Pinkbike Poll: What's Your Ape Index?

Jun 18, 2021
by Seb Stott  
Illustration by Taj Mihelich

I've seen a lot of comments in articles about geometry, bar width and bar height referring to ape index. This is the ratio of your armspan to height, which is typically around one:one. Leonardo da Vinci's Vetruvian man famously depicts an "ideal" human body having the same armspan and height.

Ape Index is often discussed in other sports such as rock climbing and boxing, where longer arms are usually considered an advantage. It's relevant to mountain biking too because - for example - if you have a particularly high ape index (meaning long arms for your height), you may prefer a longer reach, lower bar height and wider handlebar than a rider of the same height with smaller arms, or visa-versa.

Ape index is sometimes described in absolute terms, as in armspan minus height. But this isn't ideal because people often don't specify whether they're working in centimetres or inches, and because having an armspan 5cm greater than height is a bigger deal for a short person than a taller person because it's a bigger percentage difference.

So for this poll, measure your ape index as a ratio, by dividing your armspan (from the tip of one middle finger to the other at full stretch) by your height. You can use centimetres or inches, as long as it's the same for both measurements. You don't lose points for using a calculator.

Obviously there's existing data on average values for ape index, but I'm keen to see what the range of ape indices are among mountain bikers.

The data will feed directly into designs for the Grim Doughnut 3.0.

What's your ape index as a ratio of armspan divided by height?

If you don't have time to measure and just want to see the results, click on the option at the bottom.




191 Comments

  • 136 4
 The rock climbers among us didn't need to measure, we've already memorized it.
  • 296 3
 7 inches.... Wait.. Hold on... What are we measuring again?
  • 138 0
 @bigtim: ...3 inches...guess I'd be pretty safe in that Race Face edit

It's cold out, OK? DON'T JUDGE ME!
  • 38 1
 @jlevandoski: Hate to break it to you man but it’s the middle of summer.
  • 150 1
 I always thought ape index was the percentage of ones back that's covered in hair.
  • 37 0
 @bigtim: username checks out
  • 3 0
 @bigtim: Generous
  • 2 0
 @bigtim: chimpanzee
  • 6 0
 @bigtim: Damn big tim really is big
  • 6 0
 @bigtim: Ape indix?
  • 2 1
 @bigtim: name checks out
  • 4 1
 @jlevandoski: "I just got back from the pool, and the water was cold!" Name that show...
  • 2 0
 A lot os sports use that, for example Based on main lifts:

Deadlift person will be above 1
Squat person below 1
  • 2 0
 @bigtim: so that's 5 then.
  • 1 0
 @bigtim: post/handle
  • 2 0
 @bmar: Seinfeld
  • 3 0
 @jlevandoski: grower, not a show-er!
  • 3 0
 @dcaf: phenomenal cosmic power, itty bitty living space!
  • 17 1
 @bigtim: I am 6' 10".


those are two seperate measurments
  • 2 0
 @kcy4130: yes and it does alter aerodynamics
  • 2 0
 @bmar: Seinfeld for the younger generation
  • 2 0
 @bmar: Seinfeld
  • 2 0
 @bmar: Seinfeld
  • 3 0
 @bmar:
"The sea was angry that day my friend....like an old man trying to return soup at a deli"
  • 112 4
 Humans are in the ape branch of species classification, so I contend that every single human has an ape index of "yes"

You apes are of course open to disagree, but you'd be wrong you damn dirty apes.
  • 35 0
 Oooh oohh aahh aahh *throws poop at you*
  • 4 0
 Vanilla Gorilla
  • 1 0
 Goddamn dirdy yapes!!
  • 15 0
 ♫♪♩ I hate every ape I see.

From chimpan-a to chimpan-z,

No, you'll never make a monkey out of me.

Oh, my God, I was wrong,
It was Earth all along.

