andy jack

We have had the same problem with montesa rear wheels,piddocks swapped a rear wheel on a bike we bought from them as the tyre (x11)kept coming off the rim.We also had the same trouble with the spare wheel(brand new montesa wheel) which had a new Irc on it.Did half a trial the tyre went down on its own then came off the rim as I tried to get back to the van to pump it up.Think the irc tyres don't fit as well on the rim.