"Larry Jaques" wrote in message
news
On Thu, 11 Jun 2015 09:03:33 -0400, "Jim Wilkins"
wrote:

.....The HF manual I-beam trolley's bearings are quite loose
on their axles.

To lower rolling resistance, I'm sure.

Only if the ball bearings jam from dirt, which is possible since the
ones they used don't all have seals on the hidden side. They didn't
waste any extra effort making those things. I'm doing a more careful
job for the practice.

Yes, always keep spares! That's another reason I like buying from
Zenni. An extra pair (stainless framed hi-index bifocals) costs
about
$30, so I buy two pair at a time, keeping a pair with the brand new
prescription as a spare each time. My old prescriptions are in a
drawer, the new spares in the truck (now in my BOB) at all times.

How is Zenni to deal with? I got a second version of the prescription
for normal bifocals with reading lenses on the bottom which I think
would be good for driving and better for extended close work. My eyes
are too different for drugstore reading glasses to work well. I
speed-read which requires a wide field of sharp vision.

-jsw