I couldn't find a how to for this particular job so I thought I might put one together for you...
Well first question to answer is "How do I tell if I need to replace them?"
This is an easy thing to check, put your stand down and rock the weight of the bike onto it so that the front wheel comes off the ground, then move the bars from left to right. It should move smoothly through the full range, if you feel a notch anywhere (usually in the centre) then it's time for new bearings.
If you need to replace them, read on... and yes I know my bike needed a wash, I did that as soon as I had finished doing the bearings...
Getting the front off the ground:
First thing is to put the rear on a stand, then get a piece of wood to go under the headers and use a jack to lift the front end up, if you have frame sliders it would be a good idea to support the bike from those, exactly as I have done below.
Remove your front wheel:
Undo the mounting bolts for your brake callipers, remove them and hang them so that there is no weight being supported by the lines. DO NOT squeeze the brake lever once the calipers have been removed!
Next, undo the big bolt on the end of the axle then loosen the four pinch bolts. You are now ready to withdraw the axle from the front wheel, you will find it easier to remove if you place a screwdriver through the holes in the end of the axle and use it as a handle.
The front wheel will pretty much fall out once the axle comes out, just be careful not to loose the spacers or which side each one was on. Once the wheel is out, undo the mounting bolts for the front fender and remove it, it may require a little muscling as they are quite a good fit.
Front wheel off:
Remove the top triple and clipons:
Next, undo the top triple clamp and clipons and remove them, you don't need to remove anything from the clipons as there should be enough play to allow you to remove them.
Remove the forks:
Now its time to remove the forks, this is not as daunting as it may seem! Simply undo the pinch bolts on the lower triple and the fork will slide out.
Removing the head nuts and stem:
If you look at the top of your head stem tube you will see two nuts, and between them is a washer with some tabs on it, you will need to bend the tabs off the top nut like this:
Once you have done that just use a c spanner or a hammer and screwdriver to spin the locknut off completely.
Now you are ready to undo and remove the head stem tube and lower triple from the bike, undo the second nut while holding the stem tube and triple in place, once the nut is completely off you can slide the stem tube out of the stem.
Remove and set aside the top dust seal, you will need this when you put it all back together. remove the top bearing race and bearings. These can go in the bin.
If you look down the stem you will see the bottom race and an indent that has been provided to make life easier, just use something like a screwdriver or a piece of round bar to knock out the top and bottom races. Don't hit it to hard, lots of small hits are better than one big one because you are hitting the side of the race it will try and twist in its housing possibly causing damage. Here is where to hit it:
Removing the bottom race from the stem tube:
This will require a little patience and care, what you need to do is hit a cold chisel down between the dust seal and race, being careful not to damage the stem tube. It will take a while but it will come off. After the race is off, remove and discard the dust seal as well.
If you do damage the stem tube with the cold chisel, don't worry it's not the end of the world, just take a smooth file and de-bur it.
Time to put the new races in:
Well, your now ready to start putting it all back together, first thing is to grease the new bearings up, here is a video of how to do it properly (just a random bloke on youtube who is doing it right)
Next thing is to put the new dust seal (with the lip facing away from the triple and race onto the stem tube, there are a few ways to seat the new race but the two best ones are to use a piece of pipe to go over the stem tube and sit on the race and either a press or hammer to seat it all the way down.
There are also two ways to put the races back into the stem, either knock them in with a hammer or you can use a piece of threaded rod and a couple of large washers and simply tighten them down, using the old races as dies to press the new ones in.
Putting the stem tube and triple back:
Nice and easy... just slide her back in... one it is in there place your greased top bearing over the stem tube and then the old dust seal that you have cleaned back on with the lip facing down. After that put the stem nut back on.
Seating and adjusting the bearings:
Tighten the nut up till it is quite tight, but no need to pretend your superman , then move the steering left and right a few times to seat the bearings.
Loosen the nut back off whilst holding the stem tube in place, and do it back up as tight as you can by hand, then give it an extra 1/4 to 1/2 a turn. This should get the right amount of torque and preload on the bearings.
Alternatively, if you have the special tool for the nut you can do it up to 22 ft-lb, seat the bearings and then do it up to 35 ft-lb.
Put your locking washer and locking nut back on and do the locking nut up hand tight, then holding the bottom nut in place with a c spanner continue to do the lock nut up until it lines up with the tabs on the locking washer. Now bend your tabs up...
Remounting the forks:
Place your upper triple back over the stem tube and put the nut back on to hold it on there but leave it loose enough that the triple can rotate.
Slide the fork through the lower triple, then through the clipon and into the top tripple then do up the bolt on the top triple hard enough to hold the for in place.
When you look at the fork you will see a ring around the top, this is to show where it should be aligned on the top triple clamp, the ring should sit about 1mm above it. Get it in the right spot and do it up to 17 ft-lb. Repeat for the other side.
Do up the nuts / bolts in this order:
1. The nut on the stem tube to clamp the top triple down properly. (76 ft-lb)
2. The pinch bolts on the lower triple (20 ft-lb)
3. The clipon pinch bolts (17 ft-lb)
Replacing the wheel:
Put the fender back in first, then hold the wheel in place (making sure you have it round the right way, there are direction markings on the rim and tyre) and slide the axle bolt through the wheel from the left side to the right. Put the bolt back into the right hand end of the axle and do it up to 43 ft-lb.
Now do up the right hand pinch bolts to 16 ft-lb.
Bolt your callipers back on, mounting bolts are to 22 ft-lb, and put the bike back on the ground. Bounce the front end up and down a few times (while holding the front brake in) to seat the axle properly then do up the left hand axle pinch bolts to 16 ft-lb.
