Its a a mavic something or other and it takes schraeder vales – though i have plastic inserts to adapt to Presta
Whatever i do every single tube rips at the valve – and not in the same place
I have retaped and examined and there is nothing sticking out- even tried using a piece of old inner tube.

Before someone suggests tubeless – its not a tubeless rim- and before i bin the rim anyone any suggestions as to what to do as its rather annoying

Tyre too loose on rim?

Tyre spinning on rim for some reason, would clean tyre/rim bead and check rim tape is centrally located in rim and not in bead.

Would also talc inside of tyre to prevent tube sticking.

I had the same on a past Dyfi enduro going through four tubes before getting to CAT :(. Worn sidewalls on the rear tyre allowed the tyre to slip slightly on the rim resulting in the inner tube getting slashed at the base of the valve. Steep learning curve

As above. Most likely tyre rotating on the rim. Two solutions (other than new rim\tyre) is to stop the tyre rotating or mitigate the effects. To stop it rotating put a few dots of superglue on the rim. Just on one side so you can still fix a puncture. It’ll peel off when you want a new tyre. Or let the tyre rotate but put talc in so it doesn’t drag the tube with it. Less good but simpler

FWIW a layer or two of Gorilla Tape will make it a tubeless rim. Add a valve and some sealant and you’re good.

Worn sidewalls on the rear tyre allowed the tyre to slip slightly on the rim

How do sidewalls affect that?

OP – same brand of tube?

FWIW a layer or two of Gorilla Tape will make it a tubeless rim

Really? Not in my experience. At all.

a layer or two of gorilla tape might stop the tyre spinning on the rim, too

Just fill it with expanding foam 🙂

different tubes al- makers and types have been tried

Will try some method to stop the tyre rotating and if that fails I shall just use expanding foam and superglue

though i have plastic inserts to adapt to Presta

This may be the problem?

cynic-al – Member 

FWIW a layer or two of Gorilla Tape will make it a tubeless rim

Really? Not in my experience. At all. [/quote]

It is in my experience, very much. Not even Gorilla branded tape, just B&Q’s own brand similar stuff. Follow the pinkbike method and works fine. Done it four times now and all work perfectly.

Not only that but not even tubeless ready tyres. So long as plenty of sealant is used they work fine. Only difference I find with TR tyres is they sometimes seat a bit easier.

That Maxxis tyres though. They seem to work tubeless especially well, TR or not.

I’ve had the same problem withMaxxis tyres and 717 rims.
In the end I put a smear of black ‘The Works’ sealant on one of of the beads to hold it in place on the rim and stop it migrating round.
When I asked the same question on this forum, it was completely hijacked by tubeless evangelists who turned it into a ‘how to tubeless’ thread! Just ignore them!
F

I also had a similar problem with a particular rim/ tyre combo. In the end I switched tyres and that fixed it – the new one was an absolute pig to get onto the rim, and sufficiently tight that it didn’t shift.

I’d also consider washing up liquid on the bead when seating the tyre; as it dries it goes sticky.

And talc the tube !

This may be the problem?

nah i tried them after it kept ripping schraeder and I ripped one of each today
I do run tubeless as well FWIW
its definitely a floppy ill fitting tyre so it seems the most likely cause.

KY Jelly

I don’t know if it still happens but it was common to put a screw or two into trials bike rims to stop the tyre rotating (not that I’m suggesting that as a solution in this case)

Try a fatter tube instead of the one your using now ?

Pressure holds the tyre on to the bead. I can’t see how a loose bead will matter. If it’s not rubber at the bead then that might make it grip less

That’s the thing though. Folk are now running tyres at very low pressures. Those trials bikes I referred to had extremely low pressures to create additional traction – hence the tyre rotating on the rim.

clean beads and rim, stop braking so hard.

Tyre rotation and ripping valves out is a problem that can be solved by either roughing up/ chiseling the inside of the rim sidewall or increasing the circumference of the bed of the rim with tape.
Used to be a real problem on enduro bikes (propper ones with engines and stuff) Ripped them out under acceleration on the rear and the opposite way under braking on the front.
Or go tubeless and the tyre can creap all it wants without touching the valve.

it was common to put a screw or two into trials bike rims to stop the tyre rotating

Colin, I remember that being common practice on trials bikes,self tapper into the bead.Never seen it done to a mountain bike rim though.

Pressure too low

and/or tyres too baggy.

I would wrap some tape around the bead area to make the tyre fit tighter.