Nick. There is NO way. No way possible that a change from 170 to 175 cranks will produce the dramatic changes in positioning, pedal feel or anything else! There is a reason the wrenches in wrench sets come in 2" increments. If your HANDS aren't sensitive enough to perceive the changes in leverage of less than 2", why on earth do so many of you think that your LEGS can??!! The hip, thigh, leg, foot system contains the biggest most powerful muscles in the body and there is a reason that after 100 years of bicycle development there isn't much that has been done to make a wider range of crank sizes available: it isn't really necessary.