BMW K100 - Sir Ulrich

The BMW K100 custom motorcycle named Sir Ulrich is a complete transformation by NCT Motorcycles, the Austrian workshop known for turning classic BMW platforms into stripped, electronically rebuilt track-ready street machines with handmade frames, Brembo brakes, and a meticulous attention to clean mechanical aesthetics.

The Concept

NCT Motorcycles approaches every build the same way: strip it to the frame, question every component, keep what works, replace what does not. Sir Ulrich follows that principle to the letter. The BMW K100, the German manufacturer's iconic inline-four brick motor of the 1980s and 1990s, is the ideal platform for this approach: robust, characterful, and with a profile that rewards clean minimalist bodywork. NCT named this build Sir Ulrich, a nod to Ulrich Schwanke and the culture of precision engineering that the K100 represents.

The Build

The K100 was stripped completely before any work began. The engine received a full overhaul and was treated with a black coating. The original frame was revised and given a custom handmade rear section fabricated by Manuel, redesigned to accept the new seat unit. That seat is hand-shaped and upholstered in light brown leather. Once all fitment was confirmed, the frame was finished in black powder coat.

Electronics were rebuilt from scratch. An M-Unit replaces the original loom, with a lithium battery concealed under the seat. The system includes Keyless Go ignition and an integrated alarm. The instruments use an Acewell speedometer. The handlebar is an LSL unit fitted with M-Switch controls and Motogadget components. Lighting was redesigned front and rear: a CNC-routed front mount carries the new headlight, integrated turn signals, and the rear light. Brakes are new Brembo units throughout. The exhaust is handmade by Kurt and Manuel with a slip-on addition from a specialist supplier. Air filters remain original items, correctly sized for the K100's demands. There are no fenders, a deliberate choice that opens the silhouette and signals the machine's summer-riding purpose. LSL footpegs and a JSS strut complete the ergonomic refresh, and a stainless steel licence plate mount finishes the rear.

Performance

The BMW K100 inline-four is one of the most reliable engines the brand ever produced: smooth, linear, and almost impossible to wear out when properly maintained. The overhaul completed by NCT brings it to as-new condition, and the lithium battery reduces weight at the centre of the machine. The stripped fenderless configuration, minimal electronics, and revised geometry give Sir Ulrich the responsive, lightweight character that heavy-stock K100s typically lack.

Specifications

• Builder: NCT Motorcycles, Austria
• Base Model: BMW K100
• Build Name: Sir Ulrich
• Engine: Overhauled, black-coated BMW K100 inline-four
• Exhaust: Handmade by Kurt and Manuel, specialist slip-on
• Air Filter: Original BMW
• Frame: Revised with custom handmade rear section (Manuel), black powder coat
• Seat: Handmade, light brown leather upholstery
• Electronics: Full M-Unit loom rebuild, lithium battery, Keyless Go, alarm
• Instruments: Acewell speedometer
• Handlebar: LSL with M-Switch and Motogadget components
• Lighting: CNC-routed front mount, integrated turn signals and rear light
• Brakes: New Brembo
• Footpegs: LSL
• Rear Strut: JSS
• Licence Plate Mount: Stainless steel, rear
• Fenders: None (summer configuration)

Discover the full NCT Motorcycles Collection at TheArsenale.