Working with all those bikes you can't help but learn a thing or two about what works and what doesn't and you also learn a lot about the best way of going about the task. Building a bike from scratch can be a daunting prospect, but properly managed it can also give an enormous sense of achievement. When you wheel the bike out in to the daylight for the first time and fire it up the feeling of satisfaction is overwhelming.

Although many people start projects and see them through to completion, just as many start only to give up, convinced that bike building is a soul destroying and expensive experience. Why is this? The reasons can be many, but the most common reason of all that I have come across over the years is poor planning. The art of building a custom bike that is going to look good and function as a useable and enjoyable ride is not quite what you would expect.

Frame first? ... er, no actually!

How many of you out there, if asked in which order would you buy the parts for a project bike, would say frame first and then engine and transmission? I would suspect the vast majority of you ... but in our experience this is wrong. When RMD start a project we always decide on the rest of the bike first; we establish the style of bike required - softail, rigid, FXR for example – but before we decide on the frame, we also take account of other important factors. We need to decide on the forks we are going to use (especially if we wanted to run forks from a Japanese bike or one of the aftermarket companies like WP, Cerrani or Marzocchi) and also the wheels. You can then get the swinging arm made to take the wheel and brake set up and calculate the amount of ground clearance required. This is one of the crucial points in the project that a lot of people get wrong ... the ground clearance is very important. If you intend riding your new creation on British roads then you need adequate cornering, so what type of controls you intend to use too is also important when making the frame because you can get all the lugs on the frame in just the right place for you, you may have short legs, really long legs or one of each - all these factors must be considered.

The oil tank and the fuel tank too are items that can be made to fit with much cleaner lines if you have them when making the frame. The fenders are also useful to have around, so you can make the fender struts fit just right, and position the fender rail mounts on the frame to accommodate the wheel choice. The look of the exhaust system is also very important. You may think, 'What the hell has the look of the exhaust got to do with anything?'. Well, if you have decided that you want a long set of straight drag pipes coming past the rear axle then you'll have to consider the implications that would have on the motor ... if you are planning on a nice big engine with loads of power, then I am afraid those drag pipes are not an option, but I'm getting ahead of myself, I'll cover engine choice a bit later on. What RMD do is assemble all the parts that fit the criteria for the bike we are going to create and THEN we make the frame. At this point you can then set the headstock position to give the correct amount of ground clearance and also get the lower tubes parallel to the floor when all the weight is in. And as mentioned previously, you can also offer up the oil and fuel tanks so that they fit perfectly.

The major problem with buying an off the shelf frame is that the frame maker has naturally designed the frame around a standard style ... and therefore in order for it to look, handle and perform you are restricted to the forks, wheels and tanks that the frame was originally designed for. Getting all the bits you want first and then making the frame allows you to have a much wider choice of components and with that comes a personal style and one-off individuality without necessarily costing any more.

Being careful with stainless.

Well, that's the basics out of the way, now you have all the parts you need to put them together. I know a lot of people like to use stainless steel wherever possible but this is not always a good thing. Stainless steel has some very attractive properties, unfortunately it has a lot of very undesirable ones too. The first thing you should know about stainless steel is that although it is hard it is not HIGH TENSILE, which means that it is hard to cut and machine but it does not have the type of hardness that matters in say a common nut and bolt. Stainless steel nuts and bolts stretch very easily when tightened, and you may find that they will strip their threads all too easily. Because of this tendency to stretch you should NEVER use stainless steel nuts and bolts to replace high tensile items, especially in certain applications. Some of the more obvious places are head bolts, disc bolts, sprocket/pulley mounting bolts, head steady bolts and engine mounting bolts - all these are prone to failure with expensive and potentially extremely dangerous consequences.

Yes, agreed, there are some grades of stainless steel that have tensile strength - but very few stainless fasteners that you buy for bike building are made of this grade. I have even seen stainless steel bolt kits for discs and sprockets - and I've also seen the damage caused when they let go - its not pretty.

