I have question about cranksizes. I'm a 5'6" rider at a 155 lbs. My inseam is 30". I have a couple of mountain bikes, one with a 170mm crankset and one with a 175mm crankset. I buy small frame sizes, because the stand over height is better for me. I can ride both equally well, but seem to be able to climb better with the bike (which happens to be 3lbs. lighter) with the 175mm cranks. Does this make sense? I thought the shorter cranks with my height would allow me more power transfer for climbs. I'm getting ready to upgrade, but I'm not sure what size crankset will perfom better. Any input would be great.