try iolo , as leesons frames dont go over 1050? ( feel free to correct me someone in the know ) and also seeing as mr iolo is building them from steel ( cause its real yo ) you could get that shiznit welded back up if it decided to go snap on you. which is always nice. failing that i do believe you could buy bolt on disc mounts for the rear from woolly hat shop, no idea about current frame compatibility though. as i've only seen them on jump bikes.