Classic BMW boxers are so prolific as custom donors, that most builds these days are very formulaic. But there are dozens of swing-and-miss examples out there, that prove that it still takes a sharp eye and a measure of good taste to get them right.
This 1974 BMW R90S scrambler from Injustice Customs in Sweden doesn’t tread any new ground visually?but it’s extremely sharp and impossibly clean. It’s also sporting a refreshed motor and a thoroughly modern parts spec, with upgraded suspension, wheels, brakes and electronics. So it’s far more capable and reliable than most 47-year-old bikes.

Injustice’s Anton Knutsson runs the shop as a one man army, and has a penchant for building bikes that are crisp and minimalist. This BMW came from a customer in Norway, who’d been riding it in stock form for years, but had dreamt about owning a custom bike. And it wasn’t too beat up either, despite its age. ?After discussing this build with the owner, we agreed on aiming for something like what Singer does with old Porsche 911s,? Anton tells us. ?We wanted to keep much of the traditional lines that are iconic on the Airhead, but add a lot of modern technology and performance.?

With the R90 well-maintained and the motor in pretty good shape, there was no need for a full rebuild. But Anton worked through it anyway, and replaced anything that wasn’t absolutely tip-top. The updates included a Silent Hektik ignition, and a handful of parts f...