You finally made a monkey... ♫♪♩
  • 6 0
 @everythingsucks: Doctor Zaius Doctor Zaius, Doctor Zaius...
  • 2 0
 @everythingsucks: Can I play the piano anymore?
  • 1 0
 @suspended-flesh: good band
  • 1 0
 @T4THH: HUH - hadn't heard them before - not my thing, but OK. I'm more of a Gorilla Biscuits fan.
  • 73 0
 another metric we should be exploring is torso height proportionate to total height. I have a body like salamander so have to ride larger frames with a low saddle height. It'd be good to understand leg length vs torso height so you know if you need a larger frame or just a longer seat post.
  • 30 0
 Long torso gang. Digging the longer lower bikes. No more choosing between risking the berries or feeling cramped.
  • 1 11
flag makripper (Jun 18, 2021 at 12:47) (Below Threshold)
 This isn't a new idea. It's been around for decades....
  • 21 2
 Yes! The Canyon online size calculator’s response to my inseam to height ratio: you must have put your numbers in wrong…
  • 12 0
 @makripper: has there been a poll like the one above? I'm not claiming I'm breaking ground on any ideas I just think it'd be neat to see the data. chill nancy.
  • 5 0
 I'm in the opposite ditch with a perfect 50/50 ratio between inseam and total hight (92/184 cm). Finding bikes that has enough stack height/headtube length/steerer tube length to not give me a ridiculous saddle to bar drop is a challenge...
  • 11 0
 And another variant, I have a short torso, with long arms and long legs. So I need a fairly long reach, tall seat tube and a tall front end.
  • 15 0
 @spudrovision: I too have been personally attacked by the Canyon online calculator. #corgibrotherhood
  • 6 0
 **googles "Body like a salamander" *** Ahhhh!
  • 7 0
 @Nygaard: Why are bike companies scared of long head tubes?
  • 5 0
 i have long arms long legs and no torso
  • 13 0
 @makripper: The problem is that many bike companies calculate it completely wrong, exactly the opposite of how they should.

Especially on road bikes they often say you should get a certain frame size based on your inseam. While actually the size of your inseam is not important at all on a bike: Who cares if your seat post sticks out 10 or 20cms, your position on your bike will stay exactly the same.

But your torso length is super important: If you have a short torso for example, you should also have a shorter frame because you can't change the top tube length and changing the stem length will noticeably effect the handling of the bike.

It should be all about the torso and arm length, inseam is the least important measure of all.
  • 4 0
 @murphenzo: but long arms, legs and short torso comes in handy when scratching our gonads. You see these people that are all body with itty bitty limbs and wonder if they have to place their asswipe on the ground and skootch across it like a dog with and itchy butt.
  • 1 0
 @Mattin: ahh, no. See murphenzo above. Inseam just as important as torso and arm length. Arm and leg length correlated.
  • 1 1
 @TotalAmateur: no lmao but sizing for ape index, torso length and leg length isn't new.
  • 1 1
 @Mattin: it's not a bike company calculation..it's a personal one to know what dimensions work best for your build.
  • 3 0
 @Doogster: because they are not aesthetically pleasing. Short head tubes look good.
  • 2 0
 Another long torso/short legs here. Nice to finally have bikes that fit properly now due to new school geometry - especially at 5'9" where there's traditionally seemed to be an assumption that we're almost identikit proportioned at this height range.
  • 5 0
 This is called the #GumbyIndex
  • 3 0
 @stubs179: A tower of spacers below the stem looks even worse - not to mention the unfortunate effect a short headtube has on the bearings.
  • 1 0
 @stubs179: until it is set up to actually ride and there are a stack of spacers or bars with goofy rise.
  • 1 0
 @Nygaard: I was just mentioning why, not that I agree with it.
  • 2 0
 @Doogster: but it sure looks good in the bike shop or test photos. At least with taller bars you don’t lose reach.
  • 1 0
 @stubs179: Acurate.
  • 1 0
 I have short inseam, long torso but positive ape-index and ride what are defined by marketing-gangs like oh-so-short frames for my size... At 1m88 I ride P2 Privateer 161, and medium '21 Ragley Mmmbop, where I'd ride P3 or even P4 161, and of course a Large Ragley if I'd follow their size guides.
  • 2 0
 @makripper: wait hold the phone, are you telling me that the length of our arms, torso, and legs has been around since before we started talking about it in this thread?? I call bullshit, torso length and arm length is a brand new concept that I invented in this thread.



