I’ve written about the possibility of non-pneumatic tires on footbikes in the past: the idea seemed a non-starter.
Then I put the non-pneumatic front tire on the Footbike and rolled it down the hill. (I only had a 700C from the bicycle, of course.) The Footbike with an “airfree” front tire rolled twenty feet short of the Kickbike – game over. Neither Nu-Tecks (out of business as of December 31, 2011) nor Greentyres come in 18″ for the rear wheel, anyway; just 16″ or 20″.
Well, I reinstalled the Nu-Teck tires on my bicycle after dealing with a flat, of course, in the rain. (You haven’t lived until you’ve dismounted a retro-direct rear wheel by the side of the road.) Near the Nu-Tecks in storage were a pair of non-pneumatic inserts I had once bought to try out (to replace innertubes), but didn’t get around to. A pesky idea insinuated itself into my fevered brain.
If I could cut one of these inserts to the correct length, I could try one inside the rear tire of one of my footbikes. It turns out that the Maxxis “Birdy” that came on the back of my Kickbike City Cruiser, on the Footbike’s Alex DA16 rim, is a perfect fit. A little levering got the insert piece inside the “Birdy” and onto my Footbike’s rear rim. (A certain degree of fit is necessary as my Kickbike’s Alex X101 rear rim left some room, and the tire made a “squink” noise as I rode.)
A little electrical tape over the valve hole on the rim and I was off for a test ride. Maybe because of the small size of the wheel, and the fact that a rear wheel is not involved in steering, but I could feel no difference from the pneumatic that came on the Footbike.
Of course, it’s heavier, but, again, a it’s small wheel to start with. For any kind of competition application this wouldn’t work, but for my utility “bakfietstep,” it’s just the thing. I only need to carry a front spare tube and don’t need to worry about unmounting a tight 18″ tire on the road to fix a flat (which would be right up there with unmounting the retro-direct rear bicycle wheel).
By the way, Kenda (American Airless) sells 18″ non-pneumatic inserts in 18 x 1.75″ and 18″ x 2.125″. Presumably an 18″ x 1.75″ (355 ETRTO size) tire will fit the former, but it would require a leap of faith to buy both and then find out. But I’m good, thanks…
Update: I broke down and bought an airless 700C from [another company now out of business] to try on the front of my Footbike, and you know what? It’s fine! Maybe it’s because the Footbike’s hub is so smooth, but it’s no problem kicking, and the peace of mind is awesome.
It’s actually a little better than on the bicycle, because my legs are natural shock absorbers. So I’ve been using the Footbike as a commuter: Look ma, no spares or pump!
Further update: Nu-Teck and Noflattires.net have both apparently gone out of business; non-pneumatics just can’t cut it for bicycles. For casual footbiking they are still viable on small wheels, as on Xootrs and Know-Peds, and tire manufacturer Kenda also still advertise non-pneumatic inserts and some tires, mostly for medical scooters and wheelchairs, on the site American Airless, and which are available at these locations.
I also had previously included links to Hugh Waters’ felonious scam site “Air Free Tires.” Avoid it.