Implying that they were just a bunch of hipsters from Seattle looking to make a statement on national television, Café Racer Magazine’s Mike Seate said this “Franken-bike” project by Twinline Motorcycles would never work.

If marrying a Honda and a Kawasaki wasn’t tough enough, Twinline also took on new challenges that they’ve never tried before, like building a custom gas tank, rebuilding an unfamiliar engine and manipulating and strengthening a frame for a powerhouse that it was never intended to house. 

Although it was ambitious and took a bit longer than anticipated, Twinline, led by a group of young craftsman and artists, proved that mixed technology and generations can work. Yes, the future of custom bikes is good.

Bike: “The Thorn” 1977 Honda CB550 and 1990 Kawasaki EX500


Frame:  1977 Honda CB550, strengthened & gusseted

Subrame: Modified stock, gusseted

Engine: Rebuilt 1990 Kawasaki EX500, Bored to 600cc with Engine Dynamics kit, Webcam 245 cams, Barnett clutch, heavyweight springs

Carburetion or FI System: Keihin CR33, 70mm velocity stacks

Rear Swing Arm:  Modified stock

Rear Wheel (Size): 2.15” x 18” Warp 9 rim, stainless spokes, KDX200 hub

Front Wheel (Size): 2.15” x 18” Warp 9 rim, stainless spokes, Warp 9 KTM hub

Clip-Ons or Bars: Woodcraft 35mm clip-ons

Seat: Custom one-off seat and upholstery

Tank:  Modified CB550ss tank, Pingel high flow petcock

Rear Sets: Motobits pegs, levers, linkage, Moto-R bracket

Tires (Sizes): Front: Avon AM22 110/80-18, Rear: Avon AM23 130/65-18

Exhaust : Modified stock headers, hand made cones

Paint: Frame: 20% powder-coat, Bodywork: none, raw mild steel

Headlight: CB350 bucket, H4 bulb, handmade mounts

Front Brake: Nissin 14mm master cylinder, stainless braided line, Brembo dual pot caliper

Rear Brake: Nissin CBR master cylinder, stainless braided line, Nissin caliper

Top Steering Clamp/Triple Tree:  Modified stock, steering damper

Electronics: Trail Tech Vapor gauge, Shorai battery, stock CDI, customized wiring harness

Twinline Motorcycles

2106 S. Holgate st.

Seattle, Wa 98144

Phone: 206-768-8686




More photos and specs for “The Thorn”

[nggallery id=85]