How Important Are Derailleurs On A Mountain Bike?

by | Last updated on January 24, 2024

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The best mountain bike derailleur helps you shift quickly, efficiently and silently. It may seem like a small thing, but the humble derailleur is

one of the most important attributes of your mountain bike

, as it’s responsible for moving between gears so you can tackle whatever gradients you come across.

Is a derailleur necessary?

Are Front Derailleurs Necessary? These days

front derailleurs are essentially not necessary

, on mountain bikes at least. Now even high-end road bikes are starting to lose their front derailleurs. With a larger rear cassette, it’s possible to get the same number of gears without the need for a front derailleur.

Do derailleurs make a difference?

It is more about the package not just difference in a single part.

The higher end parts are going to perform somewhat better

. How much really depends on the person and how they are going to use it. If you are going to only ride your bike a few times a month, then the Deore level is a great component set.

What does a derailleur do on a mountain bike?

The derailleur is the device that

changes gears by moving the chain from one sprocket to another

. There are two derailleurs: one on the rear and one on the front. The highest ratio (when the bike can go fastest) is produced when the chain is on the biggest sprocket in the front and the smallest in back.

Why MTB has no front derailleur?


Removing the front derailleur opens up options to make rear suspension pivots wider, meaning more stiffness and longer lasting bearings

, which makes our riding lives better/happier/more fun.

Should I ride with derailleur clutch on or off?

It’s easy to see the on/off switch for the clutch mechanism.

Turn it off to tune your gears or when you need to remove the wheel, otherwise run it on for the quietest ride of your life

.

Can you ride without a front derailleur?


Yes, although it’s something that recumbent riders probably do more than upright ones

. When your chainrings are something like 20T/50T/70T there’s no way to shift that easily with a front derailler, so ankle shifts are often no worse than a modified FD trying to shift bigger jumps than it was made for.

Are front derailleurs obsolete?

Since then,

the front derailleur really hasn’t changed much at all

. It’s still a basic component, comprising two metal plates that shove the chain across the chainrings, and the stiffer those plates the better the shifting.

Why bikes are being sold with only one gear in front?

Q: Why bikes are being sold with only one gear in front? These bikes are called 1X or OneBY drivelines.

They have only a single chainring and a wider ratio rear cassette

. Their advantage is that they don’t have a front derailleur or shifter.

What is the purpose of a clutch on a derailleur?

The clutch on Shimano derailleurs adds tension to the chain, reducing chain bounce in rough terrain, therefore minimizing “chain slap” against the frame, and keeping as much chain wrapped snuggly around the chainring as possible to prevent it from dropping off the ring.

How much does a good derailleur cost?


If you take your MTB into a local bike shop the average price to replace a rear derailleur is going to be $110

. If you DIY replacing a derailleur will cost about $50 (plus your time) This price will depend a lot on the actual derailleur needed. Usually a bike shop will also take care of other problems.

How do I know what derailleur I need?

When buying a new rear derailleur be sure to

match it with your drivetrain ‘speed’

. 10-speed drivetrains use narrower chains than 9-speed so you’ll need a mech to match. Most rear mechs are made of a polymer and alloy mix but you’ll find carbon fibre in top-end models to shave even more weight.

Can you use any rear derailleur?


A derailleur for your mountain bike should match the specifications on the original derailleur

. That is, while it doesn’t need to be the same model of derailleur, it does need to be the same brand, in almost every case. It also needs to match the number of gears, or have more intended.

When should I replace my derailleur?


Derailleurs will last almost indefinitely

. The jockey wheels will wear out in time (tens of thousands of km) but the rest of the mechanism shouldn’t see significant wear. It could be that the spring will break at some point due to material fatigue, but that is also a relatively easy to replace part on most derailleurs.

What gear should I use on a flat road?


Middle Gear

This is a great gear for everyday terrain when you’re cruising along on a flat road or on undulating terrain. You want some resistance, but not too much. If the road goes up and down a bit, you’ll probably flick between the rear gears to cater for changes.

Why do mountain bikes only have 11 gears now?

So why do mountain bikes have less gears? Mountain bikes have less gears for quite a few reasons, however the primary reasons being

less maintenance, lighter weight, and the need for only the quickest shifts when running into such a varied terrain

.

Is 8 speed bike enough?


8 speed drivetrain is great, everything else about it sucks, forks and brakes are terrifying

. My other bikes are mostly 2×9 or 3×9, which works fine, with one 2×11 XT. The 2×11 is the clunkiest of the lot, really does not feel like a high-end drivetrain.

Can you put any derailleur on a bike?

Shimano derailleur compatibility

This means that

you can use an 8 -or 9-speed mountain bike derailleur with road shifters or vice versa

. The only exception is pre-1997 9-speed Dura-Ace gearing, which won’t play nicely with anything because it uses a totally different cable pull ratio.

Should the clutch be on or off on a MTB?

It’ll be just fine. Just like you said, the clutch keeps the chain from bouncing and makes for a quieter ride. When it’s off, it’s just like every other derailleur that doesn’t have one.

If you ride smooth paths and road, it’s honestly not even necessary so if you leave it off it’s one less thing that can wear out

.

How do you tell if a derailleur has a clutch?

How does a derailleur work?

What happens if I remove front derailleur?

Removing the front derailleur isn’t really a good idea, gear wise unless you have a good reason to. All you’re doing is

taking away the little mechanism that moves the chain from one front ring to another

. If you’re not happy with the shifting, get it tuned, not remove it.

Does speed matter for front derailleur?


The number of rear speeds (the 9 in 2×9) marked for a front derailleur isn’t too important

, but the cage of the derailleur may be thinner for higher number of rear speeds (so if your chain isn’t designed for high enough speeds, you may have some rubbing on the cage, especially if you don’t adjust it properly) — as …

Can I use a Shimano front derailleur with SRAM shifters?

Condensed Answer: In general,

it’s possible to combine a Shimano front derailleur with a SRAM shifter

because both brands use extremely close cable pull ratios for the front mech.

Can I use MTB chain on road bike?


Road and MTB chains are interchangeable when they are of similar length and designed for the same number of speeds

.

Can I use a MTB front derailleur on a road bike?


Works perfectly OK

. What you want to avoid are combining a road front mech and MTB shifter, or MTB front mech and road shifter. For some reason the design MA for each are slightly different.

Rebecca Patel
Author
Rebecca Patel
Rebecca is a beauty and style expert with over 10 years of experience in the industry. She is a licensed esthetician and has worked with top brands in the beauty industry. Rebecca is passionate about helping people feel confident and beautiful in their own skin, and she uses her expertise to create informative and helpful content that educates readers on the latest trends and techniques in the beauty world.