Congrats, your finished!
Well first question to answer is "How do I tell if I need to replace them?"
This is an easy thing to check, put your stand down and rock the weight of the bike onto it so that the front wheel comes off the ground, then move the bars from left to right. It should move smoothly through the full range, if you feel a notch anywhere (usually in the centre) then it's time for new bearings.
If you need to replace them, read on... and yes I know my bike needed a wash, I did that as soon as I had finished doing the bearings...
Getting the front off the ground:
First thing is to put the rear on a stand, then get a piece of wood to go under the headers and use a jack to lift the front end up, if you have frame sliders it would be a good idea to support the bike from those, exactly as I have done below.
Remove your front wheel:
Undo the mounting bolts for your brake callipers, remove them and hang them so that there is no weight being supported by the lines. DO NOT squeeze the brake lever once the calipers have been removed!
Next, undo the big bolt on the end of the axle then loosen the four pinch bolts. You are now ready to withdraw the axle from the front wheel, you will find it easier to remove if you place a screwdriver through the holes in the end of the axle and use it as a handle.
The front wheel will pretty much fall out once the axle comes out, just be careful not to loose the spacers or which side each one was on. Once the wheel is out, undo the mounting bolts for the front fender and remove it, it may require a little muscling as they are quite a good fit.
Front wheel off:
Remove the top triple and clipons:
Next, undo the top triple clamp and clipons and remove them, you don't need to remove anything from the clipons as there should be enough play to allow you to remove them.
Remove the forks:
Now its time to remove the forks, this is not as daunting as it may seem! Simply undo the pinch bolts on the lower triple and the fork will slide out.
Removing the head nuts and stem:
If you look at the top of your head stem tube you will see two nuts, and between them is a washer with some tabs on it, you will need to bend the tabs off the top nut like this:
Once you have done that just use a c spanner or a hammer and screwdriver to spin the locknut off completely.
Now you are ready to undo and remove the head stem tube and lower triple from the bike, undo the second nut while holding the stem tube and triple in place, once the nut is completely off you can slide the stem tube out of the stem.
Remove and set aside the top dust seal, you will need this when you put it all back together. remove the top bearing race and bearings. These can go in the bin.
If you look down the stem you will see the bottom race and an indent that has been provided to make life easier, just use something like a screwdriver or a piece of round bar to knock out the top and bottom races. Don't hit it to hard, lots of small hits are better than one big one because you are hitting the side of the race it will try and twist in its housing possibly causing damage. Here is where to hit it:
Removing the bottom race from the stem tube:
This will require a little patience and care, what you need to do is hit a cold chisel down between the dust seal and race, being careful not to damage the stem tube. It will take a while but it will come off. After the race is off, remove and discard the dust seal as well.
If you do damage the stem tube with the cold chisel, don't worry it's not the end of the world, just take a smooth file and de-bur it.
Time to put the new races in:
Well, your now ready to start putting it all back together, first thing is to grease the new bearings up, here is a video of how to do it properly (just a random bloke on youtube who is doing it right)
Next thing is to put the new dust seal (with the lip facing away from the triple and race onto the stem tube, there are a few ways to seat the new race but the two best ones are to use a piece of pipe to go over the stem tube and sit on the race and either a press or hammer to seat it all the way down.
There are also two ways to put the races back into the stem, either knock them in with a hammer or you can use a piece of threaded rod and a couple of large washers and simply tighten them down, using the old races as dies to press the new ones in.
Putting the stem tube and triple back:
Nice and easy... just slide her back in... one it is in there place your greased top bearing over the stem tube and then the old dust seal that you have cleaned back on with the lip facing down. After that put the stem nut back on.
Seating and adjusting the bearings:
Tighten the nut up till it is quite tight, but no need to pretend your superman , then move the steering left and right a few times to seat the bearings.
Loosen the nut back off whilst holding the stem tube in place, and do it back up as tight as you can by hand, then give it an extra 1/4 to 1/2 a turn. This should get the right amount of torque and preload on the bearings.
Alternatively, if you have the special tool for the nut you can do it up to 22 ft-lb, seat the bearings and then do it up to 35 ft-lb.
Put your locking washer and locking nut back on and do the locking nut up hand tight, then holding the bottom nut in place with a c spanner continue to do the lock nut up until it lines up with the tabs on the locking washer. Now bend your tabs up...
Remounting the forks:
Place your upper triple back over the stem tube and put the nut back on to hold it on there but leave it loose enough that the triple can rotate.
Slide the fork through the lower triple, then through the clipon and into the top tripple then do up the bolt on the top triple hard enough to hold the for in place.
When you look at the fork you will see a ring around the top, this is to show where it should be aligned on the top triple clamp, the ring should sit about 1mm above it. Get it in the right spot and do it up to 17 ft-lb. Repeat for the other side.
Do up the nuts / bolts in this order:
1. The nut on the stem tube to clamp the top triple down properly. (76 ft-lb)
2. The pinch bolts on the lower triple (20 ft-lb)
3. The clipon pinch bolts (17 ft-lb)
Replacing the wheel:
Put the fender back in first, then hold the wheel in place (making sure you have it round the right way, there are direction markings on the rim and tyre) and slide the axle bolt through the wheel from the left side to the right. Put the bolt back into the right hand end of the axle and do it up to 43 ft-lb.
Now do up the right hand pinch bolts to 16 ft-lb.
Bolt your callipers back on, mounting bolts are to 22 ft-lb, and put the bike back on the ground. Bounce the front end up and down a few times (while holding the front brake in) to seat the axle properly then do up the left hand axle pinch bolts to 16 ft-lb.
Congrats, your finished!