HELP!! Conversion questions, yipee! 1974 schwinn derailleur, brakes, crank, and freewheel conversion

howdy!

basically, i have a 1974 Schwinn varsity with all original parts, sans pedals.

i want to replace my brakes, crank set, rear derailleur, freewheel, and front derailleur (if necessary)

the catch is that i want to get all new components, but retain a 2 x 5 setup.

Ive found where i can get 5 speed freewheels, and double crank sets, and i think any new brakes should be compatible.

my problem is, i cant find any 5 speed derailleurs. Ive found contradictory information as to whether a standard 8 or 9 speed derailleur would be compatible, as 5 speed freewheels go up to 28 teeth and the 8 and 9 speed derailleurs have a maximum 27-tooth capacity.

some people say you can squeeze in 28, but is this really true? would it be a big hassle to do so?

if this is impossible, would i be able to use a 8 or 9 speed freewheel without modifying my frame?

 

FYI. You can use an 8-/9-speed rear derailleur with a 5-speed Freewheel ...

It simply becomes a cosmetic issue since the parallelogram on most-if-not-all 5-speed rear derailleurs hang vertically (the original SUNTOUR rear derailleur may be the only exception ... it's very rare, AFAIK, and I doubt it is what you would have handy to use).

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If cosmetics are moderately important, then you can get either a CAMPAGNOLO Nuovo Record OR Gran Sport rear derailleur on eBay ... not counting postage, figure $15-to-40 for most Gran Sport rear derailleurs & $20-to-45 for most Nuovo Record rear derailleurs ... condition + demand-of-the-moment will dictate how much they cost.

Most Schwinns had heavy HURET rear derailleurs ... figure on $10-to-?.

Some later Schwinns may have had the black (some Delrin) SIMPLEX rear derailleur ... also, $10-and-up.

• Although you probably were not wondering, by my reckoning, most 5-speed rear derailleurs could be used on a bike with an 8-speed cassette (and, possibly a 9-speed cassette) if the pulley wheels were simply changed to narrower 8-/9-speed pulleys.

If you are moderately motivated, you can modify a Shimano Freehub to fit in a frame whose rear dropouts have 120mm spacing and use almost any abbreviated cassette.

BTW. The apparent reason that Shimano has such a conservative spec for the largest cog which their rear derailleurs can handle is probably because of the miniscule drop on a the Campagnolo rear derailleur hanger on Campagnolo horizontal dropouts ...

So, yes, you could use a contemporary rear derailleur on your vintage Schwinn Varsity without modifying the frame.