BSA D3 Trials Custom

What a fascinating piece of engineering! Purists of the BSA will study the photos with great intent, finding all there is to find to this somewhat Frankenstein Machine - built and modified throughout an entire lifetime. The Bike at hand has been in the same family for at least two generations - and now set for many more after its full restoration with us.

This fantastic Trials machine was used throughout the childhood of the owner and older siblings, - The Eldest sister, who of course was taller, took the reigns and rallied around the small field behind the family farm house, That didn't stop the owner getting a helping hand from father when setting off, all well and good until you needed to come to a stop! Where a leap of faith become a necessity! 

The Frame is a Mid-50's Bantam D3 Swing, the engine is also D3 from 1949-1956. The front forks are a modified combination of A7 Stanchions, and D10 Supreme Legs with hand-made spacers to eliminate any spring bounce. Restored Hand beaten adaptors hold the new rubber gators firmly in place.

The seat has clearly been hand-fabricated in its day - we are told that this was once a just a piece of sponge tied on with string for use round the yard! So we opt for a simple, pre-65 style saddle which was hand made by Viking Motorcycle Seats. The original base was carefully aqua blasted to create a unison finish underneath.

The Rear wheel assembly and brake backing plate is all Bantam D1 with spacers to tailor the D3 Swing-arm. Shoes relined by Villiers with modern composite. The Rear rim has been replaced with a slightly wider rim for the the tyre to fall between its safe fitment range. This gives a lovely stance!

The Front Wheel uses a Grimeca Hub (Used on Royal Enfields, Fantics etc.) again with spacers to accommodate the forks. Fascinating stuff!


The engine has been fully rebuild with new bearings, seals and bushes. The Cases have been carefully restored using High Pressure Glass Bead (Aqua Blasting) by Suffolk Blast Clean Ltd. Cases are then cleaned thoroughly making sure oil ways are clear before bearings are pressed into place, and gears are set into place and checked for operation.

This particular engine had to have a replacement big end, so the crankshaft was rebuilt by Scholar Engineering - our trusted heavy engineering firm. Upon return, we then reamed the new small end bush to make the perfect fit with the NOS 0.20"+ Piston. The barrel was bored out to accommodate this adjustment. The Barrel, refinished in VHT was cured upon first start.

All Hardware is replaced with correct UNF or CEI where necessary to achieve that real original restored finish. Shaft Ends, Cylinder head Studs and Levers all plated in-house to suit.

The fibreglass mudguards were carefully restored back to a blank canvas - using specific fillers to build back shape. The original design was then recreated using colour matched base coats, finally finished off with U-POL Superior 2K Clearcoat. The Mudguards are all rubber mounted to achieve the best possible longevity. 

A substantial amount of time was spent removing the dents to the front end of the tank, to create the original shape that was lost. The simplistic design that brings in the two partnering mudguards was applied, before being cleared for that final fuel-proof finish. A Subtle, of period BSA Logo was chosen to set the bike off nicely. A Steering stop was manufactured and welded securely to the frame prior to painting to ensure dents from the fork legs never return. The Tank is lined with a premium tank liner that is tried and tested with other restored examples.

This bike truly demonstrates the work that Lacey's Motorcycles can achieve - even with the challenges surrounding the renovation of so many original aluminium components. The choice of replacement parts have been soo critical on this one - with the breif being, "restore the machine to as close as it would have been back in the day." Everything from Tyre Tread Choice, to choice of grips, cable routing and everything in-between. 

It has been an absolute pleasure working with this fantastic example of a D3 Trials, the 6 month restoration period has paid dividend to its final results and photography - This sentimental machine is to be returned to the owners private collection - in perfect storage conditions. Whist always having the opportunity of scrambling around that field once again!

Every single bespoke item that was once produced for this individual bike was recognised, carefully removed, restored and dressed to create results that would otherwise be unrecognisable without before photos. Aqua Blasting somewhat re-kindles aspects of the machine that would otherwise be lost if refinishing was chosen. Upon close inspection, all the fine detail remains to aluminium components such as the Chainguard, foot-pegs, mudguard supports, Speedo housing and Engine brackets which gives the bike a real charm. The bike has had pride of place in our showroom and has created quite the interest - with hours spent with cups of tea, discussing certain individual aspects of the machine and stories it could tell, with delighted customers.

D3 Trials Before

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D3 Trials After

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