here’s how to measure pad x and y (or pad reach and stack). or at least where to measure it.
saddle height, bottom bracket center straight to the top of the saddle, 4cm behind the nose of the saddle.
in this case i believe your 608mm more than i believe my 640mm. however, that 608mm is going to give you pretty good drop, probably 135mm or 145mm, something like that, i’m guessing. which is fine.
now, the 479mm, retul measures to the back. so add 40mm to that, you’re getting around 520mm to pad center. either you ride very steep, or you have pads considerably in front of your shoulders, or it’s just that really really really long torso.
love to see a pic of you aboard your bike. your situation causes me to wonder if i’m not “honoring” morphology enough in my outputs.
You have me at 602/470 vs. 565/505. That puts me on the wrong size bike, but not by much. I’ve ridden 470 before, and say your stack has a ‘safe’ range of +/- 20 mm, so you’d really want to prescribe a bike that hits between 580 and 620 – that would almost work. But not quite. And for this reason I still think you need a subjective assessment on how competitive this person expects to be. If I’m a Division 1 cross country runner or swimmer just getting into the sport, I may not know anything about bikes or fits, but I’d still want something consistent with my performance expectations. So in my case you’d err to a 51 P5 vs. a 54 P5, a 51 IA vs. a 54 IA, Small SC vs. Medium SC, etc. – because you prescriber puts me too low on the bigger sizes stack envelope for what my goals are
now, the 479mm, retul measures to the back. so add 40mm to that, you’re getting around 520mm to pad center. either you ride very steep, or you have pads considerably in front of your shoulders, or it’s just that really really really long torso.
Do we need to add anything to your x/y to compare with the Stack/Reach Database? http://www.slowtwitch.com/stackreach/ I guess that is to top of frame rather than pads?
e.g. I have a -8deg 90mm stem with 3t aerobars, 10mm spacers blah blah which is x,y away from head tube?
You have me at 602/470 vs. 565/505. That puts me on the wrong size bike, but not by much. I’ve ridden 470 before, and say your stack has a ‘safe’ range of +/- 20 mm, so you’d really want to prescribe a bike that hits between 580 and 620 – that would almost work. But not quite. And for this reason I still think you need a subjective assessment on how competitive this person expects to be.
you and LAI are in the same boat. you see those guys well below and to the right of those red squares?
that’s you. you and LAI. i’m not criticizing your positions. just, those red squares are male pros. what box should they be checking when asked how ardent their race ambitions?
your position is not orthodox. which is fine. be yourself, that’s what i always say. but i can’t “teach” you. i can’t recommend you. i have to output for the fat of the bell curve, not for the outlier.
now, in reality, in 5 years you may come back and say, “well, my position has evolved.” that’s what happened to mark allen, after he won the ironwar. that’s what’s going to happen to matt hanson if it hasn’t happened already. i can’t skew the results toward the outliers knowing full well that history is on the side of orthodoxy.
image is great. and thank you and it somewhat places me at ease. if we’re going to prescribe a bike using a static system like this with very minimal data input, what is really a bummer is getting the X axis wrong. it’s easier to change Y. you pedestal, or unpedestal. but X is hard to change on superbikes, especially if they don’t have a lot of fore/aft adjustability as many of them don’t.
in your case we nailed it on the Y but you had 30mm more X than our prediction and that was worrisome for the “system” devised. but looking at your position, it would be hard to prescribe this position. don’t get me wrong, it’s a good position. but you’re quite forward it looks like to me. more so than the typical rider.
now, i’d like it if we were a little closer to this position of yours. maybe only 15mm or 20mm back of your position. but if your position was dead on center of the tri bike riding public and we prescribed 30mm rearward of that, i’d be more concerned than i am.
but this feeds into another theme of mind that i’ll be publishing on within a few days, which is a worrisome trend among bike makers to shrink the fit window of their superbikes.
