After reading all the info on the site, and with some discussion with my rigger, I chose Schaefer to supply my traveler. They (Schaefer Customer Support) told me that the small 4 wheel car was sufficient for my boat. I have not had had a problem moving the car, even though I chose manual stops over shorter traveler with car blocks. Schaefer, for a small fee, radiused the traveler to a template I made of the curve on the deck in front of the lazerette. Except that I was slightly off, so I had to gradually pull in the traveler a bit, it was an easy job to mount the rail. The four wheel car handles that radius as though it were not there. A 6 wheel car might hang but I can't be certain.
Just cause, I chose to use double fiddles with the bottom one holding a jam cleat and I have been very happy with the set up. I find it easier to pull the sheet into the cleat that way, and it is very easy to free it as well. That does mean that the car will move as you pull the sheet so sometimes you have to adjust your lead.
John G.
Valhalla
Commander No 287