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Tubeliss System Revisited

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I did a search and some reading.  There were some posts discussing using modern tubeless tires on vintage bikes / rims and how some owners have had issues with the tire dropping off the bead at the low pressures normal run.

My 73 OSSA has an Akront rear rim.  Unfortunately, probably on account of the slight ding in the rim from the previous owner, my Dunlop D803GP tire is dropping off the rims bead area.

The oem Akront rear is a 1.85 width.  Dunlop is suggesting a 2.15 width.  I purchased a used OSSA wheel assembly from a different model than the MAR and unknowingly, it had the 2.15 wide rim.

So, looking for opinions.

Stay with the 1.85 wide rim and install the Tubliss setup.

Install the 2.15 wide rim, and hope the spoke lengths are acceptable.  The wheel was rebuilt recently with new spokes so it should disassemble easy.  Then remain running a tube setup.

Or go all in with the 2.15 wide rim and Tubliss setup.

Consider, the Tubliss setup is specific to each rim width and does not interchage according to part numbers. Although, possibly it is only the width of the special Tubliss rim lock.

It seems some have converted to Tubliss, so any info there would be good also.

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Tubeless Dunlops and 1970s Akront rims are not a happy combination. Wider (2.15) tube type rims do work better with tubeless tyres but the fundamental problem is that the bead seats in those Akront rims is too narrow. It's very likely that you will be able to reuse the spokes so give the wider rim a go and if the Dunlop still won't stay on, then use a tubliss.

I did an experiment that probably not many people would want to do, but it has worked for me. I wanted to see if I could get a tubeless tyre to stay on a narrow tube-type rim (TY250D rear rim) by cutting a groove in the bead seat for the tubeless tyre bead to key into. I did the experiment about 3 years ago and it has worked a treat. The new X11 Michelin tubeless tyre I fitted (with no tyre clamps) to the TY250D rim has never popped off the rim or slipped and is now almost worn out.

I also bought a tubliss at the same time, expecting to need it, but it is still on my shelf

Edited by feetupfun
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@feetupfun I am just about to transfer a set of Arkon rims from a TY250L mono over to my Ty175. I want to go with the tubliss 2nd gen system when I do this with a set of Dunlop 803GP tires. My main reason was to use the forks on this one but why not go all out right? I am interested in the grove you are speaking of (pics?). Is this just roughing up the bead area so it sticks? As i read this you are still running a tube with a tubeless tire right? Currently i am running a new IRC tubeless reject on my standard ty175 rim with a tube but gotta love those gold rims so this is going to happen. 

--Biff

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 Last I checked Tublisss did not offer a system for 1.85 rim, has that changed?

 Feetupfun, if there's no photo of the modified rim can you post a sketch of what you did? I can't picture it.

Edited by motovita

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4 hours ago, motovita said:

 Last I checked Tublisss did not offer a system for 1.85 rim, has that changed?

 Feetupfun, if there's no photo of the modified rim can you post a sketch of what you did? I can't picture it.

Agree on not quite following the modified rim idea.

According to the Tubliss website, the 18' fits both 1.85" and 2.15" rims.

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9 hours ago, motovita said:

 Last I checked Tublisss did not offer a system for 1.85 rim, has that changed?

 Feetupfun, if there's no photo of the modified rim can you post a sketch of what you did? I can't picture it.

I posted a photo when I did it years ago but finding that might prove difficult and I'm not ready to pull the tyre off just yet to take another photo. Maybe I can describe it better. If that doesn't work I'll do a sketch.

The bike is on a stand with the rear wheel fitted, but with no tyre fitted to the rim and no chain on the sprockets.

I cut a circumferential groove in each bead seat with an angle grinder fitted with a 2mm wide cutting disc. I spun the wheel by hand to start it spinning then started cutting and this kept the wheel spinning.

I cut one groove about 2mm deep in each of the bead seats.

The rubber on the surface of the tyre beads deforms into these grooves once the beads are up on the seats (40psi and WD40 to seat the beads). This keying effect prevents the tyre bead from slipping sideways back off the bead seats when the pressure is let down for riding.

Yes there is a tube in there - it is a TY250D tube type rim and a Michelin X11 "tubeless" tyre

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10 hours ago, biffsgasgas said:

@feetupfun I am just about to transfer a set of Arkon rims from a TY250L mono over to my Ty175. I want to go with the tubliss 2nd gen system when I do this with a set of Dunlop 803GP tires. My main reason was to use the forks on this one but why not go all out right? I am interested in the grove you are speaking of (pics?). Is this just roughing up the bead area so it sticks? As i read this you are still running a tube with a tubeless tire right? Currently i am running a new IRC tubeless reject on my standard ty175 rim with a tube but gotta love those gold rims so this is going to happen. 

