Det är Cykling genom rymden och tiden med < a href="http://www.isfdb.org/cgi-bin/ea.cgi?1573"> Mike Sirota :
Cykling genom rymden och tiden (1991)
Den ultimata cykelvägen (1992)
The 22nd Gear (1993)
Från författarens blogg :
So Jack meets an alien named the Old Guy in downtown San Diego (he’s the only one who can see the alien) and learns that an extra gear has been “installed” on his 21-speed mountain bike, a gear that will allow Jack access to other worlds, dimensions, the past and future, literature, and so on. By the end of six chapters Jack has visited a world of giant talking sea slugs that think he’s a gross-looking life form, and another where, incapacitated, he’s dumped into a cartful of animal manure by a strange little dude who plans on taking him to a witch in order to be cured. There’s a whole lot of silliness in those first fifty or so pages.