So this is the year I pull the trigger on a tri-specific bike. The road bike won’t cut it for future IM’s.
I had a bike fit done (by a reputable fitter) and I was a bit skeptical at the suggested bikes recommended for me. While I felt comfortable and great on the trainer and don’t question the numbers, I feel like the bikes I would fit are the bikes in the showroom and not necessarily the bikes that actually fit best.
Below are my numbers. For those that know your geometries, please feel free to comment. I’ll leave the bikes/sizes I was recommended out of this initial post to get an unbiased opinion - will post later. Let me know your thoughts…
Stack: 541
Reach: 417
HX: 490
HY: 610
SX: 150
SY: 630
Saddle Height: 713
Nose to Bar: 490
Drop to Pad: 35
Setback from BB: -4
Armpad Width c-c: 290
Crank Length: 172.5
Pad Stack/Reach: 650/455
Not to be rude, but I would question that fit before asking about bikes because those numbers don’t add up. I doubt that position is very good, and no way you should be on 172.5mm cranks with that saddle height. The arm pad width…I didn’t know you could get arm pads that far apart! Don’t get me wrong, you can obtain that position on a few bikes (Small Trek Speed Concept with a High-Far stem, for instance), but I would really be reticent to do so until you know that position is sound.
Do you have pics or video of the fit session?
What saddle was used?
Is the pad stack measured to the back or middle of the arm pad?
Well basically there is usually only one way this works:
People come here and ask for fit advise and get told to get a proper bike fit done. You then go ahead and get that done, come here with your results and turns out people tell you your bike fit is crap. And then with the help of some more details and in the best of cases with some pictures and more data the forum will get you properly fitted and you’re all set.
I think it would save everyone a lot of money if we would skip right to the part where the forum does the fit.
In your case I don’t think the numbers look so bad with two exceptions:
a) Your fit has you sit very high in the front end. Very very unusually high. (read: too high) Unless you can think of any special reason it should be like this? (back injury etc…)
b) Its current trend to use smaller cranks. 172.5mm is pretty much what I’d get in a road bike, with a tri bike you can go right down to 165mm (as per current trend)
c) we can’t really judge the reach numbers without seeing the proportions of your body and knowing if thats measured to beginning of armpad or middle (thats about a 4cm difference)
If you want to do some looking around yourself here some ideas to check if you’re in the right ballpark:
https://custom.diamondback.com/…?__country=DE#step09
Step 9 of the Diamondback Config tool will allow you to enter a fit calculator that will output X/Y stack and reach coordinates based on your seat height or inseam and your body height. You can use these to compare to your bike fit results
nose of saddle to end of extensions (add 3-4cm when using ISM PN or 5-6cm for ISM pr) = roughly seat height from BB - usually this is useful if you know your seat height.
you can modify both 1) and 2) to suit you better if you know if you’re short or long legged (inseam/body height), as a shorter torso would sit a little bit further back while a longer torso… you get the idea
usually a saddle on a tri bike will sit in front of the bottom bracket to achieve the steep seat angle that triathletes prefer. In your case this is accounted for with the ISM saddle as those run shorter. This number seems to be in the right ballpark.
PS: I guess its somewhat safe to say already that unless something really unexpected is going to happen in the end you will need a size 51 or 54 bike depending on some more specifics of your fit and bike model specific geometry.
That arm pad stack and reach IS achievable on a number of 50-51cm bikes. You would need a basebar that allows the clip ons to move very wide, and the clip ons themselves would need a bunch of width adjustments, Profile Design clips and the right basebar can get you to 29cm center to center.
BUT, no way. I’m with Jim. Those numbers overall just don’t add up for a 5’9" 150 lb rider. 172.5mm crank is a big clue. I believe you tried 170 and didn’t notice a difference, but at 3.5cm of drop, you were not likely taken to the limit of your existing crank before you made a change. And 170 isn’t exactly what I would consider a change… just another crank length that is way too long. You needed to try stuff at 165, 160 and shorter.
29cm of armrest width, while achievable, is a width I’ve used exactly twice in 12 years. Both times for riders that were roughly 6 inches away from getting their elbows together in a basic mobility test. So maybe that is you, but I’m skeptical.
