I have a 1981 Colnago that I am using a 9 speed cassette hub on the rear that has 126mm spacing. The bike needs to be painted and I also have a newer wheel with a Campy hub with 130mm spacing. When I get the frame painted I plan on also having the dropouts spread to 130mm so that I can then have use of both wheels. Can I just put on a 2mm spacer on both sides to get it to 130mm? If so then there wouldn't be as much axle to stick into the dropouts. Would I need to buy a new longer axle?