170 Vs 172.5 Cranks Comparison – Which Is Better?

Regarding cycling, every little detail can make a difference in your performance. One such detail is the length of your cranks. While the difference between 170mm and 172.5mm may seem small, it can impact your power output, comfort level, and overall riding experience.

If you’re an avid cyclist, you may have heard of the debate between 170 vs. 172.5 cranks and which is better. The crank length refers to the measurement from the center of the bottom bracket to the center of the pedal axle and can impact your cycling performance.

While both lengths are popular options, there are some key differences to consider when deciding which suits you. We will compare the benefits and drawbacks of each size to help you decide which is better for your individual needs and preferences. So, whether you’re a seasoned cyclist or just starting, read on to learn more about this important component of your bike setup.

170 Vs 172.5 Cranks

What Is a Crank Length?

What Is a Crank Length

Due to how human hands and feet interact with cranks. There is a small difference between 170mm and 172.5mm cranks regarding “proper” length. The 68cm Shimano catalog lists their 45-degree original bars as 414g. Some measurement sites may say this bar links out at 415-427, but I think they refer more to the distance.

From the crank arms pivot point than the actual shaft nose length. There are similar handling benefits to shorter sticks. But you can also use longer bars if fork rakes are not an issue for your climber, or vice versa. I don’t think this setup will work well on all bikes, but it’s just something I wanted to share based on what that same catalog says. About 25% of people go smaller than 172 5/8cm and consider getting stem length quickly.

What Is a 52/42t Chainring?

What Is a 52/42t Chainring

52 X 17T = 431mm (18 sizes)  – – Translation: A 53-tooth tick in the smallest available gear with 54 teeth on the bigger ring. Another term for these rings is an “X4” setup because it has four larger than-normal rings. And smaller ones, even though most people don’t know that they technically have 5 of each. It is a way for big ring riders to “cheat” and make it work or gain more climbing speed.


You can also use these rings successfully as children of grown-up bikes due to the smaller circumference gears. In this situation, 44t chainrings replaced 52T, whereas 53 MTB chainrings would be used instead of 42t tubular (riding 38 X 19). I don’t know what setup that is.

Cur ado is on, but it does not appear to be the enormous possible crank where one would use a double and triple chainring setup. I highly recommend using indexed shifter levers with double or fixed lengths. Because partial adjuvant engagement can cause issues for people who have short fingers compared to bigger knuckles, this spider-type shifter might work but may require more force than a standard lever due to the nonlinear leverage ratio of such a super low-level wrench.

I weigh about 150 lbs and stand around 5’4″. I don’t recommend any rings less than 42t for this bike size. This setup might work ok on kids’ bikes that come in different sizes, but it probably won’t be ideal for them since they usually have relatively narrow gears.

Difference Between 170 Vs. 172.5 Cranks

Difference Between 170 Vs 172.5 Cranks

When it comes to bike components, even the smallest differences can impact your ride. One of these differences is the length of the cranks. While 2.5mm may not seem like a lot, it can affect your bike pedaling efficiency and overall comfort. The main difference between 170 vs. 172.5 cranks is the length of the crank arm. Generally, a shorter crank arm like the 170mm will offer more clearance for technical terrain and tighter turns. Making it ideal for mountain biking or cyclocross racing. On the other hand, a longer crank arm like the 172.5mm will provide more leverage and power for road cycling or time trials.

Ultimately, choosing between 170 vs. 172.5 cranks comes down to personal preference and intended use. It’s important to consider your riding style, terrain type. And comfort level when selecting your bike components to ensure a smooth and enjoyable ride.

Are Shorter Cranks Better?

The answer to this question is very complicated. Many factors go into choosing the best crank length for your bike. First, you must understand what type of riding you will do on your bike. And what type of crankset would work best. Some riders prefer shorter cranks, during others like longer ones because they can change their cadence and get a smoother ride.

The next step is understanding the strengths and weaknesses of each size and how it will affect your riding style. For example, if you plan on using your bike primarily for climbing, choose a smaller crank length with wider-spaced rings to get more pedal power without using too much effort at high cadences.

Alternatively, you can try to use the full travel of your up-hill gear. Which will allow you to maintain high-speed power without torque loss or skipping gears. Most people recommend choosing a crank length based on their needs and preference. However, when trying different cranks, ensure they fit correctly onto your hub after adjusting . The pedal spindle(crown) back angle from parallel with its superior position (toe).

