On Wed, 23 May 2007 13:44:56 +0100, The Natural Philosopher
wrote:

Ian wrote:

9) When the retaining bolt is out, the thread in the crank is actually
smaller than the hole in the disc through which the retaining bolt
passes. Furthermore this hole is threaded to take a bolt to draw the
disc off the crank. I'm not very up on bolt threads but I THINK it was
described as 1/4" when I got it. It is about 7/16ths diameter and
pitch is about 19 per inch. The head has three radii on it which I am
sure indicates something! Over to someone else on this one.

I cannot conceive how screwing a bolt back into the crank after you have
removed on from it will 'draw the disk off.'

Hi NP
The bolt concerned is NOT the retaining bolt and does not go back into
the crank but into the disc....

The threaded hole (No1) in the disc is slightly larger than the
threaded hole (No2) in the crank. The retaining bolt passes straight
through hole No1 but screws into hole No 2 . A bolt of the correct
size for thread of hole No1 is put in Hole No1 and the end of this
bolt bears against the end of the crank- not being able to go into
hole No2 since the bolt is larger than the hole.
Tightening this bolt 'winds' - this might be a better word than
'draws' - the disc away from the crank.
I'd try some ASCII art but the last time I tried I failed
miserably...so I hope this additional explanation makes sense.


Please reply to group - email address is not monitored
Ian