Does anybody know anything about tubeless valves?,i bought one today from a local(sandifords montesa) dealer,he said it will fit any rim,but theres no way i can get the bloody thing through the hole in the rim.I`ve tried soap,oil etc but no joy.My mate says its the wrong one.Aparrently there is a couple of difrent sorts,threaded ones and non threaded,which is the one that i have been sold.Obviously the part i got was for a mont,my bike is a sherco.Any thoughts ideas gratefully accepted.

The rims with the flange like the Montesa and TYZ type rim, usually take the car type valves, so the valve is all rubber. Where it seats in the rim, similar to a gromment, it has a groove cut into it which sits in the hole in the rim and the lips either side of the groove seal against the inside/outside of the rim. The only thread is for the dust cap.

The GasGas, Sherco type Morad rims use a different valve which is threaded along its entire length and has a rubber seal at the head. When the valve is pushed through from the inside and the nut is tightened it pulls the head and seal against the inside of the rim to seal it. The head sits relatively flush against the inside of the rim to allow the sealing rubber to fit into the well of the rim.

Does sound like you have the wrong valve, the Montesa type sticks up inside the rim, not flush, as on the Montesa type rim there is no sealing rubber to seal the spokes as they fit externally on the flange.

Thanks woody,all that makes sense,i will get one of the other type,cheers