncture occurs in the tread area, a tubeless tire will probably hold air much longer than a tubed tire.
5) Through the rim itself. Some processes for making rims let the metal itself be porous enough to leak air out.

I don't know why tube type rims don't have the hump to help keep the bead seated in case of pressure loss. Here's a guess. Maybe someone figured out that, when the bead stays seated despite air loss, the driver is much less likely to lose control. Manufacturers (or the DOT) might have decided that when rims were made to accomodate tubeless tires, the bead lock feature should be incorporated at the same time. Just a guess.

The first GSes had spoked rims and tubes. I think that in the second model year, GSes sported cast rims. GSR has had many threads on this topic. It seems that the first cast rims were not suitable for tubeless tires. I'm pretty sure that all 1982 and later cast rims were good for tubeless tires, and think that most 1980s and 1981s were also.

The change from tube-type to tubeless cast rims seems to have been what manufacturers often call a "rolling change". A better part gets built into some bikes before the specs require it. Some riders have successfully used tubeless tires on cast rims not marked tubeless. So we know that before the word "tubeless" was cast into the rim, the quality was there. But we don't know how when this started. Nor do we know if all models changed this way at the same time. Or even if the front rim was OK for tubeless and the rear rim on the same bike wasn't.

A well made, well designed tubless tire, mounted properly on a well made, clean rim with a good valve, unless it is damaged, should not need to have air put in it more than once per year. I once ran a set of car tires 2 1/2 years without adding air. Minor problems with the rim, valve or kinked beads might require adding air every couple of months. If you have to add air as often as once per month, there is a problem that should be found and repaired. That being said, bikers should be checking air at least monthly with a gauge, and at least weekly with a thumb.

(I worked a long time in tire factories.)

 

[rphillips]

I'll say this again, at the risk of being wrong. I don't remember tubeless motorcycle tires, per 1979. If there were no tubeless tires when the early cast wheels were made, why would any co. stamp "TUBELESS" on the rim. I would rather think the cast wheels came first, then the tire mfg realized the cast wheels, with no spoke holes, would hold air without the use of tubes, and then started the tubeless tires. If the tubeless tires came first, they had to be tested on wheels that didn't have "TUBELESS" stamped on them, as nobody would put "TUBELESS" on the rim, if there were no tubeless tires. After the introduction of tubeless motorcycle tires, of course the bike mfg wanted to advertise you can use these new tubeless tires on our rims, thus the "TUBELESS" stamped rims. Who knows where to find out when the tubeless motorcycle tires were introduced for normal customer use?

 

[hp1000s]

Excellent discussion on an interesting subject....alot of great and informed input! Thanks,
Hugh

 

[tomcat24551]

Here is a little more info that I probably should have put in an earlier post.

I bought my '79 GS 850 in 1980 from the original purchaser when it had 4500 miles on it. The bike's manufacture date is 12/78.

The front wheel is the original Suzuki OEM cast wheel (MT 1.85x19) by Enkei and it has a date 11/78 embossed into it. It is not marked "Tubeless Tire Applicable".

The rear wheel is also original Suzuki OEM cast wheel by Enkei and it has the date 10/78 embossed into it. It is size MT 2.50x17 but it is clearly marked "Tubeless Tire Applicable".

So, for what it's worth, here we have a tubeless wheel made a month before a narrower, identically appearing but tube type wheel. I would have thought that the natural evolution of design would have put the tubeless wheel later than the tube type. What gives?

Maybe the narrow width of the front wheel is the problem. Later 850's with front wheels marked "Tubeless Tire Applicable" used an MT 2.15x19 wheel--but they also have the raised ridge.

I replaced the rear tire on this bike in Aug 2004, but to be honest, I don't remember if I ever noticed whether it had a raised ridge on both sides of the wheel's center well or not. I have never been concerned because the wheel says to go tubeless and that's what I do. I use a tube in the front 'cause that's what it says to do (so to speak)!

There was a British guy named Tony Mills who used to manage Dunlop's Motorcycle Tire operations in the U.S. in the 70's and 80's, I think. If anybody in New York knows of him, they might be able to get him to shed some light on this tube vs tubeless discussion.

