I have this 1991 Specialized Sirrus with Shimano 105's that has seen some time abandoned outside.

I'd like to convert this into an amateur triathalon racing/backup commuter bike. Crank, BB, front wheel, frame, brakes, fork, handlebars, are all in good condition.

I'm going to replace all the brake and derailleur cables, chain; however, I would like to get a new rear wheel. As one day a few years ago I decided to play mechanic on the rear hub, for which the guts are now missing (bearings, cups, cones) . I was trying to remove the rusted freewheel, for which I had no idea at the time what I was doing. (Didn't realize I needed a special tool)

Anyway, the old rear wheel is a Shimano 105 7 speed free wheel, Wolber rims, 32 spoke. When I look around most new rear wheels have 8-9 speed "cassettes". What will work on my bike? My shifter is 7 speed.


SharpT