When I already have all the parts on hand, I put them together to see if they "work." I care not what the manufacturer's specs are. When they don't "work," my experience is that the bike will protest and let you know it does not want to do what you are trying to make it do well before any damage is done - you only have to listen to your bike. However, if you go out immediately mashing under heavy loads, all bets are off.