Christian's ExesoR
By Anthony van Someren - 10 Dec 13
You may have seen this beautiful CB250 already but we had to have her on The Bike Shed, and besides, we have a few extra 'unseen' photos of the bike, and of course our unique Bike Shed angle on the build - and the bike is pretty special, especially for a Shed build.
The man behind all the hard labour is Austrian engineer, Christian, who has never worked on motorcycles professionally, but his skills have clearly been applied to this remarkable bike which is laden with exotic materials, one-off bespoke items and clever engineering solutions.
Having rehearsed his bike-building skills on streetfighters Christian's attention eventually turned to the cafe racer scene. He started out with a CB400 which was modified to run at Classic bike races, and then along came this 1976 CB250. It was an Ebay find in terrible condition, but at least it was cheap at just €250.
Being a proper engineer Christian started with drawings. He'd wanted to build the bike for a 'well-known coffee company" but this didn't work out, so he needed to create an alternative brand & logo, and ExesoR was born. ...I can almost smell the beans roasting now.
Unlike most builds on here - especially shed builds - Christian's goal was to use as few stock parts as possible and to manufacture as many of the replacement components himself. His second rule was to avoid silver chrome, so every metal part on the bike is either nickel plated, black chrome, galvanised or raw metal.
One thing Christian is particularly proud of is the way he concealed the throttle cable inside the handlebar. While this isn't unique, it is very clever, and it wasn't achieved through any off-the-shelf kit. Another notable feature is the use of "Diamond-like Carbon" (DLC) coating on the fork internals, which is a new treatment you might find on modern KTMs and race-bikes.
Many of the main components on the bike were created using CAD (computer-aided design) which Christian had to teach himself to use as he went. The designs were then used to create CNC parts. This clearly went very well.
Along with all the clever exotic stuff there were some more familiar engineering upgrades. To compliment the coated fork internal surfaces Christian fitted Wirth springs. The rear swing arm, from a CB400, is suspended with Koni shocks. Motogadget clocks (of course) take care of instrumentation but the mount was custom made.
The bike also got a stronger motor, courtesy of a CB360 bored-out to 390cc and running hot cams and open velocity stacks. A Dyna ignition maximises the spark along side a light-weight mini Lithium Ferrous Phosphate battery, and the drive-train uses a race clutch.
All this work took Christian 460 hours over two and a half years to complete, and it's real mix of ultra-modern tech and old school design aesthetics. Whether you're a tech-loving, race-bike convert to the cafe scene or an old-school petrol head who likes things to look right, this bike has a little bit of something for everyone.
Christian wants us to thank Photographer David Matl who is responsible for these beautiful photos, taken in an old coal mine, and which David credits for helping him win a Custom Bike Magazine contest this year. Yes, they're lovely pics, but it's also a remarkable bike. Thanks for sharing with all of us here at The Bike Shed. See more from this build at the ExesoR Motorcycles Website.