On Sep 21, 11:56*am, Dave__67 wrote:
OK, this is somewhat on-topic.

O own a motorcycle, it has a large gap between the 1st two gears, a
popular mod is to replace ONE of the two gears that make up the 2nd-
gear pair, the new gear has fewer teeth.

How on earth can you change the number of teeth on just one gear of a
pair when they are set at a fixed distance?

Dave

It's called a modified tooth profile, modified addendum, addendum
shift, et al... Done every day. Not a big deal. Rather straight
forward. I always find it very amusing that it's basically only old
machinery users that don't know about it or think it can't be done
because they're so used to standard gears and moveable center
distances. In the rest of the world, we deal with envelope constraints
every day and "standard gears" are not the standard.