Anyone riding with long (180+) cranks?

[bigreen505]

I have a long inseam relative to my height and several of the online calculators/formulas put me on a 185-190 crank.

Has anyone else switched to a long crank? Could you tell a difference?

Thanks!
Bill

[David Kirk]

I have a long crank.......... I mean that I use long cranks.

I have 4 bikes and 3 of them (BMX, MTB, and Cross) all use 180's and the 4th (road) is set up with 190's.

Can I tell the difference? Yes, in an instant. The question would be do I like 180/190 better than the standard 172.5s? Hell yes. For me they just work better and feel more natural. With 170ish cranks I feel cramped and it feels like someone else's bike. With the longer cranks it feels just right. Sort of Goldy Locks and the 3 bears like.

If you want longer than 180 things get interesting. It's harder to find cranks and depending on the frame design and size of your feet you can run into other issues - like your heel hitting the rear derailleur or the pedals whacking the floor. If you stick to 180 they will work well with most frames and they are fairly common.

What are you using now?

Dave

[dekindy]

Studies show that crank length has almost no impact on efficiency. Try it. If it feels better it will not negatively impact your riding.

Need to revise, the correct statement is that it has no impact on power output. Going longer may reduce efficiency due to higher oxygen consumption and decreased aerodynamics due to a higher riding position. See reply below (#19) for reference to an article explaining these points.

[rugbysecondrow]

I have a long crank.......... I mean that I use long cranks.

I have 4 bikes and 3 of them (BMX, MTB, and Cross) all use 180's and the 4th (road) is set up with 190's.

Can I tell the difference? Yes, in an instant. The question would be do I like 180/190 better than the standard 172.5s? Hell yes. For me they just work better and feel more natural. With 170ish cranks I feel cramped and it feels like someone else's bike. With the longer cranks it feels just right. Sort of Goldy Locks and the 3 bears like.

If you want longer than 180 things get interesting. It's harder to find cranks and depending on the frame design and size of your feet you can run into other issues - like your heel hitting the rear derailleur or the pedals whacking the floor. If you stick to 180 they will work well with most frames and they are fairly common.

What are you using now?

Dave


What helped drive the desire for a longer crank (did I just write that?)? Is it foot size, shin, over all leg? Is there a rule of thumb for crank length to foot/leg/height?

Thanks
paul

[bigreen505]

What are you using now?

Dave

Thanks Dave. I have a 172.5 triple and 175 compact. Initially when I switched to the 175s I noticed an immediate decline in performance and took them off, though in hindsight the performance decrease was from a cracked frame. :crap: What initially fueled the hunt for longer cranks was realizing I was more comfortable on my 175 cranks on the MTB. I don't notice much of a difference between the 172.5 and 175 on the flats, but as soon as the road turns up the 175 feels a bit more natural.

The thought is to see how the 180 feels, and if it is good, perhaps get a custom frame designed for the longer cranks. FWIW my inseam length is 885 mm, height is about 5'9" (all legs).

[Lifelover]

I'm a pretty standard 6' 1" and run 170's on my road SS, 172.5 on most of my road bikes, 175s on one of my road bikes and 180s on my urban assualt Bike (SS MTB geared for road use).

I can kinda feel the difference at the two extremes but I can't say that it improves or diminishes anyting.

I think it will really boil down to how sensitive you are to little changes. For what ever reason (slow, fat and old) I don't or can't notice little changes. Other folks, like Mr. Kirk, are very sensitive to them.

[dave thompson]

I'm a pretty standard 6' 1" and run 170's on my road SS, 172.5 on most of my road bikes, 175s on one of my road bikes and 180s on my urban assualt Bike (SS MTB geared for road use).

I can kinda feel the difference at the two extremes but I can't say that it improves or diminishes anyting.

I think it will really boil down to how sensitive you are to little changes. For what ever reason (slow, fat and old) I don't or can't notice little changes. Other folks, like Mr. Kirk, are very sensitive to them.
Dave's also a whole lot taller than 5'9"!

I think the OP going to have a hard time finding cranks as long as he wants, relatively inexpensively, so he doesn't wind up with an costly failed experiment.

[David Kirk]

What helped drive the desire for a longer crank (did I just write that?)? Is it foot size, shin, over all leg? Is there a rule of thumb for crank length to foot/leg/height?

Thanks
paul

I'm 6'4" and have average length legs for my height - meaning long.

