The seat is the original dual seat with cowl. The cowl was painted and pin stripped. You can read about how I disassembled the cowl from the seat here.

• 46 BMW 1977 R100RS Remove, Disassemble Body Work
  • Remove & Disassemble Seat Cowl and Seat

Parts

The parts I purchased are shown below.  I replaced the rubber bumpers on the front of the cowl, miscellaneous hardware, the rear roundel and decal on the rear of the cowl, and two of the seat hinge screws.

Part #	Description	Qty
52 53 1 232 904	SUPPORT – H=16 COWL BUMPER	2
07 11 9 907 639	FILLISTER HEAD SCREW – M5X10	1
46 63 7 686 746	BADGE – D=70MM	1
52 53 1 235 872	STICKER – SILVER	1
07 11 9 900 811	COUNTERSUNK HEAD SCREW – M6X10	2

Install Seat Cowl

Here is the seat and cowl before assembly.

Here are the parts I use to install the cowl to the seat pan.

On the top left and center are the washers and screws to attach the cowl to the seat pan. Top right are the cowl bumpers.

NOTE:
I show (4) cowl bumpers due to my confusion about the number needed. I only need two.

On the bottom are the rondel and R100RS cowl decal.

Install Cowl Bumpers

The two cowl bumpers go through the two holes in the front of the cowl so the face of the bumper is on the bottom of the cowl. The bumpers have a “tail” and I push that through the hole and then pull the tail all the way through the hole with pliers until it seats.

Attach Cowl to Bottom of Seat Pan and Grab Rail to Cowl

The phillips head bolts and washers go through the edge of the cowl into the threaded inserts in the bottom of the seat pan.

The grab rail attaches with four screws and special shaped standoffs.

This is the front bolt, washers and standoff.

The bolt threads into a square nut inserted into the plastic plug that goes into front end of the grab rail.

Here is the rear bolt and standoff.

Here’s how the front bolt and stand off are attached. The bolt threads into the square nut in the front end cap of the grab rail.

The rear bolt and standoff attach with a locking nut.

Attach Rear Pad to Cowl

I use 3M trim adhesive, aka “Gorilla Snot” to attach the rear pad to the inside top of the cowl.

Attach Seat Hinges and Seat to Frame

The seat pins on the frame of the R100RS point to the rear, but on the /5 and /6 frames, the pins point toward each other. So, installation of the R100RS seat hinges is a bit different from what I show for installing the /5 seat hinges.

• 00 BMW 1973 R75/5 Final Assembly
  • Attach the Seat

The two seat hinges are different and only go one way on the bottom of the seat pan. They attach with (6) countersunk pan head bolts,

I attach the rear hinge with three screws.

I attach the two screws on the front of the front hinge and then install the seat onto the pins.

I install the last screw up from the bottom though the hole in frame that aligns with it using a long socket extension and an Allen socket.

I install the c-clip in the groove of the rear seat pin to keep the seat from coming off the pins.

NOTE:
On the R100RS the pins face to the rear and the seat can slide off the pins. This lets me install the hinges on the seat pan and then slide them over the pins. BUT, I didn’t understand that and I installed the hinges using the procedure I use on /5 and /6 seats. When I was done the seat came off the pins 🙁 Then I saw in the parts fiche there is a c-clip. Looking closely at the rear pin I see a groove for the clip. Problem solved. 🙂

Here is the seat installed.

Install Roundel and Decal On Cowl

The roundel is a stick on piece and so is the R100RS decal. I believe BMW intended to install the cast plate used on later model bikes but for some reason didn’t/couldn’t on the first year bikes. The decal is low class in my opinion, but I put it on to be faithful to the original design.

The decal has both a rear backing and a front protective paper film. I peel the rear backing off and install it in the rectangular cavity under the Rondel on the rear of the cowl.

Then I soak a paper towel with water and rub the front paper film to get it to release and peel it off the decal.

Here is the finished cowl with roundel and decal installed.