Turnertech engineering logo Mechanical engineering workshop Wiltshire and South West

Engineering workshop in Wiltshire for classic bikes- lathe turning, milling, slotting, welding, CAD, nothing too small.


Motorcycle Engineering: Classic motorcycles, modern, road and racing motorbike parts and repairs in Wiltshire.

I specialise in making custom parts for classic bikes, vintage motorcycles and racing motorcycles. From manufacturing obsolete and no longer available parts to general classic bike engineering and fabrication.

Motorcycle engineering from a special bolt to a complete custom motorcycle from our engineering workshop in Wiltshire.

On the right are some early construction photos of my one off vintage racing motorcycle. Inspired by the classic racing motorcycles of the late 1920's that competed at the Brooklands banked circuit in Surrey, a racing showcase of what I can produce.

The entire vintage racing custom motorcycle is designed and made in my Wiltshire engineering workshop where I specialise in one off parts for classic bikes and modern, racing and road motorcycles.


billet motorcycle engine engineered in Wiltshire

Billet racing motorcycle engine

June 2018: My Brooklands SS 500 wins 'Most Interesting Motorcycle' at the Bath Festival of Motoring.

2017 saw the new foot change gear linkage fitted to my Brooklands SS reproduction vintage racing motorcycle, along with a number of small improvements. In July it returned to the Brooklands Museum for it's first accent of the famous Test Hill. Since then refinement has continued with the manufacture of a one off quick action throttle. The latter proved it's worth when we returned to Brooklands for the Motorcycle Show in July 2018 with a very rapid accent of Test Hill. Development continues as they say!

Wadkin-Snaith vintage racing motorcycle

In June 2017 I was approached to recreate a lost motorcycle from the 1920's: The unique Wardill supercharged 2-stroke. Not to be confused with the Dunelt, which might appear superficially similar, the Wardill featured a special phased charging piston and in competition tests proved very successful, sadly the company was a victim of the Great Depression.

Very soon the project changed to initially producing a batch of replicas with a modern engine, Turnertech to design and manufacture the prototype of the new bike, following the original as closely as possible.

Some of the major components such as the frame and girder forks were manufactured by 3rd party suppliers. Despite setbacks with some suppliers the bike was largely complete in time for the Brooklands Museum Motorcycle Show on 1st July 2018 where it was very well received by show goers and 2 preliminary orders taken. It has been a great pleasure working with Mr. Wardill, who's boundless enthusiasm for the project has driven it on so rapidly.


A new project bike beginning in Autumn 2018: A completely new Honda 125cc race bike using a CB125S engine. The new one off custom frame is now complete and I hope to have the bike on it's wheels by spring of 2019. All built in my Wiltshire motorcycle engineering workshop.

Check out Turnertech Engineering on Instagram for the latest updates.

Honda CB125S race frame

A little over 4 years after I began the design of the engine, I finally got to ride my one off custom billet motorcycle in anger with the National Sprint Association in October 2016. It must surely be the ultimate shed built custom motorcycle, as I designed and built everything myself, and I'm pleased to say teething troubles were few and performance far better than I expected. Here despite wheel spin and going sideways out accelerating an R1! It really was a special experience riding a custom motorcycle entirely designed and built by myself.

Updates for next year include minor modifications to the valve gear design, and for racing purposes a foot gear change. The Brooklands style hand change is just too limiting for sprinting, roll on the 2017 racing season!

Riding my custom built racing motorcycle for the first time.

2016 What a wonderful day at the Brooklands Museum! My 1929 style billet motorcycle was 99.9% finished for the show and 2 weeks later was fired up for the first time. The culmination of 4 year's spare time in my engineering workshop.

My Brooklands SS custom motorcycle at the Brooklands Museum

A really fun project completed for a customer in Dec 2016; this Suzuki GS400 Brat Style bike has emphasis on practicality for Summer fun:

Shortened fork stanchions, taper roller head bearings, custom fork brace, rebuilt caliper, power coated hubs and rims, aftermarket silencers fitted with more efficient stainless steel baffles and pipe adaptors, cut down rear sub frame and custom seat, modified custom rear light, tiny digital speedo and modified Honda CB100N headlamp with custom brackets, hand formed custom front mudguard, CNC machined mirror, ignition switch re located under the petrol tank and host of other small modifications and improvements.

Customer's comment after the first ride: ".. absolutely fantastic, feels so spritely and grin inducing."


Suzuki GS400 bratstyle custom bike.