I raced pro BMX back in the day and tried 190 mm cranks for that and loved them. I was faster with them due to the increased torque coming out of the gate. BMX is of course all about getting out of the gate.

When I started riding/racing on the road I used whatever cranks were on the bike I bought out of a box - in this case 170's. I was new to road riding and didn't know **** about what it was supposed to feel like but I knew it felt cramped and unnatural. That bike was stolen (thank god) and I built up a new one with 175's which were long at the time. They felt instantly better and more natural. At the time you could easily get 180 mm MTB cranks so I did and they felt even better. In time I changed all my bikes to 180's.

About 6 years ago I was having some knee pain for the first time in my life and one thing lead to another and I decided I wanted to try longer cranks. I got a set of Zinn 190's for my new JKS and built the frame with them in mind (i.e. less bb drop) and I like them very much. The knee issue turned out to be shoe related (long story) but I kept the cranks and still like them. If/when I build myself a new road bike it will get 180's just so everything is the same to lessen chance of knee issues coming from switching lengths.

So for me it doesn't come down to a number but to a feeling and the shorter cranks just feel short. You know how if you walk behind someone in the snow and you try to walk in their footprints and they have a much shorter stride than you do that it feel super awkward? That's what 170's feel like to me. Am I faster on 180's? I don't know. Maybe a bit because I'm more comfortable. Do I enjoy it more with 180's? Yes. And since the only reason I ride is to have fun they make sense.

dave

[David Kirk]

Thanks Dave. I have a 172.5 triple and 175 compact. Initially when I switched to the 175s I noticed an immediate decline in performance and took them off, though in hindsight the performance decrease was from a cracked frame. :crap: What initially fueled the hunt for longer cranks was realizing I was more comfortable on my 175 cranks on the MTB. I don't notice much of a difference between the 172.5 and 175 on the flats, but as soon as the road turns up the 175 feels a bit more natural.

The thought is to see how the 180 feels, and if it is good, perhaps get a custom frame designed for the longer cranks. FWIW my inseam length is 885 mm, height is about 5'9" (all legs).

I'd try them. Unless your bike has a huge amount of BB drop and you do crits your feet won't hit the floor. If you want a new bike later you can do that. Be sure to lower your saddle by 5 mm when going from the 175's to 180's so your leg extension is the same and take a few easy short spinning rides before you hammer on them. it gives your knees some warning :)

dave

[rugbysecondrow]

You know how if you walk behind someone in the snow and you try to walk in their footprints and they have a much shorter stride than you do that it feel super awkward? That's what 170's feel like to me. Am I faster on 180's? I don't know. Maybe a bit because I'm more comfortable. Do I enjoy it more with 180's? Yes. And since the only reason I ride is to have fun they make sense.

dave

Good analogy...this makes sense. Thanks.

[Ken Robb]

I'm a normal 6'1. I bought a bike with 180 cranks though most of my bikes have 175mm. I was pleasantly surprised how I could muscle up known hills with this 53-39 double when I usually rode a triple.

After a couple of weeks I had some slight knee pain so I went back to shorter cranks and the pain left. It may have been because the extra leverage encouraged me to revel in muscling up hills rather than the extra flexion longer cranks caused. I don't really know.

[David Kirk]

I'm a normal 6'1. I bought a bike with 180 cranks though most of my bikes have 175mm. I was pleasantly surprised how I could muscle up known hills with this 53-39 double when I usually rode a triple.

After a couple of weeks I had some slight knee pain so I went back to shorter cranks and the pain left. It may have been because the extra leverage encouraged me to revel in muscling up hills rather than the extra flexion longer cranks caused. I don't really know.

The longer crank does make your knee bend at more of an angle and that can make things irritable. Did you set the saddle lower to compensate?

dave

[Ken Robb]

I played around with it up and down. You know if you lower the saddle so you can reach the bottom of the stroke you are increasing the flexion angle at the top so that may have been a wash for me.
At first I thought the longer cranks and my new-found power were wonderful things then I felt the discomfort in the knees. "Pain" is probably too strong a term. Since both of my knees have had surgery I'm pretty alert to any twinges in them. My problem was probably due to me using the increased leverage instead of the lower gears that I usually rely upon. Heck at 67 and after years of athletic abuse it's a miracle that my knees work at all.

[Dekonick]

What helped drive the desire for a longer crank (did I just write that?)? Is it foot size, shin, over all leg? Is there a rule of thumb for crank length to foot/leg/height?

