hi,,,my son and i have just changed for the winter from mx....neck brace,,and full body protection,,,,we are still using mx helmets,,until father xmas calls,,from full to none,,,but once we start to try things a little harder we will use the horse riding body armour fits very well under a top...i have had very little time on the trials bike but fallen off more in 2 months than the the last two seasons,,,but find the trials bike 10 times more fun,,,we almost forgot what fun was on the mx,,,,