Been thinking tires.

[mrbill5491]

Okay been thinking about this tire/tube thing on my bike. Here is what I have, I run Dunlops. Front is a 491 Elite II MM90-19 61H date is 1604, tire is in great condition, no cracks or anything lots of tread and is fairly soft to the touch. Rear is a D404 120-19 65H and is 2 years old. So a new tire. Both are tubeless tires though the front tire says Tubeless: on tubed rim fit tube. Rear tire just says tubeless. Part fiche says there are tubes. Neither of my tires have tubes, I've been running that way for 20+ years with no problems. Pic of the front tire.

We had a guy here in town that did nothing but bike tires and said with today's technology in tires, it isn't that critical any longer. The Dunlop rep was at the shop one day and I asked him as well, he said as long as the rim is in good shape and the bead area clean, there should be no problem running tubeless on an alloy wheel. So there you have it. What say you?

[loud et]

Did you mill out the back your rims/rims, to accept the tubeless valve stem?

[mrbill5491]

Did you mill out the back your rims/rims, to accept the tubeless valve stem?

Nope, found some tubeless valve stems at the bike shop that fit really nice. Absolutely no play in the mounting holes.

[loud et]

I may have to look for that. The reason I asked is that I changed to some new tri spoke mags from an 83 1100e. Tubeless rear and tube front. I was ultra super ridiculously careful not to pinch the tube and to my dismay it goes flat. New Shinko 230's.
I should have tested the tube before I installed it, but I did not.
Manufacterer defect or installer error, it does not matter now. It made me consider running it tubeless. Just sayin.
Will watch others responses to your post.

[mrbill5491]

I may have to look for that. The reason I asked is that I changed to some new tri spoke mags from an 83 1100e. Tubeless rear and tube front. I was ultra super ridiculously careful not to pinch the tube and to my dismay it goes flat. New Shinko 230's.
I should have tested the tube before I installed it, but I did not.
Manufacterer defect or installer error, it does not matter now. It made me consider running it tubeless. Just sayin.
Will watch others responses to your post.

Here is a pic of the valve stem.

[Nessism]

Tire technology is irreverent relative regarding whether or not someone should or shouldn't convert from tube to tubeless. The issue traces back to the fact that tube type wheels do not have the extra wheel bead intended to hold the tire in place in case of deflation. Some people don't care about the extra bead, others (like me) would rather error on the conservative side and run a tube.

[Steve]

Tire technology is irreverent relative regarding whether or not someone should or shouldn't convert from tube to tubeless. The issue traces back to the fact that tube type wheels do not have the extra wheel bead intended to hold the tire in place in case of deflation. Some people don't care about the extra bead, others (like me) would rather error on the conservative side and run a tube.

That would be this bead.




The other issue concerning whether to put a tubeless tire on a "non-tubeless" rim is that some of the early wheel castings were rather porous, and air would leak out, so a tube was necessary. Newer wheels had better castings, and were certified as "tubeless".

.

[mrbill5491]

Okay my rims have that hump and never had any problems with tires leaking down.

[salty_monk]

Your rear one might (but I doubt it)... be very surprised if your front one does as even the 1983 1100E 19" wheels don't have it on the front.

The G wheels were tubeless rear by 80, think you have to wait to 82 before you get a tubeless front.
The 16" front wheels were all tubeless.

[Tim Tom]

I know my '82 850G says tubeless on the front tire. Never has a problem with leaking air until the rim got destroyed . The replacement rime from an '82 650GL also says tubeless and as far as I can tell identical in every way.

[mrbill5491]

Well my rims are 80-81 GSEs, so from what I gather, I probably should be running tubes for a measure of safety then.

[Nessism]

Only the tubeless wheels have that extra bump.

Tubeless wheels are imprinted as such. No reason to guess.

The 1100E wheels are Tube Type. No extra bump on those.

[sedelen]

I run tubeless tires with tubes on both my bikes.
I do that because the fiche shows tubes for my models and year.
I don't want to take chances with my tires. I survived one rear blow-out on a bike once, doing 70 with a passenger, I was lucky. Didn't think I'd get a second chance.

So, do you trust your friends/mechanics advice enough to put your life on the line, as you're the one riding the bike?

[mrbill5491]

Point taken. Looks like tubes in the near future.

[bwringer]

This is a front rim from an '82 1100G. Yes, it's marked tubeless.

Look closely: no ridge.


The photo shows how to use a counterbore and pilot to cut a flat face for a valve stem. This did not need to be done on this rim, of course, but I had it hanging on the wall so it was pressed into service as a photo prop.

Here's an utra high-res version if you'd like a closer look:

http://www.pix.bwringer.com/d/5148-1/DSCI0473.JPG

I think the real difference may be porosity -- I've noticed a light gray epoxy-like coating inside tubeless wheels. There might also be a tighter fit -- no hump, but maybe the OD of the bead area is a little tighter. I'm not all that sure, honestly, but lots of folks have converted without problems.

The rear tubeless rims I've seen, like the one in Steve's "hump" photo above, do have the ridge.


Here's another shot of the counterbore and pilot I use to convert to tubeless -- it takes about five seconds with a cordless drill to make a nice flat face for a valve stem. You do NOT have to bore out the 8mm hole to a larger diameter -- simply use a proper motorcycle valve stem instead of something intended for a pickup. The pilot part is blunt, so it merely uses the existing hole to center the counterbore as it cuts the face.

5/8" counterbore with 5/16" pilot: