I am learning to use a tripod more and I am looking at an L bracket and gimbal adapter for my D7000 with Nikon battery grip.

The Wimberly Sidekick and other brand adapters to allow gimbal style use of a standard ball head looks like something I would like to try rather than buying a dedicated gimbal head right now. The Sidekick has a vertical attachment so I assume that an L bracket is necessary to shoot horizontal shots for BIF photos.

My question is about flexing of the L bracket when it is attached with the weight hanging off the side of a Sidekick rather than sitting directly over a ball head when shooting vertical off a standard tripod set up.

Is this an issue or no real concern?

I'm looking at the RRS L bracket since it seems to allow access to the side ports and battery. The Kirk bracket does not allow left side access.

Edit: longest lens I'm using right now is 70-300 VR which is pretty light.

L bracket is not necessary, one simply rotates the AS equipped tripod collar to orient body to landscape/BIF posture.
You'll find it next to impossible to "balance" the Sidekick trying to mount at the camera body.

I don't have a collar on the 70-300 VR. I will look to see if one is available. Thanks.

If you're using it at 300mm...the tripod collar from the AF-S 300 f4 will work (w/teflon strips)
I did the mod on one I found on the B&S here for $35. Guys get the Kirk replacement, and often sell the OEM.
However, you'll still have balancing problems...it'll work with better a BushHawk.
Don't have a pic handy of the 70-300 collar mod and the BushHawk, but here it is shown with the StedyEddy.
**This could work with the Sidekick if you could live with the aforementioned balance issue.
(just add an A.S. lens plate)

Tha.ks TM. I didn't even consider the balance issue. Looks like I need a collar now.