I’m very fond of tubeless fat bike wheels and moved to a set of SUNringlé Mulefüt rims (on Hope hubs) in mid-2014. These have worked great until the last two weeks when they went wrong with the On One Floater tires I’ve been using in snow. I was experiencing slow leaks on the rear that seemed to get more rapid as the day progressed, yet when aired up at home and in room they’d hold air reliably for days on end.
After a real rough time at the FunPromotions FatBike Series race yesterday at Addison Oaks (rear went flat slowly making for a hard ride / need to stop / etc) I gave a more serious look at the problem. Here’s what I found… The side knobs on one half of the rear tire (drive side) have become torn. I had noticed some slight tearing along the edge knobs before, but as the tire held air fine as tubeless for numerous rides before this, I didn’t think it was a problem. Apparently now it is. (This high res photo shows a bunch of the typical diagonal wrinkles, and the end of each one has a torn side knob.)
I suspect that a combination of new tears developing while riding and the freezing cold keeping the sealant from working normally resulted in the flats I was experiencing. I could dump more sealant in, get these holes to seal, and hope for the best, but I’m not sure that’s the best idea… Instead of hoping for reliability out of something visibly failing I’ll switch to a tube on the rear.
The Surly Nate has seemed like a good winter tire and I could grab a pair of them to replace the Floaters, but I’m not too keen on rushing to buy new tires now just for the remainder of winter… Maybe I’ll just stick with a tube on the rear for the time being, and then decide what to do snow tire-wise some time before the next winter.
My experience with 27 TPI Nates was not so good. If you dropped the pressure past a certain point (which I sometimes tried for a flatter profile), the rolling resistance would shoot through the roof. Even at a good pressure, they would have significantly more rolling resistance than most tires until I got up to 8mph or so. Maybe the 120 TPI would be a big improvement. My only comparison is 120 TPI Dillengers, so I can’t be sure if it’s the tread difference or the thread count, but my D4 are superior in every way except uphill traction.