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BMW K100RT – Motofication

Posted on August 6, 2015 by Andrew in Café Racer. 20 comments

Written by Marlon Slack.

Some bikes lend themselves to customisation more than others. Twin-shocked stalwarts like the SR500 and CB750 are so easily stripped back and chopped, lowered and lightened it takes something pretty special to grace the pages of Pipeburn. Other bikes, like this 1985 K100RT from Nuremberg’s Motofication, take considerably more finesse, planning and cutting discs to be transformed into something truly attention-grabbing.


Motofication is a small team lead by Marc, whose work first gained an online presence a few years back after a K-series cafe racer he’d built was featured on a few motorcycle blogs. It generated some interest and more than a few compliments so he decided to attach some photos to an online store, with the aim of branching out into building some customs on commission. And that’s where the owner of this bike first saw his work, clicking the ‘add to cart’ option and paying online right then and there. That was Friday night. ‘Next Monday morning I had a phone call, asking how I was going to ship the bike to him,’ Marc says. ‘Ouch. That’s not possible, it’s mine and it’ll stay mine!’


After an apologetic phone call explaining that no, he hadn’t bought the K café racer, he told the customer he’d love to put together something for him, but he’d need to hunt for his own suitable donor bike as a starting point. Thankfully, the client understood and in a short period of time found himself a clean metallic grey BMW K100RT which he packed up and shipped to the workshop. After he swung by to talk over the options with Marc and the team, they were ready to go to work. They were given carte blanche to design everything, with the only caveat being he wanted some Motogadget-gadgets to hold the build together.


‘We started in December 2014, ripping everything off and cutting up the frame’ Marc says. ‘We cut the frame and bent it so the lines would flow a little better.’ The workshop cut down the tail too, welding a new loop in which holds the new brake and tail light unit together with the aluminium cowl. The seat was sourced from a local saddler, Martin Kuethe while some aftermarket rearsets, last manufactured in the 1980s, were tracked down and mounted.


That kind of frame work is pretty much par for the course, but other aspects of the K100 were a little tricker to work with. ‘The BMW K is full of electronics. Bosch fuel injection, digital speedo signal, gear display, brake light safety system and so on. We had to run those through a little device from a flying brick forum member named ‘Maru’. We improved it a little, managing to run the device and battery in the tail section.’ The finish was already decided on, with Motofication opting to use as little paint as possible. The fuel tank and tail have been polished, while powder coat was only used sparingly.


By the time this BMW was finished, the porky K was shaved down to 200 kilograms, which, when matched to a new injection system and a revised airbox, might surprise a few people with its acceleration. They were tempted to go a little further with the mods, with USD forks, carbon or magnesium wheels and even an ABS system being considered. ‘But that’s not what we want from the K. It’s just a cool ride that not everybody has,’ Marc says. ‘And it’s a tribute to the flying brick system, first on the road in 1983, 32 years ago.’


[Photos by Thomas Riese]


  • guvnor67

    Kool. Really diggin’ the polished tank and tail, and even the brown seat! Flying Bricks are hard to make nice, but this is pretty darn good. Well done!

  • Hardley T Whipsnade III

    Its pretty decent and nicely done but to be honest I’ve seen better ‘ Special K’s ‘ elsewhere .

  • ccc40821

    K100s are great, in part because they’re great bikes to ride, and in part because they’re dirt cheap. Would like to see some more rough ones, though. Like this one:

    • Hardley T Whipsnade III

      Now that is one serious Bad Boy looking K bike that I like rough or not . A ‘ Special K ‘ truly worthy of the moniker . Dang that bike looks mean . I could easily see some German 1%er , Sohne der Anarchie type riding this in a heartbeat . Sorry to repeat myself but dang but I like this bike . A lot ! This yours by any chance ? I want to see more !

    • TruthBringer


      • Hardley T Whipsnade III

        XLCR Sportster-fied with a healthy dose of Arlen Ness and a serious injection of getaway bike perhaps . But then again not really . No . This thing is pure bad ! Just looking at it has me wanting to crouch behind that fairing , black leather head to toe with full face matt black helmet riding the beast like the Devil himself was chasing me keeping it within arms reach of the ubiquitous ” Sausage Monster ” staying a mere step ahead all while praying to who ever if I should crash to be taken out in a single blow rather than winding up a cripple for life . So trust me . There aint no ‘ Sportster ‘ on planet earth , custom or otherwise ever going to evoke those images and emotions

    • guvnor67

      Hell yer!!

  • Dave Coetzee

    Better than I could ever do. Just a little “constructive” criticism – 3rd pic from below – would be nice if those 2 wires could be hidden and the front of the seat-pan could be lengthened slightly, with the abrupt bottom edge rounded where it would meet the tank.

  • Darrick B

    I’m impressed. These are not easy bikes to make pretty, and this one is quite good looking. And it looks to be actually rideable as well!

  • yamahappy

    That exhaust really makes the bike IMO. Too bad it can’t have one on both sides!

  • shame about the the big exhaust and number plate but i know the Germans are screwed when it comes to modifying bikes, good job then, but you can keep your EU laws and money, we don’t want them

    • guvnor67

      Yer, the whole TUV thing would give me the shits. Lived in Germany for a while and the roads are great, but sadly, they like their rules

  • roscoe

    The seat looks like it was made 4 inches too long, but through some desperate clamping, shoving, and lots of screws, they were “able to make it work anyway”.

  • Meister Robrock

    did one of you…..? no, you did’nt, did you?!

  • I’ve learned a lot from his previous builds, and like this one as well. Not a big fan of the chrome, and would prefer more upright bars, a seat for two and perhaps a fly-screen, for a bit of highway wind protection, but that would totally change the intent of the bike, so I’m talking about a different project, not really criticizing this build. Like the neatness. Hopefully I can put my K75 up her for scrutiny one day.

  • Love the brick – that big block of motor anchoring the whole motorcycle to the pavement. Talk about central mass. Best brick I’ve seen in a while.