I may be buying a 21 foot kevlar/carbon fiber kayak. Is 6 foot between roof rack cradles going to be good enough support,or do I need to extend this distance?
I carry a 21’ surfski and a 21’ Thunderbolt (both carbon) on a roofrack with almost exactly that spread, wtih no trouble at all. I use Malone J cradles (love them) and don’t bother with front and rear tie downs (flagellate me, please, everyone…). I’ve never had any problems at all at highway speeds. No cracking or flexing that I can tell.
Ya, 6’ will be finer than fine
I regularly haul a 22’ tandem on 6’ spread hullaports with no problem. I (gasp) don’t use fore or aft tiedowns either…(double strapped on longer trips though…)
Double straps do help a great deal. I use saddles with foam pads cut to fit the boat. J-cradles are excellent. Ihave the oak orchard J-cradles as well. Take the time to really get your boat to fit properly.
thanks for the advice.just happens to be I’ll be hauling a T-bolt.
One set of straps to the J-cradle
and the other set to the load bars. I happen to have mine on a T-Rack on a P/U truck, so I have confidence in the strength of my loadbar to vehicle connection. If you are not going to use tie-downs be sure to take into account the weakest link in your overall system.
I got the trac-rac system for my truck because I was told by the maker of my 22’ Huki outrigger canoe that 8’ spread was too much.
quote “You should space the distance from the front cartop cradle to the rear cartop cradle at about 4 feet, 5 feet is slightly best, 6 feet is almost too much, 7 feet is definitly too much and not as good as less. 3 feet is the minimum spread. When racking the canoe, it’s best to support the canoe “in between” the iakos which are spaced at exactly 6 feet apart, as this is the strongest section of the canoe and is designed for the stress of cartopping.”
Now that I sold that boat I use about 5 or so feet between cradles for my 21’ surfski and slightly closer for my 17’ K1 (just fore and aft of cockpit in both cases). No tie-downs. The cradles I feel are the weakest link so if I’m going on a long highway drive, I’ll use another strap that attaches direct to the trac-rac.
That should be more than enough…
I have a Subaru Forrester, and my Thule crossbars are maybe 5’ apart, and are equipt with Thule “J” racks. I carry a 20’ Tsunami double (close to 100 pounds) with no problem. Make sure you use both bow and stern tie-downs as well.
I carry my T-bolt on a Jeep Gran Cherokee with 4’3" spread & old Yakima stackers. My older Jeep had over 5’ & was better. A bow tie helps with truck wakes & wind. You will love your T-bolt!