Tube to tubeless conversion

[GS750GUY]

Hi guys and gals!!
I'm in the process of replacing the tires on my cast wheels for my 78 GS750EC. These are probably the original tires. The bike has only 11,000 miles on it and the tires are completely bald. The prior owner must have enjoyed taking chances. These tires had tubes but I want to replace them whith a pair of tubless Dunlop D404's.
Will just any wheel stem from the local auto store work, or will I have to get a special kind from the bike dealer and spend $5 bazillion dollars for them instead of just $4.95 for a pair of nice steel ones from the auto store?
I appreciate your input!
Thanks!
GS750GUY (Harold)

 

[jknappsax]

Two types of E-style mags

Two types of E-style mags

The first cast wheels were meant to be used with tubes. Shortly after, they started using mags marked "tubeless", meant to use without a tube. Some people run tubeless on the rims not marked for them, with varying results. Some are fine, but some leak slowly. The mags I got when I changed over were not the tubeless type, and I've always run tubes in them, so I don't have any first-hand experience with how they do without tubes. I've heard of people with slow leaks using what I believe is named "Slime", a sealant and balancer. I got another front wheel with a front end I was going to swap onto my 1978 GS 750, and it IS marked tubeless. As to the stems, I don't know for sure, but they look like the metal ones used on car alloy wheels.

 

[Road_Clam]

Hi guys and gals!!
I'm in the process of replacing the tires on my cast wheels for my 78 GS750EC. These are probably the original tires. The bike has only 11,000 miles on it and the tires are completely bald. The prior owner must have enjoyed taking chances. These tires had tubes but I want to replace them whith a pair of tubless Dunlop D404's.
Will just any wheel stem from the local auto store work, or will I have to get a special kind from the bike dealer and spend $5 bazillion dollars for them instead of just $4.95 for a pair of nice steel ones from the auto store?
I appreciate your input!
Thanks!
GS750GUY (Harold)

GS cast wheels are ONLY designed for a tube. You need to do some machining to the existing hole to reliably accept a tubless valve stem. Save your self a lot af aggravation and just run tubes. You don't have a 150 mph race bike......

 

[chiphead]

I was in the business when the first cast wheels came out. Tubed. Yea, I'm friggin old.
Then the tubeless rims came out. The unconfirmed factory word was that the tubeless rims were the exact same as the tubed rims except the tubeless rims were leak tested for porosity. I really don't know if this is 100% true but I do know that folks ran tubeless tires on non marked "tubeless" rims with success. Some people sealed the inner cast wheel to hedge their bets.

 

[Jethro]

GS cast wheels are ONLY designed for a tube. You need to do some machining to the existing hole to reliably accept a tubless valve stem. Save your self a lot af aggravation and just run tubes. You don't have a 150 mph race bike......

I agree with all of this.

Unfortunately, the problem is I would consider myself a pretty serious sport tourer. Tubeless tires are a huge advantage when it comes time to field repair a flat which can easily be done with a plug. I heard I could lose the tubes in my wheels as I have an 83 1100E. However, I will go from a full 32 lbs of tire pressure to 15 lbs within 3 days. So, if you ask my opinion, the GS mag wheels should be run with tubes.

 

[Joe Nardy]

I agree with all of this.

Unfortunately, the problem is I would consider myself a pretty serious sport tourer. Tubeless tires are a huge advantage when it comes time to field repair a flat which can easily be done with a plug. I heard I could lose the tubes in my wheels as I have an 83 1100E. However, I will go from a full 32 lbs of tire pressure to 15 lbs within 3 days. So, if you ask my opinion, the GS mag wheels should be run with tubes.

I consider myself in the same class. I've been running tubeless tires on my '83 1100E for fifteen years or more. My tires don't lose any more air pressure than the tubeless tires on my '04 FJR1300. I had to ream out the valve holes and I make sure the bead seating surfaces are very clean. I know of at least a half-dozen GS owners who run tubeless tires with no issues.

