Diy front wheel overhaul: Parts 1, 2, & 3

Link to Discussion thread: Link

FRONT WHEEL OVERHAUL: PART 1


DISCLAIMER: The procedures used in the following posts have been applied to a 2005 model Husqvarna TE250. Any specified torque settings, technical references, methodologies shown etc, refer to this model. Any work you do on your own bike using this guide is at your own risk.


Before commencing any similar work on your bike be sure to check your manufacturers literature, model, specifications and any technical recommendations for your bike.


The following post is written and edited in UK English..My apologies to any US readers who are thinking that I am possibly the worst speller they have ever encountered, (but are way too polite to say anything..!!). The “fractured” grammar however, is entirely the result of my lack of attention during English classes….. For this, I wish to apologise in advance.


My last few trail rides have been notable for some monumental heart in the mouth, front wheel washouts. After discussing this problem with fellow riding buddies, I have come to the conclusion that it is time to consider lowering my forks in the triple clamps and replacing the front tyre with something more “grippy”. While at it, I may just as well bite the bullet and replace the front wheel bearings and brake pads for good measure. Basically a complete front wheel overhaul. (BTW I will be fitting a Pirelli 454 Mid-Hard).


I figure that this is also a good opportunity to document the procedure for the benefit of those who feel that they would also like to be able to do this type of maintenance themselves, but up till now felt that they have lacked the necessary knowledge, skills and confidence to tackle this type of work on their own. Believe me, no special skills are required, just a good smattering of common sense…..so read on……


I prefer to do all my own maintenance. First and foremost as I have an inherent mistrust of anyone other than myself working on my bike, and secondly, I firmly believe that money saved on labour costs can be put to far better use by purchasing tools and/or parts that can be used for future maintenance.


Normally, I also prefer to work alone. Years of working on ships deep sea have taught me to work independent of helping hands. It has also taught me improvisational skills and the importance of doing the job right the first time. I am not saying the techniques described in this post are necessarily the best, or in fact, the only way to do the job, but I do feel that this description contains enough practical information to enable someone who has never attempted this type of thing before to have new found confidence and possibly even the incentive to “give it a go” and complete the job successfully by themselves the first time…


You may not have all the tools available to you that I have used or are shown in some of the pictures. However, the cash saved from this very job alone will go a long way to cover the expense of purchasing some of them. The only “exotic” tool used, is a torque wrench. These are certainly not cheap, and in all honesty, to cover the full range of torque settings found on most bikes, it may be necessary to purchase two or more of them. For this project however, you may be able to borrow/hire one….Or, you may elect to simply “guesstimate” the required torque, after all, this is what you would have to do out on the trail. Just a word of caution though, it doesn’t take too much effort to break small bolts like the 6mm pinch bolts on the fork leg or to overtighten the triple clamp bolts which may result in the crushing of the fork tubes…so be very careful…gently does it!!!


TIP: By regularly using a torque wrench whenever working in your shop, you will start get a “feel” for how tight different sized fasteners should be. Hopefully this “feel” will help to prevent you from breaking or overtightening any fasteners, now or in the future.


OK, where to start..?


It took me 3 easy hours to complete the entire job. This involved, firstly setting the bike up on a stand and checking the condition of the bearings to ascertain the extent of work required. In my case, the simple test shown in STEP 1 below proved conclusively that my bearings were definitely on their last legs, and needed replacing…. So it was onto the next steps which involved removing the front wheel, knocking out the seals and bearings. Correctly lubricating and installing the new bearings & seals, changing the tyre & tube, burnishing the axle and spacer, replacing the brake pads, then finally re-installing the wheel and adjusting the alignment etc.


Study this exploded picture of the hub assembly taken from your spare parts manual carefully. Yours should be similar to this one. Looks straight forward enough doesn’t it…?? Believe me …you can do it!!





OK..Lets get started…Firstly I would highly advise doing this job on a firm surface in a protected, well lit and ventilated area.


