31 BMW 1977 R100RS Remove Front Forks, Handle Bars, Steering Stem, Fork Lock

I already removed the fairing and front fender to repair them and send them out for paint so I have easy access to the handlebars, controls, steering stem and forks.

Remove Telefix Fork Brace

This bike has a Telefix fork brace installed which is an after market upgrade. It mounts to the top of the lower fork slider in place of the rubber bushing originally on the R100RS forks. The bike has the rubber fork gaiters installed which was a common change to prevent nicks and bug goo on the fork tubes that hasten fork seal leakage.

The brace consists of a center bracket and two outer semi-circular brackets that attach around the top of the fork slider using small Allan screws. I remove the hose clamp securing the fork gaiter, slide it up and then remove the four Allan head bolts securing one of the outer semi-circular brackets.

Telefix Fork Brace

Telefix Fork Brace Parts

Telefix Fork Brace Parts

Telefix Fork Brace Parts

The center part of the brace consists of two pieces bolted together with two large Allan head screws. This allows adjustment of the distance spanned by the center section so it doesn’t pull or push the middle of the fork tubes together or apart which would increase fork stiction.

Telefix Fork Brace Parts

Telefix Fork Brace Center Piece From the Rear Facing Forward

I slide the center part up one tube and rotated it to remove it, but I could also loosen the large Allan bolts or remove them if I had to.

The stock fork brace and fender mount, or “Bow” as BMW refers to it, is still attached to the fork sliders. It’s easier to remove this after I remove the fork sliders.

Stock Fork Brace & Fender Mount

Stock Fork Brace & Fender Mount

Remove Brake Calipers

I remove the steel brake line from the caliper and from the upper rubber hose where it connects to the steel line at the bracket on the top of the fork lower with an 11 mm wrench.

The brake calipers are attached to the fork slider by an eccentric pin that is under a cap nut screwed into the bottom plate of the fork lower the caliper pivots on. I remove the cap nut and the spring between it and the bottom of the eccentric pin.

The pin can be hard to remove. I use an M8 bolt and thread it into the center of the eccentric pin for a couple turns until it stops. I don’t force it any further.

Using M8 Bolt to Pull Caliper Eccentric Pin Out of Caliper

Using M8 Bolt to Pull Caliper Eccentric Pin Out of Caliper

I use a large expanding jaw pliers on the end of the bolt and a plastic hammer to hit the pliers to extract the eccentric pin. It’s a good idea to hang on to the caliper as it will fall out of the fork when the eccentric pin is removed.

Caliper Eccentric Pin with M8 Bolt Used to Extract it

Caliper Eccentric Pin with M8 Bolt Used to Extract it

The caliper is free and can be removed if it didn’t fall out from the upper and lower plates of the fork slider it sits between.

Remove Fork Sliders

The procedure for the 1977 R100RS is the same as for the 1973 R75/5 as shown here:

Another way to remove the nut securing the fork slider to the damper rod is with a cordless impact driver and a 13 mm socket. The fork springs provide enough friction on the damper rod to prevent it from spinning so this is a quick way to get the nut off the damper rod.

Electric Impact Driver with Socket

Electric Impact Driver with Socket

Using Electric Impact Driver to Remove Damper Rod Nut

Using Electric Impact Driver to Remove Damper Rod Nut

I keep the axle installed in the fork slider so I can slide them off together. I had to push up the damper rods into the fork tube a bit to have enough room to get the fork lowers off.

Lower Fork Sliders Removed Exposing Damper Rods and Fork Tubes

Lower Fork Sliders Removed Exposing Damper Rods and Fork Tubes

At the work bench, I remove the four large Allan bolts that secure the stock fork brace-fender mount and the brake line brackets.

Large Allan Bolt Through Fork Brake Line Bracket and Stock Fork Brace and Fender Mount

Large Allan Bolt Through Brake Line Bracket and Stock Fork Brace-Fender Mount

NOTE:
The picture above shows the INCORRECT way to mount the brake line bracket. It should be on the other side of the fender brace next to the wheel, not in between the brace and and the fork slider. The way it was mounted by the previous owner will cause fork stiction making the forks less compliant and the suspension more harsh.

Remove Handlebars

NOTE:
You don’t have to remove the controls if all you are doing is rebuilding the forks and steering stem. You can remove the bars and fold them forward to access the fork tube top nuts and the steering stem nut. Since I am stripping the bike to the frame I remove the controls.

This bike has heated grips so there are small screws that secure the heating element to the bar.

Handlebar Hole on Left for Heated Grip Wires

Handlebar Hole on Left for Heated Grip Wires

I removed the screws and also push the wires that enter the bar at the bottom, center of the handlebar toward the ends of the handlebar so there is enough slack to pull the grips off the bar.

Heated Grip Wiring Goes Inside Handlebar

Heated Grip Wiring Inside Handlebar

To remove the right grip, I remove the throttle housing cover which frees the grip. Then I loosen the brake cable at the master cylinder under the gas tank so I can remove the cable from the right perch.

Front Brake Cable to Master Cylinder

Heated Grips Have Wires Inside Handlebars-Provide Some Slack To Remove The Grips

Heated Grips Have Wires Inside Handlebars-Provide Some Slack To Remove The Grips

I remove the connector for the clutch switch before removing the left perch.

Left Perch Clutch Switch Connector

Left Perch Clutch Switch Connector

The left perch got twisted hard upwards and torn the top plate covering the clutch switch.