Of course, MY '83 is the much nicer BLUE model so that may explain why I don't have any problems. \\/

Joe

 

[SqDancerLynn1]

For what ever reason the stock original wheels on my 79GS850 rear is marked tubless front is not marked go figure

Oh the rear looses more air than the front w/tube

 

[mark]

For what ever reason the stock original wheels on my 79GS850 rear is marked tubless front is not marked go figure

Oh the rear looses more air than the front w/tube

Same here. One marked and one not marked on my '79. I've decided that both'll be tubeless.

 

[Steve]

OK now you guys went and got my curiosity up. Just went out to the garage and checked the wheels on my (wife's) '82 850L. BOTH of them are marked "TUBLESS TIRES APPLICABLE". \\/

Checked the pressure, compared it with the reading before we went on our New Year's Eve ride. Only lost 1 pound in each tire.:-D

It's too wet and sloppy to go out to the shed to check the 650, so might check it when it dries out a bit.


.

 

[Hap Call]

Tubeless tires require a special bead seat, because the beads have to form an airtight seal on the rim. Not all cast wheels, aluminium or magnesium, are suitable for tubeless tire fitment. If a tube is inserted, it is then possible to fit a tube-less tyre to a tubetype rim. Also, some tubed tires require a tube because of leakage through the actual tire, not the rim...this is true of Metezler tires. They have a special liner they put in their tubeless tires to prevent leakage.

That being said, I've run tubeless tires without a tube on my '81 GS1100E for at least 15 years with no problems. Most tire shops will not mount a tubeless tire on a tube-type rim.

Hap

 

[Jethro]

Well I don't know what the problem is with the Dunlops I run, maybe they are for tubes only? They aren't radial, they are bias-ply. But without a doubt, even when they were new they lose a lot of pressure within a week. Not really a big deal, I should be forced to check my tire pressure anyway before every ride. The front seems to lose less air than the rear.

 

[earlfor]

Well I don't know what the problem is with the Dunlops I run, maybe they are for tubes only? They aren't radial, they are bias-ply. But without a doubt, even when they were new they lose a lot of pressure within a week. Not really a big deal, I should be forced to check my tire pressure anyway before every ride. The front seems to lose less air than the rear.

I had the air loss problem with one set of rims on a GS1000 I fitted tubless tires on for a guy. I had to resort to sealing the inside of the rims with a marine epoxy barrier coat. Problem solved. Had to balance the bare rims too.

Earl

 

[GS750GUY]

Tubes to tubeless

Tubes to tubeless

Thanks Guys! I've considered all of your arguements and think I will try going tubless mainly due to the ease of field plugging any future flats. I've learned from the experience I just had at removing the old front tire from the wheel that this is nothing I want to try to tackle out on the road somewhere. Plugging is far easier Plus they make all kinds of tire bead sealants these days. Plus it will save me the cost of tubes.
THANKS FOR ALL YOUR INPUT!
GS750GUY

 

[argonsagas]

The first cast wheels were meant to be used with tubes. Shortly after, they started using mags marked "tubeless", meant to use without a tube. Some people run tubeless on the rims not marked for them, with varying results. Some are fine, but some leak slowly. The mags I got when I changed over were not the tubeless type, and I've always run tubes in them, so I don't have any first-hand experience with how they do without tubes. I've heard of people with slow leaks using what I believe is named "Slime", a sealant and balancer. I got another front wheel with a front end I was going to swap onto my 1978 GS 750, and it IS marked tubeless. As to the stems, I don't know for sure, but they look like the metal ones used on car alloy wheels.

This stuff, or one of its variants, does work on leaks, but is of little value on rims/wheels due to centrifugal force causing it to move away from the rim, and into the tire itself.

 

[8trackmind]

Don't believe the hype.

Don't believe the hype.

I converted My 1980 GS550 to to tubless tires on non-tubeless rims over a year ago. No problems, no air loss.

I just did another set of mags on my 1000 a couple weeks ago. Again, no air loss, no problems.