ITEMS REQUIRED

New set of Bearings and seals (If Required)
Waterproof grease. I prefer Castrol APX T. Have also heard glowing reports for Belray Waterproof Grease
New tyre & tube (Optional)
Brake Pads (Optional)
Other stuff such as protective gloves, 3M scouring pad, rags etc

TOOLS REQUIRED

Suitable ROE spanners (Ring/Open End) and sockets
Screwdrivers
Circlip Pliers
30mm socket (or suitable piece of pipe approx 40-41mm outside diameter)
Hard and soft faced hammers

TIP: The outside diameter of my Husqvarna front wheel bearing is 42mm. The approximate outside diameter of a 30mm socket is 40mm..This is almost a perfect size for driving in the new bearings. …. The 30mm socket can also be used during future maintenance to undo the steering head nut…!! (Check YOUR dimensions before purchasing)


STEP ONE: CHECKING THE WHEEL BEARINGS


There are many differing opinions/methods for doing this. My preference is to use the sound and feel method.


Sit the bike securely on a stand with the front wheel clear off the ground. If you don’t have a stand you can use an upturned milk crate or improvise with some other support that will hold the bike securely while you work on and around it. It is essential that the bike is stable!!!


There are several reasons for having the bike on a stand, Firstly, it gives us the ability to spin the front wheel and listen for any rumbling/clicking/ticking noises emanating from the bearings. (It is highly recommended that you remove the front disk pads when doing an audible test).


Watch the wheel carefully as it spins and slows down to see if it, “stutters”, “wobbles” or tends to lock up. Don’t be afraid to also use a screwdriver blade placed on the end of the axle with your ear pressed against the handle end….this will amplify any sounds, just like a doctors stethoscope.


Secondly, by placing the bike on a stand the front forks are fully extended and any play in these or in the steering head bearings that may potentially give false movements/sounds can be minimised.


By addressing the bike in the manner shown in the picture below you will effectively prevent any extraneous free play . This method will show conclusively if the bearings have failed. Simply press gently against the axle with your left knee and pull the fork tube gently with your right hand. This will stabilise the entire front end of the bike. Now grip the wheel at the 12 O’clock position in between the forks and gently push/pull back and forth with your left hand...





What we are looking for, is any play in the bearings, and this will be felt as a slight movement of the wheel, or, if the bearings are seriously worn, this movement will also be accompanied by a “clunking” sound. Also observe the seal face as you rock the wheel back and forth. Any free play will be shown as distortion/movement of the lip seal.


Sound, healthy wheel bearings will show virtually no discernable movement, and the wheel will be all but silent when spun.





Yes, no doubt, many of you who are reading this post will say that there are several other methods for doing this check, I agree, there sure are. My preference for doing it this way is because it can be accomplished successfully without any form of outside assistance. Remember, this post is aimed directly at those with little practical experience and a limited range of equipment and tools.


STEP TWO: REMOVING THE FRONT WHEEL


TIP: Use the tools that you normally take with you when you ride to complete this task. This will soon highlight any shortfalls of your toolkit. Hopefully this will give you the incentive to ensure that you have a fully stocked toolkit, with all the necessary tools available to remove the wheel if required out on the trail.

Once again, with the bike still securely on the stand and the front wheel elevated from the ground, undo the axle locking bolt (yours may require a hex tool).





Then undo the four axle “pinch bolts”. Taking care, as these bolts are very small, and if tight, it is possible to shear them off. Use penetrating fluid if necessary to help free the bolts


TIP: It is preferable to use sockets or ring spanners to undo fasteners. Open end spanners have the potential to damage or round off the bolt heads. Plus, there is a greater potential for the OE spanner to slip, possibly causing physical injury.





While supporting the front wheel with your right hand, slowly remove the axle by twisting and pulling it with your left.





If you cannot easily remove the axle, it may mean that you need to spread the pinch faces slightly using a screwdriver or small wedge. When doing this, be extra careful not to damage the pinch faces or the axle. Under no circumstances should you be tempted to drive the screwdriver in, or the axle out with a hammer. Personally, I prefer to gently bump the screwdriver in using the palm of my hand.





STEP THREE: SEAL and BEARING REMOVAL


With the wheel removed from the bike I prefer to work with it brake disk side up supported on an old rear tyre to help prevent any damage or scuffing to the rim.


Firstly remove the small spacer from the hub and put it carefully aside. Then, using a large screwdriver, gently lever out both lip seals. Take extra care not to bruise or score the hub.








With the brake disk side up once again, clean away any grease/crud exposing the circlip that retains the bearing in the hub. Use a pair of circlip pliers to remove the circlip (It is highly advisable to wear eye protection during this operation),








Looking down into the hub you will notice a tubular aluminium spacer between the bearings. (This is used to support the bearings when the axle nut is tightened).





