There are lots of grey areas in the custom world. The engineering on a factory bike is black-and-white in its precision: components are thoroughly tested, and they comply with a multitude of regulations. If they fail, the manufacturer could face legal action.
Unless a custom job is purely aesthetic, it?s likely to compromise this engineering. Some bolt-on mods are undoubtedly improvements, but others?especially when one-off fabrication is involved?could compromise the integrity of the machine.

The French custom shop Dab Motors sees this as an opportunity. They?ve created the first custom motorcycle that is Euro4 certified: the LM-S. It?s also the first bike you can customize online before placing your order.
Dab was established in Biarritz in 2017 by Simon Dabadie, and for this project he?s been joined by another experienced engineer? Pierre Jayet, formerly of Peugeot. It?s a good match because both guys are passionate about 3D design technology, additive manufacturing, and cutting-edge materials.
The LM-S is a mix of urban, enduro and supermoto styles, with a minimalist ethos. It?s impressively light too, weighing just 125 kilos (275 pounds).
?It represents the simplicity and essence of a motorcycle,? Simon tells us. ?A fine silhouette, light weight, a playful engine and high-end equipment. It?s the ultimate toy for custom bike passionnés.?

At the core of LM-S is the 500cc DOHC single-cylinder engine from the Husqvarna 510, chosen for its quick throttle res...