Bicycle Classic: 1957 Schwinn Corvette – Mechanical Sympathy

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– Posted on June 30, 2022

In the 1950s, when anything with wheels captured the imagination of America’s youth, Schwinn Bicycle Company engaged in some nomenclative cross-pollination with sports car manufacturers, undoubtedly with mutual benefit to all involved.  The top-of-the-line Schwinn was the snazzy Mark II Jaguar, but just underneath the Jag on the retail price sheet was the Corvette.  Both were Schwinn “Middleweight” bikes with an upgraded level of gingerbread compared to the workaday models, and although it’s a little outside my everyday bicycle fixation, I recently bought and refurbished this ’57 Corvette from Detroit’s Craigslist.  It’s a keeper.

My lovely bride and I made a day out of the trip down to Romeo, MI, and brought back a complete and clean but neglected addition to the fleet.  According to the serial number, the bike’s frame was stamped between October 15th and October 31st, 1956; therefore, it could be either a 1956 or 1957 model, but the seat’s color scheme (according to the brochures) was used on the ’57s.  The ’56 models used a single color seat (in a medium tan).

To me, the most exciting thing about the Corvette was its hub, a Bendix two-speed manual, which was superseded by the Bendix “Automatic” only a few years after this bike was built.  This was my first experience with this antediluvian bicycle hub, which wouldn’t shift correctly for reasons that I’ll explain in a minute.

Interestingly, Corvettes could have been ordered with a single-speed coaster brake hub or a Sturmey-Archer three-speed hub.  The two-speed Bendix was a $7.50 upgrade for coaster brake bikes, and by the time the original purchaser tacked on an additional $4.50 for a front brake, they could have upgraded to the three-speed unit (the total price of $76.95 was exactly the same).  One of history’s mysteries, I guess.

The bike was in excellent shape considering that it’s all-original and 65 years old.  The completely dry bearings in the front axle, the bottom bracket, and the front fork informed me that the bike had likely never been serviced, and was probably not ridden very often.  The seller apparently picked it up from an abandoned storage garage filled with bikes, so he didn’t know any of the bike’s history.

Regardless, I set about the laborious but rewarding task of completely disassembling the bicycle, soaking the various parts in the appropriate solvents, and inspecting everything for problems.  Unfortunately, somebody in the murky past HAD attempted to service the hub, as one of the bearings was not correct, as evidenced by the loose ball bearings that spilled from the hub shell as I disassembled it.  Schwinns use all captured bearings, so I knew something was wrong.

Additionally, as I later discovered after some swearing and multiple attempts at adjusting, disassembling, and reassembling the hub, the main drive screw’s gear teeth were mutilated by someone with no mechanical sympathy.  I’m not the type of person to abuse machinery; I’ve spent much of my life working on greasy parts and I have too much respect for the craft to needlessly beat on something.  Not everyone can help it, however, such as the person who drives merrily along with the oil light screaming at them, expecting a more colorful affectation of an emergency.

My theory is that the shifter cable at some point lost its adjustment, or a lack of lubrication caused the sun gear or rod and spring assembly to stick.  Someone rode along in an attempt to find high gear and in doing so ground the poor gear teeth into sharp little points.  The hub’s sun gear rides inside those little gear teeth, and the sun gear is largely responsible for the bike’s forward drive.  Judging by the grease inside the hub and the not-even-close-to-correct bearing, I’d say someone took exploratory measures, got in over their head, reassembled the hub improperly (it’s actually a bit finicky to reassemble), and somehow was rewarded with high gear only, most likely because a ball bearing was jammed where it shouldn’t have been.  Like I said, it’s just a theory.

Luckily, the world has eBay, and I was able to find a NOS drive screw and a new sun gear for a reasonable price (about $25 total).  The bike now shifts like new.

For you “gearheads” out there, this is the only schematic of the Bendix two-speed I could find, but at least it gave me some information on how to adjust the hub and what to use as lubrication (short answer – grease).  I use marine wheel bearing grease on my bicycle rebuilds.  It lasts pretty much forever.

Bicycle enthusiasts will use several concoctions to dissolve rust: Some use an oxalic acid mixture, which is inexpensive but quite toxic.  I spend a few bucks and buy Evaporust, which comes in gallon jugs.  It is non-toxic and biodegradable, and you can use it for quite awhile before it loses its effectiveness.  I pour it into a Rubbermaid container and dip smaller parts in it.  The pedals came out fairly well considering how rusty they were; unfortunately, there’s no getting rid of the pitting.

Larger items such as the wheels simply need good old fashioned elbow grease, using some WD-40 and 0000 steel wool.

I polished the Corvette’s frame with Meguiar’s Scratch-X, which is a mild polish, and followed that up with some Mothers Cleaner Wax.

The same day I finished assembling the bike, I jumped on and took a 12-mile ride out on the rail trail, and only needed to do a little tweaking when I got home.

The Corvette is a little older than the bikes I typically buy, and it’s a tank at something like 60 pounds, but it caught my eye in a way that few other Corvettes do.  With my collection currently sitting at 19 bicycles (counting our two exercise bikes and my fair lady’s three), it may be time do do a little selling rather than buying.  But first I might go out for a ride on the Corvette.