Grey Flash 2751

The history and restoration of a Vincent HRD Grey Flash

The Grey Flash features an extensively drilled and lightened headstock casting.

Quite a bit of dead weight removed here…

The Works must have deemed this appearance a little unsightly so an alloy cover plate was devised to cover up the holes and provide a place for the mercury crest transfer.

We believe this to be the original item.
It has been sandblasted on both sides.

I’m convinced this is original to the bike; accurately constructing a similar part wouldn’t be hard but correctly replicating the dimensions would require more diligence and it’s very unlikely anyone would have bothered with such a trifling task in decades past.

Period shot of the part on 2751 – the profile is identical.
Loosely affixed with what appear to be the original screws.

The question here is what might the original finish of this component have been? Usually they were polished. I feel certain that it wouldn’t have been blasted – some of the visible dings have also been subjected to this treatment indicating that the blasting was undertaken later on in the bike’s life. As the finish/presentation was a very important aspect of this early Grey Flash I suspect this plate would have been anodized along with many other of the aluminium parts. Re-anodizing might be one answer or perhaps carefully removing the blasted finish with a suitable grade of wire wool. We need to have a careful think about this before coming to a decision.

The cover plate on what is believed to be GF2921.

Drilling Patterns

Detail of the drilling of the headstock casting.

One thing we’ve noticed about the drilling on the headstock casting is that it differs from that of later examples. David Dunfey has kindly sent me some images that show a different pattern of 5/16″ holes.

Later UFMs would have been drilled thus: six additional holes in the tank bracket and the omission of the fifth hole in the casting – as indicated.

I’m finally able to report that the fork blades are stripped of all of their paint. In fact, all parts have now been stripped but I’m going to start with the forks as they are an important reference point for this part of the restoration. We know, without a shadow of a doubt, that the forks are the original ones that 2751 left the factory with. We know this because of the many unique features found on the Grey Flash Girdraulic fork legs that differentiate them from Vincent Black Lightning items. The bike was exported new to New Zealand; the only Grey Flash exported new to that part of the world. For the bike to have acquired a genuine replacement Grey Flash fork leg would have been nigh on impossible. So the legs have to be original to the machine and, under the paint, we are likely to find the anodized finish listed on the Works Record Card. That is, unless it was destroyed by someone trying to obtain a “key” for said paint…

The listed finishes.

As we have seen, the dull chromium plated finish extends to several parts of the machine, including the UFM and RFM. For now though, I will be concentrating on the parts of the bike that were anodized. This method of finishing alloy parts has been around since the ’20s though didn’t start to become widespread, beyond military applications, until the late ’50s/early ’60s. We were sure that the anodized finish would have been of silver in colour and that this would have been done to give the aluminium parts a superior appearance and protect them from oxidization.

Several layers of paint were removed exposing the finish beneath – the first time it’d seen the light of day in many decades.

Prior to stripping. This grey painted finish was applied by Peter Johnson and Terry Prince. Under this was another, different grey painted finish and a layer of primer that had been applied by a previous owner.
The stripped fork legs.

To see how these legs differ in appearance from an unanodized set, prior to being painted, they will need to compared to an original leg in that state. I have an original leg, that’s never been refinished, elsewhere and I have a plan to dig it out, strip some of the old finish off and compare it to these ones. Then, I believe, the difference in finish will be quite apparent. Looking at these items on their own, they don’t appear to be showing any signs of anodizing but I feel confident that this finish is indeed consistent with silver anodizing albeit somewhat aged.

Anyway, for the time being, let’s just marvel at them. For sure, few have ever set eyes on a set of genuine Grey Flash lightened Girdraulic fork legs…

The milled parts are an expression of just how strong the designers claimed they were. They are lightened extensively and confidently.
This close-up shot of the machining shows that the surface finish inside the milled grooves is consistent with the general overall appearance on the entirety of the forks. If the visible surfaces had been roughed to provide a “key” prior to painting, it’s extremely unlikely that the person prepping them would have extended the same level of attention to the inside of the milled grooves.
The overall condition is excellent.
These special forks have received additional finishing attention…
A standard set features this script cast into them.

