i suppose that was 3 hydroxx frames right? ..... anyway i have a hydroxx mod and its a brilliant bike, i have rear disk so cant comment on rear brake flex but the bike it self feels extremely sold and stiff(don't believe these people saying there not), square tubing on it seems to be quite resistant to dents , only the top tube dents easily since its not square only problems with it i have found is the paint flakes off though im not to concerned and the drop outs are very weak if landed on, i ended up making an insert to stop the drop out bending up on my side hop side just in case if i landed on it