That's a problem most athletes have. Once there is a hole, repairs do not always work. There are ways to help combat the problem. First you must decide if the wear is from the legs are rubbing the inside of the trouser or if the trouser legs are rubbing together. Checking a trouser inside and outside after several wearings should determine this. If the wear is from inside, the solution is a strong lining. Not a coat lining, but some heavy pocket lining, or heavy cotton drill. Or you might cut up an old pair of wash trousers. when the lining wears out it is replaced. again and again. If the wear is on the outside, the solution is to reinforce the outside area with the same cloth as the garment. see illustration, will this be seen by others? Yes, every time you stand on your head. if you are having the suit made order an extra 1/8 of a yard of cloth so the protection can be replaced. It will take up the wear that would otherwise damage the trouser. If we are speaking of rtw dress trousers that just destructed. take them to the store and see If you can find a pair of a matching color. the damaged pair can be cut up to add the protection. save the old pair, use it to do about six repairs. better than six new trousers. The tailor should see a pair of damaged trousers so that he knows where to place the protection. this also works for jeans. an ounce of prevention etc.