Choosing the right crankset for your bike can be confusing. The problem is that different manufacturers use different measurements for their parts even across the models of the same brand. In that case, are cranksets interchangeable?
Cranksets are not always interchangeable. Every crank is designed to work with a specific bottom bracket. Even if the cranks use the same interface (octalink, square taper, or hollow tech), switching them between bike brands or even models of the same brand is hard.
MTB cranks are usually spaced wider than other bikes. Therefore, if one has an MTB and another bike, interchanging the cranksets may prove to be complicated.
Can You Put Any Crankset On A Bike – Are Cranksets Interchangeable?
Every brand has its specifications when it comes to cranksets. In addition, different models of the same brand also have diverse bottom brackets specifications. These differences make it impossible to put any crankset on a bike.
All the same, most two and three-piece cranksets can work on the same bottom bracket. But there is a catch; the axles have to be of the same diameter and length.
Again, the ideal crankset will also depend on the rear pockets in use.
If the two bikes use 6, 7, and 8 gear cassettes, then they most likely have the same chain width and chainring spacing.
As earlier noted, even different bike models from the same brand may feature diverse bottom brackets. Without a doubt, this makes it impossible to put any crankset on a bike.
Are All Bike Cranks The Same Size?
Bik cranks are available in sizes ranging from 165mm to 190mm. Notably, this is the length from the center of the bottom to that of the pedal axis. The most common sizes are 170mm, 172.5mm, and 175mm.
A cyclist’s ideal crank size depends on the rider’s height, cycling habits, and other personal preferences.
Knowing the size of the ideal crank can be a minefield in cycling. Cranks are levers, and the longer the arms will amplify the effects of force applied. So, are longer cranks better than shorter ones?
According to Shimano, cranks between 170mm and 175mm provide a balance between cadence and torque.
Shorter cranks will have a shorter circumference which favors a higher cadence. On the other hand, longer cranks allow riders to pedal harder but at a slower cycling speed.
Therefore, all bike cranks are not of the same size. For beginners, it is advisable to avoid going for extreme crank lengths. It is advisable to start with the popular sizes and adjust later according to personal preferences.
What Is The Difference Between Cranksets?
The main difference that sets cranksets apart is their number of teeth. Generally, cranksets are divided into two main groups – Compact and standard.
Some manufacturers also know compact cranksets as Semi-compact. Standard cranksets have a 53 teeth big ring and a 39 teeth small ring. On the other hand, compact cranksets have a 50 teeth big ring and a 34 teeth small ring.
There are other ways to classify cranksets. For example, you can look at the number of rings or the shape of the outer chainrings.
However, the number of teeth on the rings is the most crucial factor in determining whether a crankset should be identified as standard or compact.
Compact cranksets have become popular over recent years in road cycling. Technically, they provide a performance boost when climbing hills.
They are lighter than standard crankset, but they generally cost slightly more.
While most compact cranksets have two inner rings, some have three. There are very few compact cranksets that have more than three rings.
A standard crankset with 53 teeth big ring and 39 teeth small ring provides a noticeable difference in gear ratios compared to a compact crankset.
The standard setup gives the cyclist an advantage when riding at high speeds and is more suited to time trials than hill climbing.
However, although standard cranksets offer greater speed, they are heavier than their counterparts.
How Do I Choose A Crank?
Choosing the correct crank size improves the efficiency of every stroke and reduces injury risks. Interestingly, on most bike forums, the topic of ideal cranks length has always drawn immense reactions.
After the saddle height, the second most crucial factor in ride quality is the crank length. Taller riders may not feel the difference, but the shorter a rider is, the more likely they will feel the difference between two crank sizes.
Going by the “standard” 172.5mm crank length used on most of the bikes for an average male of 5’10” height as a point of reference, the ideal crank size should be 9.7% of a rider’s height.
| Rider’s Height | Crank Length(cm) | ||
| 6’0″ (1828mm) | 177.5mm | ||
| 5’11” (1803mm) | 175mm | ||
| 5’10” (1778mm) | 172.5mm | ||
| 5’9″(1753mm) | 170mm | ||
| 5’7″ (1702mm) | 165mm | ||
| 5’5″ (1651mm) | 160mm |
When Should I Replace My Crankset?