We need to “upset” this spacer so that we can gain access to the inner race of the bottom bearing. To do this simply insert a screwdriver or drift and gently rock the spacer off centre. This will expose enough of the lower bearing for us to be able to drive it out using a soft “dolly” or punch. Take extra care when doing this as we do not want to damage the bore of the spacer.








Once the bearing starts to move, the spacer can then be easily moved to enable us to drive the bearing out “square” by tapping it equally around the circumference thus ensuring it does not “cock-over” in the hub. If you drive it out squarely, it will come out easily and smoothly.





Remove the centre spacer, and if fitted, the piece of supporting foam from inside the hub.








Thoroughly clean the hub internals and bearing faces. Making sure not to remove any metal as this may adversely affect bearing fit.





Now flip the rim over and repeat for the other side. This time all of the inner bearing race will be exposed, so you can easily drive it out with the punch or perhaps use an appropriately sized socket this time.


TIP: You can keep an old bearing for use in driving in the new bearings. My preference however is to use a neat fitting socket or piece of tube to do this, as an old bearing may end up being stuck back in the hub. To avoid this happening, it is possible reduce the outside diameter of the old bearing by filing/grinding/sanding thus ensuring it has a clearance fit in the hub.

The very action of driving the bearing out by hitting it on the inner race, is in effect enough, to ruin the bearing. The hammer blows, no matter how gentle, transfer the impact through the balls, causing flat spots. This will cause the bearing to fail prematurely. I never re-install bearings that have been removed this way. It is far cheaper in the long term, to simply throw these bearings away and replace them with new. The same applies for the lip seals.

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CONTINUED in PART 2

FRONT WHEEL OVERHAUL: PART 2


STEP FOUR: AXLE and SPACER OVERHAUL


Now it is time to turn our attention to the Axle and spacers.


The axle is continually subject to abrasion and wear caused by trail gunk/grit being caught under the lip seal. Unfortunately, if this gets too bad and the axle becomes so deeply scored that the lip seal is no longer effective, it may require replacement. There is no easy fix for this, apart from regular maintenance and inspection.


Very little can be done about the scores on the axle save for trying to "buff" them out. It is not wise to attempt to polish them out too aggresively using abrasives such as emery/carborundum paper. It may be possible to use a very fine wet and dry paper (800 grit) but if the scoring is only light I prefer to use 3M green scouring pads. I use these to polish the axle with a cross hatch motion across the score (Not parallel to it). This is done by holding the axle in your left hand, wrapping the scouring pad around the axle and gripping it firmly with your right. Push and twist the axle through the scourer.


The small outer spacer can also be refurbished this way. You may have noticed that I have replaced the standard aluminium spacer with an after market stainless steel one. This is highly recommended improvement, as they are far more durable.


This pic shows the scores in the axle and spacer prior to hand buffing with a scouring pad.





5 minutes of hand polishing and both the axle and spacer are like new....Well almost!!


TIP: When cleaning the inner spacer make sure that you check the bore to ensure that it is clean and free of damage, also that the axle slides smoothly through it. Check both ends for mechanical damage and burrs. The ends must also be square as they seat against the bearings




STEP FIVE: BEARING REPLACEMENT

OK, now it’s time to prepare the new bearings. This is done by removing the seals and replacing the grease with good quality waterproof grease. A full explanation on how to do this can be found here


http://www.cafehusky.com/forums/showthread.php?t=2553


Despite my new replacement bearings being a “quality” brand from a reputable source, it is obvious from the pic below they have been poorly “packed” with an unidentifiable grease. Never, ever, insert bearings straight from the packet….take the time to inspect, clean and properly grease them using a quality waterproof grease.





TIPS: For Front Wheel Bearing Installation

Only use quality Brand Name bearings and seals. Cheap No-Name bearings are false economics.
Apply pressure ONLY to the outer race of the bearing
Apply pressure evenly so that the bearing remains square to the wheel hub
Remember to install the inner spacer between the bearings
Use a quality waterproof grease


OK, once again working with the brake disk facing up, thoroughly smear grease all over the hub bearing surfaces. Place the bearing squarely on the hub and start it off with gentle pressure just using your thumbs. It should not be necessary to heat the hub or freeze the bearings. Continue pressing the bearing in by alternating pressure around the circumference.


TIP: If your bearings are particularly tight you can sit the hub in the sun for a while in a calm location or heat it with a hair dryer or heat gun to expand it. Place the bearings in a plastic bag and leave them in the freezer for 30 minutes or so. For this method to be effective it is essential that you work quickly.





