Originally Posted by
cyclezen
lately?
meaning sometime time since the '50's ?
general road geometry for HTS and STA hasn;t changed much in 40 + yrs, with some exceptions.
54 to 58 has generally fallen in to the 73+- x 73 +- (lemonds tended to slacker STA...) with smaller sizes progressively having Slacker HTA and steeper STA. Reverse for 59/60 cm and larger.
Track bikes have always been 'steeper'. Track dropouts - Track bike, track geometry. Fixie maybe. Bike meant for derailleur/road setup, not likely.
Since compact became common, sizes hereto never heard of (47 and smaller) were available. Those very small sizes, from what I've seen, all come with slack HTA and steep STA.
There's lotsa reasons for this. I actually won;t get into these, since I don;t think you can rustle up ANY Road Geometry chart showing a 50 or smaller frame with any angle approaching 73, now or from any distance time in the past.
The only frames I've seen, off-the-rack 'ROAD' bike below 52 with anything even close to 73 angles were the Italian steel frames from the 70's and early 80's.
Sizes 47 and smaller were never heard of before compact geometry simply because of compact geometry in itself. "Compact" geometry really only refers to the shortening of the seat tube and sloping of the top tube. Today's size 47 is very equivalent to a size 50-52 of yesteryear. In example, the size 47 typically has a c-c seat tube measurement of 47cm while the top-tube measurement is typically between 51cm and 52cm. Before classic geometry, this same bike would have a 50cm seat tube and be measured as such. Also, prior to compact geometry, (with some exceptions) any bike with smaller sizing than this would mandate the use of smaller wheels, i.e. 650c, etc.
I understand that toe overlap occurs in smaller frames, but that seems like a small price to pay for a bike that actually handles well. The slack angle issue really only seems to occur in bikes 52cm or smaller for the most part, excluding bikes explicitly labeled as "endurance" or "comfort" models.