 

[tomcat24551]

The guy that mounts my tires (and who used to race bikes himself) says that it is somewhat risky to mount tubeless tires on cast wheels not marked for tubeless tires. This is because if the tire should suddenly lose air pressure when you are leaned over pretty hard, there is nothing to keep the tire's bead from sliding down into the well with disastrous results. He says he's seen it happen--on tires he's mounted without tubes on early-type cast wheels.

This is apparently why the manufacturers changed to a wheel that was made with a raised ridge at the edge of that center well--the ridge acts as a barrier to the tire bead slipping down into the well.

You can see a short discussion with drawings in the Continental Motorcycle Tire Tech manual at this site:

http://www.conti-online.com/generator/www/de/de/continental/motorrad/themen/download/handbuch_uv.pdf

See page 133 (or 137, depending on how your browser numbers the pages).

Motorcycling is risky enough as it is. Why add to it? A good quality tube costs less than $20. I think my body is worth it!

Tomcat

 

[mark]

The guy that mounts my tires (and who used to race bikes himself) says that it is somewhat risky to mount tubeless tires on cast wheels not marked for tubeless tires. This is because if the tire should suddenly lose air pressure when you are leaned over pretty hard, there is nothing to keep the tire's bead from sliding down into the well with disastrous results. He says he's seen it happen--on tires he's mounted without tubes on early-type cast wheels.

This is apparently why the manufacturers changed to a wheel that was made with a raised ridge at the edge of that center well--the ridge acts as a barrier to the tire bead slipping down into the well.

You can see a short discussion with drawings in the Continental Motorcycle Tire Tech manual at this site:

http://www.conti-online.com/generator/www/de/de/continental/motorrad/themen/download/handbuch_uv.pdf

See page 133 (or 137, depending on how your browser numbers the pages).

Motorcycling is risky enough as it is. Why add to it? A good quality tube costs less than $20. I think my body is worth it!

Tomcat

Your point is valid and has merit for me because I've heard some in the "field" make the same one. Others I've talked with say that the risk is so small to be almost non-existant. I've just had to make a decision that I'm comfortable with.

Just a question however (I really am curious, not trying to prove a point). You're in a corner with a tire with a tube on it and you suddenly totally lose air pressure. How does the tube keep the tire in place on an old style rim? I don't get how a flat tube helps you.

 

[earlfor]

Just a question however (I really am curious, not trying to prove a point). You're in a corner with a tire with a tube on it and you suddenly totally lose air pressure. How does the tube keep the tire in place on an old style rim? I don't get how a flat tube helps you.

It doesnt help at all. The only thing a tube may do is allow the tire to deflate more slowly. A blowout on a tubeless tire is instantaneous (or close to it). With a tube, the tube will likely quickly deflate but not instantly. I dont believe either is more prone to separating from the rim.

If you blow a tire in a corner, either way, methinks there will be a problem coming shortly. LOL

Earl

 

[Steve]

It doesnt help at all. The only thing a tube may do is allow the tire to deflate more slowly. A blowout on a tubeless tire is instantaneous (or close to it). With a tube, the tube will likely quickly deflate but not instantly. I dont believe either is more prone to separating from the rim.

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.


.

 

[tomcat24551]

I guess I think of the situation this way:

Some group of engineers probably thought long and hard about putting that raised ridge next to the center well in the tubeless wheel, and there must have been good reasons prompting them to do it.

And management had to approve the extra cost--which they did, probably so the company could cover its rear end in court.

Then probably the whole industry trade group looked at the problem and approved the solution, probably again for liability reasons.

But we don't have the data the industry used in making its decisions, so I'm not willing to second guess 'em. If the wheel doesn't say "tubeless tire applicable", I use a good quality tube. I like to think the tube's bulk might tend to fill up the center of the wheel and discourage the bead from slipping into the center well, but, of course, that's just a guess.

In the end, every rider has to make a decision he's comfortable with.

Tomcat