What’s it all about? Tires.

So in terms of bike nerdery, I’m all about Tires. My fixed commuter (the BeeBike) was built specifically to run the tires I prefer (Grand Bois Hetres if you must know). Much bike hacking was done to make that possible.

Now I’m considering a different ride, and I’m trying to figure out what seems to me to be important: Tires. Today I’m messing around with running an Inner Tire on a Tubeless setup like this. Schwalbe makes a version of these you can buy, and I’m making my own, Ghetto style. More about that at the end.

Tires: According to Kent Peterson, and just about all the folks who rode the divide back before 2010, the tires to run are WTB Nanoraptors, but reports from after 2010 say that the quality of the tires went down hill after it was shifted over seas.

The consensus is that Tubeless is the way to go, and most folks report running a ‘more durable’ tire (which generally means that they are less supple and have more rolling resistance). I’d really prefer to run a more supple mountain bike tire, spending time repairing tires (not tubes) on the trail seems like it could be a loosing proposition.

Enter Tubliss motorcycle tires, and Schwalbe DouCore. Basically: run an outer tire ‘tubeless’, but also run an small innertube. The inner tube does a couple things:

  • It keeps the tubless Outer tire from ‘burping’ when you corner hard (the tire bead lifts off the rim and lets out air – bad news)
  • It protects (at least somewhat) agains pinch flats and rim damage, by providing a firmer inner core
  • because of points 1 and 2 you can run your outer tire at incredibly low PSI, which makes for better grip and lower rolling resistance

So the Schwalbe system is interesting, but it’s also $200, and who knows if it really fits wide rims. Rather than paying a lot to find out, let’s BikeHack it up at home!

These guy goes into prettty deep detail about how to do this yourself. Basically, what you need is a method of constraining an innertube so you can inflate it to high pressure. This is typically called a ‘Tire’. So, for DYI Double Chamber tires – install a skinny tire & tube inside your big fat tubless tire.

The only real trick here is that you need to have 2 stems, one to inflate the inner tube and 1 to inflate the outer tire. Typically this would involve drilling a new hole in your rim, but since Clyde (by TD bike) has Surly Rabbitholes, there are already extra holes inthe rim. All I really need to do is install a 2nd stem in one of the Rabbit Hole holes, then make a small hole in my inner tire and go to town!

With any luck, I’ll be doing this later today.

I’ve already experimented with sewing my own tube constrainer out of kevlar (mixed results – seems to work, but my sewing wil need to be stronger to contain 80psi of tupe), and installing an 23mm and 28mm tires on my Rabbit holes. They both work just fine. Next step, getting a 28mm cheapie tires and drilling a hole in it (to allow air to flow out of the inner tire and into the outer tire), and setting up for Tubeless.

I’ll let you know how it goes…