As many others have already commented, you don't need to do much as these old Schwinns are super durable and great riding bicycles IF YOU CAN ACCEPT THEIR HEAVY WEIGHT AND SLOW NATURE!
Trying to CHANGE OR UPGRADE THEM IS LIKE TRYING TO TURN A 1972 FORD F150 pickup truck INTO A SPORTSCAR!!! Don't try!!! Just enjoy them for what they do great and that is an extremely comfortable but slow ride and durability that is unsurpassed in the case of 1970 and later Collegiates & 5 speed SUBURBANS. The Varsity has one major weakness compared to the 1970 and later Collegiate & 5 speed Suburban..................that weakeness is the hunk of junk HURET ALLVIT rear derailleur which is garbage compared to anything from SHIMANO or SUNTOUR!!!
This is the ONLY upgrade that will really help as these old SCHWINNS were really well made..........................so for all VARSITY models, excepting those that were built on days in the seventies when the Chicago factory productrion line was out of ALLVITs and substititued the Shimano built GT-100 (1970-1973) or the Shimano built GT-120 (1974-1977) from the five speed Collegiate/five speed Suburban......................so for all VARSITY models except those, YOU NEED TO Junk the ALLVIT and instead install a Japanese rear derailleur made by SUNTOUR or SHIMANO...................................very simple and low cost........and it makes the VARSITY totally bombproof and unbreakeable..............................just don't try riding in the rain downhill and you might realize something about UN-BRAKE-ABLE!!
The original Chrome STEEL WHEELS are fine and you will have adequate braking as long as you do not ride in the rain. WET STEEL RIMS WILL REQUIRE SUBSTANTIALLY LONGER STOPPING DISTANCES........translation is that you won't stop in time if you're already exceeding 12mph in WET conditions!!!
The 1967 and later VARSITY with the Schwinn TwinStik (s) stem shifters and the 52/39 front crankwheels are SIGNIFICANTLY BETTER than earlier VARSITY models.
Schwinn for the 1966 model year for all bicycles, increased the THICKNESS and STRENGTH of the Headtube, thus requiring a slightly thinner diameter stem. 1966 and later Schwinn stems WILL NOT interchange with 1965 and earlier Schwinn stems which are common'industry standard'.
The 1970 and later COLLEGIATE and the five speed SUBURBAN are the BEST and MOST DURABLE ELECTROFORGED SCHWINNS EVER BUILT........much much better than the VARSITY , CONTINENTAL, or 10 speed SUBURBAN, and much better than the 1964-1969 Collegiate.
The MODEL J freewheel of the (1970 - 1977) Collegiate and five speed Suburban 32-26-21-17-14
The MODEL F freewheel of VARSITY-CONTINENTAL-10speedSUBURBAN and 1964-1969 Collegiate 28-24-20-16-14
If you remember nothing else.......Japanese engineering = great and European engineering = not so good
F denotes France and J denotes Japan
THE ONLY THING THAT IS REALLY CRAP THAT THE EUROPEANS NEVER CAME CLOSE TO THE QUALITY OF THE JAPANESE is the Rear Derailleur when discussing bicycles. Otherwise, the Europeans did a very fine job. The Japanese came in and essentially copied the best European rear derailleur design and re-designed it just enough that the manufacturing was better and the materials employed would last and tolerances, workmanship, and functionality was vastly improved.
Customize your old vintage Schwinn however you wish but there is an old saying about a fool and his money. I am gonna say that you would be a dumb azz if you opt to install an expensive 3 piece crank and superlightweight components and wheels and attempt to do away with friction shifting.. THOSE CHANGES WILL PROBABLY MAKE THE VARSITY LESS DURABLE AND WILL NOT IMPROVE THE RIDE OF THE BIKE, AND CERTAINLY WILL NOT LIGHTEN THE BICYCLE ENOUGH TO MAKE IT A SPORTING SPEED DEMON!! As they say you will be peas ing in the wind, and wasting your time and money. Too often, many doofusses that are too afraid to be seen riding such a simple and low-tech Schwinn because of the stigma of electroforged, unsophisticated, bicycle rider as opposed to serious "cyclist", will try to add components that don't do a damn thing but say hey look I've upgraded so now you can tell the bike apart from those folks who might own them and reside in a C10 van down by the river or in the Walmart parking lot.
Sure, you can swap the better freewheel from the seventies era Collegiate/five speed SUBURBAN that will give you the 32 teeth first gear for better hill climbing. Beyond that or fitting an aftermarket seventies era SUNTOUR freewheel with 34 teeth first gear, you need not consider any changes other than the REQUIRED JUNKING OF THE HURET ALLVIT REAR DERAILLEUR. You should junk the ALLVIT even if you make NO CHANGES and keep the stock Model F 28-24-20-16-14 freewheel. WHY? Because the JAPANESE rear derailleurs were massively better than anything European (Huret-Simplex-Campagnolo...it doesn't matter as they are all junk compared to the best from Japan, SUNTOUR & SHIMANO)....... There is a reason that by 1977 that rear derailleurs from Shimano & SUNTOUR had virtually wiped out the European competition....and nearly all quality bikes came fitted with them because they were light years better than the Euro junk. Bike afficianados had known this since at least 1971 or 1972.
Have fun with your SCHWINN!
As they say, STAY THIN, RIDE A SCHWINN.......the extra weight will give you a better workout.
The beauty of an electroforged SCHWINN is the simplicity and bomb-proof durability as well as comfortable ride.
Nothing is nearly as durable! You won't find anything that is more user friendly if you want to Do It Yourself. Yes, the installation of new tires on the COLLEGIATES and other 26" (597mm) schwinns is rather difficult for the novice to seat them properly. This was difficult 55 years ago, so it has nothing to do with the KENDA tires of today. The 597mm 26 x 1 3/8 37-597mm KENDA tires are great tires..........................the BLACKWALL version will outlast the GUMWALL version but no worries because you'll get years of good service from even the GUMWALLS........................be sure to buy quality thorn resistant heavy duty tubes.........................DO NOT ATTEMPT TO USE thin tubes and TIRE LINERS BECAUSE THAT IS A VERY POOR SUBSTITUTE!! You must remember that weight is not a bad thing when you do get unmatched durability and reliability.
THERE IS NO REASON ON EARTH TO CHANGE YOUR VARSITY FROM ITS 27" 32-630mm wheels BECAUSE THERE ARE MULTIPLE SUPPLIERS OF ADEQUATE TIRES. The Varsity isn't a speed demon flyer so any NEW tire, even the lowest cost economy tires will be adequate. You do have several 27" tires that are more than great considering the VARSITY cannot come close to takingthose tires to their limits.
KOOL STOP brake pads will provide the best potential wet stopping, and dry too....................but if you're not gonna ride in the rain or wet, any new fresh decent brake pad will be excellent, even if it costs only $2.
Customize it with your choice of seat, your choice of pedals, and if you'd like to ride UPRIGHT, install cruiser-Northroads handlebars like SCHWINN 7881 bars or Velo orange tourist, or something salvaged from anything you want or perhaps something WALD makes.
Laugh about it all you want to but the old Chicago built electroforged SCHWINNs are outstanding bicycles and although Schwinn called them "lightweights", they were definitely not lightweights when compared to the competition of their day, but they were more durable and un-breakeable than anything else then or now. If you don't mind the weight and comfortable but slow nature of them, there is perhaps no better bicycle around for durability. The simplicity and easy DIY servicing is just another reason why they are great bicycles.