I have bike with 165, 170, and 175, I hardly notice any difference beside the obvious toe overlap on the bike with 175, it's generally in your head rather than actually noticing the difference.
(edit are you referring to yourself being 5'1 or your sister?)
I would eer on the side of caution by getting 165mm instead of 170 for your sister thought.
I have bike with 165, 170, and 175, I hardly notice any difference beside the obvious toe overlap on the bike with 175, it's generally in your head rather than actually noticing the difference.
(edit are you referring to yourself being 5'1 or your sister?)
I would eer on the side of caution by getting 165mm instead of 170 for your sister thought.