What's the skinny on the use of tubeless tires on a 1980 GS750E?

[Cipher]

anyone want to email ENKEI or ASAHI and ask an actual engineer involved in the transition? I doubt many are around now but at least the answers would be based on facts.

[sharpy]

The tube people can't provide evidence because it doesn't exist.

.

Im not worried about evidence. I just feel safer when my front wheel "lands" 200lbs of front end on the ground at 185kph and theres a tube inside helping me to be as safe as possible. Yes i dont do it all the time but any good ride involves me doing that at least 3 times a ride. Im not a loonie, just act like one. Do what ya want, its your bike.

[Sandy]

The tube people can't provide evidence because it doesn't exist.

Their argument goes out the window when you realize that the OEM's were selling bikes with tubeless tires using rims that did not have the extra safety bumps to keep the tire seated.

Those safety bumps ARE a positive safety feature, but they are not strictly necessary to be able to run a tubeless tire. The OEM's knew that which is why they installed tubeless tires without them.

Nope, no evidence here and not planning to be the first any time soon. Pretty small sample group, maybe a year or two only, for a tire/rim combination that they quit producing when they realized the error of their ways.

[Nessism]

You tube guys got nothing but speculation. You ASSUME that a tube will reduce the chance for a sudden deflation such as would occur if a tubeless tire came off the bead. But the only way for the tire to come off the bead is if it's drastically deflated already. If the pressure is low to the point where the tire can come off the bead it will occur regardless of whether or not there is a tube inside the tire or not. And let's say the tire does come off the bead and there is a tube inside, do you actually think the tube will push the tire back on the bead? Really?

[Sandy]

You tube guys got nothing but speculation. You ASSUME that a tube will reduce the chance for a sudden deflation such as would occur if a tubeless tire came off the bead. But the only way for the tire to come off the bead is if it's drastically deflated already. If the pressure is low to the point where the tire can come off the bead it will occur regardless of whether or not there is a tube inside the tire or not. And let's say the tire does come off the bead and there is a tube inside, do you actually think the tube will push the tire back on the bead? Really?

Pretty much wrong on that theory. At low pressure a during minor momentary bead shift/separation the tube will maintain air and push the tire back against the bead enough to keep from pinching the tube and maintain pressure. That event without a tube will lead to immediate deflation.

[Nessism]

Pretty much wrong on that theory. At low pressure a during minor momentary bead shift/separation the tube will maintain air and push the tire back against the bead enough to keep from pinching the tube and maintain pressure. That event without a tube will lead to immediate deflation.

I doubt it.

The tire bead will have to shift about 1/2" inward away from the rim shoulder before it would come away from the rim and deflate (tubelsss). No way some soggy deflated tube pushes the tire sidewall back on the bead.

[sharpy]

So your telling me the tyre has to be 1/2" away from the rim before the tire would start to deflate? If not. please tell me what is the minimum you think a tyre needs to be to loose air? Remember this isnt a trick question and it isnt about tube or non tube, if just fact about what you think the air gap is to deflate a tubeless tyre.

[Nessism]

Yes, the tire sidewall would have to move inward away from the rim shoulder by about 1/2" before a gap between the tire and rim would develop and the tire would depressurize.

Basically, the outside edge of the tire would have to move all the way inboard until the tire fell into the valley between the beads. If this occurred and a tube was present, the tube would shoot into the gap and get pinched.

[Sandy]

I doubt it.

The tire bead will have to shift about 1/2" inward away from the rim shoulder before it would come away from the rim and deflate (tubelsss). No way some soggy deflated tube pushes the tire sidewall back on the bead.

Read what I typed Ed. I said push it back against the bead, it's obvious there's not enough to reseat the bead. You'll still have some air left, better than no air left.

[Nessism]

Read what I typed Ed. I said push it back against the bead, it's obvious there's not enough to reseat the bead. You'll still have some air left, better than no air left.

How much air are you talking about? Again, I doubt a saggy deflated tube inside will do much to improve safety.

[sharpy]

So when Michelin brought some tubeless tyres out with a little transfer attached to the rim area on it tyre. That little piece of plastic was enough to cause leaks and we had to get in there and pull every lil yellow sticker from the tyre. Thats way, way less than the 1/2 of tyre deflection thats been mentioned. So ill stick to my tubes for safety sake and the sake of the customers we served for over 20 yrs.. Do what ever you please with ya own bike.

[Nessism]

So when Michelin brought some tubeless tyres out with a little transfer attached to the rim area on it tyre. That little piece of plastic was enough to cause leaks and we had to get in there and pull every lil yellow sticker from the tyre. Thats way, way less than the 1/2 of tyre deflection thats been mentioned. So ill stick to my tubes for safety sake and the sake of the customers we served for over 20 yrs.. Do what ever you please with ya own bike.

Way to go! You totally changed the subject.

[1980GS1000E]

The thing to realize is that on the tube type rim, there is only the air pressure holding the tire against the rim flange. There is no bead retention system built into the rim. The "floor" of the rim, for lack of a better term, is not going to seal the tire from air loss as a tubeless rim can. I can see how a tube could prevent total air loss under a low enough pressure condition allowing a minute gap to appear between the bead and flange running tubeless. That being said, I check the tire pressure and ride tubeless anyway.

[Rijko]

Way to go! You totally changed the subject.

nope he did not

[Nessism]

nope he did not

Yes he did. A piece of FOD causing a leak would affect any tubeless tire, regardless of the type of wheel bead present.