Wednesday 10 June 2020

The Chassis, Transmission and Cycle Parts

Decisions have to be made on all the main components as to whether they are restorable or whether new components need to be sourced. I categorize components as follows:

     1)    Nearly impossible to source and difficult to make: frame, forks

     2)    Nearly impossible to source but relatively straightforward to make: hubs, sprockets, gears, mudguard stays, cable parts (inner/outer/nipples/ferrules), petrol tank etc

     3)    Easily sourced: wheel rims, spokes, mudguards, tyres, chains, levers, etc

Luckily, there are good sources of parts for category 3. Rims and tyres of the correct sizes and readily available, there are individuals specialising in mudguards, correct period levers etc.. and so these parts are simply a question of picking a supplier – either online or at an autojumble, spending the money and buying the bits.

Clearly, what you put into category 2 depends on what facilities and abilities you have or have access too. I try to be as independent of 3rd parties as possible and to make as much as I can in my own workshop. I have therefore invested over the years to buy a decent lathe, milling machine, TIG and gas welding, simple heat treatment, 20 ton press, measuring equipment etc but there are still process that I haven’t got and don’t plan to acquire. A good example of this is internal keyways and splines; I do not have equipment to make these …..BUT I do have, locally, a friend with 50+ years experience in spark eroding and is an expert in making internal keyways and splines.

The point of this preamble is that it is necessary to invest in your own equipment and skills whilst cultivating a network of specialist services that you can call on for the things that you can’t do. Having this, widens the spectrum of category 2 components and changes “where the hell do I find one of these” to “I know how to make that”.

Category 1 components are the ones to be really wary of. If the frame is so badly corroded or bent that all the tubes need replacing, whilst this is not impossible to resolve, constructing a new frame – maybe even casting new frame lugs, is not a task for the faint-hearted.

The first job here, therefore, was to have the frame and forks grit blasted to make an assessment of what lay beneath.

It transpired that the frame was quite sound but one of the legs on the girder forks was too badly corroded to be used safely. Repairing girder forks is a specialist skill in itself and, in addition to the skills of the few people that undertake this work, it also requires access to materials such as tapered tubing of the correct gauge. One such person is JakeRobbins, who luckily lives within an hour’s drive from my house. The forks were duly dropped off with Jake and returned, re-tubed, a couple of weeks later. Great job and problem solved.

The first step in a rebuild is the so-called “dry-build”, namely assembling the bike with metal in the unpainted and unplated state. Some people apply paint to parts as soon as those parts are completed. Personally, I think that is a mistake because you then have to protect those parts from damage as the build progresses and parts might need modifying at a later stage of the build. The one exception to this is the wheels; the hubs/spokes/rims need to be finished before assembly.

I also believe it is an advantage to get a rolling chassis, ie frame, forks and wheels built up as the first milestone because everything “hangs off” of that.

I luckily have a first-class wheel builder. Steve, a 20 minute drive away. I drop off the hubs and tell him the offset (where the wheel centre is located with respect to a datum on the hub) and he takes care of the rest …getting the rims and piercing them for spokes, black finishing the spokes, nickel plating the nipples and building the wheels. Looking at Steve’swebsite, I counted 8 bikes (Matchless G80, Velo Thruxton, Velo KTS, 2x vintage Nortons, Ariel V-twin, AJS K7 and the AJcette) for which he has built wheels for my restorations ….so he must be getting something right..

Whilst I had a good front hub for the K7 I did not have a complete rear hub in good condition; the hub and wheel that came with the bike was beyond redemption.

The rear hub consists of 2 main parts: the “cotton reel” that holds the bearings and the spokes and the brake drum/sprocket that is bolted to the cotton reel. Whilst I had a good spare cotton reel, I did not have the brake drum/sprocket part and therefore had to make one.

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