How to Adjust Shimano Gears on a Mountain Bike


Hearing that annoying noise coming from your Shimano derailleur or having to deal with shifting issues can ruin the mood of the ride.

But going to the bike repair shop for even the slightest adjustment can end up costing a fortune and leave you without your bike for a couple of days at least.

What if you could do the adjustment by yourself? That’s right, you get the idea. You can definitely learn how to adjust Shimano gears on a mountain bike and that’s exactly what you’ll find below!

How to Adjust Shimano Gears on a Mountain Bike?


The efficient and smooth gears of a bike can make your ride enjoyable. It is important to learn how to adjust Shimano gears on a mountain bike. Undoubtedly, Shimano is a famous brand in the industry. The gears are operated using STI (Shimano Total Integration) levers. These gears need two levers for efficient working.

It will be easy to know if these gears need adjustment. There will be some tell-tale signs to notice, such as the chain is falling off or the gears are unresponsive and sticky.

Possible Changes to Rear Derailleur


You can make some changes to the back derailleur, such as lower and upper limit settings. Change cable tension and use a B tension screw. Initially, shift a derailleur down to the small cogs. Make sure to adjust the small barrel adjuster (round knob) attached to a cable. Turn the knob in a clockwise direction to get sufficient room for other changes.

The higher of screws will set a high limit, and it is located from a barrel adjuster. It will be easy for you to turn it with the help of a screwdriver. Bring the derailleur inward through a clockwise motion when moving it in the opposite direction. Unscrew a cable anchor at the base of the derailleur. Pull a cable to make it tight and tighten a cable anchor once again.

Start shifting the back derailleur by spinning the pedal for consistent wheel spinning. It must shift smoothly, and if it is unable to work smoothly, you may tighten both low limit screw and barrel adjuster. Move back to barrel adjuster and spin it clockwise. Remember, it may impact the smooth working of gear as you move upward. After adjustment of the derailleur, it can work smoothly.

You have to move the derailleur to below the big part of the cogs. A screwdriver is necessary to turn the low limit screw. The commonly required adjustment is to turn the derailleur in a clockwise direction to make it tight. Avoid making it too loose or too tight because it can impact its performance.

Moreover, you can see a B tension screw under a cable and use it to alert the derailleur angle. Move it clockwise to spin the derailleur down because the counterclockwise movement can bring it upward. The derailleur must be close to a cassette without hitting a cog.

Modification in Front Derailleur


The mechanism can move the chain from a ring to another. You have to check the height. If the cage of the derailleur is low or high, feel free to change it. Different models of bikes are available; therefore, you have to check instructions about gears.

The rotation angle of the front derailleur is next on this list. The approach for adjustment of gear may vary in each case. The limit front derailleur screws are marked “H” and “L”. Feel free to test them and set them correctly. The “L” controls the movement of derailleur toward the small rings, and “H” stops the movement toward the biggest portion of the ring.

Make the Cable Tight


Turn a barrel adjuster clockwise on derailleur until it is completely dialed in. choose the small sprocket (highest gear) on a shifter. Pull a cable tightly at the derailleur and use a cable anchor to fasten it to the body. Once you are done, choose the third Shimano gear on the shifter and pedal forward gently for chain shifting.

Evaluate the position of the wheel associated with the cassette. It must directly fall under a third sprocket. A barrel adjuster will help you to fine-tune the position and tension of the cable. You can increase tension on a cable by turning an adjuster anticlockwise. In this way, you can bring a derailleur nearby the wheel. Clockwise movement can decrease tension.

Chain Shifts in Properly Indexed Rear Gears


If a chain is not running to the base of a cassette and shifting over a big cog in the spokes, it means a bent back hanger requires replacing or straightening. A damaged or crash bike may need this replacement. There is a problem is down-shifting is working well, but upshifting is slow or sticky. Dirty housing and cables may cause inaccurate or slow shifting.

Properly Index Gears


Remember, properly indexed Shimano gears on a bike mean every click of the shifter can cause one shift down or up the gears, rear or front. In case, you are skipping gears or shifting is stuck, you have to adjust indexing.

Undoubtedly, indexing problems are common because of cable stretch that is normal for the bedding-in procedure of new cables or bikes. Limit screws play an important role to control the movement of the derailleur. If they are not properly set, your chain can drop from chainrings or cassette. Remember, it may be dangerous for bikes and riders. For your safety, it is essential to replace bent or broken parts of gears.


Even thinking of adjusting your Shimano derailleurs by yourself can be frightening – but there’s nothing to be worried about.

Once you get a hang of the process, you’ll learn a skill that will pay off big time in the long run. But if you’re ever stuck and the written guide isn’t your thing – I highly recommend you to check out the best DIY bike repair course.

These step-by-step video lessons really taught me everything I know today and I haven’t visited a bike repair shop in a long time.

It isn’t always the money (even though you can save a lot) but it’s the ability to have the mountain bike ready as soon as possible without having to drop it off in the repair shop. That’s what I think is the best thing of being able to do the adjustment by yourself!

Did you learn how to adjust Shimano gears on a mountain bike or you still need some help?

Don’t hesitate to leave your comments or questions below and I’ll do my best to help you out!

One Comment on “How to Adjust Shimano Gears on a Mountain Bike”

  1. When you adjust Shimano bike gears, you have to work with a positioning clamp in order to check the height of the derailleur. Make sure that the derailleur is at the correct height, which is about 1 to 3 inches above your bike’s biggest chain ring. This guarantees that your gear will not shift poorly and will not rub against the bike chainrings.

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