Kawasaki Z650 By Smith And Son Motorcycles

Coming from family of bike races, Jamie Smith always had an interest in bikes from a very young age and riding, racing, and building bikes is family tradition.

His latest build is a 1980 Z(KZ) 650. This bike came to him in a very poor state, barely running, and badly modified. Jamie wanted a bigger capacity 900 or 1000 Z, but the budget wasn’t quite there. Since his last build was a Honda CB500 four cafe racer, this time he wanted to go with a muscle, tracker, street vibe.

The design brief was pretty simple: Keep the overall silhouette of the original bike, but give it plenty of up to date attitude with a monoshock conversion and modern front end.

The frame although fairly stock-looking has had a lot of work, particularly the monoshock and frame bracing, other things include battery tray, rear light, foot rest brackets and integrated rear turn signals.

The rear swing arm is a period JMC deep braced item from a GPZ1100, held in place with a Nitron Shock stolen from an R6 while the front end is from a GSXR1000 running a stepped top yoke to get some ride height back. Front and rear wheels had to be spoked. The rear is 17×5″ laced onto an XR650 rear hub, the front is 17×3.5″ laced to a Cognitomoto from hub. Brakes are R6. Tyres are Dunlop Mutants.

Exhaust is a homebrew of brought and made parts. Engine has been ‘refreshed’. The seat base was made in house ad covered in leather. The petrol tank has had a filler from a GSXR400 welded in.

The bodywork is actually modular. Side panels can be swapped out for the original Z items and the front number board can be switched with a round LED headlight. All in about 15 minutes.

The frame and engine covers are all textured powder coat and Jamie went for an asymmetrical pattern on the paint.

The electrics got a lot of love. H scrapped everything and started fresh with Motogadget M unit, instruments, and key-less ignition. Switches are Motone and all wired in through the bars to give an uncluttered look.

Now Jamie is just waiting for the UK summer to pick up so he can get some miles on it.

Follow his work on Instagram and Facebook so you make sure you don’t miss any news.


  • Front end – GSXR1000 K4 with S&SMC stepped yoke and modified mudguard
  • Front wheel – Custom hub laced on a 17″ x 3.5″ rim
  • Front brakes – GSXR1000 K8 Calipers with Triumph 955RS mastercylinder
  • Rear End – Monoshock conversion running Modified JMC Swing arm, Nitron rear shock (R6), GSXR1000 linkage and machined adjustable dog bones.
  • Rear wheel – Honda CRF450 wheel hub laced on a 17″ x 5.0″ rim
  • Rear brakes – Honda XR650R caliper with GSXR750 mastercylinder
  • Tyres – Dunlop Mutants
  • Electrics – Motogadget Electrics and Speedo, with Motone switches, and Boyer Branson ignition
  • Exhaust – Deklavic down pipes. Fabricated link pipe and Danmoto can
  • Foot pegs / Hangers – Modified GSXR1000 rearsets
  • Seat – Custom base. Black leather applied by Nostalgia Upholstery
  • Bodywork – Modified petrol tank with GSXR filler cap
  • Engine – Stock Z650 Paint and powder coat finish
  • Carbs – GPZ750R1

Report by smithandsonmotorcycles.bigcartel.com