These are some of the more basic things you will find in the magazine. We also have indepth articles about building specific bikes or components for those more advanced mechanics.

Rupert Ratio explores the D.I.Y. approach to Wiring your Bike.

How to make a wiring harness. Part 1. Preparation and planning.

As with most DIY there is much to be gained by having a go yourself - you get it done cheaper, you get it done your way, and you get it done properly - in theory. Thing is you also risk making a mess of it and throwing money away. Some suggestions for avoiding the latter. Stage 1. Obtain a wiring diagram for your bike. For non-standard systems draw one yourself, but perhaps use a diagram from a similar machine as a starting point, which you can then modify to suit. Remember to use all the standard symbols and codes for electrical components and cable colours rather than making up your own. What you will also need to show are the earth wire connections (use a red pen for these to aid clarity) which are not usually included in wiring diagrams. This is where you can improve upon original BSA wiring by including an earth wire to connect every component and not rely on the frame or mudguard or whatever to conduct electricity. Being steel they should, but connecting onto them adequately is not easy and is the biggest potential source of problems in your electrics. I would recommend connecting a red earth wire to every component (except the alternator) in a suitable place - either to the earth terminal provided or a suitable mounting bolt/fixing screw. Stage 2. Next produce a drawing showing the routes taken by all these wires. A good way of doing this is to produce a simplified drawing of the bike frame with the approximate location of all the electrical components shown . Then you take each wire shown on the wiring diagram (stage 1) in turn and draw the route it takes from one component to the next along the frame tubes. Those wanting to make the best of this job will draw these cables in colours approximating to the real ones, but be prepared to rub them out and re-draw them as you add more to the drawing, and as you realise exactly where they will need to run together in parallel or branch off from the rest. Do this drawing BIG! Stage 3. Is to make a list of all the materials required to make the harness. Firstly the cables - list each of the cables shown on your frame drawing, i.e.

......... Cable........ ........Colour......... Length.

Alternator to rectifier. White/Green. 0.5 metre.

Alternator to rectifier. Green/Yellow. 0.5 metre.

Rectifier to ammeter. Brown/Blue. 1.5 metre.

And so on until you have all the individual cables listed, including earth connections (red!) Try to work in metric when doing this (even if it brings you out in a rash of boils!) as it makes ordering the materials easier. To find the lengths to enter in the third column get the wife's dressmaking tape measure out and measure along the frame tubes of the actual machine. Always be generous and if any guesswork is involved in measurements always round up to the nearest half metre. Remember too that you want the handlebars to turn after the finished harness is attached so do allow for a generous loop around the steering head. Similarly if cables have to cross gaps from frame to component don't measure directly across, think how the cable will fall when in place and allow the tape to sag and loop in the same way. Next thing on the shopping list is sleeving for the cables. Refer back to the frame drawing (Stage 2) to determine how many cables will be bunched together along different parts of frame. From this you can work out diameter and length of sleeving required. Note: Each size of sleeving has a recommended number of individual cables it can carry. You can often persuade an extra cable in above this number, but don't use this as your approach as it just makes life hard when building the harness. Black shrink-wrap tubing is a possible alternative if you want to avoid that baggy look, but it doesn't bend so easily as standard sleeving and sometimes flexibility is a positive benefit. It's your choice but I would recommend male and female bullet connectors, as original, by this I don't mean the crimp-on type usually colour coded by having pink insulating plastic around them, or some equally gaudy colour for other sizes of cable (I ask you - pink cable connections on a classic bike, don't laugh, Richard Gray didn't when he put them on his!) What I mean are the females covered in black rubber (read into that what you like!) and the solid brass male bullets to go with them. The latter are designed to be crimped onto the cable ends, but personally I feel this is inferior to soldering, so I do this instead to all connectors which would otherwise be crimped. I have heard say that soldered connections are more susceptible to fracturing due to vibration but this isn't a problem that I've ever encountered. So, back to the shopping list, total up the number of each type of connector required, bullets - male and female, spade lugs, ring lugs, etc along with insulating covers that go with them. Lastly - tape, get two types (not sellotape and masking tape!) black PVC insulating tape (sticky) and black self amalgamating tape (not sticky except to itself). Other things to buy:- Soldering iron, electricians solder, extra flux, and wire strippers/crimpers. For wiring materials I would recommend 'Merv Plastics' of Beeston, Nottingham.

