Grey Flash 2751

The history and restoration of a Vincent HRD Grey Flash

This has been a giant faff!! Much more than was anticipated… The Grey Flash exhaust pipe is just a 2″ straight-through racing pipe, right? Well, there were several types employed and there is very little data out there. The period shots we had of 2751 were as good as any a place to start.


Several reference points here.
And here… The original pipe had been bashed; a crease is plainly visible adjacent to the timing chest.
This shot was most useful – the length could be calculated accurately by studying it. Not all is as it seems though – the bike is canted and it’s also likely that the photograph was taken from quite a low angle.
Cutting ‘n’ shutting…

Bert decided to make a template from the old pipe to make the pipe bender’s job easier. For a full week we back ‘n’ forth’ed his tweaks. Getting the bend right around the tacho drive was, to say the least, challenging… Too much taken out or added meant that the pipe was no longer parallel to the ground and looked hideous. It had to be right.

MPH 866 features a fascinating account by Jim Mathers of his rescuing of 3685. He was lucky enough to acquire an NOS racing pipe, from Harpers, which appeared identical to the one fitted to 2751. The tragedy is that that bike was badly damaged in the NMM fire though…

Notes by Bill Hoddinott and David Dunfey were devoured; their input and advice is always much appreciated.

Finally, the bike was ready to be transported to the pipe benders for an exhaust pipe to be fabricated by the traditional method.

Ben doing his thing…

Ben at Raysons set to work… Two weeks later Bert got a call to come and collect the bike.

Bellissimo!

Safely back in Bert’s workshop he set to work. The pipe needed trimming to length, brazing up at the port and the bracket sorting out.

This and the following photos speak for themselves…

So much work went into this… We may not have got it perfectly correct but it’s as close to “dammit” is to swearing! And this was a crucial undertaking as the pipe is very visible and would have looked horrible had it been angled incorrectly. Big thanks to Bert and Ben! Off to the platers with it now. It’ll come back as shiny as a new pin and will need tarnishing.

Whilst we are waiting for the exhaust pipe to be made I thought I’d post a bit about the seat we will be using.

Early Vincent HRD racers came fitted with a trimmed version of the standard road-going seat. I believe these were a Feridax product that featured a Dunlopillo foam with “cells” cast into it to provide adequate cushioning. Later on a special racing seat was designed; a lean and purposeful item that enabled the rider to assume a lower racing crouch with ease. When I acquired 2751 it came with an NOS one of the these racing seats.

A rare and wondrous thing…
NOS from the ’50s…

I was initially elated though this turned to disappointment when I learned that 2751 would never have been fitted with such a seat. So I offered it to a friend who had a Black Lightning and he bought it from me for US$7,000 – this was a big help in recouping a bit of the initial purchase price of the bike (some US$90k).

Here are some period shots of the seat originally fitted to 2751:

Hardly svelte…
Comfy, no doubt…
Not very in-keeping with the lean and stripped nature of the Grey Flash but no doubt eminently practical.

The seat that came fitted to 2751 and was used in anger, by Peter Johnson when racing the bike, is actually not that far out shape-wise.

Compare this to the above period shots.
This is how it looked when I acquired 2751.

I had an original seat and cover complete with Feridax badge on stand-by to cut down. However, early Feridax seats did not feature a badge to the rear. Later a silkscreen printed logo was featured to be later replaced with the brass badge most Vincent owners are familiar with. So 2751’s original seat would not have had a badge.

As seen here…

Rather than try to recreate an exact copy of the original type we have decided to use the seat that the bike came with. It is not so far from the profile of the original and a little thinner – it actually looks better in our opinion. A newly made replica would be out-of-keeping so we will go with this. In addition, it has been actually used on the bike when raced and it is very well made.

The work of Peter Johnson?

We feel that this is an acceptable compromise. 😊

NB: Peter has been in touch with me and informed me that the seat was acquired from Ted Davis.

Amongst several of the period shots that I have of 2751 racing in-period is one set of 4 images. The photos have been marked differently but were obviously taken at the same event. Recently I was looking closely at them and noticed a road sign was visible.

This is plainly visible…
…but quite illegible.

One of the captions mentioned the Matarawa GP. I started researching old NZ road racing circuits and the enormity of the task soon became apparent; there were scores of courses and many of even the larger ones were re-located several times… I may be accused of being many things and being persistent is one of my more annoying characteristics! I became obsessed with this side project and spent any free time on the computer poring over any leads and trying to find corresponding terrain on Google Maps. About one week in I started trying to track down another annotation that read ‘Senior Taranaki GP’. Then I had a stroke of luck: I found the image of an old programme from the inaugural race held on November 25th 1950 – the course layout was depicted in an aerial shot. This corresponded with the date written on the photo and Weston Webb would have taken delivery of the bike then as it was despatched from The Works on 11th November 1949. I started studying the Waitara/Tikorangi area and environs to see whether I could find a road layout that matched that depicted on the programme cover.

Ngatimaru Road – boom!!

I’d nailed it! Then it was a case of carefully searching likely spots for a match at Street View level. This took longer but I managed to find the exact spot where the photographs had been taken over 70 years previously!! I was so engrossed in this work that I didn’t get to bed that night until 3am… So, here are the photos with corresponding shots grabbed from Google Maps:

The Norton mounted rider is possibly Pete Stone. They look as if they have just come in off the course as they are pointed away from it.
The next shot shows Len helmeted though this doesn’t necessarily mean he’s preparing to ride – the bike has no stand fitted and would have been leaning against Len. I think he was about to roll it forward and put his helmet on rather than risk dropping it.
The helmet is not done up and all three riders look dusty as if they have just come off the track. Note the straw tied to the electricity pole to act as a cushion in the case of a collision.

