David
There's a widely held misconception that bicycles and bike components were accurately manufactured. During the Bike Boom era of the 70s, most European bike components were with equipment that predated WWII and some of it even WWI.
Much of European manufacturing was devastated during WWII. Bicycles were the cheapest form of transportation after the war and a such, there wasn't much capital to invest in new equipment. As the European economies improved consumers moved up to mopeds, motorcycles and eventually autos.
I've seen photos of manufacturers like Campagnolo and Cinelli taken by friends who visited those hallowed halls back in the 1970s. I was shocked to see that those sacred places were not much more than blacksmith shops!
The operant term for bicycles back then was "hand crafted" which also meant "hand fitted". While there were some better quality cottered crank components like those made by Campy, Stronglight, Zeus and so on, most cottered cranks were produced for entry level bikes and the quality reflected that.
There were at least 8 different size cotters commonly used by British, French, Italian and Japanese bikes. They came in 8.5mm, 9.0mm and 9.5mm diameters with different tapers.
Peugeot used 2 different styles, the older ones had a long full length taper while the later cotters were closer to the French "standard". We frequently had to buy the old style Peugeot cotters from the local Peugeot dealer - when they had them!
I can remember many times when the same size replacement cotters didn't work in both sides of a crank! Cottered cranks were a pretty crude design for attaching a lever to a shaft that carried over from at least the 1800s.
Many of the replacement cotters that we got from bicycle parts wholesalers were dead soft. Those were the ones we had the most failures with. The hardness varied from batch to batch too!
We occasionally had to ream out the holes in the crank arms because they had been damaged from running with a loose cotter or were improperly sized from the factory to begin with.
That's why cotters frequently needed to be filed. Good riddance to a quaint anachronism!
Bicycles started off as a rich man's folly and then became a poor man's necessity. In many ways they have come full circle. Before the Lemond era, professional bike racing was a poor man's sport! ;-)
Chas. Colerich Oakland, CA USA
David Bean wrote:
> I have never understood why filing crank cotters is so widely recommended.
> Two new crank cotters (of the same mfr and type, of course) must have the
> same bevel. Using a file on that bevel seems likely to render it less flat
> than it started out; therefore more likely to come loose in service. What
> am I missing here?
>
> David Bean
> Arlington, MA USA
> beandk at are-see-enn dot com