1978 BMW R100S

Used MotorcyclesSport Touring


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SOLD.....1978 BMW R100S Custom, Red! Complete Rebuild.

This bike started life as a 1978 R100RS. The previous owner did a complete rebuild on the bike at 46,500miles. He did a beautiful job, then less than 2000 miles down the road the RS fairing and front fender was damaged.

He was very discouraged about the damage after putting so much work in the bike, so we bought it from him with the intension of making it a R100S.

His work: Motor top end rebuilt with new pistons, springs, valves, keepers, and unleaded valve seats conversion. Lightened flywheel, new rear main seal, new oil pump cover and o’ring. Rebuilt starter, bearings and cap, new starter relay. New neutral switch and oil pressure switch. Updated breather valve and K&N Air Filter. New clutch. Transmission rebuild by Rubber Chicken Racing.

Motorrad Elektric high output alternator, Motorrad Eleckric diode board and mounts and voltage regulator. Ground wire upgrade on diode board and frame. Dyna ignition booster, Bosch Super Blue coils, new plug wires with NGK caps. New exhaust headers, crossover, and mufflers.

Carburetors rebuilt by Rubber Chicken Racing, new everything. All new cables. Rebuilt complete braking system; new hoses, new caliper pistons & seals, new master cylinder pistons & seals front and rear, new pads. Rebuilt forks, new springs, dampers from Huckys. Tostertan upper frork brace and Telefix lower fork brace. Barback handlebar setbacks. Grand Touring grips. Wheels bead blasted and clear coated. All new rubber parts, new Avon tires. Progressive Suspension rear shocks.

Whole bike stainless steel fastener kit. Motorrad LED brake light. Sargent tour seat. BMW Touring cases with powder coated mounts. New centerstand. New Petcocks. New BMW Tool kit. And, of course, the new BRIGHT red paint.

Our work: As we do on all BMWs that we fix up, we checked the frame for straight with our BMW Factory Frame Gauge. We found it to be slightly bent. We selected a straight 1978 R100S frame with a clear title from inventory, and we had the frame, subframe, centerstand, swingarm, side lift handle, “S” Seat grab handle, and hand controls powdercoated black for a lifetime durable finish. New steering stem bearings were installed. The wheels were checked for straightness, and new bearings and seals were installed, adjusted, and serviced. The front fork was completely disassembled and carefully inspected. We found everything to be straight and perfect. The rear drive unit was found to be in very good condition, and installed on the swingarm.

As we tore down the R100RS, we noticed that the motor top end had been resealed with Silicon sealer; the death to all airhead BMW motors! We took the motor down to the bare case and cleaned out all the oil passages with high pressure detergent water, then rinsed, and cleared all the passages again with high pressure air to be completely sure that none of the deadly silicone sealer remained in the motor. It is very fortunate that we did this tear down, as we found wear on the lower rod bearing shells. We checked the mains and found them perfect, and fitted new lower rod bearing shells. Everything else on the entire motor was carefully measured and scrutinized for wear or damage and all was found to be very good, as would be expected of a motor with less than 2000 miles. We reassembled the motor with all new seals and gaskets. We replaced the timing chain and tensioner and tensioner spring.

R90S handlebars were installed. New throttle gear and throttle tube were installed. A pair of new BMW “S” throttle cables were installed. A pair of R headlight mount ears were painted and installed. A R90S fairing was painted to match the red paint job, the front fender and fuel tank were also repainted, and the whole bike was hand pinstriped with a single narrow silver stripe. A San Jose dark smoke windshield was installed on the “S” fairing. New long black BMW mirrors were installed. New Speigler dual braided stainless brake lines were installed on the front brakes, and a Speigler braided stainless brake line was installed on the rear brake. A new Yuasa battery was installed. Proper R100S emblems were installed on the motor and tail cowling.

As we assembled everything, we greased / serviced / adjusted EVERYTHING to proper specifications and operation. We were unhappy with the way the carburetors responded, so we cleaned them thoroughly, and did a complete rebuild on them with new diaphragms, gaskets, o’rings, and float needles. New Genuine Continental braided cloth covered fuel lines were installed.

The bike came out beautifully! It looks fast just sitting still. The motor starts immediately when you touch the starter button, then settles down to a slow steady thumppeddythump thumppeddythump thumppeddythump. We eagerly await a test ride as soon as the snow melts and the streets are clean and dry.

If you wish, we can add a pair of BMW Touring cases to this bike.

We would be happy to answer any questions you have about this BMW motorcycle; please call us at 614.837.1160. To see more high resolution views of this bike in detail, please copy the link below to your browser search bar to direct you to our online photo storage on Picturepush, or request our series of high resolution photos via an email to bmwparts@re-psycle.com.

PLEASE NOTE: It was snowing when we took the photos. The white spots are snowflakes falling. (We'll take new photos soon)


Click on one of the thumbnail photos on the left to see it larger on the right. Then click on the larger photo on the right to see it in a full screen pop-up window. Then scroll down to the bottom right and click on the word “Full”. This blows it up to maximum size (about 6 times window size) and you can use the scroll bars to move around your view point like your eye is 2 feet from the bike.

If you would like to take this bike out on a test ride, please plan it for a dry day, and call 24 hours ahead to schedule.

We would be happy to provide you with a quote for enclosed, insured, to-your-door delivery by a carrier we have a good history with.


*Price, if shown, does not include government fees, taxes, dealer vehicle freight/preparation, dealer document preparation charges or any finance charges (if applicable). Final actual sales price will vary depending on options or accessories selected.
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