| BMW K100 custom |
 A café flat four made for the curves...
Spurred by cause and aided by convenience, the basis of this feature bike comes from a period that fits neatly into motorcycling’s not too distant evolution. Like it or not, the K100, was truly a revelation; BMW’s first new engine design since Max Friz spun the firm’s Douglas-inspired, opposed twin ninety-degrees for the R32 some 60 years earlier. Fully entranced by the modern/retro café racer movement, VMOL’s inbox is filled with fresh, new designs that yet retain a distinct measure of traditionalism. Florida’s Thorsten Strenger -whose resume’ features everything from show winning restorations to ultra-light aircraft production- provides a splendid example of this with his café K100. “The goal was to lighten the sport-touring "Brick" as much as possible” said the owner, “for better looks, handling and performance. All this resulted in a lightweight (approximately 400-lb dry) ‘Brickster’.” Powerful and smooth, the performance benefits are obvious and made even better by retaining every ounce of the K100’s legendary longevity and reliability. The K100 was developed in response to the staggering governance the Japanese enjoyed during the 1970s. The inline four had become an industry staple and if BMW could ignore it no longer. In classic ‘bitza’ style, Strenger K100 café began as an assortment of separate components; the frame is late 80s issue, the engine and transmission from 1985. Smooth and ingeniously clever, Thor carefully mixed his basket of factory parts with owner-engineered pieces and select aftermarket items to fit together so well, the machine could be mistaken for a production motorcycle. The frame, Aprilia RSV-style ¼ fairing and the K’s stock wheels were bead blasted, etch primed and finished in dark blue pearl base with glossy clear 2000. The fuel tank, seat, side covers and front fender were coated with glossy clear with a center stripe in Indigo Blue Pearl base with pinstripes. All of the body parts (except the front fender) are in aluminum alloy and display considerable workmanship. Despite being an all-new design, BMW’s “Project K” displayed some historic parallels. Conventionally inline, the engine was dropped on its belly then spun -R32 style- 90-degrees: cylinder head to the right and the crank/output shaft opposite. The assembly is held in a straightforward tube frame via four mounting points and acts as a stressed member. Simple, solid, yet unique and avant-garde, this configuration gave the K100 instant engineering charisma; important factors to current and would be BMW owners. The one piece alloy crankcase holds four 67 x 70mm Galnikal coated bores and mates with a 2v DOHC cylinder. A long chain drives the K100’s twin cams via spur gears that act upon the valves with bucket-type followers. Completing the drive line proved a challenge for BMW’s engineers, who feared a straightforward assembly would stretch the K100’s wheelbase to unreasonable limits. Great expense was directed to compress the space between engine and BMW’s traditional shaft drive. Unlike the twin (which drove its gearbox from the rear of the crankshaft) the proximity of the output necessitated a secondary shaft. This was accomplished with a set of gears below the crank, which linked the shaft to a single disc dry clutch then back towards the K100’s five speed transmission.
The K’s whirring, whispering mechanical tune is smooth and zippy with nary a tingle felt through the bike’s chassis; all very composed and business like. Nudge the lever and release the K100’s feather light clutch and the machine responds predictability; the 987-cc four spins freely and moves the bike with confidence. In this case, appearances aren’t deceiving, as the “Brick” melds its Teutonic personality with every aspect of its performance. Criticized for nagging vibration during the 55 mph era, the K100’s true personality is revealed when cruising near the ton, revealing the sweet spot of the engine. Largely stock, fully serviced and tuned the 2v engine is Thor’s K1 café uses a relocated (external) Bosch fuel pump/filter for ease of maintenance. Smooth and supple, the bark from its 4-into-1 header/carbon muffler fits well with the machine’s look and purpose. Chassis specs include slotted brake rotors on the Fridel and Sachs leading axle fork and a fully adjustable rear gas monoshock with a variable rate Progressive spring. Blessed with a glowing mechanical record, the K100 has returned astronomical feats of reliability and longevity over the last 25 years. No surprisingly, many remain in daily use, spinning their six-digit odometers two or more times without the aid of rebuild. Not that they exist without warts; well known is the Brick’s oil blowing dilemma, the result of oil seeping past the valve guides when the bike is parked on its sidestand but the pluses vastly outweigh any negatives. Simply put, the K100 is one of motorcycling’s greatest accomplishments. Nolan Woodbury *** Moving onto other projects and addressing needs, Thorsten Strenger’s custom café K100 is available for purchase. Interested? See the contact information and links below: Thorsten Strenger 407 781 6592 eBay listing: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=330431033034&viewitem= Video: http://www.youtube.com/watch?v=hfKlsQyrmgo&feature=player_embedded
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motorcycle manufacturers. Realizing history suffers not fools, the knowledge and expertise extracted from that steep learning curve has propelled modern production wares to the point of no return. Indeed, the performance capacity of modern motorcycles is so great, so utterly compounding, that it can not be fully exploited on public roads by anyone but the most gifted or fearless of rider. And while in and of itself this discourse provides no great revelation, the path to this junction is worthy of pause and consideration.
Groundbreaking on many fronts; the liquid cooled, DOHC engine was uniquely mounted in longitudinal fashion with Bosch fuel injection, computer controlled engine management and a compact drive train that featured a massive alloy mono-swingarm. While journalists (correctly) viewed the K100 as the dawn of a new day, history reflects a slightly different outcome.
A recent conversation with former Cycle editor Steve Anderson revealed just how close BMW was to actually halting motorcycle production altogether. Anderson, who held a close 
acquaintance with BMW’s Stefan Pachernegg, explained that the project’s chief engineer arrived on the scene after many of the K100’s details had been finalized. Pachernegg held the keys to the 110-million dollar investment, with the power to kill the project or see it to completion. “The twins were expensive to produce and drained funds,” said Anderson. Ultimately, the K-series proved essential for the company’s survival and with 85.510 sold between 1983 and 1991, it’s clear Pachernegg’s hunch paid off.
