MarioTB wrote:
Thanks for the response, here's my answers:
Saddle was an ISM Racing (they said it was the closer to the ISM Prologue I have).
Don't know about the 52mm drop...
B16 was the output. I know it is old, but that was the only 561x461 listed in it... it is in this link too
https://www.slowtwitch.com/stackreach/ If the saddle was too steep, what now? Should I repeat the fit?
Pad reach to the edge or center... again don't know... I will ask. Should be the center.
No side pictures... I thought I was going to get that too.
From what I can tell, your fitter made two major mistakes that make your recommendations nonsensical. The first one is that the fitter let the athlete take charge of the fit too much and let the saddle come way too far forward. The ISM Racing is a stub-nosed saddle and it has to be set up a couple of cm behind the bottom bracket. Going forward with that saddle to +6 mm in front of the bottom bracket is a saddle position that many bikes - such as those with a 78 degree neutral seatpost angle - can't support. The other consequence of going that far forward is that it's created a scenario where your armpads are so far forward that your bike options are unnecessarily limited.
This is a mistake I've made before. This is a mistake my fitters have made before. And it's a problem you can fix with some math (assuming the position is, otherwise, pretty good).
I think every good fitter using a fit bike has created a saddle position that's too steep - if not on a tri bike fit, then for sure on a road bike fit. So this is forgiveable (we have a competitor that uses a fit bike, provides ZERO fit coordinates, and writes down a list of bikes that supposedly fit on a post-it note and those bikes often have no geometric relation to each other and his customers have no idea how poor that process is or his fits are - so don't be too hard on your fitter because at least they put their fit coordinates out there to be scrutinized).
The second mistake is the fit photos aren't useful. There is
no excuse not to provide fit photos showing a side profile while in motion. That front-facing photo while you're in the middle of a conversation is useless and indicates the fit software was used sloppily. Without any fit photos, it's impossible to know whether your fit is actually any good. That 52 mm drop, while on the smaller side, might be absolutely appropriate. Without photos, it's impossible to tell.
Fit photos are more important, by far, than body geometry measurements (which you also don't have). I've seen a number of fits that have good body geometry measurements that, because the acceptable ranges are so big or marker placement was poor, was actually a terrible fit once the fit photos/video were analyzed.
Those two mistakes tell me that your fit is likely not all that great. Your fitter may be very good, but the fit is not for whatever reason.
Let's assume your position, outside of being too far forward, is otherwise pretty decent. You report a pad stack of 677 and a pad reach of 500. If that pad reach is to the middle of the pad, you can subtract 40-45 mm to get to the pad edge (which is a better measurement of position in my opinion). So now you're at 677 and 455.
The saddle needs to come back 25 mm and that brings the cockpit back another 25 mm, so you're at a pad reach of 430.
Since you pulled the saddle back 25 mm, you need to lower it a bit as well - let's say 5 mm - to maintain a similar saddle height. If the saddle drops 5 mm, the cockpit should drop the same, so now we have a 672 mm armpad stack and a 430 mm armpad reach.
Using our internal fit tool that measures to the armpad edge, I've attached the resulting report.
Understand, these recommendations are based on several major assumptions that may not be true: 1) your initial fit is good, just too far forward and 2) the changes I've made won't be destructive. Some of the bikes listed will support a steeper saddle position and a more forward armpad position, so you may very well find that you don't have to go as far back as I did in my math. I've also made sure the bike choices provide you the opportunity to lower the cockpit, as I suspect a 52 mm drop might not be as low as you can reasonably go.
Our fit report also includes bike photos and details of each bike, but I had to only provide the first page due to Slowtwitch only allowing attachments of 250kb or less.
All of this is intended as a thought exercise since I can't see whether your fit is of any quality, so please consider the recommendations list with a grain of salt.
Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