in case you can't catch the sarcasm, nobody is arguing that these measurements are new. once again, I'm just saying it would be nice to see some aggregate data of riders. Chill, Nancy.
  • 1 0
 @TotalAmateur: call bullshit all you want
I've been sizing bikes like this for decades. Not sure why it's hard to believe. Sorry you are triggered by having a not new idea. Who's Nancy?
Maybe do more research before commenting, being wrong then pretending to be sarcastic?
Try and breath, step away from the computer and think about other things like the ocean or a forest full of naked guys
  • 1 0
 @makripper: lol how am I being wrong for suggesting we should have a particular survey on this site? You were the one trying to correct a claim I never made, like I'm taking claim for inventing a measurement. Are you really so thick you still don't understand my original point, nor my retort? Nancy is someone who gets salty bc she misunderstands something, in this case, you.
  • 1 0
 @makripper: "i've been sizing bikes like this for decades. Not sure why it's hard to believe"
First, you clearly missed the sarcasm. Nobody thinks this is a new measurement, nor is it unbelievable. I just want to see aggregated data representative of the users on this site.
Second, no shit it's a legit measurement. Literally nobody in this thread has said it isn't.
Third, although I've said it like 5 times and is the first point in this comment, I AM NOT ACTUALLY SAYING ITS A NEW IDEA.
Just take your L and move on already.

Nancy.
  • 1 1
 @TotalAmateur: not sure what you mean by Nancy? Do you have mommy/daddy issues? I don't judge. I'm here for you in your trying time. Heres an egg. It's ok to be wrong sometimes guy. Don't be too hard on yourself. Hugs
  • 2 1
 @makripper: lol ah the old "I've made an ass out of myself but I'm going to insist I didn't". Took a page right out of old Bidens playbook.
  • 1 1
 @TotalAmateur: who's lolah? Yeah it's hard to hear when you make am ass out of yourself. Good to hear you are owning it. I'm proud of you sunshine. Hugs!
  • 1 0
 @makripper: can't read or write, you're right, you are making 'am' ass out of yourself XD
  • 1 0
 @TotalAmateur: your puncution is complete shit. Read your last post. I was trying to write so you can understand it
  • 1 0
 @TotalAmateur: we should hang out sometime. You seem like a very interesting person.
  • 1 0
 @makripper: 'puncution' lmfao, keep trying, I'm laughing my ass off.
  • 1 0
 @makripper: seems as long as you only use two words you can avoid spelling/grammar errors. lmfao
  • 2 0
 I concur. I have an ape index of 1.03 and stand just under 6'2" but I have a relatively long torso despite having a large wing span. I prefer bars around 760mm with more rise and backsweep than the norm and I ride an extra large frame (I'm right at the ragged edge of large vs. extra large frame sizing).
  • 1 0
 @mior: Are you human?
  • 1 0
 @Nygaard: I agree. Get a bar with a significant rise rather than having a large stack of steerer tube spacers.
  • 48 1
 The look my wife just gave me when I tried to explain why I was measuring my arms was priceless...
  • 27 0
 Same. I got the old, "So you mean to tell me that while I am folding laundry, you're on Pinkbike...?"
  • 3 0
 So, she reached over and clicked "just show me the data" for you
  • 37 0
 A bit challenging to measure armspan alone… If someone could give me a hand…
  • 90 0
 Username checks out
  • 3 0
 @pnwshreddin: haha comment of day mate Smile
  • 7 0
 Choose an easy reference point on a wall to place one hand, such as a doorway. Stand facing the wall and flat against the wall with one hand touching your reference spot, and stretch out your other hand. Hold that new spot with your finger and grab a tape measure with your other hand. Measure back to your reference spot
  • 10 0
 Reminds me of Neil from The Young Ones because he tried to crucify himself but "...there's no way you can hammer in that last nail".
  • 1 0
 @pnwshreddin: he doesnt need a hand he needs a leg
  • 30 0
 Hahaha I love that the "Can't be bothered" option is over double the rest of the options combined. Perfect.
  • 2 0
 Worldwide shortage of tape measures
  • 2 0
 Apparently most of Pinkbike commenters are lazy as f%&^ if they can't be bothered to gather two simple measurements
  • 21 0
 I have a negative ape index and I blame it for all my short comings.
  • 6 0
 I have a positive one and do the same as you
  • 16 0
 Defer to the T-rex index?
  • 10 0
 Also, I don't think the ape index is as appropriate as arm length. Since body width affects the total ape measurement. You could have identical ape index but have arms 6 inches shorter than the next guy because you have really broad shoulders.
  • 7 1
 Sure, but in this scenario, the guy with very broad shoulders is still starting his reach to the bar from a fairly wide point. It would take a scenario of radically broad shoulders, with radically short arms for this to become important - and that is an absolute rarity/edge case.