Reasons to Use 172.5 Cranks Over 170mm Pact

Reasons to Use 172.5 Cranks Over 170mm Pact

Choosing between 170mm and 172.5mm cranks can be difficult for cyclists. While both options have their benefits, there are several reasons why one might choose to use 172.5mm cranks over the shorter option. Firstly, longer cranks can provide a greater range of motion, which can help to reduce stress on the knees and hips during pedaling.

This can be especially beneficial for riders with longer legs or those who experience discomfort during extended rides. Also, longer cranks may provide more power and efficiency, allowing for a greater leverage ratio during pedaling. Ultimately, the choice between 170mm and 172.5mm cranks will depend on individual preferences and riding style, but it’s worth considering the potential benefits of longer cranks before deciding.

Ways of Knowing When to Use Each One, and Why Its Importance

When choosing between 170 and 172.5 cranks, a few factors must be considered. The length of the crank arms can affect the leverage and power output of the rider, as well as their pedaling efficiency. Generally speaking, shorter crank arms (170) are better suited for riders with shorter legs or a higher cadence, while longer crank arms (like 172.5) may be more appropriate for taller riders or those with a slower cadence.

It’s important to note that the difference in length between these two options is relatively small, so the impact on performance may not be significant for all riders. However, for serious cyclists looking to optimize their performance, choosing the right crank arm length can make a difference. Ultimately, it’s up to each rider to experiment with different lengths and determine what works best for them and their riding style.

Ways of Choosing My Chainring Size for Your Bike

Ways of Choosing My Chainring Size for Your Bike

When choosing the right chainring size for your bike, there are a few factors to consider. One of the most important is your riding style and preferences. If you prefer a faster cadence and quicker acceleration, a smaller chainring size may be better for you. On the other hand, if you prefer a slower cadence and more power with each pedal stroke, a larger chainring size may be more suitable.

Another factor to consider is the terrain you will be riding on. If you are tackling steep hills or mountainous terrain, a smaller chainring size can help make climbing easier. However, a larger chainring size can help you achieve higher speeds if you are doing mostly flat rides or sprints. Ultimately, trial and error is the best way to choose your chainring size. Test out different sizes and see which feels most comfortable and efficient for your riding style and terrain.

The Benefits of Reducing Your Crank Length

The Benefits of Reducing Your Crank Length

Stride Length- This measures the total distance traveled for a given period, usually in revolutions per minute. “Every thread you start adds one more when it’s finished.” – George Bernard Shaw. I used to have an old Low Flange Hub back when I was playing with SS bikes. Some factors unaccounted for in conventional measurements can add to quite a bit over varying lengths and feel-good reasons for actual measurements.

So, what Stg stands for? Gain Side clearance = The distance side spring assemblies can clear the rims at the mid-bottom crank position before reaching their minimum vertical extent -Ground Clearance = Similar to above but refers to any overhang of chainset from sprockets or pedal axle itself.

This graph shows how much gear reduction occurs when you reduce your spokes bight by 3mm. Hover over parts of the graph to view additional info. This is an actual measurement on an SRAM Force CX1 Mid-Range built using White Industries 24-hole rims laced to DT Swiss 300s or Shimano 7700 hubs with Lekkie Bluthner one-piece freehubs (moved tilt forward for this bike).

This shows some benefits when you reduce your spokes bight by 3mm, namely less drag due to increased side clearance. I prefer the angle shown above to help me get a better feel of what’s going on with my wheels, given that there is a risk associated with having this off.

Consider how it looks or disappears depending on whether you have a DL or SL9-type brake setup and your frame style/geometry. Reducing Crank Length can increase Ground Clearance, helping prevent cog jump while allowing for bigger tires in wet weather.

Why are standard cranks the length they are?

Why are standard cranks the length they are

The length of standard cranks has been debated among cyclists for years, with many wondering why they are the length they are. The most common crank lengths are 170mm and 172.5mm, with some manufacturers offering lengths ranging from 165mm to 175mm.

The crank’s length is determined by several factors, including the cyclist’s leg length, riding style, and personal preference. While there is no one-size-fits-all answer for crank length, it is generally recommended that cyclists choose a size that allows them to pedal comfortably without putting too much strain on their joints.

