Derailleurs come in three sizes: short, medium and long cage. Derailleur capacity is proportional to cage length. For wide range MTB cassettes with three front chainrings, it is practical to have a long cage derailleur.

Are all derailleurs the same?

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.

Which is the best derailleur?

Best mountain bike derailleurs

• Shimano Zee Freeride. A modern clutch rear derailleur for those who need Shimano 10-speed compatibility in a compact package. ...
• MicroSHIFT XCD. ...
• Shimano Deore XT Long Cage. ...
• Sunrace MZ900. ...
• SRAM GX Eagle. ...
• SRAM XX1 Eagle AXS. ...
• TRP TR12.

Do I have SS or GS derailleur?

For your particular gearing range (50/34 compact double and 12-25 cassette), an SS will work. GS is for wider gearing ranges that will result in more chain slack when the drivetrain is crosschained small-small, like on triples or if you are running a very large cassette on a double.

What does Shimano SGS mean?

Shimano MTB rear derailleurs last letters will be GS or SGS, which stand for "Short cage" or SGS for long cage. A XTR rear derailleur will be RD-M970-GS (for short cage) or RD-M970-SGS (for long cage)

What is total capacity rear derailleur?

Derailleur tooth capacity explained

The total capacity of a SS (short cage) Shimano derailleur is 35t and 39t for a GS (medium cage) derailleur.

What is front derailleur?

The front derailleur is the mechanism that shifts the chain on bike with more than one front chainring. There are many different makes and models, but they all share the same basic design and functionality. Front derailleurs are attached to the bike with either a clamp or bracket. Clamp mounted derailleur.

What is Shimano derailleur?

A derailleur is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another.

What is derailleur capacity?

All derailleurs have a maximum cassette size. This is often indicated as the maximum number of teeth that can be on the biggest cog (often referred to as low sprocket max in manuals). So when you see that a derailleur has a maximum cassette size of 30T you know that the biggest cog on the cassette cannot exceed 30T.

What model is my Shimano derailleur?

Shimano stamps the rear derailleur model number on the underside/lower plate of the parallelogram.

What is a rear derailleur?

The rear derailleur is the mechanism that shifts the chain at the rear sprockets. There are many different models but they all share the same basic design and functionality. Derailleurs are secured to the bike with a mounting bolt to the frame's derailleur hanger.

Which is better Altus or Alivio?

The main difference between these two is the Alivio offers some additional crankset components that are not present in the Altus. There are also variations in their weight and overall build. The Altus groupset is slightly cheaper so if cost is a concern it might be a more suitable choice between these two.

Can I use a 7 speed derailleur on an 8 speed cassette?

8 speed shifter and cassette, 7 speed derailleur? You'll be fine. There's no "probably" about it. 6-, 7- and 8-speed gear is all cross-compatible in terms of chain width.

Can I use a 9-speed derailleur on a 7 speed cassette?

Can I use a 9-speed derailleur on a 7-speed cassette? The answer is yes because the rear shift ratio of 9-speed and 7-speed derailleurs is the same if you stay within the same brand.

What is H and L on bike?

The Front Shifter & Derailleur. The front derailleur is controlled by the left shifter. Many shifters are marked in some way, often numbered or with an 'H' for the high gear and an 'L' for the low gear. The '1' or 'L' refers to the innermost chainring (closest to the bike).

What is a top swing derailleur?

Low clamp (aka top swing)

This type of front derailleur mounts low down to a round seat tube with a band clamp. Because the clamp sits low on the frame (near the bottom-bracket junction) and the derailleur itself pivots above it, these are commonly also known as 'top swing' front derailleurs.

What rd means in bike?

R. Rear Derailleur: Also known as Rear Der on the picture, also known as Rear Mech or Mechanism. Rear Shock:The rear suspension on a full suspension bike, it adsorbs the bumps.

What is Max Front difference?

Maximum front tooth difference is an invented spec that Shimano has begun using to attempt to present compatibility data to consumers in a way they think will be simpler or more effective or whatever. Maximum front tooth difference contains zero information not already present in the total capacity number.

Which is better long cage or short cage derailleur?

It's generally best to go for as short a derailleur cage as you can get away with, as long as you can avoid the chain contorting on the extremes of the cassette, such as using the largest on both sprocket and chainring. Smaller cages tend to have snappier gear changes, they're lighter, and also less exposed to damage.

What is chainring difference?

The number of teeth in the chainring determines the output you create in moving the bike forward while you pedal. For example, a 28t chainring will feel lighter and have less resistance when pedalling while a 36t chainring will feel harder to pedal against and have a strong resistance when pedalling.