Tomcat

 

[Guest]

Iteresting info, tomcat. You have established that at least some 79s came with tubeless cast wheels, and that my theory of a "rolling change" is quite possible. If I had your bike and wheels, I'd probably choose tires the way that you do. Or else buy a newer front rim on Ebay to go to tubeless all around.

 

[jknappsax]

Argonsas, Earl

Argonsas, Earl

Argonsas, You're absolutely correct about Slime and centrifugal force. DUH, what was I thinking? Oh, that's right,NOTHING! But it's the FIRST time that has EVER happened!
Earl, that's a great solution for this! I never thought of this, and I use barrier paint!

 

[boris]

well ive just gone from tube to tubeless on non tubeless marked rims lol
will keep my eye on them to see if their is any loss of air

my bikes a gs450e 1987
so im hoping that by 1987 stock they had sorted the porus issues out

 

[GS750GUY]

Tube to tubeles wheels

Tube to tubeles wheels

I mounted new tubless tires on my 1978 originally tubed cast wheels a month ago, used soapy water to check for leaks at the time of mounting, found no bubbles, inflated to 25 lbs and they have been at 25 lbs ever since.
GS750Guy

 

[salty_monk]

On my 80 the rear is marked as suitable the front isn't... weird huh!

Dan

 

[mark]

On my 80 the rear is marked as suitable the front isn't... weird huh!

Dan

Same on my '79.

 

[t3rmin]

Wanted to relate my experience trying to go tubeless.

My rear rim is marked tubeless, but not my front. I tried to go tubeless in front, thinking worst-case scenario would be slow seepage. However, I was instead treated to rather rapid deflation at speed. Fortunately I didn't wreck, but if it'd happened on a corner I'm sure I would have.

Funny thing is it wouldn't loose hardly any air sitting in the garage (after several days), but it only took a few miles of highway-speed riding to completely deflate.

Back to a tube for me! Scary stuff.

 

[GS750GUY]

For what it's worth. An old Suzuki mechanic summed it up pretty much for me when he said that if you have a tire failure......tubed or not.......on a machine that weighs almost 500 pounds by itself coupled with the weight of the rider, or riders additional weight, and you are flying at highway speeds..........nothing is going to keep that tire from going to the center of that wheel regardless of wheel design. He said an inner tube under those brutal conditions has nor more structural integrity than a childs water balloon. All it's there for is to hold air. Either the tire does it or the tube does it. And if one does the job....you don't need the other.
GS750GUY.

 

[Grandpa]

The more modern GS front wheel will interchange perfectly with the "pentagram" older wheel. In other words, if one can locate a front wheel, for example, off a 1982 GS850G or GL, it will fit an older GS850G or GS1000G just fine. The 82 (or more recent) front wheel is clearly marked for tubeless tire application.

On my 1984 GS1100GK, this tubeless-tire front wheel is stock. I also use an old-style "pentagram" wheel off one of my old GS850's. It fits the GK just fine.

I have two front wheels and two rear wheels, alternating one with the other. That way I can have a new tire installed on an unused wheel at all times. When it's time to replace a tire, off comes the old one and on goes the new one. No downtime necessary. I alternate the stock 16-inch GK wheel with the 17-in wheel off an old 850. They both interchange perfectly.

I see front wheels meant for tubeless tires on eBay all the time.

 

[tomcat24551]

The more modern GS front wheel will interchange perfectly with the "pentagram" older wheel. In other words, if one can locate a front wheel, for example, off a 1982 GS850G or GL, it will fit an older GS850G or GS1000G just fine. The 82 (or more recent) front wheel is clearly marked for tubeless tire application.

On my 1984 GS1100GK, this tubeless-tire front wheel is stock. I also use an old-style "pentagram" wheel off one of my old GS850's. It fits the GK just fine.

I have two front wheels and two rear wheels, alternating one with the other. That way I can have a new tire installed on an unused wheel at all times. When it's time to replace a tire, off comes the old one and on goes the new one. No downtime necessary. I alternate the stock 16-inch GK wheel with the 17-in wheel off an old 850. They both interchange perfectly.

