chiggy

I am trying to buy a used bike on Ebay and have done a ton of research. But my fit numbers are so far off the norm that I don't feel comfortable pulling the trigger. I need to talk through it and see if i'm heading in the right direction.

I'm 6ft with a 34.5" inseam using the book method. Long legged w/long shins, short torso, but only average arm length. The result seems to be a worst case bike fit (Ideal runner proportions though!). My current bike is a 58cm trek 1.1 which is a compact endurance geometry same as madone. I don't like the fit or else i would just match it. Looking back the place I bought it really put zero effort into sizing it for me. Competitive cyclist spits out the following for the "competitive fit":
No bike exists that comes anywhere close to this top tube/seat tube combo!

Reach: I have a 90mm stem and 85mm bar. Saddle to bars is currently 52cm which is below recommended, and I still feel a bit too stretched out when on the hoods! This may be due to bar reach and setup. I think i can angle the bars down, and move the hoods up the bar to reduce reach quite a bit, but haven't tried it. Currently the top of the bar is parallel to ground with the drops pointing more down (traditional bars). Anyway, real life feel on my bike supports the short top tube recommendation.

Stack / drop to bars: I currently have no spacers under my stem and can ride in the drops for half of a 2.5 hour ride with no issues. (Granted my bike's geometry is fairly relaxed.) I'm hoping i'll be ok on a smaller and more aggressive bike, but use more spacers. I could reduce stack by about 4-5cm, then raise stem by 2-3cm with spacers, for a net of 2cm below current setup. I have medium to poor flexibility from a desk job, so i'm a little concerned here.

Saddle Height: Calculated is 80.9cm by CompCyclist and 77.4cm using 0.883xinseam. Those are way different.... Then, using the heel on pedal + minor adjustments I am settled at 75.6cm which doesnt agree with either. It feels pretty good and powerful while riding though. One thing that has me concerned is compact geometry such as Specialized, since the short BB to top seat tube may mean too much seat post exposed on a smaller frame for my height. My lower preferred saddle height surely mitigates this concern somewhat, but I just don't know how much. This is something easily tested in person but I don't have that option.

Option 1, 56cm endurance geometries have the shorter reach I need and can get low enough for my tastes. However all of them seem to be compact frames and have a short seat tube. Which gets me back to my concern about having miles of seat post exposed.
Option 2, 54cm with a traditional geometry is easy to get my reach and seat tube numbers, but i'm slightly concerned about it being too aggressive. This is the direction i am leaning right now.
Option 3, quit biking and go back to running.

If you made it this far in my post I hope your head isn't spinning too much. I know mine is. Any sort of advice welcome.

P.S. I know the recommendation will be "get a bike fit and try them in person." However my current location and circumstance makes that difficult, even for craigslist. Ebay is my best option. So please humor me.

ksryder

My opinion (remember, advice is worth what you pay for it LOL): I'm 5'11 with a 33" inseam and I rode a 54 for a few years (based on a similar online calculator) and I always felt cramped and twitchy on it. Been riding a 56 for several years now, usually with a 90mm stem, and fits like a glove.

IMO, the most important measurements in that calculator are top tube and stem. I'm skeptical that a 54 top tube is going to be enough, regardless of how short your torso is. Part of the problem with a 54 is that you'll have about a mile of seat tube sticking out, especially with your long legs.

Personally I'd try a 56 with a 90mm stem first.


I'd rather eat glass.

CliffordK

You might try Craigslist. Find a bike that is close, try it out, see how you like it. Then if you want something different, toss it back up on Craigslist.

Then, once you're satisfied with the fit, go track down your dream bike.

If you do go for a 54 with a 1 1/8 steer tube, the you'd be much better off with an uncut steerer... which may be harder to locate used. If you go with a short steer tube, then you'll need a riser stem which works, but is less than optimal.

In theory the women's bikes (WSD, Dolce, Lexa, Ruby, Amira, Contessa, etc) are supposed to be designed for long legs and a short torso, but at least some of them aren't that different from men's bikes with different paint. Nonetheless, that would be an avenue to pursue.

Phamilton

I'm the same height as you with only a 1cm inseam difference (34 1/8"), and I consider myself short-legged and long-torso'd. I have a 57cm frame that I ride with a 130mm stem (should go 120) that works for sporty riding, and a 63cm frame 85mm stem that is more upright and I use for commuting and foul weather. I don't think your body proportions are that far off from the norm. IIRC Competitive Cyclist numbers ended up being just about spot on for how I comfortably ride that 57cm frame. I had some flexibility, core strength, and saddle setback issues to address before it worked (still working on first two).

