I’ve bumped into a wee problem with my fatty- I can’t get a new Maxxis Minion FBF to seat properly on an older On-one rim and am looking for advice or experiences. It’s a problem with the tyre bead not sitting correctly on the inner surface of the rim bead.
With my old On-one tyre, it sits ok if over-inflated to 20, then dropped to the running pressure of 7psi. Below 7, it drops off the bead and then runs unevenly.
The new tyre will sit in place when heavily over inflated at around 30+psi but drops back off the bead in places at about 12psi, leaving a ‘wobble’ in the tyre.. If I persevere with it, will the tyre gradually stretch very slightly to fit better? Any suggestions? I’d be loath to bin an otherwise acceptable rim and replace with a new one.

Are you running it tubeless? If not stick a tube in and leave it at the higher pressure for a while.

Tubed always.

The FBF doesn’t seem very stretchy- certainly not as much as say a Bud which grows a lot. But leaving it pumped up higher for a few days has got to be worth a try.

For whatever it’s worth, I didn’t find anything unusual about mine, on cheapo 80mm rims. Good fit, not tight nor slack, pretty much what you’d expect from maxxis.

I found it nigh on impossible to get tyres to go up properly on fat rims with a tube. Tubeless they go on first time (if at all), but the tube adds too much friction and pins the tyre to the bottom of the well.

I’ve never had a problem with tubes inside On-one Fatty tyres, on either On-one or Halo Tundra rims. Seem to fit easily, hence the posting about a problem now with the new Maxxis. The Minion is proving to be as good a front tyre as I could hope for in all other ways, grippy, rolls ok, controllable drift in the dry; also tends to stay in a straight line when floating across mud, which is a bonus.
I’ll try leaving it parked for a few days over-inflated and maybe ride it a couple of times at much more psi than normal, see if that helps. I’d like to get it down to 7-8psi to get the best benefit.