10mm isn't much, so check the clearance you have now from the belt to the rear tire and the clearance you have from belt to any frame member. the 10mm will be split 5and5 on each side. if the clearance is there, go for it.
Just keep in mind that there will be some expansion of the tire at speed and the wheel actually does flex to a degree. You may also check with the tire manufacturer to see what the actual tread width is. I have found that car tires vary quite a bit even though they are supposedly the same size.