The location I’ve pinpointed seems to have been used as an off-course assembly point. There is one more shot from this race:

Len is riding 2751.

The following year, 1951, saw Len travel to Europe to ride in the Isle of Man TT (and other races) where he came 9th in the Senior riding a Norton.

The Taranaki GP was held from 1950 – 1956 on the above course.

This is a very satisfying result which has added considerably to the provenance of 2751. 😎

In this post I will give instructions on how to mate with a 1940s Smiths chronometric tachometer… 🧑🏻‍🏫

Okay, that was a lame joke BUT such is the patinated beauty of this instrument that just looking at it positively generates an erection…

The re-profiled bracket.

The bracket was re-profiled as outlined in a previous post. It was then sent out to be dull chromium plated for the second time…

Oh no, I’ve “premmed”…

That looks so in-keeping with all this restoration has been focused on: the icing on the cake, a veritable visual smorgasbord, a riot of the senses, an orgy of ocular splendour, a classic motorcycle aficionado’s wet dream, a… I could wax lyrical ad infinitum…

In the meantime, Bert has been wrestling with the profile of the exhaust pipe… Details of this to follow.

A correct pattern tacho drive gearbox was sourced and fitted replacing the incorrect unit fitted to the bike as acquired.

This was supplied by uncle Franco.

Sorting out the tachometer wasn’t quite so easy though… 2751, being an early bike, wasn’t ever fitted with the rare racing “yellow number” tachos.

Such as this example fitted to the Ehret BL.

Using what came with the bike + another head, Bert assembled a correct pattern unit using a period face and bezel acquired from David Woods.

Outstanding work Bert!

This required much research and faffing by Bert but the end result is spectacular and will look just the part once mounted.

Sourcing the correct herringbone patterned oil/fuel pipe has not been easy… There are still some stocks of 3/8″ ID pipe available but stocks of 5/16″ ID pipe have dried up and none is currently being manufactured.

Oil feed.

The correct run of the oil feed pipe was determined to be as above. We decided to stick with 3/8″ pipe for this as all the feed fittings present on the machine were sized to accommodate this ID – and many of them appeared ancient and possibly original to the bike. Below some shots of the other pipework in place.

Jubilee clip compression mark visible but no correct pipe available so this will have to remain!

The title is self-explanatory so I’ll just annotate the photos.

The period cables look incredible.
Some are likely to question the run of the throttle cable…

Running the throttle cable over the brake lever like that looks weird. In-period some were set up like this though and it’s actually the best route for the cable. We might revert to running it behind the lever later on – it can be changed easily enough.

The carb is now fitted. The solder on the UFM marks where the remote float bracket was.
The HT lead and pickup cable have been taped together with cloth tape as per period photos.
The primary chain case cover is now in place and looking purposeful.

All Vincent racers were supplied with Axle bolts rather than the T-bar arrangement seen on the roadgoing models. This is quite an obscure component and falls into the “not a lot of people know that” category… This rare racing part is depicted in the Spare Parts List.

We can see that these are waisted for lightness.
And not “wasted” as some are wont to write! 🤤

2751 was missing these important parts and they needed to be made for the project. Where to start… No drawings or dimensions exist and few original items survive. Many years ago Vincent legend Big Sid sent me some pics of some NOS racings parts that he held and was looking to sell – these, I believe, ended up being used in the Gunga Din rebuild.

These three images appear to depict the just the one axle – an H25/3AS front item. In addition, I had a few pics of this component in situ on various bikes.

The above two images show the bolt/nut clearly – this is the Ehret Black Lightning. Note the protruding tapered “lead”.
The rear of the same bike.
Here seen on another Grey Flash.

Working in conjunction with David Dunfey, and cross-referencing our available info, a drawing was made and tweaked until we were as satisfied as could be. Down in Australia, Stuart Penn kindly pulled one of the axles on his uncle’s BL and sent me the dimensions.

This is also a front bolt. Above it are two Series D axle bolts and a hollow axle, for purposes of comparison.

Yes, the Series D also utilises bolts rather than the T-bar configuration – these are available new from the VOCS and could be adapted? Well, no… In addition to the waisted centre portion, the threaded portion features a tapered end or “lead” to enable the axle to be pushed home and locate quickly under racing conditions. This taper means that the racing items are a little bit longer than they would need to be on a roadgoing bike. In addition, the bolt head is actually a nut brazed into place…

First the waisted axle shafts were machined up.
Nuts brazed on and dressed.
In situ. Note repair to rear fork.

A lot of research was required to enable these axle bolts to be manufactured – the waisted portion had to be right to prevent catastrophic failure. Machined from high tensile steel, they will now need to be finished and would originally have been cadmium plated. I would like to thank David Dunfey, Stuart Penn and Franco for their assistance. 🙏🏻

Throughout its long racing career 2751 suffered many incidents that left their mark on the surviving original components. The magnesium gearbox casing bears “witness” marks from where primary chain slackness had been adjusted to the point where the casing was pushed up against the G50/2 pivot bearing plate.

Unacceptably close.

Once a new primary chain had been fitted, it became obvious that more clearance was needed as the top of the gearbox casing was perilously close to the plate at nearly full adjustment. Bert got around this issue by fitting a cranked link, shortening the primary chain by just one roller.

The cranked link and soft riveting link.
Fitted.

There is a now a nice gap twixt gearbox case and plate enabling future adjustment to account for chain wear.

Much better! 👍🏻