I have an old Schwinn, which I believe started life as a Speedster. The bike is rather fun to ride, but it has the stamped steel fork that is a little insecure at anything over 5 mph. Being the tinkerer that I am, I would like to replace the fork with a better one. The tubular Schwinn vintage forks for the Continental (and I assume the Super Sport) are not common. On the other hand I can get my hands on standard Japanese forks easily.

From my reading over at Sheldon’s informative page on American bike parts Parts for older American Bicycles, it looks like the outside diameter of the Schwinn steerer tube is the same as that for Japanese forks. The inside diameter is different, but that is easy to deal with.

Can anyone confirm or dispute my understanding that I can replace the wimpy Schwinn form with a better non-Schwinn fork?

You can certainly replace the fork with a tubular type, however note that the original fork is made of forged (not stamped) steel and is quite strong. After all they came on several million Varsities and considering the abusive riding many of those bikes would have experienced you don't see that many with bent forks. Unless the original fork is bent I think replacing it is a waste of time and money.

Thanks, Meta. I would agree that replacing the fork would be silly, but like I said, I like tinkering. And regardless of the strength of the fork, the fact that the blades are flattened means that they flex when cornering. I am curious how well the bike will ride once I fix that.

Besides, this bike has already been modified extensively. No reason to stop now! (I should add that it has a rear brake now too.)

Get involved with a bike co-op to source low cost, vintage parts. You need to know the length of the steer tube currently on the bike before you buy a replacement. Look for a 70's Schwinn "World" fork, they are 1" also. Has tubular arms and they were made in quantity, so common. Should not be expensive. Don