It would be best if you replaced your bike’s crankset when you start having problems shifting. Mostly, cranksets can last a long time, but sometimes a combination of wear and tear can cause a problem.
A crankset can outlast two or three chains and cassettes. However, if you ride a lot and your crankset has survived for five years without issue, then it’s probably time for a replacement.
So let’s answer the question, “when should I replace my crankset?”
You don’t want to push your luck. Here are some tell-tale signs that it might be time:
1. A Crunchy Noise When You Pedal
Broken or worn teeth usually cause this on your chainrings. On the other hand, the bottom bracket could be worn out, or the crankset isn’t tightened properly. Therefore, it is advisable to confirm where the noise could be coming from.
2. When Chainrings Are Bent
In most cases, pedal cranks are made of aluminum. If your pedals were to hit a rock – or maybe even a curb – it’s possible they could bend and cause all sorts of problems.
3. When The Spindle Is Bent
A bent spindle could also cause a crunchy sound, but it’s less likely to happen because usually, a problem with your bottom bracket means a bent spindle.
4. The Chain Skips
It’s easy to think your derailleurs need adjusting, but it’s probably not the case. Instead, the teeth on your chainrings are wearing out, and they don’t engage properly with the gears anymore.
Cranksets come in various teeth size options, so it’s important to replace your worn crankset with the same size crankset that came with your bike or one that has similar gear ratios.
How Do I Know If My Crankset Is Compatible To My Bottom Bracket?
Like we had observed earlier, cranksets are generally not interchangeable even across models of the same brand. So, how can you tell that your crankset is compatible with your bike’s bottom bracket?
First, you need to know the ‘type’ of the bottom bracket that runs inside your bike before you can figure out whether it is compatible with any crankset. Most manufacturers will print the type on the bottom bracket shell of your bicycle. Look for a match between the “shell width” of the bottom bracket and the “diameter” of the crankset’s axle.
If both are equal, use the crankset.
On the other hand, you can use the BCD (Bolt Circle Diameter) to check compatibility. The BCD is the diameter of the bolt circle that holds your chainrings to your cranks. This varies between manufacturers and also by brand.
Frequently Asked Questions
1. Do All Cranksets Fit All Bikes?
Bicycle cranksets come in different sizes with different fittings for the types of bikes in the market. Therefore, as we had discussed earlier, cranksets range from 16mmm to 190mm.
Also, some bikes have wider bottom bracket shells, and this calls for a specific axle. Therefore, all cranksets don’t fit all bikes.
2. Are All Mountain Bike Cranksets Universal?
Mountain bike cranksets are not universal. Every brand and model is unique from others. Therefore, the choice for a crankset doesn’t rely on the type of bike you are riding.
There are other factors such as chainrings, bottom bracket shells, and the brand also matters.
3. Are All Road Bike Cranks Compatible?
Not all cranksets are compatible with modern road bike’s bottom bracket shells. Actually, compatibility depends on brand and model.
Cranksets attach to the bottom bracket, and there are different types of bottom brackets in the market. In addition, most chainrings can’t work across bike brands and models.
4. How Much Does A Crankset Cost?
The price for a crankset depends on the brand and model. But most high-end cranksets will cost about $250. The price for mid-level cranksets can vary from $150 to $225. And low-end cranksets usually cost around $40 – $100.
Also Read: Can You Put BMX Cranks On A Mountain Bike?
Final Take – Are Cranksets Interchangeable?
It is essential to understand that cranksets are not interchangeable. They can vary in the physical dimension, weight, length of the crank arm, number of chainrings per side, and gear ratios.
Indeed, understanding these specifications before purchasing will ensure you get the right fit for your bike frame size and riding style.
Different bikes have different-sized frames that accommodate their specific type of crankset.
Therefore, if you change or replace your frame with a different one from what the manufacturers initially built, there may be some difficulty fitting new components due to mismatched sizes.