Originally Posted by
Minion1
and there is a rule of thumb that one degree change in STA or HTA equals one centimetre of reach, so that would (artificially) add to the reach number listed. Also, with a slacker seat tube angle, as the saddle goes up, compared to a bike with a steeper STA, your saddle gets further away from the bars by comparison so that helps lengthen the bike too - they are things that don't really show up on the frame's dimension drawings.
STA is completely unrelated to the reach dimension. Reach is the dimension form the bike's BB to the top of the centre of the head tube. This is why if you want to properly compare bikes to other bikes you just look at reach and stack. They take out all the wildly varying components of the geometry puzzle. Where HTA will matter is if you raise your stem and bars up off the steerer bearing. The higher you get, the further back you will come, how much depending on the HTA. For taller bodies, the primary concern with STA is if you can put your saddle where you want it to go, as the longer the seat tube plus post, the further back you will be.
Originally Posted by
Kaben
Fair enough - I thought it would be ok as looking at the Argon 18 Electron Pro frame that Glaetzer is riding at the moment, that has 76 degree seat tube and 72.7 head tube, so i assumed this would be workable as its "similar".
What do you think about the geometry angles of the Look 875 Maddison? I expect its more tuned for endurance track riding but i would primarily be using it for Sprinting? My current Planet X Track Pro is too short in reach for me to get into a long & low aero position for sprinting.
In the beginning, anything will do. I started off riding a way too small 58cm Cinelli frame (could never find what model it was but it was the same geo as the Vigorelli, it came before it though) that I thought was awesome, but just too small. In the end when I stripped it down to sell it I had big fat skid marks in the chainstays where I was flexing the frame enough to leave a LOT of rubber. Now I'm on a 63cm TT custom Duratec. Stiff as hell and a whole lot bigger!
The problem that I saw with larger bikes in general, road and track, was that frame specifics like layup and tube profiles didn't change from the small through to the big boppers. That made for some less than stiff big size bikes. That concern pushed me away from a lot of brands, but some notable exceptions that I ended up putting money down on are Felt, Canyon and my Duratec track bike. Duratec know their stuff and changed tube profiles and thickness to give me what I wanted - the biggest frame they had made that wasn't a tandem and stiff enough to make a wannabe sprinting giant happy. I was hesitant steering away from carbon, but super happy in the end