Once the bearing becomes too hard to move it any further by hand (and you are absolutely sure it is square) drive it in the remainder of the way using a correct fitting socket (slightly smaller than the outside diameter of the bearing), or piece of tube and gently tapping with a hammer. Do not be to aggressive with the hammer, just tap gently and alternate the point of impact around the outer circumference. You will know when the bearing is fully “housed” by the change in sound it makes when you tap it.


Now, Clean, grease and re-fit the circlip. (Don’t forget to wear safety glasses)





Flip the wheel over, insert the supporting foam into the hub and then grease and insert the inner spacer tube. Once again grease the bearing surfaces in the hub and insert the bearing using the same method as described previously.





Check that the inners spacer tube is aligned correctly with the bearings, so that the axle shaft will pass through freely. Grease the inner surfaces and lips of the seals then fit both lip seals by hand and seat squarely using a socket or gentle pressure from a clean hammer handle on the outer edges of the seal





STEP SIX: TYRE REPLACEMENT


While the wheel was off I turned my attention to fitting a new tyre.


The various methods of removing and replacing tyres and tubes is beyond the scope of this post. There are several references on how to perform this task available on the net, just as there are many different ways of performing this procedure. The only way for you to perfect this task, is to practice it over and over, so that when you have to do it for real, out in the scrub, it will be second nature to you.


For a very authoritative and informative explanation of this task …Take a look at these two videos


http://www.youtube.com/watch?v=TVKzoaL8qaI


http://www.youtube.com/watch?v=IMYQ6L2jKKQ


While we have the wheel off in a controlled environment, it is worthwhile spending some extra time prepping the rim before fitting a new tube and tyre.


I like to firstly buff the inside of the rim by hand using a stainless steel wire brush. This will remove the bulk of the gunk that has made its way onto the inside of the rim. Tougher gunk can be scraped away with a screwdriver blade with particular care taken to also remove any signs corrosion deposits. My final task is to buff the inside of the rim with a 3m scouring pad. Wipe the rim clean and lay down a run of electrical tape over the spoke nipples to protect the tube from abrasion





Cut in the holes for the valve stem and rim lock using a round file. Then check the integrity of each individual spoke by tapping them with a spanner. Bright sharp sounds indicate correctly tensioned spokes. Dull lifeless sounds indicate loose spokes.


Next, it is time to clean up and inspect the rim lock. Paying particular attention to the base of the rimlock thread for corrosion


TIPS: Always fit Ultra Heavy Duty tubes. Never tighten the rim lock until the tyre has been fully inflated and is properly seated on the bead. I prefer not to fit the valve stem lock nuts, as I like to allow the valve stem a bit of movement…(optional)





STEP SEVEN: BRAKE PAD REPLACEMENT


This is simply a matter of removing both safety clips and withdrawing the pin then removing both pads. Take some time to inspect the caliper and remove any gunk that may have built up. Give the caliper a good spray with "Brakleen" before fitting the new pads. It may be necessary to retract the pistons before fitting the new pads and this can be done by levering or pushing them back with a suitable tool.


TIP: Do not be tempted to pump the brakes while the wheel is off..!!





After replacing the pads and fitting the pin and clips the pads can be further separated by gently levering them apart with a screwdriver blade. Be careful to avoid scoring the brake pads whilst doing this.


Some really good information on Brake Overhaul here:


http://www.advrider.com/forums/showthread.php?t=161264


STEP EIGHT: FITTING THE WHEEL


Take another look at the exploded drawing of the hub. Review that you have all of your tools and components to hand, and in their correct positions.





OK, firstly check that the brake pads are sufficiently retracted to allow the brake disk to be easily inserted.


Check that the fork legs are square and both facing forward. Smear some grease inside the axle supports on the bottom of the fork legs, onto the four pinch bolts and completely smear grease thoroughly over the axle itself and the axle nut threads.


Fit the small spacer into the seal on the disk side of the hub and perform a trial run by standing the wheel up and inserting the axle completely through the hub to ensure everything is aligned correctly and the axle rotates smoothly.


Now place the wheel between the forks. Ensure the small spacer is still sitting squarely in the seal. With the axle in your left hand and partially inserted into the right fork leg, lift the wheel up (you may need to use your knee for assistance) and guide the disk in between the brake pads. When everything is aligned, gently push the axle in with a twisting motion till it is fully home.


