"Crash Into Religion": Are we coming up on a record number of posts yet?

Per Phil, Squid-in-Training:
Seven found a crack in the thing and they think that's why it failed.

Do you think it was cracked before you had ever even ridden it?

I'd say it wasn't. Put quite a few miles on it with no problems.
My guess is that it's my 220# still trying to learn how to do a decent bunny hop
and jumping off 2-3 curbs on the way to where I ride. I keep asking Seven if
they've got anybody on staff that's my weight but they keep dancing around a
specific answer.

They acknowledged all the flat spots in the threads on the new one
but opined that it "should work"...

I hate to say this but I tell customers "it should work" when I don't really
know if it will or not, but fool myself into thinking it will. I have the
feeling the same thing's going on here.

That's been my feeling from the start. I also think there's some kind of
quality control problem with the casting of the old monolinks. Seems to me
like the only way for what I've observed to have happened is that the inside
area where it's threaded is not a perfect cylinder. I suspect it's out of round
and, in some cases, has flat spots.

That's the only way I can picture the tapping process leaving patches of no
thread (which it did on one monolink). If they were all just one half threaded
and the other not, I could imagine that the tap was applied off-center... but
with patches where the threads outside of the patch are OK and the threads
inside of the patch are OK....


Do you have an extra one now? I would ride the current one without
readjusting it so that it fails, and then when you constantly send back new
ones, they'll finally get the hint and send you something that works.

I think I've about tapped out their good will. Got three of the things right
now... I'll play around with them and when I get down to the last one and/or
it's a couple months before vacation time I'll spring for the alu version.


My guess is that there's not enough thread material to make the screw/tapped
hole a self-locking system. This condition is met when pi*f*dml where f is
the force, dm is the mean diameter, and f is the coefficient of normal force
friction.

That's been my intuitive conclusion - especially since it's ok when put in dry.
OTOH, I tried LocTite Blue one time and still had problems - but now we're
getting into a problem of controlling variables: some of the monolinks have
more thread than others....and maybe I didn't get all the grease out before
applying the LocTite.
--
PeteCresswell