650 wheels on a cross bike?

[whsh93a]

OK - I'm a guy whose wife uses a 650c bike and wanted some decent tires for doing a bit of cx and winter commuting. You all have found out that no one makes them. So...I converted some 700c to 650c. It's not hard but takes some patience.

Here's how to do it. Not sure if this will take multiple posts or not.

Find some not too knobby cross tires like Specialized Speedmax. Too lumpy and the tire won't clear the brake stays.

Tools and stuff needed are scissors, Dremel type rotary tool (get one at Harbor Freight sometimes for free). Hot glue and gun, Metric box nut with tangs for #3 metric stainless steel screw. Barge (or equal) rubber cement. Some fabric - I used some from a nylon grocery bag. Phillips screw driver. Model saw or maybe Xacto blade. I like the model saw because I won't likely cut myself with it. A power drill and a 7/64 drill bit. See photos 1 - 4.

So - pick a tire and cut it in half. Use the Dremel to cut the wire bead - both sides - and use the scissors for the rest. See photo 5 - 7.

Take a 650c rim and slide the cut tire onto it. Overlap the tire ends and slide them together ALL the way so that the bead is inside the rim. Mark the point where the inner tire end entered into the outer end. Photos 8 and 9.

Remove the tire and cut the inner tire's bead again at that point (both sides, of course) with the Dremel. Trim off the bead with the scissors. Photos 10 - 12

Cut off all but around two inches of the soon to be denuded bumps tire section. Trim the bumps off the inside tube (the section without the bead now) using the model saw or Xacto or whatever you want. You only need to trim the bumps from a couple of inches. You could get away without trimming anything but it makes for a better fit. Then, if you are a bit of a perfectionist, flatten out the remaining bits with the Dremel. Photos 13 - 17

See next post for part two