Is this the right back break?

Have you tried loosening the bolts are re-secure everything in alignment with the wheel?

Maybe the wheel needs some truying too.

Basically what is the problem? Does it touch the rim whilst its not in use or is it not touching the rim enough whilst braking?

It looks like the brake pads are kinda low on the brake surface. Are these the correct brake pads for this brake block - wheel?

Is this the correct wheel for the frame?

Are these the correct brake blocks for this frame - wheel combination?

It would not be a bad idea to change the cables too. Maybe you wanna use a torque wrench so you will secure the cables correctly. The LBS's around here charge 5 euro for a general tune-up plus materials.

it mostly only seems to wear on part of the wheel rim (lower) i have adjusted the break pad as much as possible but it still only wears on part of the wheel i so i get uneven wear on the pad and wheel. not sure why.

It looks like the previous owner did a franken - job when replacing the brake pads and didnt even notice or care.

The LBS could probably tell you if these are the correct brake pads for this brake block, or the correct brake block for this frame - wheels.

Thanks i will take it down to a local shop soon.

thanks for help all

There is nothing wrong with the brake but it is slightly rusted and badly out of adjustment.

Loosen the brake bolt and tighten the centering screw so the top of the head stands a bit proud of the caliper. Turning the centering screw to the right (tightening) rotates the caliper to the right, but it also shifts the right pad down and the left pad up, and it brings both pads closer to the rim. You might need to loosen the cable.

Next, realign the pads so they hit the rim squarely. The top should be a millimeter or two below the edge of the rim and the bottom should not be below the machined braking flat. You don't want the pad rubbing the tire, and if it protrudes below the braking surface, it will form a hook as it wears. The hook will get stuck on the rim when you release the brake. If the pad is too worn for this adjustment, replace it.

Next, center the caliper the best you can by hand and tighten the bolt. Then use the centering screw to fine-tune the centering so the two pads hit the rim simultaneously.

While you're at it, replace the brake cable and housing--they're rusted and worn. Also drip a bit of thin oil, such as Tri-flo, into the pivots, and wipe the whole caliper with a slightly oily rag. This will keep the corrosion at bay.