Have you compared actual stack and reach calculations/dimensions of your current ride vs. prospective new ride?

Is the shorter reach you are looking for necessary because of low flexibility? Or will a longer reach help you achieve better flexibility, strength, and performance?

I'm not an experienced cyclist, just a long distance commuter who's had a lot of fit drama.

Colnago Mixte

I don't claim to understand the science used to achieve proper fit, and all the various theories and assumptions, all I know is that riding a frame that's too small is not a curse I would wish on anyone.

And most of the people fitting bikes seem stuck on putting people on frames that are too small. I have never understood that.

These days I like riding frames in sizes so big a bike fitter would faint, 3-4 cm bigger than most of them would recommend. Large frames seem more stable and comfortable, though maybe not if a lot of climbing or sprinting are involved. But for steady, mostly flatland riding they're my pick, FWIW.

Phamilton

Yeah, my 63cm frame is comfortable, but riding out of the saddle is just about pointless and the drop bars are pretty much ceremonial.
When I compared stack, reach, and geometry of my 57cm frame (mid-80's Raleigh road bike, 27" tires, straight top tube, etc), to what's on the market now with similar numbers, it basically describes a modern 56cm cyclocross/gravel bike with a higher standover. The 57cm is the top tube length, but nominally it was sold as a 23" frame (58cm, by seat tube length).

The nice thing about stack and reach is that it takes all the tube lengths and angles and bottom bracket drops and stuff out of the fit equation and turns them into handling characteristics. Buy the frame with the right stack so the bar height is where you want it, then adjust reach with the stem. I could be preaching to the choir on this, but it's a recently gained understanding of mine and was very revealing about my bikes and fit experience - the more I measured, the more it made sense.

When I was test riding new bikes (that I never bought by the way), I usually felt more comfortable on a 56 than a 58. I thought this was because of the reach, but in my case it was counterintuitive as I later learned there was only 3-4mm in reach and closer to 25mm in stack difference between the two frames. I suspected I'd have been comfortable on a 56 with longer stem, and here I am later riding a 57 with 130 stem comfortably.

Standard or straight top tube vs compact geometry muddies the waters considerably when comparing different frame sizes. I don't know if that's part of this situation or not, but it sure was part of mine.

Colnago Mixte

I find it interesting that Lance Armstrong, at 5'11", rode a 58 cm frame to many Tour victories. He also used a long stem too, maybe a 130 mm? It seems that some people can really stretch out on a big frame, almost like an octopus, while others can't, or it simply doesn't suit their riding style or body proportions.

chiggy

I've never seen real statistics on proportions. From scouring forums and just everyday life I gathered i was more leggy than average, though not by a crazy amount. I'm very slender, so maybe it just appears that way. Who knows really. Regardless, it's interesting that you prefer much larger frames while I feel stretched (on a short reach endurance frame with a short stem no less). Maybe it's an arm length thing.

Anyway, yes I'm basing all decisions on stack and reach. My 58cm Trek is 598mm stack and 391mm reach + 90mm stem + 85mm bars. Fairly upright even though I have the stem all the way down. If I want to get a lower position i will have to go to a smaller frame.

Like you i'm surprised that most of the difference between sizes of the same bike is in the stack, about 15-20mm per size, while reach only changes by 5-8mm or so. I have geometry notes on about 20 bikes and it holds true for nearly all of them regardless of endurance or racy geometry. So, running a 90mm stem I could go down two sizes on nearly any bike and still easily achieve my current reach with a longer stem. The question is the stack since there is greater variation there, although i'll have a little wiggle room to come up with spacers.

Phamilton

If I gave the impression I prefer larger frames, it was unintentional. Stack and reach of that 57cm Raleigh are 569/387. I've had the Raleigh for about 5 years. I just got the 63cm (S/R 622/404) frame a month ago. I like them both. For longer rides, the smaller frame wins. Even with 100mm stems on both bikes, I FEEL more stretched out on the Raleigh, which in my case is the desired effect, although for me the 130 is just a little long and inspires a pace and riding style I don't intend to use while commuting, so I think a 110 or 120 would be decent. If there's conventional knowledge regarding the "feel" of reach in relation to stack, I'm ignorant of it. Before I started to get saddle setback dialed in and consistent from bike to bike, I wasn't comfortable on anything.

Clem von Jones

54cm frame for someone 6ft tall is spot on from my POV. I prefer shorter top tubes with longer stems and plenty of bar drop. You might need a longer seatpost, no problem.

>I find it interesting that Lance Armstrong, at 5'11", rode a 58 cm frame to many Tour victories. He also used a long stem too, maybe a 130 mm? It seems that some people can really stretch out on a big frame, almost like an octopus, while others can't, or it simply doesn't suit their riding style or body proportions.

