> Nelson argues that unless the bolt is a press fit, it is too
> sloppy and does not share the load of
> the fork pin. First the fork pin snaps and then the load is
> carried by the bolt. He makes the same
> case for the roll pin because it's a spring.
>
> I take it you guys believe it doesn't matter in actual practice?
> Seems like a reasonable line of
> logic to me.
Like James said, I believe that once the tapered pin starts to deform (which
it will before it snaps, my broken one looked like a pretzel), the bolt will
come into shear and so carry the load. The extra friction between the fork
and shaft caused by the clamping force of the bolt will help, too. (In
fact, that may be the most important part, since it keeps the pin from being
bent back and forth.)
Plus, with two points of shear plus the friction, the bolt is considerably
stronger than the taper pin ... even if the pin breaks, the bolt will carry
the load just fine.
More importantly (to me), the tip came to me from Ken Gillanders at BFE, and
Herman van den Akker does the same thing too. These guys do a lot of
Triumphs, so they know from experience what works and what doesn't.
However, I will admit that when I did my own, I used a drill press and a
slightly undersize drill bit. The result was a hole that was a light press
fit for the 1/4" Grade 8 bolt I used. Sorry, I don't recall offhand whether
it was a "C" drill (.242") or "D" (.246"). You'll need to measure your bolt
anyway.
FWIW, Enco has a set of drills that includes all sizes A-Z, 1-60 and 1/16 to
1/2 by 1/64 (115 bits in all) for $30.
http://www.use-enco.com/CGI/INPDFF?PMKANO=47&PMPAGE=68
Randall
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