Wheel size / tires for 1980 (?) Schwinn Collegiate
 

I just picked up a 1980s Schwinn Collegiate (electric blue) to use as a putzing around town / errands bike. EDIT: pretty sure it's a 1985/1986 based on catalogs - based on Shimano 3 speed hub.

The rims measure about 24 inches in diameter and are stamped with “FEMCO 26 x 1 3/8 Made in Taiwan”. The tires also say “Made in Taiwan Inflate to 75 PSI” but nothing else. They are possibly original and the side walls have deteriorated.

I’m hoping folks here can help me figure out what wheel size this is by modern standard and what tires I would order to fit these rims.

I’d post photos but it appears I’m not allowed… Thanks!

Maybe this will help? Depending on what your present tires have written on them.....
https://www.biketiresdirect.com/olde...-sizes-article

Thanks... Unfortunately there is no size indicated on the current tires. The link above indicates that a 26 x 1 3/8 Schwinn rim would be ISO 597 though the 70s... I was able to pin down the date of my bike to 1986 based on old Schwinn catalogs (that seems like the only year with a 3 speed Shimano rear hub, which this bike has). When I went to purchase ISO 597 tires the online shop had a note that they would not fit 1980s Schwinn bikes... Unfortunately the catalog I found for the 1986 Collegiate didn't specify exact wheel/tire size.

EDIT: I see that the tires cold also be ISO 590... I guess this is probably the best bet...

I think I solved this based on a thread on the Schwinn Bike Forum (which I can't link due to my newbie status). A user JenniferC posted the following:

"Made by Giant as Bartcycle said, used a three piece Sugino steel crankset and chainring until the later 80's models when they went to an alloy crankset. They're OK bikes, your basic three speed. Blue was the basic color but later they made them in white. One or two years they made a pinkish color women's model called Dusty Rose. They're $75-100 bikes in good shape. Basic wheels for beating around. They used 26" 590mm tires instead of the Schwinn S-6 597mm tires."

So I think I have my answer... 590mm. Hurray!

Yeah, the GIANT made collegiate first appeared in 1983 after Chicago was gone.. The GIANT made collegiate has a 3 piece crank and ORDINARY 590mm wheels. It (the GIANT made for Schwinn bike) is simply a bicycle that Schwinn badged as the "collegiate" for a few years because the COLLEGIATE had been a very popular Chicago made offering.
No question about it, the GIANTs were very good bicycles and significantly lighter than the real Chicago Collegiates, but the ride quality, the durability, and the gear ratio (on 5 speed model) was never as good as the Chicago made COLLEGIATES of the 1970-1980 era.
They are very nice bicycles. Schwinn created a "Giant" by making a virtually nobody-unknown player in the international bicycle industry, somewhat of a player that essentially overtook the Chicago powerhouse very quickly as Chicago had been asleep at the wheel for almost a decade, and GIANT was tuned into making good reasonably affordable bicycles that were more like what was in demand during those bike bust years. Schwinn was just scrambling to stay alive, and to continue offering a wide product line, however possible at that time. GIANT at the time wasn't anywhere in the same league with PANASONIC of Japan, but because GIANT wasn't in Japan, they were a much more cost effective supplier at that time for inconsequential, non-enthusiast bikes such as the niche that the Collegiate filled in the Schwinn product line-up.

I love all the knowledge in this forum - thank you! What I like about the GIANT/Collegiate for a grocery bike is the relaxed geometry, upright bars, chain guard and even the weight which makes it stable under load. There are lots of modern offerings of course, but there's just something appealing about a classic bike and having a bike project!

I don't suppose anyone could tell me what the seatpost diameter is for these bikes...? It's definitely smaller than 27.2... closer to 25.4 but hard to say exactly...