Recumbent Crank Lenght 

I tested shortening cranks from 175 to 153 the same way your bike is because I have the equipment for it. I found it took away the knee pain I sometimes had after longer rides but it also took away a bit of power and even more torque (like for starting uphill or in wrong gear). This was done on an Azub Apus. Most of my riding before and on other recumbents was with 170mm cranks. Based on this I ordered expensive 160mm cranks (from TA-Specialités) when upgrading my daily recumbent and did not regret it. I found since than that 160mm is the ideal length for me so I bought more of such and similar cranks over the years. My cadence is at least 10% higher with 160mm cranks than with 170mm cranks but it was not difficult to learn to keep the same pressure on the pedals for both. The result is more power and never any knee pain. For reference I am 178cm tall and weigh 64kg.

Hi All,I have been a recumbent cyclist and racer for nearly 30 years, i used to ride my recumbent bicycles with 170 mm cranks like "Silstar".Around the year 2000 i read an article in Bicycle Quarterly ( edited by Peter Eland) about crank length, after that i started experimenting with shorter cranks. First i shortened some old aluminium cranks to 130 mm and used these on my upright bike and on my Optima Baron lowracer. The shorter cranks give a lot of freedom for shortening your handlebar and you get a lot more room in a fairing like a M5 .After a while i noticed that with the 130 mm cranks i got more cramps than with the 170 mm ones. This was only at very high levels of effort, they are very good for easy touring! Later i made some 145 MM cranks and i have been using these for some years now; these are perfect for me, no cramps and still high power levels possible with all the advantages of the shorter cranks! I don't think i will ever use longer cranks on my recumbents again; i would advise them for every recumbent rider.Greetings from The netherlands, Jan Maarten.

Dear SAUKKI , in AMAZON and EBAY some times thay have bicycle cranks and pedels ,I wish you a very happy Christmas and a very happy New year please stay safe and well,from David

I have 135mm cranks and my length is 192cm. The short cranks gave me many benefits and I could find no real downside other than losing some maximum power, which is not relevant for any distance longer than one kilometer. Average power output over a full ride is just as good as with longer cranks. A lower gearing is important because starting on the big chainring from standstill will be harder and starting on the small ring every time is annoying. And beside, when you need to climb steeply, you definitely need lower gears anyway. The best thing about shorter cranks is never having knee pain anymore and my heels do not scrape the street now and then. I can even close the footholes (Quest), gain an aero advantage and stay warmer in winter. Finding short cranks is one thing, you also want a small q-factor and this combo is very hard to find. Promax had some, but they seem to be discontinued. At this moment Box Five has a good range down to as short as 135mm and up to 170mm in 5mm increments and the q-factor is excellent when you use 103mm square taper bottom brackets. There are even shorter bottom brackets from Campagnolo in 102mm but these may present you with some complications, the extra mm less q is not worth it. Box Five is a BMX crank and made to accept only one chainring (110mm BCD). With a spacer you can still mount an extra ring on the inside.

Nice video! Two little tips: 1. For upright bike cyclists, shorter cranks also causes higher cornering speeds - you can keep peddling in corners! 2. The DF is delivered stock with 155mm cranks. There are also a number of shops who shorten cranks with warranty like your friend does.

This is very interesting. I used to think about crank length, why everything for bicycles comes in different sizes but cranks are only 170mm fix, like tall and short people would have the same leg lengths. Now I see I'm not the only one who wonders about this. Maybe I should try shorter cranks.

Nice video, thanks for the data. Something to think about.

