my stoker (the better half) likes to push vs spinning. I am only a moderate spinner <95 but she would rather ride at 70. Would a set of crank arms of different legnths be appropriate to help keep us both comfortable and happy. We have ridden a lot on a 72 paramount tandem with ta cyclotourist 170s but not always the most comfortabley. Have seen a lot of good advise and info here but being new have not seen this issue covered. Thanks!