On Thu, 21 Feb 2008 05:22:32 +0000, Babba wrote:

I want to have a go at making some custom handlebar risers for a
motorbike. I'll be using 53mm dia' round bar but I'm having trouble
working out how to drill/bore the hole where the bars seat. It needs to
be split into 2 sections, the bottom section is fastened to the bike and
the top section clamps to this over the bars. The hole for the bars
needs to be approx 22mm (7/8ths) and will have to be reamed out for
accuracy.

If I drill the hole out first then cut it on a bandsaw I'm going to lose
the accuracy of the diameter with the width of the cut, I don't think
that my bandsaw will create an accurate enough cut anyway. Is it
possible to drill through the middle of two sections clamped together or
will I have to drill two holes in the stock, cut, then mate two sections
together?



http://tinyurl.com/yrlo5d

Yes. You can clamp 2 pieces together with a shim, the thickness of the
gap you want, between the two pieces. You could run into trouble with
a drill, however. Unless you have a very ridged set-up. Even so, I
would drill it undersize, and bore it to size.

Matt