Typical example of the work I do is repairing this Triumph Tiger Cub crankcase; The oil feed union retaining stud hand been replaced with a high tensile steel bolt, subsequently broken and then attacked with a hammer. I successfully removed the broken stud without damaging the thread in the case, increased the threaded depth and faced off the flange.

Velocette telescopic gear lever

In 2015 we were approached to assist with the build of a BMW R80/7 custom bike in the Brat-Style in our Wiltshire engineering workshop. After discussion with the owner modifications were extensive including shortened rear subframe, relocation of battery under the gearbox, electronic ignition with coils and electrics located in the airbox. New billet aluminium top yoke, headlamp brackets, Smiths speedometer, new exhausts, brake master cylinder and hoses, Honda petrol tank, custom seat and a host of subtle details. The bike has now been returned to it's owner for cleaning and painting.

BMW R80/7 Brat-Style bike we built for a customer

Produced for the 2015 nostalgia drag bike season, this Shorrocks supercharger drive plate and pulley centre/outrigger bearing support for well known drag bike racer Martin Willmott. The drive plate is manufactured in nickel chrome molybdenum steel to withstand the enormous stress placed upon it in drag racing with high nitro loads. The pulley centre replaces the original John Clift item which was badly worn. Whilst making it we took the opportunity to modify the design slightly to incorporate a thread for an extractor.

New shorrocks supercharger drive plate

In November 2014 we made this new front brake drum for a rare 1937 Triumph Tiger 90 500cc single in our Wiltshire engineering workshop. The original part had cracked where the brake surface joins the rear face of the drum and was in a very dangerous condition. Investigation revealed that the casting was under 3mm thick in this critical area. The new one was made in a medium carbon steel with slightly shallower fins to increase material thickness of the braking surface.

Pre war Triumph Tiger 90 front brake drum

As of Christmas 2014 good progress has been made on the Brooklands Sprint Special motorcycle. Tanks are in primer and the exhaust is currently under development. See it on the National Sprint Association stand at the 35th Carole Nash Bristol Classic Bike Show February 7-8th.

New Brooklands style racing motorcycle

As of March 2014 the engine and gearbox of the Brooklands classic racing bike are well advanced and the majority of the chassis complete. I hope to have this classic custom motorcycle on it's wheels by the Summer followed by construction of petrol and oil tanks etc.

Shown with a BSA Bantam front hub which I replaced with a Yamaha DT50 one with a one of billet back plate. The rear shown is from a Yamaha XT500 replaced later with a modified Honda CB250RSA one.

Brooklands style classic racing bike

In 2008 we began a new racing motorcycle project based on the remains of a 1978 Honda CB125T classic bike. Very little of the original Honda CB125T remains, even the frame has been radically modified. The bike was created from scratch in our Wiltshire engineering workshop to compete in National Sprint Association events.

Now weighing under 78kg whilst producing more power than the famous, and fabulously expensive Honda CR93 limited production classic motorcycle. Despite 6 years of development much more work remains to be done as the engine still relies on standard pistons and camshaft. However even in it's current form it can match a Yamaha RD350YPVS on acceleration in the first half of the track. 2013 was memorable for the thrashing of a Ducati 996!

motorbike engineering, modify cylinder head Honda CB125T 1960's Honda GP replica

On the HondaCB125T our rider, Sharon 'The Hooligan', gives a Yamaha YZF R1 rider a run for his money.

Virtually everything on this classic bike was made in our Wiltshire engineering workshop, From the petrol tank to the ultra light hydro formed megaphone exhausts. Even the clip-on handlebars are specials, carved from solid billet aluminium. Extensive use of parts engineered in aluminium and titanium have seen the weight slashed, whilst a careful program of engine modification have produced a power increase in excess of 30%.


Honda CB125T

It's not all racing motorbike engineering in our Wiltshire workshop:

On the right a set of parts for a custom Harley Davidson chopper oil tank and a Yamaha TY175 trials bike front hub. The latter was modified to suit a BSA Bantam special trials motorcycle. All types of motorcycle engineering and modification undertaken, nothing too small.

We also remove broken studs and bolts on a regular basis for customers.


Custom chopper oil tank trials motorbike special parts

One of our earlier projects was this classic Honda CB500T dragbike. Developed over a period of 10 years in our Wiltshire engineering workshop virtually nothing remained from the original motorbike. Fitted with a supercharger from a Mercedes, pistons from a Kawasaki Z1 and with a rephased crankshaft.

Eventually producing 450% more power than the standard motorbike!

Motorcycle engineering: Our supercharged, methanol Honda CB500T