I was wondering how much lateral movement is typical in your rear rack?

I have a cheapo PlanetBike Eco Rack. One bracket goes to my seat stay mount, the brake is in the way of the other so it is hooked up to the brake bolt.

I notice that when I am pedaling hard, or when I move around the rack with my hand there is more lateral movement than I'd like. Is this normal considering how I have it installed/for this rack, or is it supposed to be more rigid? The rear of the rack moves about 1/4-1/2 and inch if I jiggle it around.

Some designs are more rigid than others. Surprisingly - some of the more expensive racks aren't all that 'solid'. Larger tubing size seems to make for a more rigid package, as does larger, shorter attachment stays.

There should be no lateral movement. Movement is going to weaken the mounting points with possible rack failure in the future and possibly of your bike where the rack is attached. Get a different rack that will mount properly, and/or go to your LBS and ask for advice.
BTW, pics help in describing the problem.

+1. Cargo shifting in motion is BAD.

I have two PB Ecos on two different bikes and have no movement on them whatsoever, even with the family groceries aboard.

Thanks, Here are the photos of where it mounts. The movement doesn't really photograph well, but with that current setup, the rack wags back and forth like a tail, not much as said, 1/4-1/2 inch. and only when loaded. with the way my brake is located, it seems like all the racks I've seen would still have similar issues since the mounts are only on the outside of the seat stays.

Wow, what an unfortunately placed cable adjuster there. Your LBS might have a Y-adapter to mount the rack to the brake bolt at the center instead of mounting it asymmetrically like that.

A seatpost clamp with eyelets might be an option. For illustrative purposes only.

I had a rack with similar mounting hardware and similar tail-wagging issues. It's a hallmark of a cheap and cheesy rack.

I've had three other racks--a Bontrager Back Rack Deluxe L, a Jandd Expedition, and a Tubus Cosmo. None of these higher-quality racks have the problem. I still own the Bontrager and the Tubus. They're like bridges.

And get another caliper. I had to do that on one of my bikes.

You got my curiosity up. I couldn't detect any play in my rack. When it went side to side so did the frame.

I'm with the others. Replace the rack or calipers or both. Or see your local LBS and ask them about it.

Thanks everyone. Looking into some alternate options for caliper or rack/mount. I'll report back once its resolved.

FWIW, I love my Toba racks. I have them on my commuter and my touring bike. For starters, they're more versatile because they place the load a bit higher and farther back, meaning that my heels don't hit my panniers, which I've had problems with with most other rack models. The other thing is that the mounts are really, really sturdy. Neither of the bikes I have them on is really designed as a touring bike but the Toba racks make it work without heel strike problems, and aside from that, they mount more solidly than any other rack I've ever had. And they're not even expensive as such things go.