Welcome to Probikeshop TV! Today, I'm going to show you how to adjust the front derailleur on a road bike.
For this task, you will need a cross-head screwdriver, a torque wrench with a 5mm Allen key bit and a 25mm Torx bit,
a front derailleur, a set of Allen keys including a 2mm Allen key
and a pair of cable pliers.
This particular bike is set up for a direct mount front derailleur.
This means that the derailleur will be attached by just one screw.
Align the derailleur with the frame
and then proceed to provisionally tighten the screw, like so.
The next step involves adjusting the derailleur on this particular axis.
The aim is to ensure that the edge of the derailleur runs parallel to the chainring
to ensure proper functioning before you lock in the adjustment.
At the same time, you can also adjust the distance between the crest of the highest tooth
on the chainring and the derailleur cage.
The gap should be between 2 and 3mm so you can make your life easier by using a 2mm Allen key
to act as a reference point
to measure the gap.
Try to make sure that the derailleur remains as parallel as possible
to the chainring whilst keeping the gap between the highest tooth and the derailleur cage to 2mm.
That seems about right.
Make sure you don't rush with this adjustment
as it needs to be right to ensure optimal derailleur performance.
You can now proceed to use a torque wrench to definitively attach the derailleur to a torque of between 5 and 7 nm (for a Shimano 105 derailleur).
Further adjustments can then be made by using a 2mm Allen key
to ensure that the derailleur cage is perfectly parallel to the largest chainring.
In this manner, you can really perfect the adjustment.
The next step is to reattach the chain before proceeding to make the final adjustments.
I have already made sure that my chain is the correct length
and you can see how to do this in one of our previous YouTube tutorials.
Work your way down through the gears until the chain is on the largest sprocket
sprocket so that you can adjust the low screw on the front derailleur.
Use a cross-head screwdriver to adjust the screw marked 'L' for low.
The aim is to position the derailleur cage as close as possible to the chain.
The distance should be about 1mm.
Once you've adjusted the low screw, you can move on to the next step which involves attaching the derailleur cable.
First things first: whilst keeping the cable taut,
make sure that your gear shifter is on the lowest setting.
The second thing you should check is the cable tension.
Reset the tension to the lowest level
before turning the screw twice in the opposite direction to enable you to make adjustments when you reach the end of the derailleur installation process.
You can also take this opportunity to check that your cable stops are correctly attached
to avoid any nasty surprises such as them coming loose and therefore slackening the derailleur cable.
Proceed to slide the front derailleur cable into place in the direction indicated.
Hold the cable reasonably taut and tighten the screw to a torque of between 5 and 7 nm.
It may seem a little excessive to use a torque wrench to tighten a cable screw but it is a good way to avoid damaging the screw.
Finish off by removing any excess cable length, leaving a maximum of 2 cm of spare cable.
Snip the cable off and then crimp the cable cap to prevent the cable from fraying.
The next step in the front derailleur adjustment process consists of adjusting the high stop.
Before you do this, make sure that the put the chain on the smallest sprocket.
You can now proceed to make the adjustment.
The aim here is to adjust the gap between the derailleur cage and the chain to a maximum of around 1mm.
If the gap is top large, the chain will jump over the chainring.
The primary function of the high stop is to prevent the derailleur from pushing the chain over the top of the chainring.
The secondary function of the high stop is to ensure smooth gear changes.
A correctly adjusted stop with correct spacing will ensure optimal gear indexing.
Use a cross-head screwdriver to adjust the screw marked 'H' for high speed.
The tighter the screw, the more the derailleur cage will be prevented from moving to the outside
and, conversely, loosening the screw will give the derailleur cage more freedom to move outwards.
That's now correctly adjusted.
It's worth noting that Shimano shifters have a trim function
which removes any chain rub which may occur when changing between certain gears
so make sure that you bear that in mind when carrying out this adjustment.
Thanks for watching and see you again soon on Probikeshop TV.
You have now successfully adjusted your front derailleur.
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