Hey everyone and welcome back to this week's Tuesday tip we're in this week's video we're gonna be asking the question does crank length matter
If you're new here every Tuesday
I try to make a tips and tricks video on anything ranging from tips and tricks having to do with your bike
Having to do with working your bike or tips and tricks having to do with tricks
Actually while riding your bike so in this week's video. We're gonna be exploring whether or not crank length matters on bicycles
Freestyle just in general does crank length matter to start it off
Let's define what?
Crank length actually is and that is the measurement from the center of the spindle to
The center of the pedal boss and this can have a huge range on BMX bikes on
little 16-inch bikes it's going to be very short on race bikes and
BMX freestyle bikes they can be a lot longer, but generally the range is somewhere between
170 and 175
Millimeters that's normal on the high end. We've got
180 millimeters
185 millimeters and sometimes even higher than that on the low end when it comes to full size
20-inch bicycles for freestyle we're seeing
160 165 millimeters and the question comes up does the length have a difference while you're riding
So when it comes to road bikes and other types of bicycles besides freestyle BMX bikes there have actually been
scientific
Scholarly studies done on whether not crank length has an effect on power output
And we'll get to those studies in the things that we talk about in this video so first of all we're gonna talk about
Cranks on the longer end and the first thing
We've got to talk about is with longer cranks you get more torque
With less force because if you think about it. This is all just leverage your cranks are making a circle and
the bigger that circle
The less force it takes to move the cranks themselves and you get more torque at the same time to give a real-world
Example of this let's say you have a stuck lug nut on your car wheel that you're trying to get off
You don't go and get a shorter wrench to try and get that lug nut off you go
And you find a pipe or something really long so that you can get more leverage on
The lug nut itself to try and break it loose same things going on with your cranks
Longer cranks more torque less force, but at the same time
there's a trade-off if you have longer cranks and your bike is set up exactly the same as
Another bike with shorter cranks the bike with longer cranks is going to take more energy
To keep the wheel spinning at the same pace as the bike with shorter cranks
Because you have that bigger circle
Which means a longer pedaling rotation to make the exact same turn of the wheel as the?
Bike with two short cranks, so you're using more energy to keep the exact same pace as a bike
That's set up exactly the same way
But with shorter cranks since we're talking about the shorter cranks now if we look at the flipside
When you're actually taking off at first from no speed whatsoever
The bike with longer cranks is going to pick up speed faster
Because you get more torque with less energy right off of the gate now
Just like we talked about before how it takes more energy to keep the same pace with longer cranks
it takes more energy with shorter cranks to have the same torque as
Longer cranks because we have that shorter pedal rotation and less torque
it takes more energy to
Pedal the bike hard enough to equal out
The same amount of torque that you're getting from longer cranks now at this point you might be saying to yourself
Okay, this guys sitting here in front of a bike is telling all this stuff, and yeah
It does make sense that longer cranks have more torque
If you think about things as far as physics go
But where's the proof and the proof is that there?
Scientific studies done as I said and in those scientific studies, which I will link in the description below
They found that on two bikes
identically set up
But with different crank lengths the bike with longer cranks
Pedaled with three percent lower gearing than the bike with shorter cranks
And what this basically means and a comparison we can make is that the bike with longer cranks?
Pedaled as if it was in a lower gear than the bike with shorter cranks
it was only 3%, but it was a
Measurable difference and now you might be asking yourself
okay, so
three percent less gearing how can this affect me and
the answer to that comes in another
scientific study that was done and instead of trying to remember and quote things and
Force you guys to sit through that I'm going to read a quote from
this study power produced with the
145 and
170 millimeter cranks was significantly greater than that produced with the 120 and
220 millimeter cranks the optimal pedaling rate decreased significantly
with increasing crank length from
136 rpms for the 120 millimeter cranks to
110 rpms for the 220 millimeter cranks even though maximum cycling power was
significantly
affected by crank length use of the standard
170 millimeter length cranks should not
Substantially compromise maximum power in most adults so that set a lot there
And I'll try and translate as well as I can basically what they were saying is that longer cranks meant a better
pedaling rate than shorter cranks in that with longer cranks
You're taking less pedals to achieve the same result than you are with shorter cranks
But what they're also saying is that having something in the media range of?
Short and long crank arm length will not significantly affect your power output while riding your bicycle
but everything that we've talked about so far has to do with the bike itself and its power output or
Functionality there are other things that crank length has an effect on that don't have to do with the bike and that is us
Crank length has an effect on us if you think about it
longer cranks making a larger pedaling rotation also means that our body has to make a
Larger range of motion to meet that larger pedaling rotation our knees are here our
pedals are here if
We have longer cranks that puts our pedals further away than
Shorter cranks would so that means we have to move more to reach those lengths that can have more of a strain on our bodies
Then short cranks would so no matter. What kind of riding
We're doing this is something that we have to consider in freestyle BMX
I personally don't believe that the torque and the efficiency
Generated by shorter cranks is worth the extra movement of our bodies
But at the same time it could be negligible because freestyle is naturally aggressive
And we're already hard on our bodies
Maybe a little extra range of motion in our knee isn't something that we're worried about
But if you have an injured knee no matter what type of riding you're doing that is something that you're gonna
Worry about and if having shorter cranks can alleviate knee pain, then maybe it's worth it to put on shorter cranks
No matter what it means for your riding
And you also have to think about the differences in
Pedaling rate that we've already talked about when it comes to shorter and longer crank arm links depending on your circumstances
having longer cranks and creating more power with less force could be better for your knee than having shorter cranks and
having to pedal harder to create the same amount of force as
Longer cranks so what I'm getting at here. Is that in reality?