So, it is imperative that we are able to feel completely confident that the fork legs are indeed anodized. Once this has been confirmed then we will be able to use their finish as a point of reference when comparing them with other alloy components that we believe may be finished similarly.

Last night Bert sent through some images that I’ve been eagerly awaiting…

We know that 2751 left The Works with special finishes because the Record Card states: “Girdraulic anodized” and “dull chrome” as the finish for the petrol tank. However, we were not sure which other parts would have been finished thus and it was with great anticipation that we reached the point in the restoration process where we would be able to strip off the paint and see what was underneath. The beautiful cellulose paint applied by Terry Prince and Peter Johnson was a uniform finish and we knew that some parts were original to the bike, due to their rarity, whilst others might be correct but not the parts that 2751 left the factory with. Stripping off the layers of paint would reveal all and we would be able to ascertain what was what.

Dull chrome??

Some years previously I had rubbed a little paint off the rear forks and had been presented with a finish that indeed appeared to be a chromium plating of some kind – this patch didn’t rust over the years that it was left exposed.

Bert set to work on the UFM and RFM with 2 gallons of thinners. He toiled away for two days, high as a kite on the fumes whilst feverishly rubbing various layers away, his nub of a damaged thumb carefully protected from the vicious chemicals.

The Reveal…

It is with a great sense of satisfaction – and even pride – that I’m able to reveal to the world, in this blog, the results of his hard work:

The stripped UFM and RFM. Both are fully chromium plated!

The UFM.

The lightened headstock exhibits a dull chromium finish whilst the oil tank is a different kind of plated finish. Note the securing bolts rather than studs on this early UFM.
The dull chrome is plenty thick and damaged in places.
A crack is visible on the bearing headrace.
The dull chrome is uniform and beautifully preserved.
It has been worn off the top of the oil tank filler neck.
The contrast in the two finishes is evident in this shot.
The finish on the oil tank has a different appearance to that of the dull chromium plated headstock.

The RFM.

Extensively drilled casting – the RFM was plated as one assembly.
This beautiful finish has been protected for decades by layers of paint. The condition of the dull chrome is truly remarkable.

So, a real pivotal in the restoration has been reached and every moment savoured! I hope all subscribers to this blog will find these images as satisfying as we are at being able to share them with you.

There has been a delay due to: (i) waiting on parts, (ii) the c-virus, and resulting lockdown, and (iii) to a medical emergency that resulted in ace spannerman Bert nearly losing his hand after a malevolent pathogen came out of nowhere and took hold… His full recovery will take some time but he’s now getting back in the workshop aided by his wife, when needed.

It took some time to ascertain what parts were needed to replicate the mudguards accurately. We decided it would be prudent to fit these up prior to the bike being completely stripped down.

This is the look we were trying to achieve.
And this is the result.

The front racing-pattern mudguard is a standard alloy blade, minus the front u-shaped stay, and cut down. The rear stay is the standard item with a spacer between the stay and the fork to allow for clearance of the air scoops.

A good, clear period shot of 2751’s rear mudguard.

The rear racing mudguard is a purpose made item and not an adapted standard item.

This is what has been achieved – temporarily rigged prior to the full bike strip-down.

The rear guard is almost a full 180˚ in circumference. The radius of the guard is the same as that of the front blade and it employs the leading u-shaped stay from the front, at the rear.

Great pains were taken to ensure the front portion of the mudguard protruded far enough.

We were delighted to learn that these raw blades were actually in stock at the VOCS – this averted a special one-off order from a manufacturer, which is what we were anticipating.

And we’d like to thank Bob Culver for constructing the stays to original specification. They will be sent for dull chromium plating which would have been the original finish.

