Until I came across this bike, I had never heard of Derbi – the Spanish (or Catalonian, depending on your geo-political perspective) brand that started producing small-capacity bikes in the early 1940s. The story of the company started, however, in 1922 when Simeón Rabasa i Singla opened a bicycle shop in Mollet del Vallès, near Barcelona. That business would go on to become Rabasa, a company that these days focuses on urban bicycles.
After a few years of experimenting with motorized vehicles under the Rabasa name, Simeón and his brother, Jose, unveiled Derbi in 1950, the brand getting its name from the phrase “Derivada de Bicicleta,” literally ‘derived from bicycles.’ The company remained an independent business all the way until the year 2001, when it was bought out by Piaggio. I’m not entirely sure it’s still producing bikes in 2025; the Derbi website doesn’t appear to have been updated since 2011.
The GPR50R was one of the first new Derbi bikes produced under Piaggio leadership. I can’t find any reviews of the bike, but the UK’s Motor Cycle News did ride the naked version, which is presumably the same machine sans fairing. Driven by a 49cc single-cylinder two-stroke engine, that bike had a peak output of 9 horsepower and 4.4 lb-ft of torque. In the UK market it was restricted to just 30 mph but was clearly capable of more.
The seller of this particular GPR50R, meanwhile, says it “will easily do 70 mph,” despite being registered as a moped. Some of that speed may be down to the fact it isn’t really a 50. Capacity’s been boosted to 75cc with an Airsal kit. Either way, I’m going to guess you have to rev the nuts off it to get it to hit those freeway speeds. And I’ll bet it sounds amazing – in an ear-splitting, atomic mosquito sort of way
“The bike is in pretty good shape,” says the seller. “However some of the tabs on the bottom of the fairing are broken (and) there are the expected small scratches and a chip or two… It’s complete but not a show bike.”
But I guess you can’t be too picky when something this rare comes along. With 4,000 miles on the clock, this GPR50R is for sale for $2,500 in Turlock, California, here on eBay.