Torn Top Plate Above Clutch Switch on Left Perch

Torn Top Plate Above Clutch Switch on Left Perch

I know a fellow who is an excellent welder. The perch is made from pot metal and has a lot of zinc in it so it takes a bit of technique to weld it. Here is the repaired perch.

Repair to Torn Left Perch

Repair to Torn Left Perch

Note there are a few holes caused by metal boiling away. I fill those with body putty before I repaint the perches.

Preparing Repaired Perch for Painting

Preparing Repaired Perch for Painting

I remove the screws securing the perches to the handlebars leaving just the handlebars attached to the top plate.

Controls and Instruments Removed

Controls and Instruments Removed

I am going to repaint the levers so I remove the plastic bushing using a small diameter socket.

Using Small Socket to Push Plastic Bushing Out of Lever

Using Small Socket to Push Plastic Bushing Out of Lever

Control Lever with Plastic Bushing (Ignore Plastic Tag Stem on Right :-) )

Control Lever with Plastic Bushing (Ignore Plastic Tag Stem on Right 🙂 )

Remove Top Plate & Instrument Bracket

The top plate has four holes in a row. This permits the handlebar to be mount more forward or rearward. When mounted forward, the instrument bracket is secured by the front studs of the handlebar clamps and the rear of the bracket is secured by two smaller bolts. When the handlebar clamps are moved to the rear, the large rubber bushing needs another bolt to secure the front the instruments bracket. On this bike, the handlebars were moved back. I remove the handlebar clamps and the front screws removing the handlebar and the instrument bracket.

Removing Handlebar Bracket

Removing Handlebar Bracket

Instrument Bracket Location on Bottom of Top Plate When Handlebars Are In Forward Holes

Instrument Bracket Location on Bottom of Top Plate When Handlebars Are In Forward Holes

The rubber grommets have steel bushing inserts. One of the larger ones is missing.

Instrument Bracket with Rubber Grommets and Steel Bushings

Instrument Bracket with Rubber Grommets and Steel Bushings

This is the top plate with the handlebars removed. I can now remove the fork tube top nuts and the steering stem top nut.

Remove Fork Tubes

The fork tubes are secured by a top nut and by the pinch bolts in the lower triple clamp of the steering stem. I use the pin wrench in the tool kit to remove the chrome caps on top of the fork top bolts.

I use a 36 mm socket that that I had ground flat to remove the bevel on the end of the socket. Since the fork top bolts are thin, the socket has to fully fit the edge of the bolt head or it will get rounded when I remove it.

Fork Tube Cap Nut

Fork Tube Cap Nut

36 mm Socket with Beveled End

36 mm Socket with Beveled End

Grinding Off Socket Bevel for A Flat Face

Grinding Off Socket Bevel for A Flat Face

36 mm Socket with Flat Face

36 mm Socket with Flat Face

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WARNING

You can get the forks out of alignment if you let the steering stem go to the steering stops while you loosen the fork tube top nuts. I use an old handlebar inserted in the opposite handle bar clamp from the top nut I am loosening and snug the handlebar clamp. Then I brace the handlebar with my stomach and loosen the top nut. I move the handle bar to the other handlebar clamp and repeat the procedure. Here is a picture of using the old handlebar when I did this work on the 1973 R75/5.

Old Handle Bar as Anti-Torque Tool When Tightening Fork Top Nuts and Steering Stem Nut

Old Handle Bar as Anti-Torque Tool When Tightening Fork Top Nuts and Steering Stem Nut

When the nut is loose unscrew it but cover the nut with a rag and keep your face away from it. The spring can launch it into you. I find pushing down on the nut as I near the last couple threads keeps it from launching.
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I loosen the Allan bolts on the lower triple clamp while holding the fork tube so it won’t slide out fall on the floor. If the fork tube won’t slide out easily, insert a large blade screw driver in the cut and gently tap it in until you can slide the fork tube out of the lower triple clamp.

Opening Fork Lower Clamp so Fork Tube Slides Out of Lower Triple Clamp

Opening Fork Lower Clamp so Fork Tube Slides Out of Lower Triple Clamp

Remove Steering Stem and Bearings

The procedure to remove the steering stem for the R100RS is the same as for the 1973 R75/5.

Remove Fork Lock

Since I am going to powder coat the frame, I remove the fork lock. The cover prevents the lock from coming out so I remove the cover

Cover Plate Obstructs Lock Tumbler Preventing Removal

Cover Plate Obstructs Lock Tumbler Preventing Removal

I open the protective cover over the lock. I use a long shaft screw driver and put it against the inside of the cover and then tap the handle of the screw driver to push the cover and it’s pin out of the frame.

Large Screw Driver with Hammer to Pop Out Cover & Rivet

Large Screw Driver with Hammer to Pop Out Cover & Rivet

Cover Plate and Brass Rivet (with Cat Fur :-) )

Cover Plate and Brass Rivet (with Cat Fur 🙂 )

This exposes the lock tumbler.

Lock Cover Plate Removed

Lock Cover Plate Removed

I insert the key in the lock, turn it clockwise and pull the tumbler out of the frame with the key.

Use Key and Turn Counter Clockwise To Pull Tumbler Out

Use Key and Turn Counter Clockwise To Pull Tumbler Out

Pulling Lock Tumbler Out with Key

Pulling Lock Tumbler Out with Key

Lock Tumbler Removed with Key

Lock Tumbler Removed with Key

Now I can replace the steering head bearings and rebuild the front forks. I document that work in a separate write-up you will find here.

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