"Ape Index" is probably a good, 2nd order measurement given that typical shoulder width accounts for a much smaller proportion of total armspan than arm length. Therefore, any natural deviation from "norm" in shoulder width is more likely to be less substantial to the total than in simply accounting for total armspan and "ape index".
  • 1 2
 @KJP1230:But by that argument they should just use a 1 - 1 ratio as the typical is 1 to 1.
  • 1 0
 @fabwizard: As we can see from the data, 1:1 is not actually typical. Additionally, the goal here is to arrive at how Ape Index maps to bar width/height preferences. Maybe it doesn't, maybe it does. Can't know until an analysis is performed.

For me personally, I am both tall-ish (6'2") and have a positive ape index of 1.043. I also have a tendency to prefer 780-800mm bar width, depending on reach (and other variables). As an N=1, there seems to be some correlation between my proportions and my preferences.
  • 2 0
 @KJP1230: I should have used the word average.

Your extra info shows that the ape ratio misses a ton of info required to make a good bike fit.

You may be 6ft 2 but how are the rest of your proportions. Do you have short legs long body and wide shoulders. Or short body and narrow shoulders with long arms



Bikes are mass produced to hit averages not outliers.

Also how accurate were the above reported ape index measurements.
  • 1 0
 But an article with "What's your Ape index?" in the title sounds far more interesting than one with "What's your arm length?"
  • 9 0
 Based on the data so far, we're building a very smooth bell curve with the 50th percentile at about 1.03 (if you discount all the people who didn't measure and went straight for the 1.0). Pretty neat.

As someone who did the measurement and came in at 1.043, I'm stoked to be "ahead of the curve" Smile
  • 4 0
 Except if you heading towards the "ideal," you're behind the curve....
  • 1 0
 I'd say we have a pretty good representative sample here
  • 10 0
 I've always wondered how hand size impacts this. If you have really long fingers, your ape index might suggest you should have lower handlebars, but really your arms might be 'normal' length.
  • 2 0
 lmfao
  • 3 0
 It's a really good point. They do wingspan like that in mma too, and unless you're using your fingers to eye gouge, it's an odd metric to go by. Centre of palm makes more sense.
  • 18 9
 My Dick Pound index is 6.9.
  • 14 0
 Let’s stick to inches, please.
  • 2 0
 If I were a scientist, I would definitely name a discovery after Dick Pound! Unfortunately, I spend my time on PB...
  • 10 0
 MONKE
  • 2 0
 Reject humanity, return to monke
  • 10 1
 0.907 i guess im more evolved or something
  • 30 1
 Allrighty then Mr. T-Rex. Unfortunately the cookie jar is on the top shelf though.
  • 13 0
 When I think of highly evolved it’s always the Irish that come to mind.
  • 2 0
 @Nygaard: If I could award comment gold, you'd get mineSmile
  • 7 0
 I suspect the normal distribution has been disrupted by liars claiming to be perfect 1:1 Vitruvian specimens. Those are the true apes among us.
  • 6 0
 I kinda feel like turning on the TV gives you a good idea of our ape index as well
  • 4 1
 6'1", 37 inseam, 76" reach. Yeah, I've got a foot of seat post sticking out of my frame and have broken my seat post more than once. Don't tell me that inseam doesn't matter. I feel like most mountain bike frames are made for people with short legs even in large/extra large sizes.
  • 4 2
 This made me laugh so hard, that the poll shows 135 times the lowest option, others are at max. 16 times with 235 responses at the moment.
My guess is, that all those who know it, are climbers aswell (probably around 80-90% of them) or live with their partner/family. All the others probably are just the cliché pinkbike keyboard warriors that live alone since all they leave their room for is the weekly trail ride and run to the store...

