I’m in the market for a new road bike. Exciting! I had a recent fit session that gave me numbers that represent what would be optimally efficient for me. Now I can hunt for a bike. But looking at the geometry charts of various bikes it’s not clear how to take my fit numbers and apply them to one bike vs. another.
Specifically, using a standard diagram like this one (from geometrygeeks), I want to take my optimal “distance from saddle to brake hood” number and apply that to various frames. How do I determine that based on knowing a bike’s top tube length?
I also have my “optimal saddle height (x) number” based on my current bike’s geometry. So I could figure out how much or little seat post would be showing on a different frame by adding ‘x’ to that bike’s seat tube distance. But that is optimal if the seat angle is the same. How might I compare things if the seat angles differ? And I think this needs to relate to the reach measurement above.
Bump/nudge/update, as the advice has been overwhelming (LOL)….
Turns out, it may not matter much at the end of the day. The bike shop setup a few options based on my numbers and brands they carried and I test rode them yesterday. I may not need to try out brands they don’t carry since there was a bike that I rode that was just so …. surprisingly and amazingly good. I may end the hunt.
The charts from manufacturers aren’t always super accurate and I don’t know of good free tools to project frame stack/reach into fit coordinates. Best bet is to use the frame coordinates to get you close as try before you buy (not always possible)
For anyone getting a fit to purchase a bike, the fitter should be supplying handlebar XY (for road bikes) along with the bar spec. If they’re not working to XY there is a reduced likelihood that your target position will be achieved.
Looks like the XY Bike Calc tool would be very useful.
Yes, my fit session gave me handlebar x/y, and saddle x/y numbers as well. Both before (current) and after (optimal). Looks like the calculator can convert those x/y’s to stack and reach; and then I can enter those stack and reach answers to get a list of bikes that would fit me. Nice!
edit - to enter my x/y numbers requires a subscription signup. argh. Will look into the free two week trial.
