How To Install Gear Shifter On Bike: Make Your Bike Shift Like New

Written By: Jonathan
Fact Checked By: Caroline Dezendorf
Reviewed By: Matt Tanner

Actually the gear shifter is a small control mounted on your handlebar that allows you to change gears by adjusting the tension on the gear cable, so when it is installed and adjusted correctly a shifter ideally helps the front or rear derailleur to move the chain between gears very smoothly.

And that makes it really easy or hard to pedal, depending on the terrain as well.

Also, most bicycles actually use trigger shifters with levers or twist/grip shifters that actually rotate, and these only match specific types of drivetrains such as: 7-speed, 9-speed or 11-speed systems.

To prove this, according to Shimano, one of the leading gear manufacturers, getting the gear shifting right actually improves pedaling efficiency, reduces chain wear and also increases drivetrain life.

So the first thing you need to do is understand how your gear system actually works, this can also help you avoid common problems like skipped gears or chain drops.

So, whether you want to replace a damaged shifter or upgrade for better performance, you need to know How To Install Gear Shifter On Bike so that you can enjoy a smooth ride.

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Tools

Tool / Material	Purpose
Gear shifter (twist or trigger)	This is the new shifter you will want to install.
Inner gear cable	It is necessary to connect the shifter to the derailleur.
Cable housing	It actually guides and protects the gear cable.
Allen wrenches (Hex keys)	It is actually used to loosen and tighten bolts such as: shifters, derailleurs, and cable pinches.
Cable cutters	This helps you cut the cable and housing cleanly.
Torque wrench (optional)	This ensures proper bolt tightening without actually over-torquing.
Screwdrivers	Use this when you need to adjust the derailleur limit screws, which are usually Phillips or flathead.
Light lubricant or cable grease	This reduces the friction inside the housing.
Crimp-on cable end caps	It is actually used to protect the ends of cut cables from fraying.
Bike stand (optional but helpful)	Yes, this is totally an option but it does help keep the bike stable while working.
Clean rag or shop towel	This helps you clean off grime and old grease during installation.

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Identify Your Bicycle’s Drivetrain Setup

When you are looking to install a new gear shifter it is important to really understand your bicycle’s current drivetrain system, which actually includes all the parts that work together to move the bicycle forward such as: learn clearly about chain, cassette, derailleur, and shifter, because if you choose the wrong type of shifter it may cause poor gear changes, and it may also lead to chain skipping or even damage your components.

1. Front or Rear Shifter?

First determine whether you are replacing or installing a front shifter that actually controls the front derailleur and chainring or a rear shifter that actually controls the rear derailleur and cassette.

Because most mountain bicycles and geared hybrids have two shifters: left for the front and right for the rear.

And yes, there are also some single-chainring bicycles available that use only a rear shifter.

2. How Many Gears Does Your Bicycle Have?

Count the number of cogs on your rear cassette, which is usually 7 to 12, and the number of chain rings on the front, which is 1 to 3.

You then need to multiply the number of front and rear gears to find the total gear combinations, for example: 3×7 = 21-speed bicycle.

Also, just remember that your rear shifter must exactly match the number of rear gears, for example: a 9-speed cassette actually needs a 9-speed shifter as well.

And the same applies to the front: a triple chainring setup ideally requires a 3-speed front shifter as well.

3. Shifter Brand Compatibility

You have to be sure, as shifters and derailleurs are not always cross-compatible across a variety of brands.

As Shimano and SRAM actually use different cable pull ratios, which literally means the amount of cable they pull per click differs, a Shimano shifter should be used with a Shimano derailleur and likewise for SRAM or Campagnolo as well.

If you mix brands it can lead to incorrect shifting and mechanical problems, so be aware of brand exclusivity as well.

4. Match Shifter with Derailleur and Cassette

Yes, all parts of your drivetrain must work in coordination, so the shifter must also match the following parts:

• This should match the number of gears on your cassette also known as the gear ratio.
• It should also match the brand and model of the derailleur.
• Additionally, the cable-pull system must be specifically matched for indexed shifting, where each click moves the derailleur a precise amount.

If you use completely mismatched components it can result in incomplete shifts, gear skipping or limited gear range and this significantly affects handling under load or climbing.

Note: If you’re really unsure about your gear setup, all you have to do is check the number printed on your cassette, simply count your cogs and chainrings and then look for the model names that may be printed on your derailleur or old shifter to find out full compatibility with it.

Read More:

How Do Bicycle Gears Work?

How To Shift Gears On A Bicycle

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How to Remove the Old Shifter

If your bicycle still has an old or damaged gear shifter and you want to remove it, there are certain steps that must be followed to avoid damaging other components.

1. Shift to the Smallest Gear First

This is really essential as it reduces the tension on the cable and makes it easier to disconnect the gear cable without any kind of sudden breakage or retraction.

That’s why it’s important that you shift your bicycle into the smallest gear possible: the smallest cog on the rear cassette and the smallest chainring on the front, if any.