So it sounds like your wheel styles don't always match--you might have the old pentagram style on the front and the newer pattern on the rear. That might bother some more meticulous folks, but it sounds like a good idea nonetheless.

I was wondering how much difference you notice with the 17" rear wheel. Is this a problem to you, power-wise or do you like the calming effect it has on the engine? Or is the difference too small to notice?

Thanks

Tomcat

 

[Grandpa]

You're right -- mixing wheel types does not matter to me one bit. I go for function rather than form in this case. For one thing, I have a GK, which has stock saddlebags, and it's hard to see what type of rear wheel is on the bike at a given moment. I ride with a bunch of old friends, and none of them notice a thing. It takes a real GS Suzuki nut to notice any kind of mismatch.

As far as the 17-in v. the 16-in: The 84 GK is already a high-geared bike, thanks to an internally different rear end. The gear ratio in the rear end makes the engine run at slightly lower rpm's at a given speed than, say, a typical 850. (All rear ends on the big shafties are exchangeable, though).

The stock wheel on the GK is a 16-incher, exactly what goes on a GS1100GL. A 17-incher off an 850 will fit with no problems, and make the gearing only slightly higher. I notice the slightly taller gearing, but the difference is too slight for me to dwell on it for very long. I just installed the 16-incher on the GK this weekend. I noticed gearing was a bit lower. It took me about 20 miles to get used to it again. No big deal. Remember -- it's an 1100-cc engine, with lots of power. Taller gearing or low gearing are inconsequential when that much power is at hand. At 90 mph plus, the taller gearing from the 17 is an advantage, but it's a marginal one.

I do notice the difference when I park the bike on the sidestand. It leans more when the 17-incher is installed. When on the centerstand with the 17 on, the rear wheel is barely off the ground. No big deal either way.

Another advantage of having a new tire installed on a wheel at any given time is that I can take my time to shop for the best deal on a tire, from eBay or any of the mail-order places mentioned elsewhere on this forum.

 

[Grandpa]

Here's my '84 GK with the stock tubeless-tire wheel on the front. The 17-inch pentagram is on the rear. Can you tell the difference? Hardly! Photo was taken in November, 2006.

As I write this, the pentagram old front wheel is installed on the bike, while I have the stock 16-incher on there. Another mismatch. I'm not concerned with whether or not they're matched. The replacement cycle for front and rear is different, so I treat them individually. Who knows when the two wheels will be matched again, and I really don't care.

By the way, the stock GK fairing and trunk were destroyed in a deer collision over 5 years ago. That's why the Windjammer fairing/lowers and the generic trunk. Saddlebags are the originals.

 

[tomcat24551]

Thanks for the reply, Grandpa. I agree with everything you said regarding appearance. But I forgot to ask you if you use a tube with the older pentagram front wheel? Its probably an MT 1.85 x 19 wheel, right?

Also, if I'm not mistaken the Final Drive gear ratio on the 850 is 3.09:1. Do you know what it is on the 1100GK? I was under the impression the difference was the 5th gear ratio, not the Final Drive. That's the way it is on the 850 L models.

By the way, where is Fort Frederick? Looks like Ireland.

Thanks

Tomcat

 

[Grandpa]

Fort Frederick State Park is in Western Maryland, just west of Hagerstown and by the old Chesapeake and Ohio Canal.

Don't know what the final ratio is on the GK. One who most probably knows is dpep (Don Pepe), who owns both a GS850G and a GK. My understanding is that the higher gearing is found only on the 83 and 84 GK, but not on the 82 GK. If I'm wrong on any of this, you or someone else please correct me.

I do use a tube in the older pentagram wheel. You got the correct size on the wheel. The more modern wheel is a bit wider than the 1.85. I have no problem using a tube in that wheel. I have my mechanic install a new tube every tire change. Both rear wheels are for tubeless tires, so I run them both tubeless.

One more advantage of rotating two front and two rear wheels is that it saves on wear on the brake rotors. Also, each rear wheel has its own driven gear (splines) set; by alternating, I'm also saving wear on the splines. I use the old-style black splines on both wheels, since the more modern splines wear out much sooner; both came off old 850's.