The original FT3 that we obtained from Franc and Greg, down in Australia, has been drilled.

The drill pattern is accurately recorded on a Works drawing which we had.

David Dunfey kindly supplied additional data which enabled us to drill with confidence. He also furnished us with photos of the original FT3 from his GF.

The finished item.

Once the lockdown has lifted and businesses are up ‘n’ running again, this will be sent off to the platers for the application of the correct dull chrome finish.

Dyl boy has carefully inspected the drilled FT3 and given it two claws up. 👍🏻

15/7/2020
The engine has now been detached from the frames and the FT3 tried for size.

It will be sent for dull chromium plating once the platers are up ‘n’ running and taking in work.

A moment of assembly this early in the process of restoration is a cause for some elation. The rear rim was exchanged for the correct 20″ item early on in the project and now the refurbished drums have been bolted to the hubs and offered up to the forks and RFM.

The rear drum.
10 bolts now, as per original.
The front hub – a very pleasing result.

The above photo features lots of incorrect parts that will be attended to later. The Elektron brake plates are still too shiny and will take a few years to dull down. We have found an American product on the market called Eagle One Etching Mag Wheel Cleaner – this should produce a pleasing dark matte finish but we’re currently unable to find any for sale in the UK.

We have discovered that the front hub features a metric bearing setup. Due to a shortage of materials during the Korean War, metric bearings with an o/d of 47mm were fitted in place of the standard Vincent item. So this item is not the original hub as 2751 was completed and shipped prior to the onset of the Korean War.

The hollow front axle complete with bearings/spacers and shims.

What to do? Replacing the hub with a new pattern item and fitting standard bearings was one option. Another was finding a period hub and hollow axle and fitting that. The former of these options is the least desirable as we would be replacing period items with new ones. The latter option seemed more in keeping with the level of authenticity we are are trying to achieve but we have decided to go with what we already have. The reason for this is that (i) it’s a genuine period hub (albeit of a little bit later vintage than what would have been fitted to the bike when new) and (ii) was used during the bike’s racing career. In addition, it features a hollow axle machined out of lightweight alloy. These were sometimes fitted to Vincents though we’re not sure whether this one is original or made at a later date. Anyway, it seems entirely appropriate to preserve this lightweight component on a racing machine.

This hub would have originally been fitted to a road-going Vincent with a speedometer as these drive gear ring retaining punch marks attest.

Recent inactivity is due to the fact that we have been awaiting and sourcing parts.

A large order of parts arrived from the VOCS.

Clutch plates for the modified Norton clutch also arrived.

As has been previously explained, the trick Norton clutch will be retained. This component is imbued with the bike’s racing history and to sideline it in favour of an original Albion unit seems almost criminal. Why delete parts of the bike that were used in-period just because they are unoriginal? It would not be particularly hard to source the correct component and return the bike to the spec’ that it left The Works with. However, we’ve decided that choice non-original parts, that were used in anger and are part of the machine’s DNA, will be retained and will be a fascinating reminder of the people that raced the bike and its racing pedigree. The character of 2751 needs to be preserved to attest to its very full and hard working life.

Head bracket as acquired.

As mentioned in this blog waay back (run a search for ‘Frames and Brackets’), It was discovered that the special drilled cylinder head bracket was found to be of the wrong pattern as the drilling appeared crude and didn’t match the drilling pattern of drawings held on file. This was a bit of a blow and the only recourse we had was to drill a bracket to original spec’. Finding an original bracket seemed a tall order and modern reproduction items differed in several ways and were completely unacceptable for this project.

As so often has been the case, Franc Trento came to the rescue! He mentioned we were looking for one to ace Vincent mechanic Greg Brillus and Greg was able to supply.

Original FT3 cylinder head bracket.
This will put to good use.

This is currently winging its way to the UK. It will be correctly drilled and dull chromium plated as per the original. Thanks Franc and Greg, you beauts!