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REH FORKS LTD

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REH – British built telescopic front forks

Article posted: July 2017

It’s exactly three years since ‘REH Forks’ returned to the pre-65 trials world.

Created by Robin Humphries in the 1960s, these first class telescopic front units were re-launched by Duncan Macdonald, from his workshop in North Yorkshire in July 2014 after nearly two years of design and prototype testing.

Duncan is well-known in classic trials through his company ‘Armac Design’, specialists in Triumph Tiger Cub trials frames and components.

Assembled damper rods

Assembled Damper Rods at the REH workshop

Macdonald:  “REH is a long-standing British brand, and we are maintaining the tradition, started by Robin E. Humphreys, of making the fork entirely in Britain. From the beginning, we wanted to make a fork that was true to the form, and ethos, of Robin’s original design, while using modern engineering methods to produce very high quality equipment.”

Adding oil to the fork

Duncan Macdonald adding suspension fluid to the assembly

Duncan continued: “We didn’t take it on lightly, but we had reached a stage in classic trials where the only way to get a set of competitive forks was to do conversions, mainly using 1970s and 1980s Spanish and Italian forks. It was always a poor compromise and they never worked to the standard that modern sections demand, so when we were offered the REH brand, we knew it was the way forward.”

Putting on the wiper seals

Putting on the wiper seals

More than 150 pairs of current REH Forks are now in circulation, in Britain, across Europe, and in New Zealand and Australia. REH Forks were on the winning BSA Bantam, ridden by Gary Macdonald, in the Pre’65 Scottish 2-Day Trial in 2017, and on Dan Thorpe’s Tiger Cub who came home in third place. Feedback from riders shows that REH forks are being used on Pre’65 bikes in modern and classic trials. The most common comments are about how much better their machines steer, and how easily they absorb rock steps and rough going. Some customers are so happy with them, they have bought multiple pairs  – the current record is 6.

Carefully measuring oil quantity

Carefully measuring oil quantity

Duncan Macdonald is known as a perfectionist through his work with ‘Armac Design’, is constantly working to improve action and options. To start with the forks were offered in two lengths, 30″ and 32″. Now they are available in 30″, 31″ and 32″ with extended top nuts providing an extra half-inch. Three spring rates, which can be used in combinations, oil choices and internally adjustable pre-load, allow the forks to be customised to bike and rider weight, and riding style.

Inserting a medium spring (yellow colour code)

Inserting a medium spring (yellow colour code)

Specification is 35mm diameter stanchions with sliders machined from 2014A billet aluminium (a very hard, strong grade), to replicate the original REH castings. One slider has a brake anchor lug compatible with Tiger Cub replica hubs. There is also a wide range of REH Options, including spindles with spacer kits (in 2 sizes), mudguard brace assembly (2 widths) and clamps (2 options), gaiters and leg protectors (2 types), brake anchor plate and hinged brake anchor bracket compatible with hubs with an anchor arm.

Tightening the top nut

Tightening the top nut

REH yokes, like the forks, are accepted in the Pre’65 Scottish Trial and are designed to work with  all classic trials bikes with 35mm stanchions.

Writing the customer name on the stanchion

Bespoke! – Writing the customer name on the stanchion.

Macdonald: “We use an aircraft-grade aluminium, and I’m confident they are the strongest, stiffest yokes on the pre-65 market. Most, if not all, yokes are made from 6082; REH yokes use 2014A, aircraft grade billet also used in REH sliders. This has a higher ultimate tensile strength and yield.”

Sliding despatch packaging onto the sliders

Sliding despatch packaging onto the sliders

It’s not an empty claim: there are several features that make REH yokes different. The depth on top and bottom yokes is bigger than other Pre’65 slab-type yokes, to give a much larger surface area in the stanchion clamping zone. Parallel with 40mm offset, they fit virtually all pre-65 frames. The spindle takes a 24mm internal-diameter bearing which is larger than most other yoke spindles, so is stronger and stiffer. The spindle is provided over-length to suit any frame, and is easily removable.

Assembly-9

The finished article, ready for despatch to the client

Macdonald: “Once you have the assembled fork legs, everything else is optional, but most people also take a spindle in 15mm or 17mm, mudguard brace assembly, a set of brace clamps, fork leg guards to save the sliders from being bashed and damaged, and the brake anchor plate.” He continued: “We also offer gaiters for the traditional look, and spare springs in three rates so you can tune the action for different bikes and rider styles; plus sets of bushes, wear rings and dust/oil seals. The idea is to future-proof the forks: once you’ve bought into REH, everything is available to keep them working to the best possible level.”

A pair of assembled fork legs costs £950, with a range of REH Options as bolt-on extras. These include gaiters, leg protectors, spindles with spacers, yokes, mudguards, mudguard brace assemblies and mudguard brace clamps with or without the front brake cable anchor. There is a full spares back-up of seals, wipers, bushes, springs and a full service offer. There are even REH soft-shell jackets; Duncan uses his to ride trials in dry, wet or windy weather.

Duncan builds every fork set to order. With all parts in stock all the time, a customer can expect delivery within a week.

More information on the website www.rehforks.com or contact Duncan Macdonald, rehforks@gmail.com

Tel: 01751 417371

REH Forks Ltd – Photo Gallery:

Trials Guru: Special thanks to Judy and Duncan at REH Forks for this feature.

BACKGROUND TO REH

Robin E. Humphreys started his motorcycle career at the age of 12, on a 1922 Levis. By the age of 17 he was scrambling a 500HS Ariel and over time drifted slowly from riding, to mechanical side of motorcycling.

He served an apprenticeship as a tool maker, then set up a engineering workshop in his father’s commercial garage. He worked on tyres and exhausts for a while, then hit on the idea of making forks.

So, REH was born in the early 1960s. The main customer in the early days was Sprite Motorcycles, with up to 100 pairs a week going out the door. In these early days, sliders were sand-cast from a wooden pattern, but later cast iron patterns were made so the sliders could be die-cast. The next step was hubs, then yokes; and REH was even used as a brand name on a complete motorbike.

Robin Humphreys’ passion was – and remains – making things, and his focus was good engineering practise. In this sense, he has plenty of common with Duncan Macdonald, who has picked up the REH baton to keep Humphries’ vision in today’s classic trials.