I can’t believe I made it almost 3yrs before experiencing significant tire damage to the fatbike tires that I run tubeless on my Bucksaw. Of course, they’re not “designed” as tubeless tires, but they work just fine.
Out on a ride a couple of weeks ago, a stick nearly the size of my thumb punctured my tire. Yowza!
I was less than a mile of easy gravel from the trailhead, so I wasn’t concerned. A quick look confirmed that the hole was too big for Stan’s to deal with. Which also confirmed that for as close as I was to the trailhead, it wasn’t worth pulling off the tire, temporarily booting it, installing a tube, and riding back. So I just walked. It was a nice day and I was in no hurry to get anywhere.
I had another set of tires at home, too, so I just threw on an older Husker Du to get me by for the time being. You see, good fatbike tires aren’t cheap. A 120 tpi kevlar bead Surly Nate tire goes for about $120 MSRP. Needless to say, I didn’t want to be buying a new tire since I’m in the process of a new build (you’ll have to wait to find out what – I have the frame, but haven’t decided on the full build yet).
So I hit teh Googles to see what people are doing to repair such tires. I’ve read about sewing up the hole so it won’t stretch, and letting the sealant do its job. Yeah, I dunno if you noticed on that hole, but my tire was missing rubber. Sewing wasn’t going to work unless I wanted a (not so)awesome hop to my tire. So that method was out. I read some reports about people using car tire patches to fix mtb tires. So I started looking for the materials needed, and car tire patch supplies are typically available in massive quantities. Sure, I’d spend maybe half the cost of a new tire, and I’d also wind up with enough adhesive and whatnot to repair tires for my day job (meaning, I wouldn’t, and a lot of that stuff would either go bad or wind up being tossed out). Fortunately for me, a company that makes lots of car tire repair supplies just so happens to make a little kit for bicycle tires.
For what it’s worth Rema Tip-Top’s product pic is a little different from what actually comes in the package.
It’s similar to the old school kits for patching tubes, but it’s critically different. The patches themselves are a much thicker rubber, more suitable for repairing the tire. The cement is also different. I found my kit at BlueSkyCycling for $8.49 plus shipping, so I spent a WHOLE LOT LESS on it than I would have for massive quantities of auto tire repair supplies.
The method is essentially the same, though. I had to clean off the old sealant film, but that was just a matter of scrubbing with a rag. I touched the area up with some alcohol to address any residual sealant goo or mold release, and then roughed the area up with the included emery paper. Apply cement and wait 5min for it to get tacky. It’s worth noting that it was fairly cool in my garage when I did this, and I don’t think 5min was quite enough. Still, I applied the patch, and clamped it between wood blocks to ensure the patch stuck well. I left it like that overnight to be certain. I finished up by applying a thin layer of silicone RTV sealant over the top, just to make sure that any loose edges of the patch were stuck down, and that any gaps would be filled. This wasn’t in the instructions, but I wanted to be extra sure it worked.
Everything appeared to work after doing a dry install (no sealant), so I installed sealant and inflated to 20psi. The patch held overnight no problem at that pressure. So I deflated to ride pressure (about 9psi for a rear tire) this morning for a chilly spin with an old friend in town for the weekend.
This is an exterior shot of the patched location, showing the missing bits of rubber and the divot left behind. I took this picture after my ride this morning, and everything held up swimmingly. I noticed no appreciable balance wobbles on the trail, which is something that concerned me with car tire patches (I never could get a good feel for the sizes of those things online, in order to choose an appropriate size).
With fatbike tires (or any good mtb tire for that matter) being as expensive as they are, I really recommend keeping one of these tire repair kits around in case you damage one like I did. I’m not sure I’d be confident in a repair like this on a sidewall cut. There’s probably a reason why car tire shops always say that they won’t work on tires with sidewall damage. A cut sidewall may well be an excellent location to sew the tire back together (and THEN try patching with this method).