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BMW Customization Workshop · Neuwied
BMW R90/6 & R90S conversion parts 70s icon
The BMW R90S was BMW's first superbike in 1973 – featuring a cockpit fairing and Dell'Orto carburetors. Together with the R90/6, it is one of the most refined bases for a classic café racer today. Here you will find everything we develop for it.
- Construction time1973–1976
- Displacement898 cc
- Performance60–67 hp
- ChassisTwinshock
39+
Matching parts
1994
Manufacturer since
TÜV
Expert report & ABE
Since 1994BMW conversion workshop in Neuwied
Conversion by assembly group
Everything for your R90 conversion
From the tail to the electrics: Select the assembly – or scroll directly to all parts for the BMW R90/6 & R90S.
01
Tail conversion
Rear frames, seats, fenders, and license plate holders – with TÜV certification.
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02
Front conversion
Triple clamps, headlights, speedometers, handlebars, and mounts for a clean front end.
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03
Exhaust
Complete exhaust systems and silencers made of stainless steel, many with ABE (general operating permit).
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04
Chassis
Struts, fork springs, damping systems, and suspension service.
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05
Electrical
Cable harnesses, ignition, regulators, and switches – assembled in-house.
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06
Engine & Performance
Overhaul, carburetor, ignition, and tuning on the test bench.
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All parts for the BMW R90/6 & R90S
39Parts available
Why Sport Evolution
Parts from the converter, not from the retailer
1994
Boxer specialist
For over 30 years, we have been building, restoring, and tuning BMW boxer and K-series models in Neuwied.
TÜV
Registrable
TÜV Rheinland certified company. Many parts come with a technical report or ABE (General Operating Permit).
i250
Custom test bench
Carburetor and fuel injection tuning on our Dynojet dynamometer.
100%
Self-driven
Our parts are created on real concept bikes – tested on the road, not in a catalog.
Guide
The BMW R90 rebuild
R90/6 and R90S – the 900cc classics
With the /6 series, BMW introduced 900 cc to the boxer engine for the first time in 1973. The R90/6 produced 60 hp, while the sporty R90S delivered 67 hp thanks to higher compression and 38 mm Dell'Orto carburetors—a real statement at the time. Both utilize the proven twin-shock chassis of the /6 series.
BMW R90/6 & R90S Profile
| Models | R90/6, R90S |
|---|---|
| Production period | 1973–1976 |
| Engine | Air-cooled 2-valve boxer |
| Displacement | 898 cc |
| Power | 60 hp (R90/6), 67 hp (R90S) |
| Carburetor | Bing (R90/6), Dell'Orto 38 mm (R90S) |
| Rear suspension | Twinshock |
Convert or preserve?
An original, well-preserved R90S is a collector's item. For a custom build, R90/6 models or examples that have already been modified are particularly suitable. Our approach: reversible modifications wherever possible that fit onto original mounting points – this preserves the value and emphasizes the character of the classic rather than masking it.
The most important conversion parts for R90/6 and R90S
- 36 mm triple trees with TÜV approval for clip-on or tubular handlebars.
- Damping system for 36 mm forks – modern fork technology with a classic look.
- Twin-shock rear conversion kits with TÜV approval for café racers and roadsters.
- 2-into-2 exhaust systems with ABE (general operating permit).
- Brake discs & pads for ATE swinging calipers.
For engine and carburetor overhauls, see Engine and Transmission Service.
FAQ
Questions about BMW R90/6 & R90S
Can't find your question? Use our parts inquiry form – we will respond personally.
Do R100 Twinshock parts fit the R90?
In many cases, yes. Triple clamps, tail conversion kits, exhaust systems, and brakes are designed to be compatible across the twin-shock R75 to R100 models. The product titles list all compatible models for each item.
Will my R90S lose value if I modify it?
A non-reversible modification to an original R90S can reduce its collector value. We therefore recommend conversion parts that can be installed without modifying the frame. We would be happy to advise you on this personally.
Do you offer carburetor tuning for Dell'Orto carburetors?
Yes. We overhaul and tune Bing and Dell'Orto carburetors on our Dynojet dynamometer.
Can I upgrade the fork on my R90?
Yes, with our damping system for 36 mm forks. It significantly improves responsiveness and damping without altering the classic look.