- Remove Front Wheel
- Remove Fork Brace and Fender
- Remove Fork Gaiters
- Remove Handlebars and Fork Springs
- Remove Fork Cap Bolts-All You Need is a Bigger Hammer
- Remove Fork Sliders
- Replace Fork Seals
- Remove Fairing Rubber Boots and Fork Gaiters
- Install New Fork Seals
- Install Felt Into Fork Dust Cap
- Assemble Fork Sliders On Fork Tubes
- Fill Forks with Fork Oil
- Install Handlebars
- Mount the Fork Brace-Fender, Wheel and Brake Calipers
When I bought the bike, the forks had both rubber fork gaiters and torn rubber fairing boots. But, I can’t turn the forks lock-to-lock as the gaiters interfere with the fairing boots. I think this is dangerous so I’m going to remove the gaiters and the fairing boots and install the black rubber cups on the fork sliders. I will wait for when I do the complete tear down of the bike to replace the fairing boots. I also replace the fork seals since I have to do all the work needed to get to them and I don’t know there condition.
The virtue of using the gaiters is they protect the fork tubes from stones and gravel that can put dings in the tube and cause fork oil seal leaks. For now, the gaiters and the fairing boots will go.
Remove Front Wheel
I remove the disk brake calipers. There are four bolts, but only the top and bottom bolts secure the caliper to the fork.
The calipers are retained but the brake line brackets and won’t fall down. I remove the axle nut and then remove the pinch bolts on each fork.
I pull the axle out from the left side facing the front of the bike exposing the bearing dust cover hat. There is a spacer on the right side as well as a bearing cover hat.
Then I remove the wheel from the calipers.
Remove Fork Brace and Fender
I remove the bolts securing the fork brace. The caliper bracket goes under the rear nut on the inside of the fender, so I hold the caliper to prevent it dropping when I remove the rear nut.
Then I secure it to the exhaust header with some wire so there is no strain on the rubber brake line.
Then I remove the fender and brace from between the fork legs.
Remove Fork Gaiters
I remove the fork gaiters by loosening the metal band at the bottom. When I do, fork oil leaks out of the gaiters. The fork seals are leaking and the fork oil is the color of the Mississippi River in a spring flood. The oil definitely needs changing. I remove the metal band at the top. When I remove the fork sliders, I can get the gaiters off the forks.
Remove Handlebars and Fork Springs
I need to remove the fork springs to take the tension off the fork sliders. To do that requires removing the handlebars that are secured with four bolts under the top triple clamp.
The handlebar clamp has a long in front and a short stud in the rear. The long stud has a metal cover that goes over a rubber bumper.
I move the handle bars toward the speedometer so I can access the fork top bolt at the top of the fork tube. I remove the plastic covers to expose the 36 mm Top Bolts. The Allen head bolt in the middle is used to fill the forks and does not need to be removed.
Remove Fork Cap Bolts-All You Need is a Bigger Hammer
And then, the fun begins. I start with the flat wrench in the tool kit and wack it with a hammer. Nothing. So I use a 2 Lb maul and again, nothing, except I dent the flat wrench and bend it.
Next, I use the 36 mm socket that I have with a ground off end so the tapered part of the socket is removed. The cap bolt is thin and the socket has to fully engage all the flats or the socket will round off the cap bolt. I use a 1 foot breaker bar and lean on it. Nothing. I use the two pound maul on the breaker bar. Nothing.
Okay, I need more leverage. I get a floor jack handle that is about 3 feet long and put it on the breaker bar. Nothing, except I start moving the bike around, but the cap bolt won’t budge.
Okay. This bolt is very stuck. I heat the top of the fork tube with a heat gun. If someone used locktite, the heat gun should melt it. Then, while it is still hot, I put Kroil on the cap bolt a couple of times and let it sit overnight. As the fork tube and cap bolt cool, the Kroil gets be sucked down into the threads. This should help loosen the bolt if there is rust in the threads. Before going to bed, I send an email to the Micapeak Airheads forum asking for advice.
In the morning, I try the 3 1/2 foot cheater with the 36 mm socket again. Nothing. The Airheads forum advice was GET A BIGGER HAMMER, and one of the bigger hammers is an air impact wrench.
Okay, I don’t have an air impact wrench, so now is the time to add that to my tools. I get a Husky 300 Ft-Lb model from Home Depot, set the air pressure on my compressor to 90 psi, chuck up the 36 mm socket and let it rip. Nothing. I run the wrench until the pressure in the tank drops below 90 psi and stop to let the compressor fill the tank to 120 psi. After three times of doing this,the top bolt still refuses to budge. Grrrrr.
