i also just gearded my 09 mgrand down to a bdx 54/66, i have 2 rides on them so far. i noticed a BIG difference! all good, but now it seems like the stock clutching is holding it back? i didnt feel it as much in the trees, and havn't got it on a big hill yet, but on the road race out, its like it hits a wall! it doesnt want to shift out. RK-Tech is next on the list!