Hey guys, just wondering, i got a orion pro 125cc, it has 47 tooth back sprocket, im thinking of going to a 40 and there is was too much acceleration in low gears and i would prefer to take that and spread it out for some more top end so that first gear will be actually useful. at the moment it feels like it would climb a verticle wall in first or second!. is this too much of a change down in sprocket size? and also, can i resize the existing chain as it will be slack with the new sprocket on. thanks guys