I go back to Home Depot and return the impact wrench (“It’s not what I need.”) and buy an 800 Ft-Lb model. I run the tank down until the compressor comes on and wait for it to recharge to 120 psi and apply the impact wrench a second time. Oh Hallelujah … It comes loose. 🙂 The top bolt faces are not deformed much, but I’m going to replace them anyway. The threads may be weakened and it’s a good idea to have clean faces on the nut so the socket will fit tightly next time.
I suspect someone put an impact wrench on these top bolts to secure them which is not necessary. I snug them to 55 Ft-Lbs and they have never come loose.
I remove the forks springs and get another surprise. Instead of one spring in each tube, there are two springs and a threaded rod with a spacer in the middle. And there is a PVC spacer in the top to increase the pre-load.
The Airhead forum says this is an aftermarket performance option. The shorter top spring compresses last effectively stiffening the spring when it compresses a lot. However, there was very little spring pressure on the top bolt so I suspect these springs are sacked. When I do the rebuild, I’ll replace these aftermarket springs with the stock ones.
Remove Fork Sliders
The bottom of the sliders have two Allen head screws; the small one drains the fork oil and the larger one secures the damper rod to the fork slider.
The problem with the damper rod Allen bolt is the damper rod wants to turn when you turn the Allen bolt. You can put the springs back in the fork and the axle into the forks and push up on the axle with a jack stand to put pressure on the damper rod so there is enough resistance that you can remove the Allen bolt. Or, you can use an impact wrench to try and get the Allen bolt loose. I have a small battery powered one and it worked with no problem.
When I remove the large Allen bolt, the slider comes off the fork and a spacer fell out from one fork. Later, when I was cleaning out the forks sliders in the parts washer, the other spacer came out. They can get stuck in gunk at the bottom of the slider.
The button on the bottom of the fork slider can contact the spacer to prevent the fork slider from impacting the lower fairing.
Replace Fork Seals
I clean out the inside of the fork sliders and find the other spacer. There is a fair amount of gunk in the bottom of the sliders. To remove the fork seals, I put a slider in the vice using rubber jaws and clamp the tube by the axle hole at the bottom.
I use a seal remover tool and carefully hook the seal in the middle where the groove and steel spring are located.
It often helps to heat the top of the slider with a heat gun before removing the seal. I didn’t do that this time since the seals came loose easily. I inspected the seating surface the seal goes into for any nicks or deep gouges. One tube is clean, but one has a couple nicks in it from previous seal removal.
I use some 220 wet/dry grit to remove the sharp edge of the nicks and smooth them out. I follow with 1000 wet/dry grit to smooth out the surface.
Remove Fairing Rubber Boots and Fork Gaiters
The old ones had a bit of adhesive applied. It helps keep them in place as the fork tubes are turned. I cleaned the old adhesive off the fairing.
They were pretty shot.
The fork gaiters are the 11 rib version instead of the 13 rib version originally used on the /5 and /6 series. I loosen the hose clamps at the top and they slide right off. They are in good shape and I’ll hang onto them. I may opt to use them without the fairing boots as they do protect the fork sliders from nicks and dings from sand and rocks.
The fork tubes are in good shape with no nicks I can feel. There is a slight bit of wear at the bottom of the tubes.
Install New Fork Seals
The new seals can be installed into the fork lowers using a 36 mm socket as a driver.
I hold the lowers in my vice using rubber jaws. I lightly oil the outside edge of the seal, center it on the hole and drive it straight in with a rubber mallet on the 36 mm socket. Be careful to keep the seal straight as you drive it in. I use some mild taps of the mallet to get it started and to ensure it’s straight. If it cocks, I can easily remove it and try again. If I drive it in crooked, it will permanently damage the seal and I’ll have to get a new one. Although I didn’t do it this time, I have also heated the lip that holds the seal with a heat gun and then driven the seal. Sometimes the fit is very tight and some heat makes driving the seal easier.
Install Felt Into Fork Dust Cap
I bought new fork dust caps that were fitted to the fork lowers on the RS. They have a felt ring that goes inside a groove located at the top of the cap.
The felt is long and needs to be pushed into the groove with my thumbs and slide around the groove until the angled ends meet up. Do not cut the felt to fit as it needs to be very tight in the groove to act as a wiper on the fork tube to keep grit and dirt from getting into the seal. DO NOT OIL IT. This will retain grit and dirt and hasten fork seal failure.
I slide the dust caps onto the fork tubes before I mount the lower sliders on the tubes.
Assemble Fork Sliders On Fork Tubes
The sliders attach to the damper rods with large Allen bolts. There is a spacer that goes at the bottom of the fork slider that acts as stop when the forks are compressed.I drop the slider into the fork lower.
