part time
At some time or other, you and your friends WILL hit your heads - might be good to go ahead and put some kind of padding on the bottom and sides (leaving the top flush). Mini-cell foam attached with duct tape works good if you have some odd pieces laying around.
Also, like the guys above said, you can also do various things to make part-time extensions. A friend has 2 8-1/2 foot pieces of wood with the shape of his metal bars hollowed out on the underside, so all he has to do is lay the wood on the metal. Tying down the canoes locks the wood pieces into place - at camp, he uses them for tarp supports.
see photos
Hi Leigh, I also have a Matrix and carry two canoes and had the same dilemma you have now. I posted some photos on my blog that should describe how I added extension pipes to the cross bars. I drilled holes into the cross bars and the pipes and fasten them with screws.
Take a look here:
http://evergladesexperience.blogspot.com/
Good luck!
Connie
Go with 66"
Leigh,
I’ve got an 09 Matrix and put 66" bars on it. All bars are the same price so I went bigger knowing I could cut them down if need be. I carry a lot of WW boats and canoes with bikes (often at the same time) so I needed longer bars. I hit my head real good once, you learn quick how much room you have. If your really worried about it use tenis balls, bright colored tape, spray paint, or some foam. But honestly, it’s not really an issue just warn you passengers. I’d go with the 66" if you just can’t take them break out the hacksaw, a few minutes of elbow greese and you can make them any length you want (a long as it’s shorter 