Yamaha's SR500 never enjoyed the GB's cachet, but it's similarly styled, similarly capable, far more abundant, and typically available for just $2,800 to $3,000. Sold in the US from 1978 to 1981, the SR has long been a popular choice among the café-racer crowd, so finding an unmolested example may be tricky. Powered by the same 499cc, air-cooled, two-valve thumper as the TT500 and XT500 off-roaders, the SR's engine has proven just about bulletproof in stock form. With no electric start, the kickstarting procedure can get old, especially if the bike is out of tune. And given that the youngest specimen you will be able to find will be nearly 40 years old, locating an SR that doesn't need some amount of rehab is likely a tall order.