Cranks are measured from the centre of the pedal axle to the centre of the bottom bracket spindle. Lengths most often range from
160mm up to 185mm
, in 2.5mm increments, and typically bigger bikes will come with longer cranks.
Are longer crank arms better?
As you’ll know from using a crowbar or a wheelbarrow, the longer the lever, the greater the load that can be lifted; so
a longer lever arm allows a rider to create more torque than a rider with similar leg strength
, but a shorter lever arm.
Are shorter crank arms better?
If the gearing isn’t adjusted, the shorter crank arm effectively gives a harder gear in terms of the force required at the pedal to create a given propulsive force at the wheel, potentially leading to more strain on the body when you run out of gears.
Which is better 170mm or 175mm crank arm?
The Basics. XC – Possible sizing needed depending on ride lengths, but
175’s are what is recommended for more leverage
. Trail/Enduro – 170mm crank arm length is the most commonly used size and is recommended to keep a good leverage ratio and have a bit more ground clearance due to having more travel.
Will shorter cranks help my knees?
Pain is relieved.
Just by installing shorter crank arms, without any other adjustment, the knee at maximum flexion is lowered by 7.5 mm. That difference provides approximately 3° to 4° of relief
.
How do I choose crank arm length?
Crank length is measured from the centre of the bottom bracket axle to the centre of the pedal axle. If you’re not sure what length the cranks on your bike are, the quickest way of finding out is typically to just
look at the backside of your cranks, just below the pedal axle
.
Does crank arm length really matter?
As far as maximal sprint power and metabolic cost are concerned, crank length can be anywhere from 145mm to 195mm and
it really doesn’t matter
. ‘A longer crank is basically a lower gear ratio. It might allow you to climb better, but its effect is tiny compared to shifting up two sprockets on your cassette.
What are the benefits of shorter cranks?
Less pressure/discomfort on the knee at the start of the down stroke
. More space at the top of the pedal stroke between upper leg and torso. this is not only because the crank is shorter but also because there is more space for the foot to dorsiflex on the up-stroke. Easier to pedal in the saddle going up hill.
What is the correct crank length for me?
| Crank Length(mm) Inseam(cm) Height, Male and Female* | 162.5 77 Up to 166.3 cm Up to 5′ 5′′ | 170 81 – 83.5 173 – 179 cm 5′ 8′′ – 5′ 101⁄2” | 172.5 83.5 – 86 179 – 185.5 cm 5′ 101⁄2” – 6′ 1′′ | 175 86 – 89.5 185.5 – 192 cm 6′ 1′′ – 6′ 31⁄2” |
|---|
What does a shorter crank arm do?
A shorter crank alone will not increase your power output, but it can be used to
reduce restriction through the top of the pedal stroke by opening up an impinged hip angle and/or reducing knee flexion
. Going back to our definition, if we reduce restriction than power output can increase.
How does crank length affect power?
Crank Call
Folk lore suggests that crank length has a huge effect on the power that you can generate, or the cadence that you’re able to ride at. Namely, the general view is that
shorter cranks allow you to spin and accelerate quicker but at the cost of high torque or power
.
Does bike crank length matter?
Crank length can be used as a tool to improve fit related issues impacting comfort, power, and aerodynamics
. Moving to a shorter crank can improve: Comfort: A shorter crank length reduces range of motion at the knee (extension and flexion), hips, and low back.
What is 170mm crankset?
Why are we using the same range of crank lengths? The answer to that is that we probably aren’t. 30 years ago, 170mm was ‘normal’, 172.5mm was longish and 175mm was considered to be quite a long crank and relatively uncommon. Whereas now
170 is ‘short’
172.5mm is ‘normal’ and 175 mm cranks are very common.
Does crank length affect gear inches?
Crank length changes the feel of the drivetrain no matter the gearing
. Longer cranks do not have the same affect/feel as a lower gear ratio, nor are shorter cranks the same as a higher ratio.
Are 175mm cranks too long?
If you are 6’2′′ then 175 is probably a small-med for your size
. If you were 5’2′′ then it would be a long crank. For what it’s worth, I’m 6′ 2′′ and run 175mm cranks on all my bikes.
Are shorter cranks better for climbing?
“I try to put anyone on the longest crank possible within their range of movement to use the muscle mass they have,” he said. “This is especially important for strength-oriented riders.
For those riders with greater cardiovascular strength, a shorter crank works better because they tend to ride at higher cadences
.”
Does crank length affect saddle height?
The main points to consider: handlebar height and saddle setback.
Handlebar height is always set relative to saddle height
. That 5-foot-2 woman moving to 165mm cranks will raise her seat about 7.5mm to compensate for the shorter cranks.
What is the difference between 172.5 and 175 cranks?
From 172.5mm to 175mm, you have only
2.5mm
difference. We set our saddle height when the pedal is at 6 o’clock position. So you should lower the saddle for 2.5mm, since your pedal is 2.5mm lower than it was.
Should taller riders use longer cranks?
People taller than 1.90 m (6’3′′) could consider cranks that are 180 mm or longer
, but these are not so easy to find (such people’s bikes probably came with 175 mm cranks). Fortunately, riding a crank that is shorter than recommended is unlikely to cause major problems.
Do carbon cranks make a difference?
In all other cases,
carbon cranks do not offer game-changing benefits
. One could even argue that they make for a poor purchase because a good set of alloy cranks is cheaper, tougher, and doesn’t weigh a lot more. Thus, recreational riders are better off buying alloy cranks.
What size cranks do pros use?
Pros often use a
55×11-tooth high gear
for time trials. On flat or rolling stages they might have 53/39T chainrings with an 11-21T cassette. In moderate mountains they switch to a large cog of 23T or 25T. These days, they’ve joined the big-gear revolution like many recreational riders.
Should I shorten my crank length?
Do lighter cranks make a difference?
Lighter crank and same saddle will be your best improvement
. As for the saddle, it’s really a personal item and you really shouldn’t give up comfort for less weight.
