Technical
Instruction sheets, quick tips or technical articles. You’ll find it all here. All information on these pages is accurate to the best of our knowledge. If however you do find something incorrect please let us know!
Technical details, specifications and fitting guidance for Kingpin Components parts to help you select and install the correct components for your motorcycle.
Using a Kingpin Components vernier sprocket for setting the ignition timing on your vintage or classic motorcycle makes getting your timing spot on considerably easier and far less time consuming. The use of this vernier sprocket allows fine adjustment in increments of just 2.35° rotation of the crankshaft.
Our combined oil tap and switch which prevents wet sumping and can be connected to bikes with magneto or coil ignition. This ensures that, if the oil tap is 'off', the switch will stop any sparks and the engine cannot be started until the oil is switched on.
Learn how to install and use a smart diode cut-out on vintage and classic motorcycles. This technical guide includes fitting instructions and specifications to ensure correct electrical operation during restoration and routine maintenance.
This guide explains how to use a magneto static timing light to accurately set ignition timing on vintage and classic motorcycles. Designed for use with all makes of magneto, and battery/coil equipped engines, these instructions provide a clear, reliable method for checking and setting timing during restoration or routine maintenance.
Our combined oil tap and switch which prevents wet sumping and can be connected to bikes with magneto or coil ignition. How you fit it in the oil line depends on the bike, this page shows you the dimensions of our taps to help you decide which one to select.
This page answers the most common questions about our oil tap with cutout switch, designed to prevent wet sumping on classic motorcycles. It covers how the tap works, how to fit and wire it, and what you need to install one on your bike.
Workshop guides and technical articles covering the repair, setup and restoration of girder forks used on vintage and pre-war motorcycles.
On this page you'll learn how to fit girder fork bushes on vintage and post-vintage motorcycles with this step-by-step technical guide. We explain how to prepare the forks, make and fit bronze bushes, check alignment and ream to size — essential skills for restoring Webb, Norton and other period fork sets.
On this page you'll find step-by-step guidance on repairing worn or stripped damper threads on girder fork links for vintage and classic motorcycles. This technical article explains how to remove old thread, fit threaded sleeves, build up female threads with Sifbronze, re-tap and restore correct suspension function on period girder forks.
This article explains how to approach making new girder fork spindles for vintage motorcycle suspension, focusing on correct material selection (EN16T or EN24T) and why unsuitable steels like free-cutting mild steel, silver steel or stainless should be avoided. It also highlights why it’s preferable to source ready-made spindles if available.
Practical workshop techniques, engineering advice and mechanical guides for working on classic motorcycles, from machining and fitting parts to general restoration methods.
A selection of technical hints and tips that we think you may find useful but don't justify a page of their own.
Wet sumping is a common issue on classic motorcycles where engine oil drains from the oil tank into the sump while the engine is not running. This guide explains why it happens, how different types of oil pumps affect it, and the practical solutions available to prevent it, from maintenance and riding habits to anti wet sumping valves and oil line taps.
Technical articles and restoration notes specifically relating to Norton motorcycles, including suspension, engine and chassis work.
Engine data for Norton singles from 1928 to 1955 including bore, stroke, compression ratio and valve and ignition timing.
This guide explains how to repair the damaged camshaft tunnel in a Norton SOHC cambox, a common issue on these engines.
There are many ways to improve the performance of OHV Norton singles, possibly one of the simplest is optimising valve timing. On this page we will talk you through our recommendations for standard and alternative cams.
This guide looks at the piston options available when increasing the compression ratio of an OHV Norton engine. Standard ES2 pistons, modified 16H pistons, BSA B40 scrambles pistons and custom piston designs are compared, along with the advantages, drawbacks and machining work required to make each option work.
Post-war Nortons can be accurately identified and dated from the engine and frame numbers. This page will show you what you are looking for.
Pre-war Nortons can be tricky to identify using numbers alone. This page will give you some insight into what you are looking for.
Guides and reference material covering the maintenance, restoration and technical details of Velocette motorcycles.
From the first MOV to the last Thruxton the M series Velocettes all used the same basic design for their cams. Look here for the timing figures for each cam along with clearances and a note on what they were originally fitted to.
Tools and guides for calculating engine parameters such as cylinder displacement and compression ratio when rebuilding or modifying classic motorcycle engines.
Engine displacement can be calculated from the bore and stroke. Once you have the displacement you are one measurement away from calculating compression ratio. This page shows you how to do all of this.
Trigonometry can be used to convert crank rotation to piston drop. If you have the former, and would like the latter for setting up your engine, this article will show you how to do the conversion and even allow you to download a handy spreadsheet to do it for you.
Trigonometry can be used to convert piston drop to crank rotation. If you have the former, and would like the latter for setting up your engine, this article will show you how to do the conversion and even allow you to download a handy spreadsheet to do it for you.
This guide explains how to convert engine RPM into road speed using the gearing and rear wheel size of your motorcycle. By using the number of teeth on the engine, clutch, gearbox and rear sprockets together with the wheel diameter, you can calculate rear wheel speed and convert it into miles per hour. The article also includes a spreadsheet tool that performs the calculation automatically.
This guide explains how to convert road speed into engine RPM using the gearing and rear wheel size of your motorcycle. By using the number of teeth on the engine, clutch, gearbox and rear sprockets together with the rear wheel diameter, you can convert miles per hour into rear wheel speed and calculate the corresponding engine RPM. A downloadable spreadsheet is also included to automate the calculation.
Reference information on thread forms, measurements and standards commonly encountered when restoring vintage motorcycles.
If you aren’t sure what thread is used where on your British bike, have a look at this page.
Most American and some later British bikes will use Unified Thread Series. Have a look here to help identify them.