He looks kinda bunched up on his bike though, maybe it's because of his odd hunch-backed posture. His knees also look extremely close to his elbows. I'm sceptical that successful pros give out accurate descriptions of their setups, because wouldn't that be a tactical mistake? They bluff it and their sponsors help them do so IMO.

One sure-fire way to compare setups is to create overlay transparencies of different pro bikes in a digital photo editing program, matching the circumference of the tires (if they use identical tires)

Phamilton

Aren't there sometimes significant differences in stack between different 54cm frames, though?

Clem von Jones

Yeah that's true but with smallish frames even a higher head tube can be manageable with negative rise stems. The thing you gotta watch is the fork length because that varies a lot between different bikes that have different tire clearances, and sometimes manufacturers don't list their fork lengths.

surak

The difference in feeling comes down to how upright your position is. I'm guessing OP sits pretty upright with arms nearly fully extended when riding, which is the opposite of what a "competitive fit" calculation would be suitable for.

I have average limb proportions at 5'9" and feel cramped on my 54cm bike with neutral geometry (1.5 stack:reach ratio). I'd slammed my stem, but then raised it a while back because I thought I might need to be a little more upright for my first century. After that event happens this weekend, I'm going to slam it again and try something longer than the 100mm stem it came with. Right now I have my seat all the way back, but I'd rather raise it and move forward to ride with a flatter back.

Phamilton

surak

It's called the Competitive Fit because it's our signature fit. We've found that this is the look and the feel that most of our customers expect out of their new bike. This is the most "aggressive" fit and suits those with an interest in racing, fast club riding, as well as those with a greater measure of body flexibility to work within the racer's comfort zones. Most modern road bikes, like the majority we offer at Competitive Cyclist, are usually pictured in sales catalogues with the Competitive Fit. But this doesn't mean that you should ride a bike that looks or fits like this.Wanna look like a pro? This is the fit. It features a low, aerodynamic bar position that places slightly more weight on the hands than on the pedals and saddle, a close knee to pedal spindle ratio that emphasizes power and efficiency, and it puts the rider low in the handlebar drops. Typically the frame chosen will be the smallest that is appropriate. In fact, since the heyday of mountain bikes in the 1990s and more recent studies of professionals looking for an aerodynamic advantage, the Competitive Fit has become most bike shop's conventional wisdom.After all, who doesn't want to look and ride like a pro? This fit is easy to sell but may not work for you since it actually best suits those who are willing to accept its clear emphasis on speed over comfort. For most of us, the pure Competitive Fit is too extreme even if it is still viable for young riders and racers, for those who love shorter, faster rides, and for those who just find this comfortable. Expect to be rather low even on the tops of the bars where you will spend the majority of your cruising time on the brake hoods, expect too to be lifting your neck slightly to see ahead of you with a rather "short and deep" reach into the bars as you push back on the saddle to stretch out.The Competitive Fit creates a more compact body position with the chest low and the back as flat as is necessary to get down into the drops. The saddle to handlebar drop is sometimes as much 10cm or more.

Phamilton

chiggy

My current position is very medium, I think. About a 5cm saddle/bar drop. I am out of spacers but could go lower if i flipped the stem. Most of my riding is only about 1hr, 2hrs on the weekend. My longest ride was 2:48 in a 100k local tour "race" at a very hard effort which I finished without any pain (minus a massive hamstring cramp). So really there is nothing wrong with my current setup, I just don't have that much room to "grow" as I get used biking. My flexibility is average to poor currently. I can touch my toes fine, but my hips are tight from a desk job.

The Eddy fit results in the same TT length, and French fit goes up to ~55.5cm. What's frustrating about that fit calculator is they don't provide the saddle-bar drop (or stack/reach).

chiggy

Used bike I'm looking at vs my current bike *and notes on how to get back to my current fit. Both are marketed as an "endurance geometry".

Prospective Bike : Current Bike
Stack: 565 : 598 *go up 3 spacers, from bottom to top of steerer tubeBB to top seat tube: 540 : 553 * +1.3cm seat tube exposed. I compared to a 58cm Spec Roubiax which is also 540mm
Seat tube angle: 74 : 73 *new bike has more of a setback on seat tube
Head tube angle: 73 : 73.8

Make sense?

McMitchell

surak

Century went great, I still felt like I could use more reach since it was decently windy and I wanted to get low. Some folks were riding in the phantom aero position with their forearms on the tops. I kept low and spent the majority of the time elbows bent as close to 90 degrees and hands on the hoods when in the wind. I know when I do that with my current setup that my back is arched and could be flatter. I suspect a longer reach would also have helped distribute my weight better off my hands.