Each rider has a different torque curve and power curve, and the question comes down to what is the effect of changing crank length on these curves? The torque curve maximum is sort of the cadence at which pedaling seems easiest. The power curve maximum is roughly the cadence where climbing is fastest. The short crank prescription is more or less the same as betting that the cadence for maximum torque and maximum power for a rider are closer together for shorter cranks: the torque maximum is sort of the "easiest feeling" cadence and the power maximum is the "fastest climbing" cadence. When these cadences are far apart, climbing is no fun. When you shorten the crank, the amount of torque available at the torque maximum is reduced. This is why people invented wrenches and levers. Since power is torque times cadence, the only hope that shorter cranks result in higher power is if the cadence can increase by more than the amount the cranks were shortened. The rider has to have the "cadence reserve" to provide that increase. And shortening the cranks at first seems the least sensible way to increase cadence. After all, what are gears for? My bikes are all set up so that in the lowest gear, 60rpm cadence results in about 2.4 kph. There is no need to reduce cranks to make the bike "easier to pedal". The only reason I would consider would be kinesiology: if there was something wrong with the way my knee tracks during pedaling. You can actually predict from the torque and power curves whether a different length crank - or a lower gearing - will make the bike feel better but still climb as well or better. So a lot of people seem to like shorter cranks - and this means they didn't have a huge amount of torque at lower cadences. But some people, and I am one of them, have a lot of torque endurance and not much reserve cadence. I have 172.5mm cranks on one of my bikes because I forgot to specify 175. I would like 180 even better. Why am I different? Probably because I am 160cm tall and weight 115kg, and a lot of it is leg and back muscle. For a few decades my main workout was power lifting, so my deadlift (265kg) and squat (250kg) were a bit more than most other people. Well these legs I've built up can produce a lot of torque. I have bent cranks and bottom brackets to prove it. But cadence is a big problem. I have trouble maintaining 80 rpm for more than a few minutes, even though I can ride at 72 rpm for hours. Even with no resistance, 90 rpm is really difficult. Going by this, 150mm cranks would make no sense whatsoever, that would change by very comfortable 72rpm to a difficult 84 rpm. And because I have very low gearing on my bikes, I can already pedal at that I get that most people are not torque monsters, but some of us are. I would also point out that knee health isn't really about cadence. It has a lot to do with how well your stroke avoids any sideways or twisting motion. You want the knee joint to have NO secondary motions while under load. When you lift heavy, you learn to keep your joints lined up to avoid any unnecessary stress - and this applies to cycling as well. I would advise that people who have had knee pain for any reason while cycling figure out exactly what the issue was with their stroke. Too much torque is a possibility, but I think that is mainly because torque magnifies the bad effects of secondary motions as much as it is a problem by itself. I see a lot of people clipping to their pedals which are too close together for their natural stance. There is a reason why weightlifters learn the correct separation of their feet to keep their knees tracking without problems. And cyclists should too, but from what I see, almost none even think about it. Most riders should have the pedals farther apart. And this is even known in the cycling world: crank extenders are called "knee savers"! I would try wider pedal spacing 100% and lower gears before I would try shorter cranks. So shorter cranks may be a good idea for some people, but there are other things that should always be considered as well. The one I think most people skip over is correct pedal spacing. And for some people, if you move the pedals further apart you might very well want to shorten the crank length - but also sometimes you might want to lengthen it. Everyone is different, and accommodating a motion of the knee which reduces twisting and sideways motions is just as important as reducing torque.

Great and informative video Saukki! I’m a little bit opposite here as I prefer longer 165mm cranks. I had 155mm cranks in my WAW velomobile for a long time. For a few months last year I did some testing and tried everything from 150-165mm cranks. All my cranks are Origin8 and I got them on Amazon. My legs are about the same size as yours and the recumbent crank length calculator recommended around 150mm. I tried each length for a few weeks before switching. I discovered that I like the longer 165mm ones the best and I was fastest with them. I did not care for the shorter 150mm cranks as they didn’t feel right to me. I noticed my average cadence was the same with each size and did not change (around 90rpm). I can still spin my 165’s up to over 130rpm on a downhill sprint pretty easily.

Very informative video. On my recumbent trike I have 155mm and that feels really good. I also have a recumbent bike that have 175mm and that feels totally to long so I will shorten them like you have done :) On my upright road bike I have 172,5mm and that feels good.

Crank length is a popular topic among us unicyclists. Very typical lengths are 125mm and 110mm.

Thanks for the recumbent crank link. I must have got lucky with the length I’m using now. Knees aren’t too high, but high enough for hills and leverage.

Thanks a lot for the interesting video about cranks Maybe an idea for a next video: What do you think about tubeless tires for velomobiles?

Thank you Saukki. What a great video! Not a lot of information on youtube, that adresses this perticular subject. Recumbents are a different game. I am putting 60 - 65 mm. on a recumbent trike. They are for a Schlumpf drive, so they are unique cranks that fit together with the Schlumpf system.

