Thursday 23 March 2023

Velocette KTT 55 and KTT 305: INDEX Page

This is the INDEX page for the restoration of 2 Velocette Motorcycles, KTT 55 and KTT 305

Velocette KTTs 55 and 305

Velocette KTTs 55 and 305: Project Kick-Off

Velocette KTTs 55 and 305: Wheels - Part 1

Velocette KTTs 55 and 305: Wheels - Part 2 - Cup-and-Cone Bearings  

Velocette KTTs 55 and 305: Wheels - Part 3 - A New Rear Wheel Hub

Velocette KTTs 55 and 305: Wheels – Part 4 – Completing the Hubs

Velocette KTTs 55 and 305: Patterns for Castings

Velocette KTTs 55 and 305: Girder Forks

Castings Galore

Machining Castings and Progress on Wheel Building

Mk 1 KTT Cambox Oil Pumps K-102/2 and K-152 – Part 1  

Work on the Cycle Parts, Oil Pump Castings Delivered and a New Cylinder Head

Velocette Mk 1 KTT Cambox Oil Pumps K-102/2 and K-152 – Part 2

Valve Seat Inserts + a New Cambox and Motorcycling in Cambodia

Velocette Mk 1 KTT Cambox Oil Pumps – Part 3

The Rolling Chassis












Velocette KTTs 55 and 305

Now, I know that since it's inception when covid kicked off and I started documenting my projects this has been a blog (mainly) about early OHC AJSs and that the URL is but I’m now going to start on a couple of Velocette projects. Why? …you may ask. Well, quite simply, I have run out of OHC AJSs to restore and, whilst I have a couple of early AJS Big Ports that I acquired in bits and need reinvigorating, I have some early OHC Velocette projects that need attention and so, my apologies to anyone that has landed on this page expecting to see AJSs as I will be undertaking and reporting on 2 Velocette KTT restorations during the coming year.

During the last couple of decades of my working life I acquired 5 early OHC Velocette projects (people say that one should prepare for retirement) – 2x very early flat tank Model Ks, 2x KTTs (55 and 305) and another collection of bits that includes a KTP (a commercially and technically unsuccessful model that was produced to satisfy the fashion for twin-port engines although the twin-port cylinder head from this bike came in useful for the V-Twin  - see here) plus a couple of spare engines. With only one exception (KTT 305) all of these projects arrived as boxes of bits (I am not the type of enthusiast that buys complete bikes and takes them apart to populate shelves filled with rows of magnetos, carburettors, crankcases etc – a completely pointless exercise in my opinion ...but there are plenty that do!).

Anyway, I have decided to restore both KTTs simultaneously.

For reference, this is a 1930 brochure picture of a Velocette KTT.

Acknowledgement for the above picture as stated

I have been a member of the Velocette Owners Club for many years and in my opinion the Velo Club is one of the best clubs around with many enthusiastic and knowledgeable members and an excellent magazine (Fishtail) and spares scheme. GroveClassic Motorcycles also provides a range of spares for Velos, including various bits for the early OHC models.

There is probably more detailed history and technical information written about Velocettes than any other marque and I would recommend any/all of the following books to anyone that has an interest in their history.

First, a bit of background on the 2 KTTs that I plan to restore:

KTT 305

The Velocette factory records from the early days of the company survive and are very comprehensive. These show that KTT 305 was sent directly from the factory to the Isle of Man on 29th May 1931 for a rider by the name of Dave Brewster to compete in the 1931 Junior TT. I have checked the records myself

and also have confirmation from Ivan Rhodes (Ivan is THE Velocette guru). The bike still carries its original registration number OV 1023 as stated in the records.

I have 2 photos from that era; the first is with Dave Brewster pictured on the bike at the 1931 TT:

Picture courtesy of Dennis Quinlan

and the second at Parliament Square in Ramsay during the race:

Acknowledgement to whoever owns the copyright to this picture

Dave Brewster came a very creditable 18th in the Junior TT with an average speed of over 66 mph. Not bad considering the exalted company against which he was racing.

Dave was a top GP rider in Australia during the 1920s and won the Australian GP in 1924 on an Indian Chief

I have no idea what happened to KTT 305 for the 40-year period after its TT debut but it was raced competitively in the 1970/80s in Vintage Club events by a rider Barry Blythe. This is a picture of KTT 305 as I bought it (and as it is today in my garage) having been raced hard by Barry!