--Biff

Oh yeah - gold rims are fantastic

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 You can buy a tube type tire.

 You could buy a tubeless rim.

 Or you could just screw the tire to the rim. ( The old tried and true method of us old cheap B`s.)

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I have had success with tubeless tyres on a '70's Akront rim (KT 250 rims). Here's how and why;

Stuck the tyre on and yes it kept dropping off when pressure was lowered.

I looked at the rim of my gas gas, it has a much more horizontal bead area and a very small rise at the inner edge before dropping into the centre well.

The Akront rim is not that flat. I also suspect that it is slightly larger in seat diameter, although I didn't check.

The tyre has a sealing lip on the inner edge of the bead. I got the angle grinder and a sanding disc, and removed the sealing lip, and a small amount of the bead surface.

The result has been very succesfull. I've run as low as 3 psi in rocky sections and no problems. Of coarse I'm running a tube and rim locks. I've also done this for the front wheel, also succesfull. My Gas Gas is a 95 contact and I've had to do the same to its front wheel. every time it has worked a treat.

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11 hours ago, lineaway said:

 You can buy a tube type tire.

 You could buy a tubeless rim.

 Or you could just screw the tire to the rim. ( The old tried and true method of us old cheap B`s.)

I suppose, but for $95, the Tubliss setup seems pretty cost effective and retains the vintage look of the rim while adding a level of safety and reliability.

FWIW, my riding buddy was having issues with what was thought to be the Dunlop tire slipping on his MAR with an Akront rim.  For whatever reason, his tire does not drop towards the center, but constantly he would see the valve stem getting that lean to it.  He added screws to the rim in tne bead area to stop the tire from slipping.  The ironic part, even with screws securing the tire, the valve stem still tilts with use of the bike.  He removed the tire to correct the tilted valve stem, and found the screws marks were not stretched or elongated.

He determined, with the low pressure, he runs, the tube is walking about inside the tire casing and over time, with the tire flexing the tube moves enough to tilt the valve stem tight against the edge of the hole and is trying to tear the valve stem out.

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13 minutes ago, pmk said:

I suppose, but for $95, the Tubliss setup seems pretty cost effective and retains the vintage look of the rim while adding a level of safety and reliability.

FWIW, my riding buddy was having issues with what was thought to be the Dunlop tire slipping on his MAR with an Akront rim.  For whatever reason, his tire does not drop towards the center, but constantly he would see the valve stem getting that lean to it.  He added screws to the rim in tne bead area to stop the tire from slipping.  The ironic part, even with screws securing the tire, the valve stem still tilts with use of the bike.  He removed the tire to correct the tilted valve stem, and found the screws marks were not stretched or elongated.

He determined, with the low pressure, he runs, the tube is walking about inside the tire casing and over time, with the tire flexing the tube moves enough to tilt the valve stem tight against the edge of the hole and is trying to tear the valve stem out.

Yes the tilting valve stem on a trials wheel is often misdiagnosed as tyre slip. Sometimes fitting a different brand of tube in the same tyre will stop it happening

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2 minutes ago, feetupfun said:

Yes the tilting valve stem on a trials wheel is often misdiagnosed as tyre slip. Sometimes fitting a different brand of tube in the same tyre will stop it happening

Guessing, probably order two Tubliss setups, and install them, one in each MAR.  My MAR has so much rear grip it sometimes catches me off guard.  If I run the rear with Tubliss and no tube then it can seriously mess with my head...

Who knows, maybe I should polish that 2.15” rim, lace it up, run Tubliss in it with no tube and a Dunlop.  Just is a tight fit already between the swingarm with 1.85”, but it would be cool to do and simply adds to my resto-mod built MAR.

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18 hours ago, feetupfun said:

Yes the tilting valve stem on a trials wheel is often misdiagnosed as tyre slip. Sometimes fitting a different brand of tube in the same tyre will stop it happening

Never heard of a tube moving with the tyre stationary ! Every bike I've owned has tyre / tube creep with a spectrum of combinations. 

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I think feetupfun is correct;  generally I can sort the creep without moving the tyre by completely deflating the tube then locking the valve upright with the locking ring (the only use for this - I keep it locked to the valve cap normally so the valve is free to move) then inflate the tube to a highish pressure.  When the ring is undone (after letting the pressure out then inflating to 4 psi) , the valve is back at 90 degrees to the rim, the tube having realigned itself, though sometimes it takes two or three goes.  In other words, a reversal of the walking feetupfun describes.

Edited by 2stroke4stroke

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