Different front and rear track

[mr henderson]

The Tiger Avon is substantially wider at the back that the front, and doesn't have any known issues. I can't rememeber the actual difference, but it is a lot, well over 100mm IIRC

Thing is, what really counts is the distance between the insides of the rear wheels. A lot of 7s I've seen have a fair bit of clearance between the inside of the wheel and the outside of the chassis, so you may not need much spacing (or offset if you change the wheels)