The Yamaha SR150 is Taiwan’s best-kept secret. Exclusively manufactured and sold locally, the cheap and cheerful single sold in droves in its heyday, mostly to commuters and delivery riders. It’s no longer in production—but it’s found new life in the custom scene.
We’ve seen slick custom SR150s from workshops like Hide Work Custom, TwentyTwo Custom, and Twist.Co. But this plucky Yamaha SR150 bobber comes from an outfit that’s new to these pages; Balls Custom.
Based in New Taipei City, the cheekily-named Balls Custom shop is part workshop, part café. They were tasked with customizing the Yamaha SR150 by a female rider who wanted something small and manageable to scoot around on. Visual inspiration for the build came from an unlikely source—the vintage BMW R50.
The SR150 and R50 are worlds apart, so Balls wasn’t looking to copy every aspect of the classic boxer’s design. The idea was to take key elements from the R50 and reinterpret them for the newer Yamaha. A compact fuel tank, bobbed seat, and low-mounted rear fender were all on the list.
Before they tackled the bodywork, Balls tore the Yamaha SR150 down to its nuts and bolts and began massaging the frame. The pint-sized runabout needed a lot more than a subframe chop to bring it in line with the team’s vision though. Balls ended up welding in a thicker frame backbone, fettling the steering neck, and redesigning the rear end with new shock mounts.
Next, the guys modified the swingarm and installed a pair of chromed rear shocks. The wheels were swapped out for 16” items, built with aluminum hoops and the OEM drum brake hubs. They’re wrapped in matching 3.5-inch-wide Kenda K489 tires.
Next, Balls fabricated an adorable fuel tank to sit atop the tweaked frame, topped off with a chromed filler cap. A kangaroo and pig leather saddle sits just behind it.
Handmade fenders and brackets sit at either end of the bike, with a classic taillight mounted in an integrated housing on the rear fender. The headlight mount is a custom piece too, as are the brackets that hold the Yamaha’s vintage-style turn signals.
Balls kitted the cockpit with a set of stainless steel handlebars, fitted with the bare minimum controls and switches. The ignition’s been relocated to a custom bracket just below the fuel tank, on the left side of the bike. The brake pedal and gear shifter are custom stainless steel bits.
Looking to squeeze a little more juice out of the baby SR, the crew cracked open the motor and bumped it up to 226 cubic centimeters. It’s fed by a Yoshimura carb and a velocity stack, and exhales via a custom-made stainless steel exhaust system.
The crew wanted to keep the SR150’s new exhaust as unobtrusive as possible, so they built a boxy muffler underneath the bike that gently matches the curve of the frame’s lower rails. From there, a short curved section directs gasses upward and out, mimicking the look of an open system.
Other subtle custom touches include a neat aluminum front sprocket cover and a hidden box that holds a Lithium-ion battery.
The Yamaha SR150’s silver frame and fuel tank sport an electroplated silver finish that’s almost as brilliant as chrome, but with a more satin-like finish. Conversely, the silver bits on the fenders are polished aluminum, to show off Balls’ handiwork. Line and Circle Custom Studio added the blue paint and silver leaf striping, tying the whole thing together stylishly.
Quirky, yet handsome in its own special way, Balls Custom’s Yamaha SR150 bobber is the perfect cure for the Monday blues—and a great reminder that the littlest SR has miles of potential.
Balls Custom Instagram | Images by Amos Wang and Weeber Photography