Next time in Part 2 - How to avoid branding yourself with the soldering iron! Singularly Yours, Rupert.

Back to Basics, with Rupert Ratio.

This month, screwthreads.

Anybody who has tried to restore a BSA - particularly a late 60's model will know that the range of different threads used throughout the bike is bewildering, lets bandy a few names of those you are likely to encounter. British Standard Fine (BSF), British Standard Whitworth (BSW), Unified Fine and Coarse (UNF and UNC), British Standard Cycle (BSC), British Standard Pipe (BSP, or gas thread), and British Association (BA), are the most commonly found. What you are not likely to find, hopefully, are the Isometric threads (fine or coarse), except for sparkplugs which are metric but is an oddity being neither coarse or fine. These are based on metric sizes, millimetres, and not inches by which our bikes are measured - Imperial through and through - God save the Queen! A potted history of screwthreads, of which the above are merely the tip of the large and confusing iceberg, is that originally (up to the last century), everybody made their own screwthreads. With no consistency or conformity between manufacturers. Standardisation began with the Whitworth thread (Joseph Whitworth) followed by BSF and all the other common names. Standardisation means for example, that the teeth on a BSW screw will always be the same shape (angle), and there will always be the same number of teeth per inch (TPI), for any given diameter of screw. Likewise for all the other standard screwthreads. Unfortunately one-offs and non-standard threads continued to be used alongside the standardised ones. The reason being that some threads are better for particular applications than others, and sometimes jobs would require a special screwthread to be made to suit, i.e. a C15 gearbox sprocket nut is stated to be 13/8" WF, which means it uses the Whitworth tooth form (55°) but is much finer (more TPI) than it should be for a standard 13/8" Whitworth thread. Somebody at BSA decided this was the right thread for the job. The Metric system was developed and standardised on the continent in parallel with the British system, and is much simpler. My own view is that compared to the Imperial screwthreads, metric is the jack of all trades and master of non - as it was adopted for convienience and simplicity rather than being designed for specific types of application. I come out in boils if I handle metric screws for prolonged periods! Unified threads (UNF and UNC) are so called because they unify the metric and Imperial systems by having metric threadform applied to Imperial sizes. Some comparative facts about screwthreads. Coarse threads. UNC, BSW, Metric coarse Fine threads. UNF, BSC, BA, BSF. Thinner core (the solid bit in the middle) hence relatively weak. Thicker core, hence relatively strong. Requires relatively few rotations to screw in or out. Requires relatively more rotations to screw in or out. Comes loose easily on its own. Stays tight! Uses. Into aluminium castings - Uses. Ability to remain tight on a less likely to strip threads. vibrating motorcycle! Cutting screwthreads at home is done with a tap (female threads) and die (male threads) held in a tap wrench or die stock. I won't bore you with how to use these tools this time, but if you are thinking of buying some, don't waste your money on sets - especially the cheap ones down the Motorists Discount Centre, they are only tough enough for putting threads in cheese! Consider buying quality brands (usually British made) and only the sizes/threads you require, as you'll never need most of the sizes you get in a set. Two qualities are available, carbon steel (C.S.), and high speed steel (H.S.S.) the latter are more expensive but will last for longer. I would recommend Tracey Tools who advertise in the Classic magazines. Many other sizes can be found (Winged Wheel barrel stud 7/32" BSC), oddities can be found (69-70 B25 fork top nuts 11/16"x28tpi UNF), and left hand threads (A10 oil pump worm), so the likelihood of screws from your A65 fitting your Zundapp is negligible. Left hand threads (BSA in particular favoured the BSC 20 TPI series), are used where the normal rotation of the part will tend to tighten, rather than loosen the screw or nut. Normal r/hand threads slope to the right as you look at a bolt or screw, and l/hand threads to the left. Right hand threads always turn clockwise to tighten. Well that's enough verbal for this month, but a parting poser - how was the first screwthread made? Singularly yours, Rupert.