Tell that to Bike Friday, they weld on disk brake mount on their front forks and look at how small the tubing is on it. The bottom of most fork ( down where it is welded on ) is alot thicker than the spot the V-brake bosses are brazes or welded on. I have welded on 20 to 5-30 disk brake bosses and have never had one come back. I have not put one a Xooter fork but it looks like it is strong enough. Mac