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Old Schwinn 13/16" steerer--OK to bore out to 7/8"?(3 posts)

Old Schwinn 13/16" steerer--OK to bore out to 7/8"?Continental
Sep 22, 2003 8:48 AM
I have a very nice 1971 Schwinn Sports Tourer. The 1" OD steerer tube requires a 13/16" (21.15 mm) stem instead of the standard 7/8" (22.2 mm) stem because the walls of the steerer tube are thicker than standard. Would it be safe to bore the steerer tube out to 7/8" so that I can put on a higher, longer 22.2mm stem? Selection of 13/16" stem is very poor. I've already made some modifications to the bike, changing the terrible Campy Gran Tourismo derailleur to a great shifting Suntour, changing the 14-34 5 speed freewheel to a Suntour ultra 6 14-30, using a modern chain, and new tires. Preserving the bike is not important to me. Riding safely and comfortably is. Other option is to buy a new fork, but I prefer the style of the old one with the Chromed crown and tips.
It might let you down ...Humma Hah
Sep 22, 2003 11:20 AM
The original forks on my '71 Schwinn cruiser were threaded too far down the steer tube. The stem's wedge bore against the threaded section, and eventually caused it to bulge and then break. Tossed me on the ground in a painful heap one day. The replacement fork, not weakened by excess threading, held up for decades, and was replaced this spring only because I substituted a Corvette fork (with brake bosses).

I would hold out for a Schwinn stem. Parts like that are not usually too hard to find. The Trexlertown swap meet maybe? E-bay? A lucky hit in the junk bin of your LBS? I've bought several used Schwinn parts from keithsbikes.com.
Another scary solution...retro
Sep 25, 2003 9:19 AM
My first mountain bike, a Mongoose about 20 years ago, had an .833 steerer. It was too short, and I never could find a replacement that wasn't junk. I finally got a Ritchey chromoly mountain bike stem in 22.2 (and why do we call that "one-inch"?), wrapped a piece of 60-grit sandpaper around the quill and spent about two days spinning the thing in my hands to turn it down so it would fit. A machine shop presumably could do it in a few seconds, too.
Note that the stem was steel (I wouldn't do it with aluminum, shudder) and was good quality to start with. It worked fine for a couple of years until I sold the bike, but I don't think I'd do it now that I'm smarter and more experienced.