Tube Type & Tube Less Tires

[gordo]

Is there anything wrong with using a Tubeless Dunlop D803 with a tube in it, on my vintage Twin shock?

How different are the two tires; Tube Type & Tube Less. I thought I ordered Tube Type, but just realized they say Tubeless on the side. Again, they are Dunlop D803's. Thanks

[tony283]

Gordo,

I've run both Dunlops and IRCs which arrived, like yours tubeless when tubed type had been ordered. As long as your security bolts are good you won't have a problem.

Tony

[pete_scorpa3]

I've used Michelin X11's and IRC's on the back of my DRZ400 for trail bike trials with no problem.

Some say that there may be a problem with them seating on the rim but I've not suffered from this with the DRZ.

Pete

[gordo]

Is there a difference in sidewall stiffness between the two? These tubeless ones seem stiff, even with 4 pounds of air pressure. And they come off the bead, on steel rims, if I don't run at least 6 pounds.

[feetupfun]

Yes Gordo the problem with the Dunlops is that the bead slips off its seat at low pressure.

Dunlop do not even make tube type rear 803s. Whoever took your order was ripping you off. The only trials competition tube type rears are made by IRC and Michelin. The Michelin tube tyre is not the same (not as good) as the Michelin X11 tubeless type. The IRC tube type is good but requires accurate pressure monitoring to get the best without getting a floppy-feeling rear end.

If you want to use that Dunlop on your rim, I have seen people fit four tyre clamps/grips/rim clamps whatever you call them - equispaced on the rim to hold the bead up on its seat.

It is becoming more common to see tubeless rims on old bikes.

[b40rt]

Yes Gordo the problem with the Dunlops is that the bead slips off its seat at low pressure.

Dunlop do not even make tube type rear 803s. Whoever took your order was ripping you off. The only trials competition tube type rears are made by IRC and Michelin. The Michelin tube tyre is not the same (not as good) as the Michelin X11 tubeless type. The IRC tube type is good but requires accurate pressure monitoring to get the best without getting a floppy-feeling rear end.

If you want to use that Dunlop on your rim, I have seen people fit four tyre clamps/grips/rim clamps whatever you call them - equispaced on the rim to hold the bead up on its seat.

It is becoming more common to see tubeless rims on old bikes.

I'm told to run IRC's approx 1lbs more than normal to stop excess movement.

[feetupfun]

I'm told to run IRC's approx 1lbs more than normal to stop excess movement.

Yes I agree, but why are they more sensitive to pressure than the Michelin X11 tube types we used to use?

When we ran the Michelin Tube Type X11 tyres, it didn't seem to matter if the tyre had 4, 3 or 2 psi, it didn't seem to flop around but the IRC goes crazy if the pressure drops a bit.

[woody]

IRC tube type are inconsistent, some have stiffer sidewalls than others and will run ok at 3 or 4psi. If you get one with a soft sidewall they are next to useless if you weigh a fair bit as they roll all over the place with the weak sidewalls, compounded by a heavier riders weight (although I've had this with a tubeless one on one occassion) They need almost 6psi to stop the rolling but then won't grip in mud. In really hot weather they can still roll at this psi. No idea why some are ok and some aren't - made in different factories? inconsistent manufacturing? Who knows but I only buy an IRC from the local dealer now so I can check the sidewall before I buy it.

I've had a Dunlop tubeless fitted to my Bultaco for 12 months or so (on a tubeless rim) and it has performed well. Recently the rim decided it wasn't going to hold air any more for some reason and I had to put a tube in as a temporary measure. The difference was incredible. Next trial the bike would not grip at all in the mud, it didn't like the tube in it at all. It was back to tubeless for the next event.

I think with the tubeless tyres it depends on the type of tubed rim as to whether the tyre will hold or not. I can get tubeless tyres to stay on the rim of Bultaco or Ossa rims no problem whether they are IRC, Dunlop or Michelin. I can't get a tubless tyre (specifically IRC, not tried the other two) to stay on the rim of a TY or KT. They pop out onto the rim ok when initially fitting but when you start deflating down to trials pressure a section of the tyre on one side of the rim, for a length of about 12", always drops into the rim. I've never successfully run a tubless tyre on a TY or KT rim.

[gordo]

They pop out onto the rim ok when initially fitting but when you start deflating down to trials pressure a section of the tyre on one side of the rim, for a length of about 12", always drops into the rim.

This is exactly what is happening with the steel rims on my Wassell. With my Ossa I can run 4 pounds with no trouble. To tell you the truth, I never new the Dunlops on the Ossa were tubeless until I looked today.

So, I guess from everyones advice, I could try an IRC Tube Type, on the Wassell rims, since I weigh in around 150 pounds.

Edited April 25, 2010 by Gordo