Yes, crank arm length does have an effect on things having a medium crank arm length might not affect
maximum power output
But the differences in these crank arm lengths
And what they mean can help or hurt certain individuals depending on what their needs are and it's up to
The individual themself to try out different crank arm lengths and see what fits them best
But when it comes to your average person who has nothing wrong with them. They don't have knee issues
They don't have issues peddling and changing different rates and speed on the bike. They're just riding the bike
I don't personally believe
That crank length matters for those
People because most of the time the average person is riding a bike with shiftable gears
And they're doing so for leisure
not for sport
So crank arm length isn't something that these people are generally going to care about or need to care about
But that's the conclusion for your average everyday
Casual bike rider what about bike riders like freestyle or road bikes or?
Racing road bikes things like that the answer to that is yes crank arm length does matter
But how much it matters is up to the person riding the bike if it's worth it for the trade-offs to have longer crank
arms and more torque
Then that's up to that person so my advice to you would be to try out different crank arm lengths
And if you're having knee pain
Maybe take a look at your crank arms and see if they're too long or if they're too short
And maybe you need to meet somewhere in the middle
But when it comes to freestyle BMX there are things that crank arm length
Certainly has an effect on and these things profile is talked about on their website the first thing that they talked about is
Bunnyhop height profile says that with shorter crank arms you should be able to bunnyhop higher
and they say this with an example that if you
Stand with your feet closer together, you can jump higher than if you stand with your feet further apart
this is something that we can test so let's try it for the sake of the video and
Showing exaggeration we're going to start with feet as close together as possible
then we're gonna spread my feet out pretty far in pedal position and
See if we can see a difference so closer together then further apart
you
Farther apart
Another thing that they talk about is that it can have an effect on
ambidextrous spinning spinning both regular and opposite four tricks
That's another thing that we can test although. It's something that isn't
quite
Measurable on camera or you guys because it's hard to measure spin velocity
Just watching a video, but let's try that too close together
All right now farther apart
Close together
Okay farther apart I
Don't think we're gonna see too much evidence from
Jumping tests and as you can see I did jump higher with my feet closer together, but the spinning tests are pretty much
Inconclusive either way these things are subjective and things that you have to try out for yourself
but the other two things that profile talks about on their website are not as subjective and
Those are the fact that?
Shorter cranks are more rigid therefore. They will last longer
Because they're shorter and an example to think about this in comparison to is let's say you have two different
Sticks that you're trying to break with your hands if you have a really long stick in a really short stick
Which one's going to be easier to break?
obviously the answer is the longer one because you can get more leverage on it and
Pull it easier to break it then you can with the short one now
Material comes into hand here
But in general the longer stick is going to be easier to break so if you think about what we talked about earlier in that
longer crank arms create more leverage and more torque of course
it's going to be easier to break a
longer crank arm because you're putting more force on it than you are a
Shorter crank arm the last thing that they talked about is also less subjective than the first two things
We've talked about and that is that shorter crank arms are light
Obviously shorter crank arms are going to be lighter because they're made with less material therefore
They're obviously lighter
So this is one that you really don't have to test
Less material equals less weight and with that being said in this video coming to a close I'd like to point out the fact that
Crank arm length is only going to matter as much
As you let it if it's in your head that you can't do certain tricks with certain crank arm lengths
You're probably going to make that a reality
even if it's
Subconsciously whereas if you don't worry about these things as much they probably won't have as much of an effect on you
I know we all know that one person in our group of riding who has a ratty bike where they don't care about it whatsoever
But they kill it with it and chances, are they kill it with anyone's bike
They ride because they just don't care about the bike and they don't let the bike dictate what they can and can't do now
Obviously there are certain circumstances and certain people who might need shorter or longer
Cranks to fit their style, but my whole point here
Is that nine times out of ten these things are all up to personal?
Preference just like every other aspect of your bike if you think shorter cranks make you ride better
Then ride shorter cranks if you think longer cranks. Make you ride better ride longer cranks
It doesn't matter what anyone else thinks except yourself
But I will say if you do want to change up your crank arm length
And you don't have a ton of money to just go and buy parts
try them on someone else's bike or
Borrow some that are the length you're interested in first because cranks are not cheap
And it's very easy to get stuck with something that doesn't work the way that you thought it will with that being said
What do you guys think?
Does crank arm length matter does it matter to you?
I know it certainly doesn't matter to me that much but after making this video
I wouldn't mind riding someone else's bike with shorter cranks. Just to see if I can notice a difference
I probably wouldn't get new cranks to try them out
But you never know until you try so thanks for watching the video guys
I hope you learned something and I hope to see you on the channel again. If you like what I'm doing here subscribe
It's free. There's no reason not to and we'll see you next time goodbye