Plus, it actually aligns the derailleur in a comfortable position which helps during reinstallation later on.

2. Disconnect the Gear Cable from the Derailleur

All you have to do is find where the cable actually connects to the derailleur, which is usually held in place by a small clamp bolt, so just use a 5mm or similar Allen wrench to loosen the bolt.

And once you’ve carefully loosened it, you’ll need to pull the end of the cable free.

Also, if you notice that the cable is frayed, you need to carefully cut it with cable cutters, so as not to damage the cable housing or get your hands stuck.

Not only that, but if there is any creasing at the end of the cable cup, you can also remove it.

3. Unscrew and Slide Off the Old Shifter from the Handlebar

Now, it is seen that most gear shifters are actually secured to the handlebar with a clamp bolt, so use the appropriate Allen wrench to easily loosen this bolt.

And once it’s loose, you’ll now need to slide the shifter out and remove it completely from the bar.

If you notice that your shifter is integrated with the brake lever as seen with many Shimano units, you may need to remove the brake lever as well or you can loosen both components together.

The main thing is that you have to do it gently, just don’t remove it forcefully specially if it has been there for a long time as this can cause damage.

4. Remove Cable Housing If You’re Replacing It

If you notice that the cable housing is really worn, cracked, or bent, it’s a good idea to replace it along with the shifter.

Slide the old housing out of the frame guides or cable stops, so take note of how it was previously mounted, taking particular care around the frame and also under the bottom bracket, as this will certainly help you install the new one properly.

Also, when you replace the old housing just make sure it moves more smoothly and also has less cable friction, specially if the inside lining is dirty or damaged.

NOTE: Take pictures of the cable routing before removing it, as this will be very helpful when you reinstall everything correctly and is very important if you are unfamiliar with your bicycle’s setup or if it is internally routed.

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How to Install the New Gear Shifter

Now, that you have successfully removed the old shifter and there is no shifter available in that place, you now need to confirm that your new shifter should also be compatible with the drivetrain of your bicycle.

1. Slide the New Shifter Onto the Handlebar

So, first of all you have to carefully slide the new gear shifter onto the handlebar, and if you’re installing a right handed shifter then this goes on the right side of the handlebar which actually controls the rear derailleur.

Also, if your bicycle has a front derailleur, the left-hand shifter actually controls it.

If your handlebar grips are getting in the way, you may need to temporarily remove them or loosen them and insert them.

So, for twist shifters, the grip is part of the unit, so just make sure that the handlebar surface must be clean and completely dry to successfully prevent slipping.

2. Position It Correctly Near the Brake Lever

Keep in mind that proper positioning is the key to comfort and performance.

As most shifters are placed right next to the brake levers, this allows them to be operated with your thumb or index finger without having to change hand position.

And if you’re using combination units, the brake and shifter are actually built into one unit, which is also common in Shimano STI or some flat-bar setups.

Just make sure the alignment feels natural and that it doesn’t interfere with braking in any way.

Also, you have to adjust the angle a little so that it matches with your riding posture, and this is really helpful and impressive as it also reduces wrist strain during long rides.

3. Tighten the Clamp Bolt Securely

So, once you are really satisfied with its position, you now have to tighten the clamp bolt with the help of the correct size Allen wrench: which will usually adapt to 4mm or 5mm.

As most clamp bolts are really small, you should avoid over-tightening them.

If you have a torque wrench available, first check the manufacturer’s recommended torque rating: which for most shifters is typically between 4 and 6 Nm (newton meters).

And then tighten them, just avoid over-tightening them as this can crush even lightweight aluminum or carbon handlebars, and you shouldn’t under-tighten them either as this can cause the shifter to slip during use.

Note: If you are actually using carbon handlebars, you should always use a torque wrench and follow the proper torque specifications very carefully so you can avoid permanent damage as well.

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How to Route and Install New Gear Cable

So, by now you must have successfully installed the new gear shifters but you also need to install the gear cable, this is the cable that actually connects the shifter and the derailleur and must be installed carefully to ensure smooth and precise shifting.

Even the best-of-the-best shifters won’t work properly if the cables are pinched, bent, or misaligned.

1. Insert the New Inner Cable Through the Shifter

You will first need to locate the cable entry point on your new gear shifter, and most shifters actually have a small hole or slot where the internal stainless steel gear cable can be inserted.

So gently push the cable until it comes out of the exit hole at the other end.

Because some shifters require you to actually click all the gears to open the internal path, specially with trigger-type indexed systems.

So you have to make sure the cable is inserted completely and cleanly: and once it’s inside the correct channel you won’t really feel any resistance.

2. Thread It Through the Outer Cable Housing

Now the next thing you need to do is guide the inner cable through the outer cable housing, which is a flexible protective tube that actually helps in guiding the cable and also protects it from all kinds of dirt, water and abrasion.

And if you are actually reusing your old housing, you must first inspect it for any kind of cracks, rust or dirt inside the liner that can actually hinder smooth shifting.

In addition, it is often best to replace it with a new one, such as low-friction casings, which also give optimal performance.