Thanks
paul

Because she likes it that way...

Couldn't resist...

:p

[Dekonick]

I played around with it up and down. You know if you lower the saddle so you can reach the bottom of the stroke you are increasing the flexion angle at the top so that may have been a wash for me.
At first I thought the longer cranks and my new-found power were wonderful things then I felt the discomfort in the knees. "Pain" is probably too strong a term. Since both of my knees have had surgery I'm pretty alert to any twinges in them. My problem was probably due to me using the increased leverage instead of the lower gears that I usually rely upon. Heck at 67 and after years of athletic abuse it's a miracle that my knees work at all.

Makes sense to me -

[Ti Designs]

Studies show that crank length has almost no impact on efficiency.


That's odd. Crank length (along with rider position) controls the range of motion at the hip, which in turn controls the contraction range of the glutes. In isolation studies muscle fibers clearly show they have greatest efficiency within a restricted range. And yet somehow that doesn't transfer into total efficientcy numbers - something's not right here...

[dekindy]

That's odd. Crank length (along with rider position) controls the range of motion at the hip, which in turn controls the contraction range of the glutes. In isolation studies muscle fibers clearly show they have greatest efficiency within a restricted range. And yet somehow that doesn't transfer into total efficientcy numbers - something's not right here...


Here you go for your reading pleasure. Published on RoadBikeRider.com.





Martin's Revolutionary Study

At the Serotta International Cycling Institute Science Symposium, Jim Martin, Ph.D., from the University of Utah presented his study of crank length. Using special adjustable crankarms, subjects rode with lengths ranging from 120 to 220 mm -- a far wider range than is available commercially. Riders sprinted all-out for about 4 seconds on cranks of various lengths and their average power was recorded.

Most of us would assume large differences between the power output a rider is able to generate on crankarms only 120-mm long compared to 220-mm long. But amazingly, max power varied only 4% from the shortest to the longest cranks. And even more surprising, in a more normal crank range of 145 to 170 mm, the difference in power was a miniscule 1.6%.

Some riders agonize over crank length differences of 5 mm. Should I get a bike or a new crankset with 170-mm arms or 175-mm arms? If power in Martin’s study was affected only 1.6% with a 25-mm change in crank length, we can safely assume that it would change less than 1% when comparing the normal range of available crank lengths.

Even more surprising, there was no correlation to rider height and leg length. Commonly used 170-mm cranks compromised the power of the shortest and tallest riders by at most 0.5%. That’s only 6 watts out of the 1,200 watts generated by a powerful sprint.

How about tests longer than 4 seconds? In a 30-second maximum effort, using cranks from 120 mm to 220 mm produced no differences in power output or rate of fatigue per crank revolution. Crank length simply didn't matter.

So what’s the bottom line? According to Martin, “Cyclists can ride the crank length they prefer, without limiting power.”

So the crank length that came on your bike is just fine. And you don’t need special cranks for time trials, sprinting or climbing.



Attention: Time Trialists

Martin's study has a specific application for time trialists. Traditionally, TT specialists switch to 2.5- or 5-mm longer cranks for races against the clock, believing that greater length provides more leverage to push big gears during a time trial’s steady application of force.

However, Martin argues that because crank length doesn’t affect power production, time trialists should use the shortest commercially available crankarms -- 165 mm. This will let them have a lower and, therefore, more aerodynamic position that's likely to result in a faster ride.



After all, long cranks are longer not only on the downstroke but also at the top of the stroke where, in a time trial position on aerobars, the rider’s thighs tend to hit the chest. The longer the crank, the more the chest must be elevated, thus increasing frontal area and wind drag.

So with short cranks, a rider can get the chest lower without leg interference. The importance of a low frontal area in time trials is unquestioned. Pro teams spend thousands of dollars for wind tunnel research so they can determine the lowest and fastest position for their riders without compromising power. But they do it on bikes with long crankarms -- often even longer than normal.

Thanks to Martin’s new study, we now have new knowledge: Short crankarms allow a lower aero position without compromising wattage output.

[Ti Designs]

Can we defind this term "subjects" in the test a little better? My own off-season testing had some different results with far smaller changes in crank length. But then again, I spend a lot of time working on my pedal stroke and it takes me two weeks of drills before I can smoothly turn a different crank length. My guess is that if you ask the average rider to produce 4 seconds of power, they'll pedal so ugly it almost doesn't matter if there's air in the tires...

