Complete Builds | Engine and Chassis Work

​NYC Norton builds and restores our beloved Nortons and their associated parts to the highest level. Specializing in Norton Commando, Atlas, and Dominator Twin restorations, as well as Manx and Matchless Singles in various chassis, we can do a custom build to your specification, or rebuild/restore individual components. NYC Norton customers know that maintaining rideability and reliability are our priority. Tuning and performance options are our specialty.  Once the hard work is done, wrapping it up in a beautiful package makes it all that much better!
We specialize in long-term projects but always encourage smaller-scale rebuilds and modifications.


We know what works for a back road blast, or racing at Phillip Island, and everything in between

Whether we’re freshening up a stock motor, or tuning a racing motor to the ragged edge, we can make your old motor run better than the day it left the production line, and look absolutely stunning.  We measure bores, calculate piston-to-wall, set deck heights and squish bands, and provide all blueprinting and documentation.

Complete NYC Norton Motor Rebuild:

  • Your motor is disassembled completely, inspected, measured, and documented
  • Cylinder head is fit with new Kibblewhite Black Diamond valves and Kibblewhite bronze guides reamed for perfect fit
  • New valve springs, inlet seals, and heat insulators
  • Precision three angle valve seats cut
  • Head is skimmed and trued for flatness
  • New rocker arm thrust washers and springs
  • NYC Norton polished stainless fasteners throughout
  • NYC Norton one-piece polished alloy rocker spindle covers and hardware
  • Goodridge stainless overhead oil lines
  • New pistons and pins are fit with Hastings rings
  • Cylinder barrel is trued for flatness
  • Piston rings set to perfect gap based on bore size
  • Barrel is bored and honed for perfect piston-to-wall clearance
  • Tappets are reground
  • Cylinder barrel is painted in a high heat ceramic gloss black or silver finish and fit with NYC Norton stainless base nuts
  • Crankshaft is split, cleaned, magnafluxed, and completely rebuilt with new crank and connecting rod hardware
  • New rod shells are fit to rods
  • Crankcases are cleaned and finished better than new, and assembled with NYC Norton polished stainless hardware
  • New cam bushings are fit as required and line bored for perfect tolerance
  • New NJ306 “Superblend” roller main bearings on both drive and timing side are installed with crank end float shimmed to perfect spec
  • Oil pump is rebuilt and lapped
  • Timing and rocker covers faced flat for oil tight fit
  • All covers are show polished and all fasteners replaced with polished stainless
  • New crank and camshaft keys
  • New Andover Norton gaskets and seals used throughout
  • New rubber faced cam chain tensioner
  • Tachometer drive is modified with our NYC Norton seal fix
  • New NGK Plugs
  • Motor fit with our NYC Norton Reed Valve Breather setup – virtually eliminates oil leaks
  • We supply a set of NYC Norton polished stainless engine-to-frame mounting hardware
  • When it’s all done, we provide complete motor specification & blueprinting documentation for your files
  • What comes back to you is one of the most beautiful, performing Norton Twin motors available today, ready to fit

— Custom builds and performance work are welcomed

Please CONTACT US for a motor rebuild detailed quote

NYC Norton Modifications


Let us rebuild your gearbox to shift reliably for many thousands of miles

Often gearbox maintenance is given low priority by the rider, but in fact the health of this component is one of the most important in the drive train, as a faulty gearbox can lock up and cause extensive damage to both bike AND rider.

NYC Norton Complete Gearbox Rebuild: We disassemble your entire gearbox, inspect every gear, replace and update the sleeve gear bushings, springs, fasteners, and bearings. We install and shim the new roller layshaft bearing for perfect end float, cases are refinished, and covers are show polished.  What comes back to you is the smoothest shifting and best looking gearbox on the market.  $750.00

NYC Norton Close Ratio 4-Speed upgrade: Our Complete Gearbox rebuild service, as listed above, with the addition of a close-ratio 4-speed upgrade, bringing the gear ratios closer together for better shifting in the power band. This kit is designed for performance street riders or racers, and comes complete with all new heavy-duty hardened gears (4 mainshaft and 4 layshaft) and needle roller bearings on the sleeve gear.  $1495.00

Please CONTACT US with your gearbox rebuild needs

NYC Norton Gearbox Services


A lot of work goes into making your chassis perform 

Whether restoring a Commando back to its former glory, or working with a Seeley or Featherbed chassis, NYC Norton specializes in setting up the largest and most critical component of the motorcycle to perform at its peak. Our racing experience can translate to a better handling street bike; focusing on areas often overlooked and neglected.  A chassis with properly set up isolastics, head steady, and suspension, will transform your ride, and up your confidence and enjoyment.  We supply upgrades that make tuneable set-ups easier while retaining the spirit of our classics.

Commando Swingarm Spindle Reinforcement: A lot of blame on ill-handing Commandos is focused on the Isolastics, when often the problem lies in the swingarm spindle wearing in its bores.  Our Swingarm Spindle Modification will pin the spindle against the bore, removing slop for good.  Send us your swingarm and engine cradle, and we return it with the modification in place.  $179.00 (Purchase our Swingarm Spindle Kit HERE and fit yourself)

NYC Norton Complete Performance Fork Upgrade: NYC Norton will rebuild your entire front fork assembly, fit new fork tubes, clean, dress and show polish your fork sliders, fit the Cosentino Cartridge Damping kit (shim-stack tunable damping – best on the market), fit our top-spec Cosentino Teflon Fork Bushing Kit, and set up your forks beyond what the factory could have ever dreamed.  Send us your fork sliders and we will return completely rebuilt forks with cartridge internals allowing full adjustable compression and rebound dampening, and pre-load tunablity, ready to fit. Without question, the best Norton fork setup available today.  (Fork sliders must be in very good condition).  $1650.00

Please CONTACT US with your rebuild needs

NYC Norton Chassis Services


Every Norton is different, and that’s what keeps it interesting

  • Complete or Partial Restorations

  • Complete engine rebuilding and restoration

  • Carburetion Upgrades – Keihin FCR Kits, Mikuni, Amal Premier

  • Raise Compression and Squish Band machining

  • Piston-to-Cylinder clearance matching

  • Cylinder head helicoil and stud replacement

  • Crankshaft balancing/grinding

  • Complete Gearbox Overhauls

  • Belt Drive Modifications

  • Isolastic Upgrades

  • Performance Brake Packages

  • Cartridge Fork Internals

  • Rear Shock Upgrades

  • Custom Wiring and Electronics Packages, MotoGadget, LED Lighting

  • Wheel Building

  • Custom Machining

Please CONTACT US with your rebuild needs