Fit the axle end nut and tighten it to the correct torque specification. Thoroughly grease and insert the 4 pinch bolts, but at this stage only screw them in 2 or 3 turns.


STEP NINE: FRONT AXLE ALIGNMENT


Fork Misalignment can cause a myriad of suspension and handling problems that are way beyond the scope of this post.


Fork/Axle alignment is very “subjective” topic. So, at this point we will just touch on how it is achieved, and you can decide yourself how effective it is in your case. I am expecting some very lively debate on this topic from some of our fellow Cafe Husky members


While the bike was still on the stand I also took the opportunity and lowered my fork legs 5mm into the triple clamps, using the method described in the owners manual. If you are happy with your current handling I would suggest you leave yours as they are.





So, continuing on from where we left off, with the pinch bolts still loose and the axle nut torqued up to the correct specification. Now commence pumping the front brake to seat the brake pads against the disk, until you get quite a firm feel. Ensuring the bike is still quite stable on the stand, give the front wheel a few good spins and allow it decelerate to a stop. Spin the wheel up again and this time gently apply the brake. Do this carefully as the bike will want to rock forward on the stand. If you are sure it is stable enough, spin it up as fast as you can and apply the brake sharply. Repeat this several times. These actions will “centralise” everything.


Using a torque wrench, tighten the two pinch bolts on the brake side fork to the correct specification.


The right side fork leg is now floating on the axle. . If you have done as suggested previously, you should have grease smeared all over the axle. It is now time to wipe it clear, so that the exposed section of axle either side of the right fork leg is now clean.


This is where things start to become very “subjective”. It is said, correct alignment is achieved when the right fork leg is 100% parallel to the left fork leg, after all 4 the pinch bolts have been correctly tightened to the specified torque setting..... :-\


To achieve this we need to once again put a screwdriver between the pinch faces to allow the right fork leg to move easily on the axle. For this to work correctly the 2 small pinch bolts must still be loose enough to allow the faces to spread.





Before continuing onto the next stage once again remove any excess grease away from the axle and lower fork leg….the reason for this will be obvious shortly.


Now, gently but firmly, push the base of the right fork leg towards the hub, release it and allow it to return under its own steam. Now gently but once again firmly pull the fork leg away from the hub and allow it to return unassisted. You may need to hold the wheel steady while doing this to help stabilize things.


It should be obvious to you now that the fork leg can actually move freely. The extent should be clearly visible by the grease that is now smeared either side of it on the axle. (See, there was method in the madness of smearing everything with grease..!! :P)





Once again grip the lower fork leg and this time gently move it back and forth slightly and try to determine when you can feel stronger resistance. We are trying to find the “sweet-spot”. I have said previously, this is very subjective, so when you think you have found the spot, hold it there, carefully remove the screwdriver from between the pinch faces and slowly tighten up the pinch bolts to the correct torque specification. This goes against all my engineering principles. Personally I would like to take measurements using straight edges, dial indicators, vernier calipers etc....but where do you stop!!!





Give the wheel a few more spins and apply the front brake firmly. Take the bike off the stand and put it in a location where you can mount it safely and while standing with your weight over the front wheel, bounce the front suspension up and down. If everything is aligned correctly the front forks should feel smooth with no signs of binding or tight spots.


Continued in next post...............................................................

CONCLUSION:


Now you may think the job is finished and are heading off to grab yourself a congratulatory beer…. STOP RIGHT THERE….!!! We aren’t finished yet..
This is where you need to show some discipline. You now need to go back once again and check every nut and bolt for correct tension and security. This is the stage where many new Cafe Husky “Techs” may come to grief. It is very easy to overlook something when you are doing it for he first time, for the sake of five to ten minutes of double checking, you will be confident and 100% certain of a job well done.


The job we have just completed has involved working on several components that we trust to keep us safe when we are riding. You are now your own Quality Control…..ALWAYS DOUBLE CHECK YOURSELF..after all, you will only have yourself to blame from now on..


No…you still can’t have that beer yet. Now you are going to clean up all your tools and pack up your kit so that it is ready for your next ride. You are then going to make a list of the tools you need to purchase to round out your tool kit to cover most trailside repairs. At the bottom of your list you are going to make a heading called “Wish List” and start writing down the tools that you would also like to have in your shed. Then you are going to take one more look over your bike….checking one last time.


Now you can go and grab that beer…while you are at it, you can get one for me please….Mine’s a Little Creatures Pale Ale