There are a few features of the bike as it is today that are period-incorrect, for example, the oil tank which should have the filler on the other side. Luckily, I acquired a correct KTT oil tank some years ago as I would like to restore the bike to how it left the factory.

KTT 55

I acquired KTT 55 in 2009 as a completely dismantled box of bits. The factory records show that KTT 55 was shipped to a dealer Martin Walter Ltd in Folkestone on 22nd March 1929 and subsequently sold to a C S Hutchins on the 26th March.

However, when I checked the frame number that came with the bike against the factory records, instead of being 2781 it was 3772.

The factory records show that this fits in with a series of KTTs from1930

….but does not actually appear in the records. Ivan Rhodes suggested that it is probably a replacement frame, possibly following an accident, which would explain why it does not feature in the Velocette records.

There is another anomaly with the bits and pieces: whilst the crankcases, thick-flange cylinder barrel etc are all correct (and in excellent condition) the cylinder head, which on an early KTT should have been a cast iron item, is a later bronze head which would have been fitted to a Mk IV KTT and been produced in the period 1932 - 1934. The head is brand new – it has been machined but has never been used.

As all this occurred around 90 years ago one can only guess at what happened. My best guess would be that another frame was purchased from the factory following damage from an accident (as Ivan suggested) and, before the bike was repaired, the Mk IV came on the scene and the owner decided to update the bike with the latest cylinder head ….but the rebuild never actually happened and the collection of bits has somehow managed to stay together since that time.

I have already carried out some work on the engine of KTT 55 that I shall report on in due course. But, in the meantime, it is time to make a first and more detailed assessment and a top-down plan for each project.

Thursday 16 March 2023

The AJS 33/7 Trophy Model Restoration: Final Assembly and First Start

It’s interesting how 10% of the time on the final assembly goes into putting 90% of the bike back together whilst 90% of the time seems to go into the remaining 10%.

The bike is now completed

and running, although road testing has not yet started.

There were a few details to attend to before the bike was completed, in particular: the toolbox, wiring and the tank graphics. 

The brochure picture of the bike clearly shows a toolbox sandwiched between the frame tubes:

Luckily, Mark Barker, who attends major autojumbles such as Kempton Park and Shepton Mallet here in the UK, makes beautifully crafted period leather toolboxes housed in metal and will make these to order if a bespoke size/shape is needed. With just a simple cardboard template (to ensure the angle was correct between the frame tubes) Mark made this for the 33/7:

The craftmanship is simply outstanding. Mark doesn’t have a web site but if you want anything similar then please let me know and I’ll put you in contact with him.

I haven’t said much, if anything, about the electrical system so far. I don’t intend and I doubt if any future owner would plan to undertake any extensive night-time travel on this bike. I have fitted lights and a horn (required by UK law) with a large capacity 12V lead-acid gel battery contained in a dummy rubber battery case. There is no charging system but I have used low power (but very bright!) LED bulbs and, as such, the lighting system is more than adequate for a few hours running if required.

The wiring loom is relatively simple – lights, horn and dipswitch and after making the basic loom

I sent this away to MES in Warwick to bind my collection of wires and connectors into a proper wiring loom.

Last, but by no means least, the petrol tank needed completing – painting and the “AJS” insignia. Although the depiction of the bike in the brochure gives some idea of the layout of the petrol tank graphics a picture of original paintwork is by far the best if one can be found. I believe that this picture

Picture courtesy of Bonhams

that can be found on this bike sold by Bonhams in 2008 is original unmolested paintwork.  OK, it is a 1935 500cc model but I believe that this is almost certainly identical to the 1933 350cc model.

The tank was masked appropriately

before spraying with 2k etch primer, gloss black and gold leaf lining plus a waterslide “AJS” insignia.

This is a picture of the completed bike.

After nearly 15 months of work, filling the oil tank/gearbox/primary chaincase with oil and a few final checks the bike was now ready to be taken off the stand and wheeled into the garden for a first attempt at starting.


…..and then the moment of truth!

I was amazed – the bike started at the first attempt and apart from some oil leakage from the primary chaincase (these pressed steel cases are notoriously difficult to seal) it ran perfectly; clearly, this needs to be fixed before the first road test.

The first road run will have to wait a while – it is the middle of March and although the daffodils are out in the garden the weather is neither warm nor particularly dry at the moment (I don’t do cold and wet motorcycling these days). Nevertheless, I’m confident that this will be a lovely bike to ride and I’ll report on further progress and the first road run in the coming weeks.

In the meantime, it’s time to start thinking about the next project….