Therefore, apply a thin layer of light lubricant or cable grease can also be used inside the housing which reduces the friction and also prevents corrosion.

3. Ensure Smooth, Kink-Free Routing Along the Frame

Now, you need to move the cable along the frame of your bicycle, following the existing path.

Furthermore, most bicycles are actually designed with pre-determined cable routing paths that keep the cables neat and efficient to work with.

So, does your frame have external routing where the cables pass through the outside of the tube which can be clearly seen or internal routing where they pass through the frame, allowing the cables to be seen.

Therefore, you always need to ensure that the bends of the cable are gentle, and there are no sharp angles or tight loops, as sharp bends can actually increase friction, making shifting much more difficult as well as less responsive.

Also, when you route the new shift cable, you need to make sure the barrel adjuster has five full turns as this allows for quarter-turn adjustments while riding, which is outlined by the IPMBA.[¹]

4. Use Frame Cable Guides or Housing Stops

Yes, you will need to use any built-in cable guides, clips, or housing stops on the frame so that you can easily secure the cables in place.

As these guides actually helps to maintain the proper alignment and actually it reduces the unnecessary movement as well while riding.

Therefore, some bicycles have plastic or metal stops where the housing ends and the inner cable actually continues along; so others may use continuous housing all the way up to the derailleur.

Also, you need to make sure that each part of the housing sits firmly in these stops, to ensure proper cable tension and indexing accuracy later on as well.

Note: You will also need to wipe down the entire cable and housing to ensure no dirt enters the system, and double-check that each part has friction-free movement before putting it into place.

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How to Connect the Cable to the Derailleur

So, now that your new gear cable is actually connected through the housing and to the bicycle frame, the next step is to connect it to the derailleur: the component responsible for physically moving the chain between the gears.

1. Pull the Cable Taut

When you secure the cable, all you really need to do is make sure that your derailleur is set to the smallest gear first, which is the outermost cog for the rear derailleur or the smallest chainring for the front derailleur.

This is why you should lightly pull the gear cable until it’s taut, just enough to remove any slack, but not so tight that it preloads the derailleur spring.

As too much tension at this stage can throw off the derailleur’s alignment and result in incorrect shifting, it’s important to maintain a basically neutral tension: it should be tight enough, but not too stretched at the same time.

Additionally, electronic gear shifter systems actually provide greater consistency and are easier to activate shifting, as they are virtually unaffected by cable friction or stretch.[²]

Additionally, mechanical gear shifters actually provide better reliability in slushy or cold environments due to the sealed electronics.[³]

2. Clamp It Securely at the Derailleur’s Cable Pinch Bolt

Simply locate the cable anchor bolt on your derailleur commonly known as a pinch bolt.

And at exactly the same spot where the internal cable is clamped to maintain its position, then simply feed the fable through the anchor groove or guide which actually ensures that it is seated properly in the cable stop.

This is why you must use the correct size Allen wrench, usually 5mm, or a smaller open-ended wrench, as this will tighten the pinch bolt firmly.

If your derailleur has a built-in barrel adjuster, you’ll need to make sure it’s halfway out before clamping the cable, as this will give you room to adjust the tension later as well.

Note: You should not overtighten the pinch bolt, as this can actually crush or damage the cable and reduce its strength. You only need to tighten it enough so that it holds securely under tension.

3. Trim Excess Cable and Cap the End

So after clamping it, the length of unused cable will extend beyond the pinch bolt, so use a proper cable cutter but do not use scissors or pliers to cut off the excess portion, leaving a tail of about 1-2 inches in case future adjustments are needed.

You will then need to put a cable end cap on the cut end to protect the cable from breaking.

So, use pliers to gently adjust the cap, as frayed cables not only look messy but can also be risky and make future adjustments difficult.

NOTE: You should always double-check the cable path at this point to make sure it hasn’t popped out of the housing stop or gotten messed up during clamping.

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Conclusion On How To Install Gear Shifter On Bike

Simply installing a new gear shifter on a bicycle upgrades it for higher performance, but you need to know your gear system by routing cables because it really plays a vital role in how smoothly your bicycle shifts on the road or trail.

Plus, you need to remember that accuracy is what really counts: because even small misalignments or cable tension issues can literally cause missed gears or slow gear changes.

So just take your time to install it properly and then you must also adjust your shifter as it improves your riding experience and also protects your chain, cassette, and derailleur from any unnecessary wear.

If you still have questions then you can comment below for more information regarding this guide on How To Install Gear Shifter On Bike.

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Frequently Asked Questions

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References:

[1] Gears & Gadgets: Shift Cable Adjustments
https://ipmba.org/blog/comments/gears-gadgets-shift-cable-adjustments

[2] Electronic Shifting vs. Mechanical: Are Shimano Di2 & SRAM eTap AXS Worth It?
https://www.theproscloset.com/blogs/news/do-you-need-electronic-shifting

[3] SHIMANO Di2: The Ultimate Shift
https://bike.shimano.com/stories/article/di2-reliability.html