(Not excluding me from the general overall picture though...)
  • 2 0
 Not just climbers, also used for sizing bows. That is the only reason that I know. At 1.1 my wife refers to me as her Gibbon.
  • 2 0
 @MasCam: haha, nice name!
Didn't know that bow size depends also on ape index... At least learnt one thing today :-P
  • 2 0
 Being someone who does kickboxing I got very curious while reading this text, as arm length creates a huge benefit or drawback in that sport. I noticed I have a 1.07 ape ratio, which explains why I like having my bars that low. It also explains why sweaters that fit correctly onto my torso often still have too short arm sleeves.
  • 2 0
 @Phipu
It's a mystery to me what you were trying to communicate in that post.
  • 1 0
 @MasCam: 1.1 is nba territory!! My wife calls me monkey arms at a 1.048.
  • 2 0
 @meathooker: 1.1 is nba territory so long as you're over 6'6"
  • 2 0
 If you really want to future proof the G.D. the next thing must be the Q-factor. I trully believe that feet should be placed at hip bones level or wider. Is a pretty nonsense ride with plus 800cm handlebars and the same Q-factor as many many years before (loto feets syndrom?)
  • 4 0
 You should get a data set of torso/leg as well. Not everyone who rides a size L has long beautiful legs like Levy...
  • 3 0
 Two conclusions so far: As expected, there's a bunch of apes on PB, and also a bunch of people who think they're "perfect" with 1:1 ratio when in fact that isn't true.
  • 1 0
 1.05 index, 1.93m tall with 90cm inseam.
Generally, bikes are too short / low for me, especially in seat tube length, stack and rear centre.

Reach is ok only because brands have been harping on about it for ages at the expense of most other geo points.
  • 1 0
 I'm 182cm tall with a 195cm span. My current bike is a custom geo Starling Twist with 515mm reach and 440mm seat tube, so XL reach with L seat tube. I love it! If I bought a bike based off manufacturers recommendations it would feel like a kids bike and I'd hang off the back like Magilla Gorilla. The long reach movement is golden for me.
  • 1 0
 I've just used a calculator this week that said my legs were too short and my arms were too long however the calculator used wrist to shoulder length. This calculator, I come up close to "normal range" as I have small hands and short fingers.
I wonder if a longer upper with too much top tube is making it harder to manual etc and perhaps a higher stack and bar width is the better way to go.
  • 1 0
 1.057 here. Collar bones both badly snapped and shorter so really it would be longer. From memory from the State sporting academy measurement results I have lost 30mm before becoming broken was 1.075. 174cm tall ride a 485 reach bike very happily. Only reason I run a 35mm stem is the bike is more poppy and fun vs 45mm stem.
  • 3 0
 My ape index is only 1.04 but my shoulders quite narrow for my 182 height but my arms are really long. I'm closer to a lesser ape like a gibbon than an ape like a orangutan.
  • 1 0
 R-M-R has the most developed set of data in this area, relating body proportions to bike fit, that I’ve come across.

Some of it obvious when you think about it but as no one else is talking about it maybe not. In a nutshell my take away has been understanding how our proportions effect our centre of mass in critical and regularly occurring scenarios.
  • 3 0
 I personally like the fact that I don't have to bend to scratch my knees. "its evolution baby!"
  • 1 0
 Incredibly timely poll. Was always scratching my head as to why at 6' I always prefer the feel of an XL frame! With my score of 1.05 and legs like a giraffe this makes a lot of sense.
  • 4 0
 I am not a number I am a free man
  • 2 0
 I'm on the run, I kill to eat.
  • 2 0
 Haha, this was fun to do with my wife. We always joke with her about her t-rex arms (she is 4'11", so short all over). She comes in at 0.96, so we aren't wrong!
  • 3 0
 I’d be curious to compare men and women, I’m thinking men would have the larger ape index on average?
  • 1 0
 Great. So it's measure myself or change up my whole Sunday routine! this is so unfair!
Okay. I'll measure but I am not spitting in your face
Take it or leave it dude!

