[Granitedigger]

I've taken two rides since winter rolled into these parts in October. And I've gotten two flats, my first ever. One was a box staple, today it was a screw. Needless to say, I was pretty bummed I got less than 40 miles out of the new tube I put in, with the tire dismount/mount, that cost me about $2 per mile.

So, my questions are.

1 - For those of us still running tubes, who makes the proper size tube for the rear tire. My local shop put in an undersized Bridgestone, which seemed fine, but I'd rather have the right spec tube.

2 - For those of you running Outex since 2014, 2015, how is it holding up? Any issues with the seal going bad over time?

3 - On our 2014 models, does the rim have the appropriate hook to safely run tubeless when Outex is installed, or did that come in 2015 and later with the rim update?

4 - Are there any tubeless rims available for a reasonable price that can be laced into the 2014 hubs?

Very much looking forward to the wisdom you all will impart. . .

 

[Granitedigger]

That's a very brotherly offer @BlitzSchnell , thank you. Honestly, I think it's more of a small town problem than an uncommon tube problem. I reached the same conclusion you did about Outex the first time I was looking at replacing tubes, but often wondered if placing some type of dome over each spoke nipple, leaving room for them to turn without disrupting the adhesive would cure the most obvious flaw in the concept. Ultimately, I decided changing tubes just wasn't that much of a headache, and shouldn't happen all that often. I've changed tires on motocross wheels by myself regularly over the past few years, but my levers tend to leave the the rims with what we'll call a rather unattractive patina. I haven't had the heart to take them to these shiny black wheels. The good news is that I'm only 20 miles from the 49th parallel, so I can solve all my small town troubles with a quick run to Vancouver, where I'm sure I'll be able to find a shop with both the right tools and the right tubes. Who knows, I may even make a new friend or two in the process, eh? Tomorrow may be a good day for that, since MLK Day doesn't have a Canadian equivalent. In a former life I built lots of spoked bicycle wheels, so the idea of lacing a new tubeless rim into the wheel intrigues me, but I've only found replacement wheels, not rims.

 

[Granitedigger]

I sold my old Velox tubular repair kits as collectibles on eBay years ago. And I can't say I've missed the careful sewing project that had to be done after patching a punctured tubular. Haven't ever tried modern tubeless on a bicycle, butI will say I've been surprised by my experience with the two recent punctures on my r nineT.

Despite what I expected to happen, having read a lot of the discussion on tubes vs tubeless, both times the puncture resulted in a slow leak. The first, a packing staple, was picked up on an early morning ride before work. When I came out of the building 9 hours later, the rear tire was flat. I didn't even try to pump it up. I should have. When I got it back to the shop, we aired it up and held air well into the next day.

The drywall screw that I picked up last weekend that you see in the photo was as long as my little finger, and stuck straight into the tire. I saw it when I got back from my ride, and didn't notice anything troubling while riding. When I unscrewed it from the tire, I got the instant pssssssss as soon as the screw was extracted, and the tire came down quickly.

I'm assuming the 36 PSI is enough to create seals at the rim strip, the screw was an airtight plug, and the tube didn't split where punctured. It's obviously pretty risky to ride with a punctured tube, and if I'd have known, I may have asked a buddy to come grab the bike and I with a truck. All that said, I'm going to assume my luck is changing and the next tube will last for the life of the tire.

I did learn on my search for tubes that Continental tubes are not imported to the US or Canada. Who knew. . . But just about any shop can order the Metzler's made to fit the rear. Interestingly, my local BMW dealer said they'd need to order one in, and Seattle had 1 in stock. I guess there's not a lot of demand.

 

[Granitedigger]

Things I've picked up reading this thread and exploring a few rabbit holes along the way.

No US or Canadian distributor has chosen to import Continental tubes. I'm sure it's a business decision, but not sure what's behind it. Perhaps better margin on other brands, perhaps as a low cost leader, there is more net sales opportunity is selling a slightly higher priced tube at the same margin at scale.

There is a distinction between radial tubes and bias tubes, but talking about them that way is misleading. There's not really such a thing as a radial tube, it's more correct to think of them as tubes made for radial tires. Many motocross and off road tires are still bias ply tires, don't build the same amount of heat during use. Because they can be susceptible to pinch flats, many riders prefer to run heavy duty (thicker) tubes. Those tubes are not appropriate for use in road applications because they build and retain more heat than thinner tubes. The tubes used in radial tires tend to be thinner, more flexible, and retain less heat when in use. The Continental tubes are spec'd at 1.5mm, and the Metzler's between 1.7mm &1.8mm. The tubes for bias ply tires can be up to 4mm thick.

There is a significant difference in the rim between tubeless and tube type where the valve hole is. On tubeless type rims, there is a flat machined around the valve hole so the value can be set flat and seal properly. On a tube type wheel, the value seat integrated into the tube does the work of preventing tire from leaking from the value. As such, most tube type rims have no special treatment around the valve hole.

Speculation: I'm guessing that the reason it was recommended never to run tubes in tubeless rims with tubeless tires has to do with the valve hold situation and with the internal rim profile. It may be that the machined edges of the value stem hole are sharp enough to cut tubes. It's also possible that the valve stem seat on an inner tube won't set properly in a rim that has a narrow channel where the value hole is drilled. Again, just speculation. If you were running an inner tube on a tubeless rim and got a puncture in the tube near the valve stem (tubes do move when in use, and there is expansion and contraction that happens), the tubeless tire would loose air because the valve is not sealed to the rim in the same way it is when running a true tubeless setup.

Image of the inner rim profile on a 2014 r nineT. These are not traditional tube type rims. They do have the bump designed to hold the bead in place after the tire is mounted, which means that in theory, sealing the rim and using a tubeless tire is less risky than trying to do it on a rim that doesn't have the bump. My local shop was nice enough to snap these for me while replacing my tube and remounting my tire yesterday.

 

[Granitedigger]

Adding images of the inner rim profile from the spoked wheels on a 2017.