Hi Saukki. I am a big fan of shorter cranks for recumbents. I first started with 155mm cranks. I have now experimented with shorter cranks. I have 140mm cranks on both my Baron and homebuilt MBB bike. My velomobile has 145mm cranks. I still use square taper bottom brackets, to easily swap cranks around. 110mm BMX cranks are a good source of short cranks, and most can take a double chainring! I did try some even shorter cranks at 125mm, but they were too short, and felt I lost too much power. I'm very comfortable with my shorter cranks! Good video as always!

Hi Saukki! Very well done video! Thanks for the interest you had on that important subject, for the informations you share with us! Have good rides! 😉👍🤙

A recumbent bike requires a shorter crank length than a conventional bike for this reason: The hip moves backwards slightly into the seat, away from the direction of the foot, as a force is ut on the pedal for a recumbent bike; in a conventional bike the hip moves slightly downward in the same direction as the foot, as force is out n the pedal. If you carefully think of the geometry in both cases, the crank length should be shorter for a recumbent bike than for a conventional bike. Also, the distance between the two pedals should be 10mm to 20 mm wider (i.e. farther apart) than for a conventional bike.

Hi Saukki, Love your youtube videos . Im riding a performer jc26 trike and do to a knee injury need 155mm cranks on my left side. I rode for 6000 km with one side 155 and at the other 172 . never noticed and difference as my leg length is different . this year i changed the other side to match and i now ride faster than i did before. most of my power is from my good leg on the right and that is the one i had at the reg length before. Im in Nova Scotia Canada and hate driving in the cold, but its a must here. Just ordered a High Racer recumbent for next summer riding with upright cyclists.

Very interisting tip. I have ordered azub MAX and this give lots of thinking matrial.

I'm 190cm tall and have 160mm cranks in my Df. When riding on flat roads I feel that they are slightly too long. But when peddling a steep uphill, I might have issues with shorter cranks. My legs would not have enough torque, so I guess those cranks that I chose may be a happy compromise.

Did some quick googling. There seems to be "Origin8 Triple Alloy Crankarms, Silver" listed on amazon.com, several reviews mention recumbents. Also "Origin8 Alloy Crank Arm Set (110 BCD)" cranks seem to be sold in lenghts 140mm to 175mm. Speedandcomfort.com seems to be selling "COBB ALLOY GXP SHORTCRANKS", at €263.86 though. Several shops list "Crank Young 145 mm 35", seems to be directed for youth use. P.S. Hyvä video Saukki, hienoa, että otit tutkimukset mukaan videoon. Seuraavaksi empiiristä testausta eri kammilla?

Ordered 140mm for my next recumbent project. I'm 183cm. Hopefully this eases my knee issues a bit.

Absolutely agreed, by direct experience too 👍🏻👍🏻. Well done finding the articles about this topic! A friend of mine can actually do the modification so for now I'll rely on his help, but I've found on ebay, amazon and online bike dealers some stuff about 150...155 mm cranks. They are usually devised for "junior" road bikes, just be careful because the chainring holes are usually on a 110 mm path (BCD) so you'll need to get specific chainrings too. Something can be found very cheap with single gear (usually dedicated to children's bikes 😅) or for mtb. Starting price is around 55 €, of course you can spend much more at your own will 😉.

Loved this video! Really nice and informative

Great information. Thank you

Great video and very good info Saukki

I'm 203cm, I don't think I'll ever have any issues with things being too large for me.

crank shortener is good for different crankset. Iam using 145mm. Good to find between 140mm-160mm with 2holes sizes between (weight). Smaller sortener is lighter

I get my short cranks from 24inch wheeled mtbs, I've found 140mm and 156mm on cheaper bikes (children's sizes) I know the cranks aren"t name brands and heavy but I"m not worried about saving grams.

Thanks for the data Saukki

I have a 36 inch inside leg and use 180 mm crank length on my Pinion P1.18. I ride a HP Velotechnik Scorpion fs 26. Using a shorter crank is like riding a kiddies bike.

The cheaper shimano cranks are not hollow, you (or someone capable) can cut a new thread wherever you want and remove the excess length. I have the external HTII bearings and nice looking 155mm cranks.

Interesting subject , i have wondered about this myself . When you think about it , it really would not be too hard to engineer some cranks with slides in them to make them infinitely adjustable ( up to a point :) ) , possibly may a slight weight penalty though ..

