: My wife wants a double and I'm OK with the idea but we need to be able to put
: it on top of our car which doesn't have a long roof. Does anyone have
: experience with a 21' kayak on a roof rack that only has a 43"
: separation of the front and rear cradles?

43" doesn't sound too bad. I've carried two doubles on a rack with shorter
spacing than that, and I'll admit it was frightening and 50 mph was the
limit ... but nothing went wrong :-)

But with a bit wider spacing, it all becomes a lot easier. IMHO, the critical
thing is the position of the front bar, and the legality of overhanging the
boat at the rear of the car. In the UK you must add a flag to the back (or
a red light at night) if the load overhangs by a metre or more, so I always
try to put boats on avoiding that much overhang. The issue is then that the
front bar needs to be forward of the balance point of the boat, otherwise
the boat just wants to drop onto the bonnet (US: hood).

With the rack that came with the car, the TOTAL load is not meant to exceed
75 kg. Two doubles weighed 73 kg, but to get them to balance I had to have
almost all the weight on the front bar, and tie down at the back, which added
extra load. Yuck. Threw that rack away and used a much stronger home-made one
(using all eight M6 bolt attachments to the roof, not just four). That coped
fine with two doubles and two singles (with spraydecks, buoyancy aids and
similar bulky kit inside), for a total load of about 140 kg. Loading the
doubles onto the roof on my own in a force nine crosswind (interrupted by
having to chase after a carbon paddle blowing across the campsite...) was
entertaining, but once the boats were on, the whole thing was solid and we
drove several hundred miles home...

Moral: build your own rack to cope with the load.

Personally, I hate having a tie down rope blocking my view through the
windscreen, so I never use end tie-downs, and have not had any problem with
the boats lifting at speeds up to about 85 mph. I've carried a big 18' open
boat at 100 (upside down) and 90 in a crosswind (on its edge, with several
kayaks adding weight to the roof). Basically you build up slowly to these big
loads and high speeds, watching and checking the security as you push the
envelope, and find your own comfort limits...

The pic here shows a double (white, right), the open boat with a kayak inside,
another plastic river kayak, and a sea single on the roof, with three plastic
river boats inside. This all felt quite secure and avoided needing to tow my
trailer as well. The rack spacing can't have been much different from your 43".
I've made rack extensions for my new car, so I can get six boats on the roof
(which we did to drive across Europe and back - no problems:)

Andy