Another undesirable property of stainless is that it has a chemical reaction with aluminium. Stainless corrodes the ally at an alarming rate and you should always use an anti seize compound on the bolts when used to hold on the outer covers. But I suppose the most undesirable property of stainless is its willingness to work-harden with use. Any amount of movement will work-harden the metal at the point at which it flexes and it will very soon become brittle and break! This is most commonly seen on chain guards and coil covers.

Don't get me wrong I like the look of polished stainless as much as the next man, but you must be extremely careful where you use it.

Dry Build.

When you build a bike you must always do what is called a 'dry build'. This involves building the bike almost to the point where you could ride it down the drive, but with no paint or polishing done at this stage. This is the opportunity to find out what is not quite working right before you're committed. And put the WHOLE bike together. Don't fall into the trap of thinking 'Oh this or that will fit, I can't be bothered to put that on, just to have take it off again!', because guaranteed, Murphy's Law clearly states that that particular item will be that very part that doesn't quite fit right when you've just paid the airbrush artist a grand! The dry build is the most important part of getting the finished bike just perfect. It may seem like a lot of work at the time, but believe me it's essential, great for peace of mind and it potentially saves a fortune in the long run.

Loc-tite.

Another invaluable item that you must have is a bottle of Loc-tite: that little bottle will be the best investment you have ever made. Harleys vibrate, and no mater how tight you do something up, if you get the resonant frequency of that thread it will undo it self in less time that you can say 'OH SHIT', and your coil cover, or other cherished part of your motorcycle is bouncing down the road and smashing itself to bits.

In Drag racing you would be amazed at how much can fall off in the space of 20 seconds, and this is after you've done a nut and bolt check before the run. Air-cleaner cover screws seem to be the worst and if you don't Loc-tite them they will fall out on a single run. I have often wondered if it would be possible to undo the bolts by hand in the time it takes them to fall out, but drag racing has taught me a lot about how to put things together that will not fall apart in the first 10 miles, because when you drag race a bike you are putting more stress on the entire bike than any other kind of motor sport: it's not just the engine and transmission but also the chassis and suspension that take a hell of a pounding.

Onwards & Upwards.

The only items that I will make comment on below in any detail are those items that are core to all bikes and that RMD have had experience with. Most of the rest of the bike is purely cosmetic and is, as such, down to individual tastes.

Engines.

You would be wise to consider a few points here about engine choice: For example; if you are planning on building a long low Swedish style chop with 18-inch over forks and a stretched out headstock, then you would be basically wasting your money buying a monster 100+ inch motor! Why? Because you would never be able to use all that power and in fact, what's worse, you could find yourself with a bike that was so hard to ride it'd be no fun at all ... and lets face we all want to have fun on our bikes, don't we?

On the other hand if you are building yourself a bit of a Streetfighter then a stock 80-inch motor just isn't going to cut it. You also have to consider the type of riding you plan on doing, are you going to use the bike on sunny Sundays or are you intending to tour Europe? If you are just going to use it on Sundays and the occasional weekend away then okay, you can have a radical motor. But if you want to do the miles, you may want to consider the overall reliability ... and the cooling.

Cooling.

A lot of people like the old polished crankcase look - dead pretty - but beware. If you polish your crank cases and the rest of the motor you can reduce the effective cooling area by as much as half! 'How is this possible?' I hear you cry. Well think about it like this; if you look on the map of Europe you will see that Switzerland is only a small country and by comparison France is huge. But if you were able to roll Switzerland out flat with a rolling pin you would find that the area covered would be almost the same as France. Well the wrinkled finish of the cases is like that – Switzerland I mean: the surface is full of peaks and valleys and the wind passing over the cases is made turbulent and carries the heat away from the large surface area. When you polish away those peaks and valleys, the air slips over the surface and the cooling effect is dramatically lessened. Now this is maybe not a problem for round the block use, but consider long distance high speed riding in the Mediterranean sun ... that can spell disaster. 'Yeah right,' you may think, 'I do that all the time!' - but then consider getting stuck in heavy traffic in London or any other big city ... ! Cooling is a real issue.

Size Is Important, But Not As Important As You May Think.