Rotor makes cranks up to 150 and you can try to search for triathlon cranks because there also use short ones

2 wheeler is beautiful. velosRus

Of course, the closer your foot is to the spindle, the less torque you'll have for climbing. I was lucky to be able to copy my race bike's crankarm length (172.5) in my velo.

It is a shame our demand for short cranks tends to keep us recumbent riders in the old square taper world. For a lighter more modern alternative, the two kid bike manufacturers Kania and VPace offer a Hollowtech 2 crank in various short lenghtes (which differ between the two companies). The crank uses the SRAM direct mount standard. I didn't know it and learned that direct mount on a crank means a chainwheel can be directly mounted sans bolt circle but via a serrated fit, similar to direct mount disk brakes. Another option for SRAM direct mount is to use a spider for 1 or 2 bolt circles, e.g. dual-BCD setups 110/74 or 104/64, and build a 2/3-chainwheel setup that way. Other than this Kania/Vpace crank, there are the much more expensive Rotorcranks with a great choice of lengthes (steps are between 2.5 ... 5 mm over the spectrum)

specialites-ta.com/75-paire-de-manivelles has several cranks that start at 155 mm and up in length. This is the road cranks. They also have mountain cranks and such. They are expensive though.

The aero advantage of shorter cranks on non-faired recumbents is something I would like to see explored further because the legs are the most prominent obstacles to the air flow over the body, especially when in a highly reclined position (think lowracers). I wouldn't be surprised if cranks as short as 125 mm would be optimal for super laid back recumbents. Surely any power lost would be more than offset by the slimmer path of the legs through the air, similar to how upright time trialists sacrifice some pedaling power to tuck their torso and head lower to cut through the wind easier.

I’ll join one other subscriber and request a discussion on Tubeless tires for recumbent trikes

I got my cranks from bikesmithdesign.com/Short_Cranks/index.html and he also supplied ( by request ) aluminum chain rings . I have had three sets and I am 6'1" with a 43.5 inch x-seam. I ride 153-155 mm crank arms on two different recumbents . We have 22-25% grades on some of the hills around here and I do not walk any of them. I certainly do not race up them either.

Hi Saukki, ROTOR ( rotorbike.com/ ) make some very good crank sets from 150 mm up. With my new Alpha 7 I got 155 mm cranks by velomobileworld.com - they feel much better than the 170 mm cranks in my Strada… so I now have one more item on my "Strada needs upgrades" list.

Is it easier or not to learn with shorter cranks.

120mm/Quest - I suppose we have same friend to do crank shorterings ;)

Where can I buy just a frame? Carbon?

i definitely need shorter cranks , my pedals feels to far away

Longer cranks apply more torq but with a geared system we don't get more power. Most riders can generate 200-250 watts. I am 6'1" and my action bent has 175mm cranks My question is do longer cranks contribute to pedal steer? In other words would a shorter crank arm length (which reduces torq) reduce pedal steer?

Kids cycle cranks 155mm

i have found it, the crankshortner, only 13 euro no special toolz needed

Hi! I have heard about you from Tapio-T

How about efficiency? I do a lot of touring with my regular bike and just recently started using an Alleweder A4, and I don’t dare use it for touring yet, but I am testing it for longer and longer drives, 240km on 2 days is my highest test. With my regular bike I can peak at 250km on a day, and sustain touring around 180-190km a day, even in Denmark and Sweden.

Bikesmith design in the U.S. www.bikesmithdesign.com has been selling and modifying short cranks for many years. A truly nice guy with great service. He also has custom parts for recumbents, tandems and other "weird bikes". Highly recommended.

You can get 152 length cranks here: www.utahtrikes.com/PROD-498.html

Hello Saukki and folks, a question: where can I find / how is it named the type of handlebars you have on your Azub recumbent?

Here is maybe another option to shorter cranks: www.utahtrikes.com/PROD-428.html

what is the high BB, med BB and low BB they're talking about? :o

i know that unicycles have short cranks. Like the nimbus

Its length...not lenght..sorry...😇 Nice video though!

Don’t discount longer cranks. You’re shortening the flexion at the knee and limiting muscle recruitment.

Any size crank you want. zinncycles.com/custom-cranks/ BTW.....200mm cranks aren’t silly if your inseam is 1000mm. A Dachshund can’t intelligently comment on a Grayhound’s leg length.

When you dont know shit, dont reccommend anything..