I am considering purchasing an Undercover Flex. This is a fairly new design for Undercover and I was wondering if anyone has one of these and can speak regarding their durability and water tightness. I live in the Pacific Northwest and I really don't want a Tonneau that leaks badly since we have rain about 9 months a year.

 

Installed one about a month ago. It just went through Isaac and on the wet side no less. I did not have a drop inside, but would not guarantee that in all installs. I see places water could enter, but it seems as waterproof as any of the folders. I had a Undercover Classic on my Z71 and it leaked around the locks.

Their directions call for mounting the side rails even with or slightly above the truck bed rails. That left nearly a half inch gap between the rubber flap seal of the cover and the top of the truck bed rails. I ended up mounting the Flex rails about a half inch below the top of the truck bed rail tops. This seems to work well.

The flex rail has a channel extruded into it for channeling water to the tubes on the front end. Neither end of this channel is closed. I used the rubber key fob from the Ford dealer and cut plugs for both ends and siliconed them in place. I was only able to get the rear plugs installed before Isaac hit. Looks like they worked.

CX

 

Like Charlie, I've had my Undercover Flex for about a month. I also had to drive through Isaac's leftovers when going through Arkansas on the way to Illinois for Labor day weekend.

I have a BedRug liner and found that there was moisture in the rear of the bed after driving through heavy thunderstorms. I think Charlie has nailed it in that the aluminum channels need plugs for the rear. My guess is that Undercover figured the forward slope of the bed would cause all water to drain forward. Interestingly, I never had any moisture towards the forward bulkhead of the box.

All in all, I am very satisfied with the Undercover flex. I'm going to mod mine like Charlie did but it is still pretty good as is. The only thing I really don't like about it is that you have to open the tailgate in order to open the top. It is a little inconvenient if you are the kind of person that always locks the tailgate (which I am). It is a very minor thing...

Pics..

 

Here is a picture of the extruded aluminum rail at the rear. Just capping the rounded section of the rail should force the water to drain to the front of the rail and keep it out of the tailgate area. You could potentially just fill it in with some silicone caulking if it sticks well to the aluminum.