One other thing about engines, big is not always better. RMD 95-inch motors typically produce as much as a lot of the 113-inch motors out there, and our 104's leave them for dead.

Transmission.

Transmissions are also an item worth serious thought and there are a few options open to you. You can get an old 4-speed box or you can get a 5-speed, or you can even go for one of the new 6-speed boxes. Prices vary dramatically: you may find a used 4-speed for £600, but be warned they can be costly to repair and very few used 4-speeds are up to much. The best option is the 5 or 6-speed boxes. The 5-speed is a good strong box, it can take an awful lot of power without any complaints and secondhand they are usually good. But check out the price of a new trannie box before you buy the used one from the guy in the pub - I have seen 6-year old Softail transmissions at swap meets for £1200 - a brand spanking new one from Harley is only around £1400!

There are quite a few aftermarket transmissions on sale now and I would have to say you get what you pay for. If you go for the cheap(er) end of the market, you invariably get a poor quality box that could well have problems finding neutral, and if you are running a big motor you could rapidly find yourself with a broken box. The top quality stuff in my view comes from Jims Machining. When I first saw one of their boxes I was at a trade show in the states, they had this transmission on a little pedestal proclaiming its newness. I turned the main-shaft and then turned to my friend, 'It feels like it's just a dummy with no gears in!' the guy on the stall had overheard me and proceeded to remove the lid. To my amazement it was a full box - there is no feeling of gears meshing together and no backlash - Jims boxes may be top price but they are also top quality. You only want to buy it once so pay the extra and get peace of mind. Jims also do the Baker 6-speed and the quality is every bit as good.

Primary drive.

Primary drive is very important. If you are running a big motor then you need a clutch that will take the power - but here lies a problem. A lot of the so-called high-performance clutches are a pig when you want to select neutral, and they may well be heavy on the lever. The new 1998-up Harley clutches are pretty good but the cost is high. The best option all round I reckon is a belt drive kit. There are several different types on the market with several different clutch types. RMD use the Belt Drives Ltd primary drives because we have found that the clutches are smooth and they take the power, with an ability to increase the number of springs from 6 to 12. We use one of these on our Super-Twins Modified class bike which produces 175 bhp at the rear wheel! Yes that is correct - 175bhp, with the aid of a progressive nitrous oxide kit too, mind - and not only does the Belt Drives Ltd kit not slip, we can even find neutral no problem. RMD did try a belt drive kit that used a Bandit Machine Works clutch but not only would it not take the power, you couldn't find neutral to save your life. I have also tried one of the Rivera Primo drives and although it would take the power, the lever was really heavy and we couldn't get a clean launch, the Rivera would snatch every time if you tried to pull away hard.

Wheels.

Now wheels are often a matter of personal taste, but there are a few things that I should point out. The size of the front wheel has a dramatic affect on handling. If you run a 17-inch wheel with a low profile tyre, the effective rolling radius of the wheel is reduced considerably. This will quicken the steering and at speed you can change direction easier, but at slow speeds (around 30 to 40mph) it will have a tendency to want to put you in a tank slapper all the time. This can be compensated for, to a degree, in the amount of offset in the yokes and is best addressed at the frame-making stage. A reduced rake angle is the best method but this may not give you the look that you want. If you want the long low look then stick with the 19-inch or 21-inch wheels. Regarding the back wheel, the only thing I would say is that the 200 section wheel does not corner quickly, and the 230 is like riding a car tyre! This is because the 230 is basically just a 200 tyre with a bit glued in the middle ... the result is a flat area in the middle of the tyre that can be a bit (ahem) un-nerving to ride for the first time!

In Conclusion ...

So that just about wraps up the 'Brief Guide to Custom Bike Building' I hope it has been informative and if I have helped some of you to create the bike of your dreams with the minimum of grief, then I have done what I set out to do ... oh, and I should mention that we can supply all the major parts required or even build it for you, and our engines are built here and come with a no nonsense warranty (Thought you might, John! Rich).

If you do have any other questions that you think I may be able to help you with feel free to give me a call. You can reach me at RMD Monday through Friday 9.30am to 6.00pm.

RMD Distribution: +44 (118) 987 4084