Kindernay Blog

Internal Gear Hubs Vs. Derailleurs - What Works Best for Mountain Bikes?

Written by Bianca de Tschaschell | 10 February 2021

Gear hubs have become significantly more versatile and technologically modified, answering the users’ diverse calls for improved performance and efficiency.
Whilst derailleurs and internal gear hubs were factually invented around the same time about 100 years ago, bikes have mostly been equipped with a traditional derailleur gear.

 

However, internal gear hubs such as the Kindernay XIV have challenged the predominant position of derailleurs and have succeeded in consistently advancing technologies and augmenting the gear ranges to the standard of derailleurs.

 

With internal gear hubs having broken free from previous constraints, which gear system is best for mountain bikes? We have gathered the characteristics of derailleurs and internal gear hubs and have compared how each system delivers on various aspects for your MTB.

 

So, what are you waiting for? Time to talk gears!

 

Derailleur gear systems

Derailleur stems from the French word dérailleur, which implies the train’s derailment from the tracks. Derailleur bike hubs function quite similarly to the word origin’s meaning – when a rider activates the lever by pedaling, the transition in the shifter cable tension maneuvers the chain diagonally, thereby “derailing” the chain onto various sprockets.

 

Derailleurs generally consist of a chain, multiple sprockets of versatile dimensions, and a mechanism that hocks the chain from one sprocket to another. The sprockets ultimately revolve between the rider’s feet, whilst being connected to the rear wheel, allowing the rider to select a specific number of gears – nowadays, the most common are 11-speed or 12-speed.  

 

The majority of modern bikes these days are provided with derailleur gears – but how come? Derailleurs are said to translate into a gearing efficiency of circa 96-99%, which is slightly higher compared to other gear types. The derailleur gears are easy to repair, relatively cheap in their acquisition, and contain a large gear range.

 

Internal gear hubs

Internal gear hubs seal all of their in size-ranging components inside a comprised, light, grease-bathed entity. Gears and lubricants are concealed within the hub gear’s shell – which is the primary difference to the derailleur gears, where the gearing process is imperiled to all elements. Unlike the majority of internal gear hubs on the market today, the Kindernay XIV is fully oil-lubricated. 

 

Generally, the internal gear hub’s mechanism revolves around a stationary axle that contains three spring-loaded and wedge-shaped metal pawls; By shifting gear, the pawls extend from the axle. The Kindernay XIV uses axial dog clutches instead of pawls that increase the torque capacity and longecity of the gear.   
Internal hubs are equipped with planetary or epicyclic gears, which overall augment the gearing ratio available.  

 

What works best for Mtb?

Which gear system is most appropriate for a mountain bike? Evidently, both derailleurs and internal gear hubs have their individual pros and cons. Let’s look at the main aspects and see how each gear system delivers!

 

Maintenance

One of the greatest advantages of internal gear hubs is their little need for maintenance; internal gear hubs are almost fully maintenance-free, the only activity being the renewal of hub oil approximately every 5000km.

On the other hand, derailleurs are far more prone to maintenance needs, requiring periodic cleaning and replacement of chains, cassettes and cables.

 

In case of any minor disruptions, derailleurs are relatively easily fixable with basic bicycle instruments, which naturally translates into a degree of calmness when on a mountain bike tour. If the derailleur needs to get replaced, it is usually do-able no matter where in the world. Whilst internal gear hubs are less susceptible to damage, they do require more knowledge for potential repair activities. 

 

Durability and Wear

With internal gear hubs enclosing all constituents inside a sealed item, the gear hub is at no time open to or in danger of defect caused by elements such as water, dirt, salt, or sand; this characteristic renders the internal gear hub extremely durable, lasting close to a lifetime of a bicycle.

 

The limited degree of wear for internal gear hubs is an especially convincing factor for mountain bike expeditions – when riding off-road or on back-country roads, the rider will never need to be anxious about water or debris potentially harming the gears, derailleur, or chain. Mountain bikes equipped with internal gear hubs can thus be ridden in damp, silty, or snowbound settings – the focus is all set on the pure cycling experience!

 

With the chain consistently remaining on the same gear type, the chain is naturally less prone towards potential wear, persevering of long duration. When using a derailleur gear and chain, the chain inflects with each gear-change, translating into shorter time between replacements.

 

Shifting

Internal gear hubs follow a “shift instantly” technique, meaning that the rider can shift gears even when not engaging in pedaling. When riding in mountainous regions, one does not need to worry about coming to a stop or having difficulties climbing with the mountain bike.


With a mountain bike equipped with an internal gear hub, multiple gears can be shifted all at once without the possibility of dumping the chain.

 

Gear Ratios

A grand gear range renders more efficiency and facilitates the climbing of steep mountains with satisfying ease and speed.

 

The majority of modern derailleur bikes are equipped with approximately 12-speeds and a gear range of 420%-520%.  

Whilst average internal gear hubs have a gear range of 200%-400%, the Kindernay XIV internal gear hub is on the forefront within the gear ratios and strongly competes with derailleurs by having a 543% gearing range and 14-speeds.

 

Performance and Weight

Derailleur gears are naturally very efficient, with the operations requiring fewer gears to transmit the pedals’ input to the rear wheel. The efficiency benefit is however not guaranteed and perennial, especially with the derailleur’s exposure to grime and mud. If the system is not properly maintained or aligned, the gears will not manage to achieve top-notch performances.

 

Internal gear hubs are naturally heavier than derailleur systems, due to the added gears and complexity. However, the Kindernay XIV is challenging this position, with a weight of 1400 grams.

 

With the added weight, internal gear hubs theoretically translate into a lower efficiency performance. But by being highly durable and resistant to external factors, one can be ensured to always reach peak results with internal gear hubs.

 

Conclusion

 

There is clearly no wrong or right as to which gear system fits best to a mountain bike; The choice of gear strongly depends on the user’s needs, preferences, and riding style.

 

Let’s hear from a mountain bike expert and one of Kindernay engineers, Jakob Deraas Grimsgaard , on his opinion which gear works best for mountain bikes:

 

“For the bikes I use most of the time like my mountain bike, training bike, trail bike, fat bike etc., I prefer to do as little maintenance as possible. I just want a bike I can throw in the shed after a ride no matter how dirty or muddy it is, and don't worry about cleaning or maintaining it. With internal gear hubs, you spend the least number of hours in the work stand. That's where the real beauty of the gear hub system comes into play, because everything is internal.

If you’re on the “racing” side of mountain biking where you need ultimate performance for a race, I would choose the derailleur systems. Here, components are built to be very lightweight and efficient, but unfortunately also quite fragile (and expensive!).”

 

At the end of the day, both gear systems are totally appropriate for your mountain bike; depending on the conditions and demands, derailleurs and internal gear hubs satisfy the requirements.

 

By being extremely durable and maintenance-free, internal gear hubs are a great companion to mountain bike tours – feel free to read more about the Kindernay XIV internal gear hub and find out on your own which gear works best for you!

 

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