rekmeyata

The 3/8th wide tire is nearly impossible to find except for few really cheap poorly made tires. However there are few really nice 27x1 1/4 tires which is only an 1/8th smaller. Schwalble makes a really nice puncture resistant tire called a HS159, and also a Marathon Greenguard with probably the best puncture resistance tread of any 27" tire on the market; also Continental makes both the Gatorskin and the Gator Hardshell in that size as does Panaracer in their Pasela line of tires which I use and really like on my 85 Le Tour Luxe that I use for weekend touring (except I use a 1 1/8th size on the rear and a 1" on the front, a 1 1/8th width is plenty wide enough for touring and dirt and gravel roads, but they do make a 1 1/4). Also Serfas makes a Seca in that 1 1/4 size.

The one thing I did notice about Panaracer is that the Pasela runs about 1/16th of an inch larger than the tire is rated, so my 27x1 is actually a 27x1 1/16th and the 27x1 1/8 is a 27x1 13/16ths, thus if that pattern continues with their 1 1/4 size you would only be 1/16th of an inch less than a 1 3/8th tire you like. There may be some of the other tires I mentioned that could also run wider. Keep in mind too that the 1 1/4 size was the size that came originally from the factory on that bike of yours.