Grey Flash 2751

The history and restoration of a Vincent HRD Grey Flash

This is a continuation to the last post on why the timing chest cover build number (96) differs to that of the build number for 2751 (42). I sent an email to the VOC Registrar, Simon Dinsdale, and he got straight back to me with some interesting information.

So, I wish to correct something that I wrote. I stated that all 128 “B” Meteors would have been branded “HRD” – this is incorrect and the truth is somewhat more complicated…

2751 is recorded as being manufactured on 27th August 1949 and left Stevenage with “HRD” castings and a “Vincent” transfer on the tank.

The “HRD” to “Vincent” logo branding changes occurred across all series “B” & “C” bikes manufactured during an 18 month overlap period between 1949 and 1950. I knew this and I also knew that towards the end of this period, bikes left Stevenage with a veritable mishmash of logos on castings and painted onto petrol tanks. As the new “Vincent” branding project gathered momentum some stocks of “HRD” castings had this old logo removed and left The Works in a plain state. To make matters even more confusing, Simon tells me that it is believed that some early “Vincent” logo castings also had the logo ground off as they had been badly cast…

The series “B” Meteor & series “C” Comet were introduced at exactly the same time with the 1st production machines leaving The Works in August 1949. To quote Simon: “The first Comets & Meteors being HRD bikes with ‘HRD’ crankcases and the change occurred in late 1949 to ‘Vincent’ – so the last ‘B’ Meteors (made up to mid 1950) actually had ‘Vincent’ on the tank and ‘Vincent’ crankcases with a few plain crankcase bikes thrown in as well. So basically don’t assume an ‘HRD’ single is a Meteor and a Vincent single is a Comet.”

I’m not sure of the exact numbers but certainly “HRD” branded singles are exceedingly rare.

Now, why the correct pattern timing chest cover with the incorrect build number…? Simon managed to shed some interesting light: “This leads to your HRD timing cover with mating number 96. I know from the records mating number 96 is from a series ‘C’ Comet that was despatched to a dealer called Weston Webb in New Zealand on the 30/09/1949 and this was the 40th series ‘C’ Comet made. The rest of the engine was last reported to be in New Zealand in the 1980’s but I have nothing since. The UFM for this Comet was reported to have been for sale on eBay in USA in 2005 but again nothing since, so it looks like the bike was broken up a long time ago.”

2751 was also originally exported to Weston Webb, so, therein lies the “rub”!! Now we know what happened. Whether it was an intentional swap (if the original cover was damaged) or whether the covers were inadvertently swapped whilst work was being undertaken in the Weston Webb shop we may never know… This has all been very interesting and another reason why complete transparency is important and can often tell a fascinating story.

And there is a faint possibility that the original timing chest cover – stamped “42” – is still out there…

Thank you Simon!

The timing chest cover has the “HRD” script cast into it. This makes it a very hard-to-find item because compared to a total of 3,791 postwar “Vincent”-branded “C” singles (all Comets) manufactured only 128 “B” Meteors were produced. These Meteors, as far as I’m aware, would have all been “HRD”-branded. There might have been some variation in the way the tanks were painted but the engines would have all had the “HRD” logo castings. So, the chances of 2751’s timing cover being original to the bike seemed highly likely. Once it had been removed it was inspected.

Oh… The build number for 2751 is “42”
As visible on the inner primary chaincase…
So why is the timing chest cover stamped “96”?

One clue is the absence of the two cover locating dowels. This cover is not original to the bike and the inclusion of the dowels would mean that it didn’t mate to the crankcases correctly – the covers were each mated to their respective crankcases. I know that a timing cover was included with the disassembled bike and parts that Peter Johnson bought. I also know that a cover was present with those parts in NZ when the bike was offered for sale – it’s mentioned in the list.

Assuming that this is the cover currently fitted then it must’ve come from an “HRD”-branded Meteor that lived in NZ. Hard to imagine what went on here – was the original cover damaged and replaced with a similar “HRD” item? This scenario seems very unlikely due to the scarcity of this part. Also, when the parts were gathered together for sale by Bill McCahon, in the late ’60s, there would have been surely little interest in trying to find an “HRD” timing chest cover when “Vincent” scripted ones would have been much more readily available. A more likelier scenario is that 2751’s original cover was inadvertently swapped with the cover of a “B” Meteor. On the off-chance I’m going to take this up with VOC numbers guru Simon Dinsdale and see whether any “B” Meteors still exist in New Zealand.

I’m a bit disappointed to have found this but at least we have the right component even if it wasn’t the one the bike originally left the Works with.

The rear chain adjusters, which were made for me, to pattern, by Vic Olsen have been fitted up.

These t-bar adjusters were a special racing item. They are easier to adjust under racing conditions and also give an easy visual indication enabling each side to be adjusted incrementally. I had them cadmium plated and it doesn’t appear to have taken very well – the resulting patchy finish fits the project perfectly.

The gear change linkage as acquired.

We knew that this side was going to present more head-scratching. The correct configuration hanger plate was fitted and the gear linkage parts loosely assembled.

This shot shows the linkage assembled from what we had including a Black Lightning gear change lever. Position of the lever pivot on the hanger plate is incorrect.

