Rear derailleurs
use a cage fitted with two pulleys. The lower pulley pulls backwards to give tension to the lower section of chain
. It is called the tension pulley, or ‘T’ pulley for short. The upper pulley guides the chain to the sprockets.
How do front and rear derailleurs work?
In terms of function, both front and rear derailleurs have the same principle.
They guide the chain to a higher or lower sprocket by pushing it while pedaling
. This pushing is assisted by specially shaped teeth, known as shift ramps, which help the chain rise/fall to another sprocket.
Can you use any derailleur on a bike?
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.
Why is my derailleur clicking?
If you hear a constant clicking (especially in certain gears), it could mean that
your shifter cables have stretched enough to pull your derailleur out of alignment
, causing your chain to ride between gears or rub on the derailleur cage. First, make sure your derailleur is aligned and that the hanger isn’t bent.
Why is my derailleur hitting my spokes?
Often, the derailleur hits the spokes
when its hanger is bent following a heavy hit
. If that’s not the case, it could be due to wobbly spokes, misadjusted limit screws, or incorrect cable tension.
How do you check rear derailleur?
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 mix front and rear derailleur?
Do not mix and match derailleurs with other parts of the drivetrain from other manufacturers
. E.g Use only Shimano rear derailleurs with a Shimano drivetrain. While some elements of a drivetrain may be cross-compatible between brands, when it comes to derailleurs and shifters, they are most often not.
What do derailleurs do?
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.
How do you use a derailleur clutch?
Who invented the derailleur?
So who invented the derailleur? The first, and best, candidate, much favoured by the French, is
Jean Loubeyre
of Paris. He indisputably patented a 2 speed derailleur device called ‘La Polyceler’ in 1895 (French Patent # 245,148).
How do you install a derailleur extender?
How do you install a derailleur?
Do I need a short or medium cage derailleur?
Derailleur cage length quick guide
If you are running a 1x drivetrain with a regular-sized cassette (i.e. 11-36t or smaller) or some 2x mountain bike drivetrains with a similarly sized cassette, you may want to use a medium cage derailleur.
Why does my bike creak when I pedal hard?
The most common cause of creaking is the
crank being loose on the spindle
. Remove the crank bolts, lubricate the threads and under the bolt head, and reinstall. Tighten the bolts to the manufacturer recommended torque. Use a torque wrench if possible.
Can I use wd40 on bike chain?
WD-40 is a great bike chain lube water based lubricant and will not only lubricate the chain well, but will also keep it rust and corrosion free
. It also minimizes the accumulation of dirt which reduces the wear and tear of the chain.
Why does my bike clunk when I pedal?
Symptoms: A clunking sound on the bottom of the bike that only occurs when you pedal
may be coming from the bottom bracket
. Solution: If it isn’t a loose pedal, chances are you may have a loose bottom bracket. To tighten the bottom bracket, you’ll need to remove the crank arms.
What do the screws do on a rear derailleur?
Derailleurs are fitted with limit screws that
stop the derailleur from moving too far inward or too far outward
. If you look closely as the derailleur moves, you can see the limit screws stopping the derailleur at each end of it’s travel.
How do you know if you have a bent derailleur hanger?
How do you adjust a derailleur on a mountain bike?
How do you align a derailleur?
Should my derailleur be straight?
unless you have it on the grannie up front (or the cranks are way off the proper chain line) it should be reasonably straight line
. It’s very unlikely that you bent the parallels on the actual derailleur, possible, but very unlikely..
Can I use Shimano cassette with SRAM derailleur?
Buyers are free to use a SRAM chain and cassette with their Shimano groupset, and vice versa, just as a SRAM chain can be paired with a Shimano cassette, and vice versa.
SRAM’s cassettes and chains are compatible with all of Shimano’s groupsets, and vice versa
.
How do I identify my Shimano rear derailleur?
Do I need long or medium cage derailleur?
If you are in-between the capacity ranges of the two, which is often the case with mountain bikes, then note the following:
long cage derailleurs will accommodate a wider gear range and deliver a better chain line, while medium cage derailleurs are less likely to be hit by rocks on the trail
.
