I have a 27 speed hardrock pro disc that has deore rear and front deraileurs. Whenever im trail riding and really get on it my gears seem to slip. Upshifting and downshifting are fine throughout the gears but when im in any gear (i do not cross them) and start pedaling down hard it feels as if it slips and grabs again. It really throws off my balance and momentum when this happens and is quite annoying when im on the trails trying to get uphill. Ive tried messing around with the barrel adjusters but it just wont fix it and with the barrel adjusters counter clockwise tightens the cable and clockwise loosens it correct (adds slack)?