Schwinn tire size question

[expjawa]

I've got a Schwinn American that I picked up yesterday. Build date 10/9/61. Should this have S-7 rims? The tires on it are marked as 26 x 1.75, not 26 x 1-3/4. Am I correct in understanding that this tire size designation means that they have a balloon tire bead diameter of 559mm, not the S-7 diameter of 571?

 

[Bendix]

I've got a Schwinn American that I picked up yesterday. Build date 10/9/61. Should this have S-7 rims? The tires on it are marked as 26 x 1.75, not 26 x 1-3/4. Am I correct in understanding that this tire size designation means that they have a balloon tire bead diameter of 559mm, not the S-7 diameter of 571?

should, may have been replaced. or, if the bike rides like it has 2 eggs for wheels somebody may have accomplished the rare feat of actually getting 1.75's on a schwinn rim!

the only practical difference between those 2 wheelsets on your bike is that the fender clearance might look a little funny with the 1.75's.....

 

[A.S.BOLTNUT]

Not sure how this would break down in metrics ? but as far as i know Schwinn Americans were normally middle weights and came from the factory with the 26x 1 3/4. s-7 wheels

- Ralph

 

[expjawa]

should, may have been replaced. or, if the bike rides like it has 2 eggs for wheels somebody may have accomplished the rare feat of actually getting 1.75's on a schwinn rim!

Well, it doesn't ride at all at the moment. The tires are a bit dried out and have dropped in off of the bead. I don't think I'd try inflating them as they are, even if the tubes held air, I doubt the tires would hold up long. I'll just measure the bead circumference when I take the wheels off and see what I'm dealing with.

Thanks.

 

[Bendix]

should, may have been replaced. or, if the bike rides like it has 2 eggs for wheels somebody may have accomplished the rare feat of actually getting 1.75's on a schwinn rim!

Well, it doesn't ride at all at the moment. The tires are a bit dried out and have dropped in off of the bead. I don't think I'd try inflating them as they are, even if the tubes held air, I doubt the tires would hold up long. I'll just measure the bead circumference when I take the wheels off and see what I'm dealing with.

Thanks.

schwinn rims will be clearly marked 'schwinn tubular s-7' i believe, and have the little hash marks between the spoke holes :wink:

 

[udallcustombikes]

I have seen a few S-7 tires marked as 1.75 but they also state they fit S-7 rims.

 

[CCR]

Bendix is right, you should see "schwinn tubular s-7" stamped in the rim, often near the valve stem.

 

[expjawa]

Bendix is right, you should see "schwinn tubular s-7" stamped in the rim, often near the valve stem.

Thanks for the info everyone. I haven't found anything stamped on the rims. It could be obscured by the rust, but I can pull the tire aside far enough to see inside the rim, and doesn't look like its tubular construction. The tires are Bridgestones, so they are clearly not original. Oh, and there is definately more clearance between the fenders and tires than on, say, my Deluxe Seven. So I'll have to assume that someone replaced them at some point.