[dekindy]

Can we defind this term "subjects" in the test a little better? My own off-season testing had some different results with far smaller changes in crank length. But then again, I spend a lot of time working on my pedal stroke and it takes me two weeks of drills before I can smoothly turn a different crank length. My guess is that if you ask the average rider to produce 4 seconds of power, they'll pedal so ugly it almost doesn't matter if there's air in the tires...

I recomend contacting SICI and get their opinion of the study or if you have questions contact Jim Martin, PhD at the University of Utah. He might even send you the study. Let us know what you learn.

I would conclude from the fact that he was invitied to speak at SICI, a regular presenter at the National Institute of Sports Medicine, and has an extensive list of studies many of which are cycling specific, that the man probably knows what he is talking about and take the information at face value.

http://www.health.utah.edu/ess/people/martinpubpres.pdf

[bigreen505]

I would be interested in reading the paper. My climbs are a whole lot longer than 30 sec. I'm more interested in sustained power output and rider comfort and my own personal experience quite contradicts his findings in those categories.

[dekindy]

http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf
This was all that I could find doing a brief search.

http://mountainbikingzane.files.wordpress.com/2009/09/cranklength-1.pdf
This is a good summary.

[flickwet]

You can have my 180's when you can pry them outta my cold dead hands, all kidding aside I don't think there is a right and wrong its just what works in your head. I do ride 180's on all my bikes, I'm 6' with a 34" inseam and they feel right and I'll take the torque thankyou (or reduced) I think the forces on my knees are actually reduced somewhat at a given output do to the greater lever arm, when I ride my son's Cervelo with 175's I feel the same way Dave feels (nice alliteration there Dave) just my two cents

[ckamp]

I ride campagnolo record 180's. I am 6'5 with 36" inseam. To me the arm length affects my comfort and possibly cadence.

[redir]

I went from 175 to 180 about a month ago. I didn't think that I would even notice the difference but I sure did, huge difference. Whether that difference benefits me or not I have no idea but it's plain and simply different.

That is an interesting study but according to the rules of science it needs to be replicated at least 3 times by independent researchers before I won't take it with a grain of salt.

The fact of the matter that people can clearly tell a difference in the way crank length feels suggests something. If the power results are true such that there is no difference then at least riders can choose a crank length on what feels right to them. And when you are 6'4" with monkey arms and legs like I am then that is all that matters. :D

[William]

In a nut shell...

When I made the switch to 180's years ago the difference was immediately apparent. The best way to explain it was I went from feeling like I was always fighting to stay on top of the gear to being able to spin it and stay on top much longer on climbs.




William

[Waldo]

I'm a normal 6'1" and I ride 190s. I like 'em a lot. I have 180s on a bike that's at my father in law's and I ride that bike a couple of times a year for a week at a time. I get used to the 180s after a while, but when I go back to the 190s, it's like heaven.

[Ti Designs]

I recomend contacting SICI and get their opinion of the study or if you have questions contact Jim Martin, PhD at the University of Utah. He might even send you the study. Let us know what you learn.

I've learned that the folks at SICI don't like me... My first question with any scientific study is how does it relate to my riders (or myself - I have the most data on myself, along with a pretty detailed injury history). So, my first question about this study is who are the riders being tested and how well do they pedal the bike? My own answer to that question comes from having coached many riders and teaching the pedal stroke classes each winter at my shop. It's rare that I find someone who can turn the pedals in circles when I start with them - in 10 years of coaching and 3 years of pedal stroke classes I've found 2 (one of them is on this forum, the other went from novice to pro rider in two years - freaks I tell you!) Most of them struggle with getting the pedal around the circle smoothly, which is as much a mental struggle for most 'cause it all seemed so easy before. A few weeks after they start they are all turning the pedals smoothly around the full circle, in fact they have to try to screw it up (that "thunk" sound as they try to cut off the top of the circle drives me nuts, so at some point they try to make it happen). In a bit of testing on myself I've found that I am somewhat sensitive to changes in crank length. Doing the one leg drill I have some initial problems, and the RPMs that I can sustain smoothly drop - this has been the case with both longer and shorter cranks (which is why I now run 170mm arms on my track bike) Given two weeks of pedal stroke work I can adapt, but who wants to do that. I'm probably not your average case, I hold the record at the local roller race, but then neither are my riders - they do the same pedal stroke work that I do over the winter...