On this day, the tenth anniversary of Cycle Exif, we present one of the most interesting custom mountain bikes we’ve seen: a lugged 29er MTB whose lugs were investment cast from models that were 3D-printed — all wrapped around a Pinion gearbox.

The process of investment casting, or lost-wax casting, dates back around 6,000 years and is still used today to duplicate a metal sculpture from an original. It’s a very effective method if you want to reproduce an object with complex detail.

Germany’s Simon Hollad is an engineer in the gas turbine industry, but in the evenings he ventures out onto his balcony and brazes bike frames together. In the case of this MTB, however, he pushed the boundaries of tradiitonal Frame building a little further.

Lugged bicycle frames aren’t really a common request for the modern frame builder as tubing manufacturers increasingly develop oversized, lighter tubes that just don’t fit the lugs that are only available in a limited range of angles and internal diameters.

Simon found a solution to this quandary through the lost wax method but first, he had to create the model. He designed them in CAD and 3D-printed them, from which moulds were made and lugs were cast by Simon’s good friend Mathias, in Aachen.

The frame was finally brazed together then mounted with the Pinion automatic gearbox and a Gates carbon belt drive (you’ll notice the splitter on the chainstay). Simon also constructed the chain tensioner/roller device to keep the belt taut.

A Rock Shox Pike fork with 140mm of travel leads the charge, hauled up by Magura MT7 brakes with massive 180mm rotors. The wheels are built up from a pair of Acros Nineteen hubs and NEWMEN Evolution rims.

It’s branded with a brazed-on top tube badge and a proudly-placed Bike Of The Week award from MTB News DE. Simon’s ‘Hollad-Rad’ is a rare adventure into innovative solutions to odd problems, but it sure as hell looks like it performs as it should.

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