When getting a massage at the finish line, the masseuse mentioned that everyone who rode the shorter distances (25/50 mi) asked for leg massages while everyone finishing the century were asking for neck and shoulder, due to the more aggressive positioning we took to stay aero. Slower and shorter distance riders may still have a large saddle to bar drop, but they aren't bending their torsos forward, so their effective reach is less for the same body dimensions.

Phamilton

Congrats on the century.

My longest ride was 65 miles. Only thing that hurt was my butt. What changes between 65 and 100 miles?

I don't follow the line of logic from what the masseuse told you anecdotally to the conclusion that riders with less effective reach are not able to finish centuries. This is how it reads to me. I may be missing something, I usually am. Do you feel like you would not have been able to finish the century had you not been as aero as you were? Was this century ride also a race? I'm asking out of sheer ignorance. I've never even done a group ride. Was the riding all in the same direction or laps on a course? What was the wind like?

surak

Thanks, this was technically the second time I've ever ridden 100+ miles. My longest ride before I started preparing for the century was 40 miles in a day, and I learned a lot about what my body can handle pacing and nutrition-wise by gradually doing longer distances in the past few months. Also, I learned to buy better bibs.

What changed for me on 100 miles in a group ride compared to a solo ride I did 2 weeks prior was speed -- I was going harder and faster on the supported ride because I knew there were plenty of rest stops. That meant I was pushing more weight through the pedals, and less weight overall being supported by the saddle. I started off but decided not to try hanging with the fast lead group because I haven't done much group riding and didn't want to overdo it, but I did occasionally ride with other, smaller, and slower groups later. Still did most of it by myself because there were a lot of little uphill sections that scattered everyone.

This ride was a single lap, some on trails but mostly on the road, with everyone going in the same direction for the same ride length -- the 25- and 50-mile routes were shorter and easier. Wind was consistent at about 15-20mph and for most of the ride mostly a headwind. To conserve energy and go fast, the century riders naturally want to cheat the wind as much as possible, even if it means going into a lower and slightly more uncomfortable position. That's less of a concern at shorter lengths because the toll the aerodynamic drag takes is both less at slower speeds and of course shorter durations, so people were not riding long enough such that they felt as badly in their neck and shoulders. I suspect there's also a large discrepancy in fitness for many riders choosing the shorter lengths. I would think for most cyclists, the pain evolves first from the legs, to the butt and hands at longer durations, finally to the neck as speed and distance leads to more aggressive posture. I wasn't saying that people who don't ride lower can't finish centuries, just that there is a larger benefit to getting long and low at longer distances to cut down the aero drag, which is why geometries of race bikes are what they are.

bruce19

I've always used Greg LeMond and Cyrille Guimard's formula. I have a 32.5" inseam and ride 54-56 very well. My current road bike is a 55 w/55 TT. Doing the math on your inseam I come up with a 58-59 frame. (FWIW the formula is .665 of inseam in cm).

fietsbob

Big top tube slope,? like the seat a lot higher than the bars?

Young and flexible..?? not me.. "french fit " short seatpost extensions

except on a sloping top tube frame..

chiggy

Well, that's the thing about those one variable formulas. If the variables are X, Y and Z, it is evaluating just X, and assumes Y and Z correlate with X based on averages. Unfortunately not that many people are average. There seems to be too much variation in human proportions to make that assumption for this purpose. For example, someone with a 32.5" inseam could very reasonably be 5'10" tall. Meanwhile, I have a 34.5" inseam and am 6'0 tall. ALL of the height difference is in the legs and torso length could be identical. Then, with longer than average legs you'd assume longer than average arms, but no, I have average arms. So in this case I could need the same reach as the 5'10 guy but a roughly 2" higher saddle height and 2" higher stack to achieve the same fit.

That's why the competitive cyclist calculator is popular, it seems to take a lot of variables into account. I'd be very interested to see the calculation going on behind the scenes. There's a quirk with the top tube results that suggests it could use some tweaks. In fact that is the reason I started this thread.

The site says, "The Eddy Fit typically features a saddle/bar drop of only a few centimeters." However, when my Eddy Fit results are actually plotted out (using AutoCAD for ease and accuracy), it resulted in a 16+cm saddle to bar drop. To fix that error and achieve the prescribed Eddy Fit with "a few cm" drop you would bring the head tube straight up, making the top tube longer than is prescribed due to seat tube angle. Long story short i think the saddle-bar reach and saddle position results are sort-of accurate, but the top tube result is useless. I thought about making a separate thread with the details. Since that is the calculator I figured there might be interest in a pretty glaring flaw. But that would take some time.