> less oiled surface) per bearing? The webs for the two extra journals
> have to take space (length) from somewhere, and unless each web is also
> drastically narrowed (by 20% each?), then there is actually less shaft
> left over for journals than on a shaft with 3 journals, especially if
> "most of the internals being compatible if not equal" (i.e., the crank
> is not longer).
>
> My mentor (40 years in the BritCar business) pointed this out right
> away. Everyone/where else says 5 is better.
>
Jerome:
If you look at the two cranks side by side, you can see where the space
comes from. The drop forged 3-main cranks have a crank throw that is
shaped like this:
__
/ \
/ \
while the throws on the 5-main cast nodular iron shaft are 90 degrees
to the shaft axis. This provides the space for the two extra bearings
without increasing length.
Ron Tebo
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