I carefully slide the lowers onto the tubes being careful to easy the fork seals onto the fork tubes so the edge of the tube doesn’t damage the lip of the fork seal. I use a little bit of oil on the lip of the fork seals to make them easy to slide onto the fork tubes. Then I insert the axle through both fork lowers to keep them aligned.I add the fork springs into the top of the fork tubes. There is a spacer that goes on the top of the springs.
I insert the PVC spacer that was used to add pre-load to the springs.
I screw in the new top bolt and washer. I replaced the top bolt just to be safe since the old ones had been tightened much too tight and it may have damaged the threads. I only screw in one top bolt on one fork tube at this point.With the top bolts installed, I screw in the large Allen bolt with a new washer at the bottom of the fork slider into the damper rod. Since this rod can rotate, I push up on the axle with my knee and then tighten the Allen bolt to 25 Ft-Lb. The spring pressure keeps the damper rod from turning. Then I remove the top bolt on that fork tube and put into the other fork tube and tighten the large Allen bolt on the other tube. I screw in the fork drain screws with new washers.
I install the handlebar clamps and an old handlebar into one of the clamps. I use this as I torque the top bolt down to 55 Ft-lbs so I don’t have the forks against the stops. This can distort the fork clamps and cause the forks to get out of alignment. I torque the top bolt on the opposite side of the handlebar. I brace the handlebar against my side as I apply the torque to the top bolt so the wheel doesn’t rotate against the stop.Then I put the handlebar into the other clamp and torque the remaining top bolt into the fork tube. I slide the fork dust caps down onto the fork lowers.
Fill Forks with Fork Oil
I use 7.5 wt fork oil. I’ll see how this works for damping. There is 5 wt for less damping and 10 wt for more damping, but a friend uses the 7.5 wt in his R100RS, so that’s what I’ll start with.
I measure 225 cc of oil and then suck it into a large syringe so it will be easy to add to the filler hole in the top nut.
When I fill both tubes, I screw in the Allen bolt into the top of the fork top bolts.
Then I install the dust cap on top of the top bolt.
The handlebar mounts at the front fit through a large rubber mount that holds the instrument cluster bracket. It is covered by a metal cap, a wave washer and the nut. But, the rear mount uses just a flat washer, wave washer and nut. The picture below shows the two metal caps, one goes on the front mount of each handlebar bracket.
Getting the metal cap in place with the wave washer and nut can be hard. I use a little axle grease on the underside of the metal cap so it will stick to the rubber bumper while I thread the wave washer and nut onto the front stud.
The handlebars need to be centered so that the rubber dash that attaches to the bars will fit. I install the bar mounts and tighten up the nuts enough to hold the bars while I adjust them left-to-right so they are centered on the handlebars.
Mount the Fork Brace-Fender, Wheel and Brake Calipers
I removed the fork brace and fender as a unit, so I carefully insert the brace between the lower fork tubes.
I check that the brackets on the brace are parallel to the inside mounting surface of the fork lowers. If there is any difference front to back or a larger gap on one side than the other, then when I tighten up the bolts holding the fork brace it will bend the forks and increase stiction. This brace is true and doesn’t need to be shimmed.
The rear fork brace bolt also holds the brake hose bracket. The bracket mounts on the inside of the brace with the locking nut securing it.
I insert the bolts with the flat washer on the outside and torque the fork brace bolts to 16 Ft-Lbs.
I install the bearing caps on the wheel bearings. I mount the wheel and axle with the spacer on the right side as I face the front of the bike.
The axle should slide smoothly through the fork lowers. If there is resistance, there maybe a burr on the edge of one of the holes in the fork lower. Remove the burr with a file so the axle will slide smoothly. I tighten the axle nut finger tight and leave the pinch bolts loose. I’ll tighten them after I get the brake calipers mounted.
The brake calipers have two bolts that mount into threaded holes in the fork lower. The brake pads don’t want to slide over the edge of the rotor, so I use a very large blade screw driver and gently pry the pads open a bit more so the caliper will slide over the rotor.
The wave washer goes under the bolt head.
I check that the front brakes work. I have to pump the front brake lever a couple times to get the pads back into position.
I take the bike off the center stand and bounce the front forks several times while holding the front brake and put the bike back on the center stand. This should remove any minor tweaks in the forks and ensure the forks sliders will be smooth. Then I torque the axle nut to 25 Ft-Lbs. I torque the axle pinch bolts to 10 Ft-Lbs.
I mount the dash and then secure the steering damper knob with the center screw.