Wanting to start a new glider club

On Saturday, December 29, 2018 at 2:45:04 AM UTC-7, James Thomson wrote:
At 03:33 29 December 2018, John Foster wrote:

Sorry to dig up this old thread, but now that winter has set in, I'm
starti=
ng to think and plan more on this project. Do you happen to know where
one=
could get one of these "polyolefin drag lines"? I've looked around a
bit,=
but haven't seen any links for such. I'm also considering various
designs=
for the pulley system. The one that you have linked from the Cotswold
GC
=
in Great Britain looks like it would take some effort to build. I've
wonde=
red about conscripting an old motorcycle wheel for this purpose and
welding=
up a frame with guides for it to attach to a tow hitch of a pick-up
truck.=
Any proven designs out there like this?

Don't underestimate the loads involved - I doubt if a motorcycle wheel
could cope! The load on the rope from pulley to glider could be up to the

weak link strength and the same load will be in the rope from the pulley to

the towcar. This means that the pulley frame and the anchor point (or
anchor truck) has to withstand twice the weak link break load.

Yes. I expect this would be the case. Do you think a rig similar to the Cotswold design, but made from many roller blade wheel bearings would be able to withstand the forces involved? I would think the more bearings there were, the more the load would be spread out, but I'm not an engineer, so I don't know for sure.