Bianchi Volpe, New Albion Privateer singlespeed, Raleigh One Way singlespeed, Shogun 300 "retro roadie" rebuild, Panasonic Sport 500 franken-3-speed, 1937 Raleigh DL-1
Differences in geometry between two similar bikes...why?
Here's hoping that thread title was helpful enough.
To get more specific, I have a Columbia Sports III. It's a 3-speed from the early '70s, with a Sturmey Archer AW hub. It has a men's frame. My friend just picked up a Ross 3-speed of about the same age, with a Shimano 333 hub, with a women's frame. We're very similar in height, and noticed some significant differences in the geometry of the two bikes, that make us both feel cramped on the Ross.
On my Columbia, the seatpost is angled toward the back of the bike, so that the pedals are slightly in front of the saddle...on my friend's Ross, the seatpost is more upright, and it makes the pedals feel too close. The head tubes are at approximately the same angles, so my bike has more of a rake, and makes the Ross's steering feel twitchy in comparison.
Is this more likely to be a difference in brand, or is it due to the men's frame on my bike, vs. the women's frame on hers? Originally, I'd thought the Ross was a British bike, and I remember being told when I first started looking at 3-speeds, that the British bikes tend to feel slightly smaller...but apparently, both are American.
I guess the real question here is, would a Columbia with a women's frame be more likely to have similar geometry to mine, or is that just how they made the women's frames then?
Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Hase Kettweisel Tandem (redundent recumbent), Merin Bear Valley (The gopher).
There are dozens of such subtle frame geometry differences. They not only exist between different manufacturers and models, but even between different sized bikes of the same model and year from the same manufacturer.
Everything on a bike works together. When you change one dimension for any reason, it often makes it necessary to change something else.