Listen, you probably got a bad fit from a “reputable fitter”. Happens all the time. Pictures would help. Wait, you didn’t get pictures from your fitter? No video? C’mon guy(s and gals), there are a ton of articles on this site detailing things like reasonable bike fit expectations, and orthodoxy. Please read that stuff first, instead of trying to fix a bad fit after the fact. I mean, how the heck do you not get photos?
interestingly enough I was recommended a 56cm Cervelo P-series or Felt IA.
in terms of injuries - i have none. however, i think i do have neck mobility issues that have been aggravated over the years using computers. i’m not the most flexible person in the world, but not awkwardly stiff. my inseam is 32inches, i’d say slightly longer legs than torso in comparison, which may show why the stack is pretty high in comparison to reach especially if consider a less aggressive/upright head/neck position.
to be honest, i was skeptical getting a bike fit in the first place for this exact reason. the fitter in question has all the certifications, accolades and even Fit Institute Slowtwitch Certified - for whatever that means. i’m probably more unsure about bike/fit before this all started. i ride a 54cm road bike - always have. fitter says 56cm frame, community says small/medium - I thought I would be fine on a 54cm Shiv, which seems to have the geometry (taller/shorter) frame size for my numbers - but also thinking my odd numbers won’t get me anywhere comfortable on any tri bike for long distances and nowhere near aero.
You’re 5’9" with a 71cm seat height and you were recommended a 56cm bike? I assume to achieve the tall stack. That pad reach is super short for a 56, you are super short for a 56, your neck mobility is probably not the reason for the high position, your cranks are without a doubt way too long, and I could go on.
You probably need to cut about 30-60mm out of the pad stack, 6-12cm out of the elbow width, and 10-20mm out of the crank. That’s your fit. It’s probably a good fit.
Or post some pics/video along with the fitters reasoning for an unorthodox position. Because it is an unorthodox position, and there needs to be a reason.
for what it’s worth, i took a look at my road bike (Giant Defy 54 cm/172.5 cranks), which I have adjusted over the past 2 years to my liking and comfortability. my seat height on the road bike is 86-87cm. I wouldn’t think there would be that huge of a difference between seat height on a road bike vs. tri bike.
I’m 5’9" too, but with a couple more centimeters for seat high (73-74) and got a Felt 56 that fits right. I have a long torso, so there is that.
I had the same question after a -probably- bad fit, but got me in the ballpark and after several questions and recommendations in the forum, I pulled the trigger for that bike. I was initially recommended a size 60! (gasp!)
If you input 5’9" in the Felt IA bike sizing chart, you get 48, 51, 53 and 56 sizes.
Here’s the link to the whole discussion along with videos of after/before.
i’ve read through the thread and have been comparing your guru fit to mine. what’s interesting is that although i may be ~0.5 inch taller, our coordinates are very different. your saddle height was longer even though your inseam was significantly smaller. i have nowhere near the reach you have, this i know, but my saddle height or pad stack now seems really out of line.
i was “recommended” a 56 Felt IA as well. but i have a hard time believing i can get in the ballpark on the reach side. not to mention, my saddle height would probably be bottomed out.
We are almost the same size–I’m a bit taller just under 5’ 10"-- I went from 175s this past spring to 165s. Never been happier & I’m “leggy” so you should be able to go shorter a bit more.
One thing that fitters do all the time: they run out of room on the bike.
Was this done on a fit bike or an existing bike on a trainer? I’m guessing the latter because you say trainer - but this can mean different things to different people.
Jim and Findingfreestyle are correct - your saddle height and that crank length won’t work. that is, unless your hip angle is open enough for it to work. My guess is it won’t be - crank length and saddle height go together but the function of crank length is opening the hips for peddling efficiency.
One thing I didn’t see mentioned is drop. You’ve got 3.5cm of drop? That makes no sense. I’m guessing that’s because the fitter couldn’t get your hips open enough with that crank length. The fit kinda reads like a road bike with aerobars on it and the fitter ran out of real estate on the front of the bike. But that’s just a guess.
Saddle height and setback look fine (setback with an ISM at your height will be between 3-6cm normally). And, yes that armpad width is way to wide but that could be a function of a bad measurement. Say, if the fitter measured the outside of the pads vs center to center.
I kinda wished I had tried 165mm cranks…not sure why it wasn’t suggested. i can follow-up on wear the measurement was taken on the pads. i don’t recall having any discussion on pad width and double guessing from the fitter so when it was pointed out, I was a bit surprised.
We have the same saddle height and I would suggest that if you are going back in, try the 155’s. You might not notice any power difference, but that is standard. And that is the point, you dont lose power, but you then get to ride in a better fitting position that is more aero…My initial jump from 175 was to 165, figured that was a lot. But then went to 155 and found the “right” crank length for my leg length and hip angles…
