Yesterday, I tried to swap out my 40-406 tires for some new 37-406 tires (Innova). I have never experienced such difficulty and frustration fitting a tire onto a rim. After two hours of pushing, twisting and kneading, I finally resorted to levers. Bad mistake. The tire eventually went on (although one lever bent in the process), but when I inflated it I discovered that I had obviously pinched and punctured the inner tube. My fingers and thumbs are rubbed raw from all the effort and I can't face trying again, so I've decided to use the LBS. However, another thought now strikes me. Assuming that said LBS manages to get the tire onto the rim and inflated, what happens if I get a puncture out on the road, in the middle of nowhere? Surely this can't be the way that things are meant to be.
Bike Friday, Bridgestone MB-6 700c, Ti-frame Xtracycle, RANS, Brompton, Dahon, Downtube IXFS, ex-Birdy & a recumbent pedicab.
You can also try a quick stick or speed lever which allows you to install and remove tires more easily than thumbs and fingers alone, esp. with the Schwalbe stuff.
The quick stick is very durable, tough, and packable, while the speed lever is a little more fragile but easier to use. I have more experience with the speed lever, but got the quick stick because I was afraid of breaking the speed lever while trying to install a Marathon. They're both cheap which is always a plus.
1984 Miyata 310, 1989 Club Fuji, 1986 Schwinn Sierra, 2011 Jamis Quest, 1980 Peugeot TH8 Tandem
Different tire brands definitely have slightly different sizing. I just changed the 406 tires in my folder. The old ones were very difficult to remove, even with levers, the new ones slipped right on with no tools. One almost slipped off too, but I caught it in time and let the air out. I have had the same experience with my full sized bikes, too.
A quick update: I took the rim and tire to the local LBS. The guy there inserted a new inner tube, got down into a squatting position, and using his fingers in a pulling action, rather than pushing with his thumbs, had the tire on the rim in under 20 seconds! It was magical, and so fast it was hard to see exactly what had happened. I wonder if speed is the solution to this kind of problem?