Ultimately, the best way to determine the optimal crank length for you is through trial and error, so don’t be afraid to experiment until you find what works best for your individual needs.

How To Measure Crank Length?

How to measure crank length

When comparing cranks, one of the most important factors is the length. To measure crank length, you will need a measuring tape or ruler. First, locate the center of the bottom bracket and measure from this point to the center of the pedal axle. This measurement will give you the overall length of your crank.

It is important to note that even small differences in crank length can significantly impact your cycling performance and comfort. For example, a shorter crank may be more comfortable for riders with shorter legs. While a longer crank may provide more power for taller riders. When comparing 170 vs. 172.5 cranks, consider your body measurements and riding style to determine which option is best for you.

Is there an optimum crank length?

Is there an optimum crank length

When choosing the right crank length for your bike, there is no one-size-fits-all answer. While some cyclists prefer shorter cranks for increased ground clearance and improved cornering, others opt for longer cranks to maximize power transfer and leverage.

Studies have shown that the ideal crank length varies based on body size, riding style, and terrain. Ultimately, trial and error is the best way to determine the optimum crank length for you. Experiment with different lengths and pay attention to how they feel during rides. You can optimize your performance and enjoy a more comfortable ride by finding the perfect crank length for your body and riding style.

How Does Crank Length Affect Power Output?

How Does Crank Length Affect Power Output

Crank length is an often-overlooked factor when it comes to cycling performanceut. It can have a significant impact on power output. In general, longer cranks (such as 172.5mm) can provide a more excellent range of motion. And allow for more leverage, resulting in higher power output. However, shorter cranks (170mm) can offer a more efficient pedaling style.

And may be more comfortable for riders with shorter legs or higher cadence. Ultimately, the ideal crank length will depend on individual factors such as body proportions, riding style, and personal preference. It’s worth experimenting with different lengths to find the one that works best for you and your cycling goals.


It is best to try out different cranks and find the one that fits your riding style. If you primarily do climbing, choose a smaller-spaced ring set with shorter cranks. If you want to do mainly downhill, try a larger-spaced ring set with slightly shorter cranks.

After comparing the 170 vs. 172.5 cranks, it is clear that there are some differences in their performance and suitability for different riders. The 170 cranks may be better suited for riders who prioritize speed and power, while the 172.5 cranks may be a better choice for those who want a more comfortable ride or have longer legs.

Ultimately, the best option depends on each rider’s preferences and needs. When choosing between these two crank lengths, it is essential to consider factors such as riding style, terrain, and body type. By evaluating your options carefully, you can find the correct crank length for your needs and enjoy a more comfortable and efficient ride.


1.Should I use a 170 or 172.5 crank?

Ans: There is no one-size-fits-all answer when choosing between a 170 and a 172.5 crank. The length of the crank arms you choose should depend on your body size, riding style, and preference. Generally speaking, shorter cranks (170mm) may allow for higher cadence and better ground clearance. While longer cranks (172.5mm) can provide greater leverage and power transfer.

2.Is a bigger crank better?

Ans: When it comes to cycling, the crankset’s size can impact your riding experience. It’s commonly believed that a bigger crank provides more leverage and power, but this isn’t always the case. The optimal size for your crankset depends on factors such as your riding style, terrain, and physical abilities. Ultimately, choosing a crankset that feels comfortable and efficient for you personally is important.

3.What is the best crank ratio for climbing?

Ans: The best crank ratio for climbing depends on your personal preferences, fitness level, the terrain you’ll be climbing, and the type of bike you’re riding. However, a general rule of thumb is to have a lower gear ratio to make it easier to spin the pedals uphill. This typically means using a smaller chainring in the front and a larger cassette in the back. Experimenting with different ratios and finding what works best for you is important.

4.How important is the crank length?

Ans: Crank length plays a significant role in cycling performance, affecting the rider’s pedaling efficiency and power output. The right crank length for a rider depends on several factors, such as height, riding style, and body proportions. It is recommended to get a bike fit to determine the appropriate crank length for optimal performance and comfort.

5.Will shorter cranks make me faster?

Ans: Shorter cranks can sometimes lead to higher cadence and more efficient pedal strokes, which may result in a faster average speed. However, this depends on individual factors such as body mechanics and riding style. It’s best to consult with a fitting bike professional before changing your bike setup.

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