Bought slightly too big outer tube - options? I've had good experience in the past with riding a racing bike with cross-bike outer tube (grip, protection against flats) in the city. So I bought similiar outer tubes again for my new racing bike.

Now, the outer tube on the front (did not install the rear one yet) touches the brake (body) with it's outer diameter and wont turn. Do I have any reliable and safe options to mount the wheel a bit lower? We would be talking about 2mm or so, I could adjust the brake pads if the wheel sat lower. I tried to use cable ties as istancers, but I don't trust this solution.

I would have the same problem with the rear wheel, But I think I have more options there (the part where the axle goes is adjustable in the horizontal, so I could get the wheel a bit away from the brake.

I could hand the tubes back to the store, but then I would be stuck with having to spend 70€ there and the tires I got are the best fit to what I want - hence this question.
You can't make your front wheel sit lower without replacing the fork, and even if you switch to longer-drop brakes (I assume they're dual-pivot calipers if it's a racing-style bike), you can't easily move the mounting bolt.

The only options I can think of are:


if moving the rear wheel in the drops works, keep both tyres for the rear wheel and buy a single smaller tyre for the front (cost: 1 extra tyre)
get wider rims, to flatten the tyre's cross-sectional profile (this is a lot more expensive than just buying new tyres though, and I'd hate to speculate on what width you need to save your 2mm+) (cost: 1 or 2 wheels, depending on 1)
get a new front fork, only if 1 works (cost: 1 fork + maybe paying your local shop to cut the steerer tube)
just get new tyres and sell the old ones - say they're unused and didn't work for your bike (cost: depends on what you can sell the tyres for)