Size and shape of bum matters too. If you only have a 32" leg but need more legroom it is likely that a nicely rounded bum is inching you forward creating a need for more legroom.
Coincidentally I am offering a bummerectomy which resolves this issue at £1500 per cheek. It moves the bum cheeks to the front thus also offering better protection in the event of a crash. Only downside is that you will require new trousers made to measure.