The hollow FT256AS tube for the rose joints is clearly too short – this would have originally been fitted to a Black Lightning which employed the Vincent “unit” gearbox. So, a new tube was manufactured. We will have it cadmium plated at a later date.

Re-manufactured adjusting tube fitted. The pillion footrest has also been fitted.
With the correct gearchange lever in place but the rubber not yet fitted.
A nipple and nut has been fitted to the gear change shaft on the Albion gearbox. The arm appears to be original.

As acquired, 2751 featured a mix of foot controls. We have looked at each component carefully to assess provenance and made a decision whether to employ the part in the restoration, replace with the correct item (I have a stock of NOS racing foot control components) or remanufacture to correct specifications.

Both footrest control hanger plates were incorrect and fabricated by Peter Johnson. Some time back I had acquired a set manufactured to the correct dimensions and drilled as per original.

The re-manufactured plates.
As acquired, the brake controls appeared thus.

From this shot we can deduce that many components have been fabricated though the pedal appears to be of the original racing type.

Correct-type plate in place and authentic linkage parts fitted to the pedal. Note footrest.

Once the linkage components were loosely assembled we could see that we were going to achieve a good result on this side without too much trouble. An NOS G108/1 arm and other original parts were employed. One of the pillion footrests was also fitted up. Very early racing Vincents featured these until the purpose made knurled racing footrest was introduced a little later on. It was also noted that the pedal pad was in road-going configuration and need to be reversed – the above shot was taken after it’d been reversed.

The pedal arm with the pad in road-going mode as acquired (top). Below is an NOS pedal with the pad correctly assembled as per racing type.
A close up of 2751 being raced in period. The pillion footrest/rubber and reversed pedal pad are clearly visible.
Having ascertained what was what and dry built the brake side we felt happy with the result.

The correct size 20″ x 2.1/2″ Borrani rear rim (supplied by John Hanson) has been laced to the hub and fitted to the rear fork. The rim was not as good a condition as hoped and the wheel builder had a bit of a job tweaking it to run true.

20″ Borrani now in place.

Being of the correct pattern, this will suffice. It will be adequate for display and demonstration but we would never advocate it being relied upon at high speed or in competition. There again, many of the original components being employed in this restoration fall into this category (the Elektron brake plates spring to mind).

A new tyre was ordered for the front rim as the state of the one fitted when acquired was unacceptable.

The rear hub features a hollow axle which passes through the hub and is secured by a nut at each end. These nuts sandwich the hub/bearings and brake plates together allowing the entire rear wheel assembly to be installed into the rear fork as one unit. This is also the method employed for the front wheel. We have already noted that the two H55 grease retainers were omitted – Peter Johnson has commented that this was to reduce friction. He mentioned that the bearings were lightly oiled before each race to compensate for this omission – a crafty race tip! Clearance is taken up by adding shims between the bearing and the shoulder on the hollow axle on each side. This was noted to be spot-on. Brake plates are then added to this “sandwich” and, with the thin retaining nuts tightened, shims further added so that the hollow axle doesn’t protrude beyond these nuts. It was noted that there was an absence of these shims which had allowed the hollow axle to stand a little proud at either end. This had caused the fork to come into contact with the protruding axle and slight damage to the threads had been sustained. This can easily be rectified and the original hollow axle retained.

The hollow axle standing slightly proud from the retaining nut. Damage to the threads at each end of the axle meant that this nut was difficult to remove.
The notorious eared nut…

This nut secures the special bolt (T-bar on road models) that passes through the hollow axle fixing the wheel/hub assembly in the fork. The tab fits into the drive chain adjusting slot and requires no spanner as it is held in place and won’t rotate. Many a Vincent rear fork has been damaged by an uninitiated owner apply a spanner to this nut… Surprisingly, instead of the tab shearing off the casting tends to split and brazed repairs to the casting are a common sight. 2751 is, unfortunately, no exception to this.

The missing H55 grease retainers and H25/4 bolt.

Instead of the T-bar, featured on road-going models, the racers employed a special waisted bolt which will have to be manufactured as it’s not present.

The rear brake plates are the original magnesium racing items.

All fixtures and fittings here appear original and correct to the bike.
The lightened brake cams are also visible.
Rear brake drums and plates with shoes fitted.

The sprocket is a lightened item and will be left. The original finned drums disappeared when the bike was in bits ‘n’ pieces many years ago – it is suggested that someone who went to look at the project took them away with them as they were a desirable upgrade over standard road-going unfinned items. Drums fitted to the rear differ in that one is drilled to prevent water build-up. Shoes are good with plenty of material. No bearing seals were fitted but there was no grease contamination present.

It was decided that before fully stripping the bike down it would be advantageous to work out the correct angles for the mudguard blades and stays. To do this necessitates lacing up the correct size rear rim. A 19″ Borrani is currently fitted but I’d acquired a correct 20 incher some while back from John Hanson. This has been sent off with the hub to be laced up and a new tyre fitted. Spokes will be zinc plated steel and we won’t be able to re-use the nipples as they don’t suit the 20″ rim.

The hub is of the 10 bolt pattern and unpolished. It’s highly likely that this is original to the machine as 10 bolt hubs were only standard on racing Vincents and the higher performance Black Shadow models.