Archer? anyone?
  • 4 0
 visa-versa (cringe)
  • 3 0
 74.8" arm span, 69" height. 1.08 index
  • 6 4
 A better way to lay the poll out would be -3, -2, -1, 0, +1, +2, +3... ect, similar to how climbing measures.
  • 2 0
 I'd also be curious about a shoulder width comparison in regard to bar width
  • 1 0
 By looking for the golden numbers that will make you breed a new Grim Do Not, you'll certainly "create" a bike that already exists. Just saying...
  • 1 0
 now if the other 5176 that couldn't be bothered to measure would just suck it up and measure we'd have a really good data set.
  • 1 0
 Thus far the bell curve seems to suggest that mountain bikers tend to be very apey. Go figure we enjoy being wild in the woods.
  • 3 1
 The long arms kill my bench press, but give me a near elite deadlift.
  • 2 0
 Holy normal distribution batman!
  • 1 0
 Maybe it was different when you posted but it's definitely not a normal distribution now. It looks like a significant amount of measurement error and selective bias now.
  • 2 0
 Measure from the base or the balls? #pleasesayballs
  • 2 0
 75 / 71 inch, with 35 inseam - i hate low stack frames and slack seattubes
  • 1 0
 My 1.08 old lady never lets me forget her advantage on the rock.

"visa-versa"...lol
  • 2 0
 Get your hands off me you damn dirty ape!!!
  • 1 0
 I didn't want to get out the measuring tape because I didn't want to get tempted to measuring my midsection.
  • 3 0
 You long armed freaks
  • 2 0
 My ape index go brrrrrrrrrrrr
  • 2 0
 clearly the ape index in PB comments relates to brains!
  • 2 0
 This’ll keep the knuckle draggers busy for a while !
  • 1 0
 Why is the Orangutan’s left arm so much longer than the right one? Can’t stop think about it now!
  • 1 0
 I'm 5'7" my wingspan is 6'3"
Ape index of 1.11

I ride large frames and 800 wide bars
  • 1 0
 I thought all humans were 1 to 1?????
  • 2 1
 Have you ever seen the wingspan vs height on some pro athletes!? Kawhi Leonard has a wingspan of 7'3" but he is only 6'7" tall. Just the average human is about 1:1.
  • 4 0
 Why? That's like saying "I thought all humans were 180cm tall". We're not all clones and we don't come off a production line. All humans are different.
  • 2 0
 @wilsonians: No, I actually thought this was a fact growing up. But realize now it may have just been a rule of thumb that i learned as a kid that is close to one to one ratio.

Big Doh moment.
  • 3 0
 @fabwizard: indeed. this is similar to the '98.6 F' body temperature. that's just an average and people can have quite large deviations from each other.
  • 2 0
 @wilsonians: Actually avarage is not 1:1 at all, it's 1.03. Not only in this poll, it is actually avarage. Many probably click 1:1 as they think it is normal but it's actually t-rex.
  • 1 0
 first MTB company noticing that taller ppl have longer arms i am hyped
  • 1 0
 my reach is 344 and im uograding to 785mm bars with a 40mm rise
  • 1 0
 The chart is starting to resemble a sine wave, WTF!
  • 2 0
 Bell curve my dude. That's how statistics works
  • 3 1
 @JamesR2026: not everything is Gaussian, there are many other distributions possible - E.g. Weibal, log-normal, etc.
  • 1 0
 Damn! I have one arm shorter than the other! I'm screwed!
  • 1 0
 Armspan 82", height 76". 1.078.
  • 2 1
 I voted the biggest just because
  • 1 0
 More importantly tho....
Whats your ape drape ratio....?
  • 1 0
 1.04.(192cm armspan 183cm height) yep I do prefer lower and wider bars
  • 1 0
 I've got this and that so yeah I need a bike like this.
  • 1 0
 I have the exact same stats as Rocky Marciano. Aside from the 43-0.
  • 1 0
 49-0 even.
  • 1 0
 I'm not helping you with the r&d for GD3 should be an option...
  • 1 0
 175cm armspan, 178cm height, 84cm inner leg. I quite out of proportion
  • 1 0
 176cm for both, guess you learn something new every day
  • 1 0
 Me Tarzan....you...ape........
  • 4 3
 why though?
  • 1 1
 I personnally don't even understand what you're talking about.
  • 2 2
 Hey Pinkbike, what the fuck
  • 4 0
 Yeah Pinkbike, answer the man!!!!
  • 1 0
 Ooh, Ooh, Ooh!
  • 4 4
 AMC To the moon
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