Probably a question that's been done to death at some point in the past but has anyone experiences good or bad of using a rear tubeless IRC or Michelin tyre with a tube on a twinshock (mine's an SWM). I've read that grinding some rubber off the bead helps the tyre to seat properly in the rim.

Edited May 29, 201313 yr by cleanorbust

I use a Michelin X Lite on the rear of my twinshock with a tube, no problems. Its an Excel rim.

I use an x11 on my mont 123 with no problems. Bultaco UK do a nice tubeless rim for £90 so you could lace it in and have have a genuine tubeless twinshock. Lower pressures, no tube punctures. I bought a spare hub to do mine so I can have both options.

I recall a thread here a while ago about this. What I recall is that the IRC tires have a slightly larger inside diameter then the Michelin. As a result the IRC tires come off the beads on some tube type rims unless they are run with more pressure.

I have an IRC with a tube and rim lock on my '74 TY250 that I run at about 11 PSI and have never had the bead come off. I don't compete with that bike, it's just a play bike for me and a buddy bike for new riders to learn on so the higher pressure is not an issue.

Is there any reason why you prefer to run a tubeless tyre? Why not just

use a tubed type tyre?

I use a tubed IRC tyre on my Ty with no problems, even when running

low tyre pressures.

Tubed IRC have softer sidewalls and can roll off cambers or the tops of rocks and can even skew the bike sideways under hard acceleration when run at normal trials pressures of 3 - 5psi.

How badly this is evident depends upon the type or level of sections being ridden and the weight of the rider. The heavier you are the worse they'll be as rider weight will squash the sidewalls more making them more prone to roll. Increasing the pressure to hold it on the rim doesn't work for trials because as soon as you go over 5psi grip is lost. So you either roll around on it or spin up...

It does seem though that they are inconsistent and some aren't as bad as others, although a few road trials will soften the better examples up a bit.

On the Jap rims they stay out on the bead until you let them down to about 10psi and then 'plop' - any lower and a section will drop into the well. Generally they are ok on the old Akront rims with no need to trim the bead. Trimming it would make it a more sure fit I guess but I've never done it in the past. Most of mine are tubeless rims now.

Is there any reason why you prefer to run a tubeless tyre? Why not just

use a tubed type tyre?

I use a tubed IRC tyre on my Ty with no problems, even when running

low tyre pressures.

I run tubeless on my modern bike and the hand-me-downs get used on the TY.

I think I'll get a Michelin X11 for my Bultaco...

Hi Cleanorbust thanks for posting this question

This one has really got me I need a new back tyre so i have had a look around And the IRC with its soft rubber looked like the one to go for, and i was thinking i need the tube type because i have a Bultaco. But most seem to think the tubeless one is better.

im a bit of a light weight at 70kg so im thinking i may get away with the softer walls on the tube tyre at least it will stay on the rim it seems like there is no real win here just work arounds, unless i fit a tubeless rim to my back wheel, my back wheel needs new spokes plus relining so may be a good time to fit a new rim.

Thanks for all the help

BR

Edited June 9, 201313 yr by bultacorock

I have fitted Michelin X-Lite tires with inner tubes to my SWM which still has the Acront red label rims. The combination works quite well.

The tires stay good on the rims, it had sometimes occurred that a partial section of the tube went off the tire bed, (around 10 - 15 cm). But only if you have very low air pressure. I did not recognized it at once first a week later. I pumped up the rear tire until the tire sat again right on the rim. I run around 0.4 bar in the rear tire works very good. The Michelin X-Lite's are one of the easiest way to save some weight (over a kg).

I will probably mount them too to my TY together with a tubeliss inner tube

..

Thanks everyone for the replies. I fitted a tubeless IRC to my SWM (Akront rims) with tube inside and ran it at 4 psi through the Highland Classic trial last weekend without any problems.

Simon, is the Akront sticker red or green ?

Shouldn't make any difference to the tyre seating on the rim, it just denotes the strength of the rim