@Lightman.

My Fatty had the same problem. I spotted this on the UKFatbike forum…

“Just to let you folks know.
Any one with a on one fatty.
There is a problem with the bottom bracket .
The crank on the drive side doesn’t butt up to the bottom bracket if you look you will find a 3 to 4 mm gap.
Because of the gap your drive side bearings are getting full of crap .
To solve the problem you will have to fit 2 to 3 spacers on the drive side bottom bracket
Hope this helps ……”

Who designed these On One fat rims? Just had to do the soapy water thing for the second week running to get the tyres seated properly. Seriously not enjoying pumping a 4″ tyre up to 40psi with an Aldi track pump either, that’ll teach me for being a cheap sod. Going to have to take note of that tubeless method once I get some tyres other than the self steering tat that’s on now.