This page is dedicated to the garage dweller, the X650 enthusiast who has that special project hidden away from prying eyes waiting for the day when he, or she, can take it for it's first ride. So if anyone out there just can't wait for people to see their pride and joy, and you want to share that secret project you've been working on for years with those who will be interested. Then this is the place!

Way back in 1980 I started building a chopper. I'd been buying American chopper magazines since the age of 12 and although they featured choppers made from many Japanese and British bikes as well as Harleys, I liked the Harleys best. So, a Harley it had to be. At that time, Harleys were very rarely seen in Australia and I was the only one I knew who had one. Long story short - it became a 9' 10" long bike with a 93ci S & S Sidewinder engine.

To this day, it's one of the toughest looking bikes I've ever seen. However, by the time it was around 80% finished (as seen in the pic above), I realized it was way to radical and would be a pain to ride. Just moving it around the garage was almost impossible, as it needed an area the size of a football field to turn around in. I'd also made a couple of fundamental errors along the way, which could have been rectified but not easily. So in the late '80s and after much thought, I made the painful decision to sell it. By that time, Harleys were becoming like armpits - everyone had two of them.

Incidentally, around 1982 when the Harley was in it's early stages, a fellow moved in across the street and he had a red Yamaha XS-650, which I thought was just beautiful. Although I was quite taken with it, I knew nothing about them, having never paid them any attention at all. I now know it was a '78SE. He stayed about 6 months and then moved on. I never thought about the bike again for several years and never noticed any others around the place either.

When I first conceived the project, I'd chosen to build a style of bike that was never very popular in Australia out of a make of bike that was almost unknown here. I'd also gone about it not by buying a Harley and chopping it, but buying the few parts of a Harley I thought I'd need - motor and trans - and the rest from wherever I could source it. These days, that's quite common but back then, it was the slowest, most expensive and most frustrating way of building a chopper. Not only that, but there was almost no chopper industry here at the time so I had to design a lot of the major parts and have them made by engineering shops who often had no idea of what they were actually making. Other than that, I'd have to fabricate what I could myself but at that time, my fabrication skills were in their infancy so all I could manage were brackets, and other minor bits and pieces. At high school, the only subject I was interested in was metalwork in which I achieved a grade 1 pass and although I could use a lathe and mill, I did not own either. I also did not own a welder, nor had I ever welded.

Also, I'd never ridden a Harley and had no idea what one would be like to live with. What if I'd got the bike finished and, chopper or otherwise, I just didn't like Harleys?

You might be wondering why I'm telling you this. Well, not only had I decided to sell it, but also to begin a new project. This would be a chopper too, but nothing like the old one - not it's radical design but more importantly, not the way it was built. The foregoing is the story of how not to build a chopper and, hopefully, what follows might be something of a story on how to do it right. Make no mistake, I'm no expert on the subject but wasting so much time, effort, and money certainly taught me something. As I've said, today you could build a bike like my Harley quite easily just by buying everything you need out of a catalogue, not have to design and make anything yourself, and never visit an engineering shop and perhaps not even a chrome shop. But we're not interested in that. No tree-hugging, vegan, mummy's boy chopper for us. This new bike will be garage built in the old fashioned way.

Once the Harley was gone I began planning the next chopper and it was going to be anything but a Harley. Just as I'd chosen that make because they were so uncommon at the time, I wanted something that was uncommon now, but what? Certainly not a BMW or Moto Guzzi, imagine the chopper they'd make. If a chopper isn't a H-D, then it's usually British or Japanese. I have no love of British bikes at all so my next chopper would probably be Japanese and the usual donor bikes were the Honda CB-750, Kawasaki 900, and Yamaha 650. That's it! My new chopper would be made from a bike like that gorgeous thing that used to live across the street a few years ago. What a stroke of genius.

I mentioned that to a fellow at work and he said he had one for sale. Apparently, he rode it to work for several years and I'd walked past the bike shed hundreds of times but don't recall ever seeing it, such was my then preoccupation with Harleys. Anyway, I went over to his house and found a very run down '77D with almost another bike in pieces. I bought the lot for AU$600 in 1988. This marked a complete departure from the way I'd built the Harley. This time, I'd buy a complete bike, ride it before I changed anything about it to see if I liked it, and use as many of the stock parts as I could. After owning a Harley and always paying "Harley prices", it seemed like the bargain of the century. Almost 2 bikes for $600. The idea was to make a chopper out of whatever bike I'd bought, thinking I'd only buy one but since I now had almost two, I'd build the chopper out of the spare parts and keep the '77 stock as a bonus.

By the way, most people who read this know me as one of the founders of the 650 Club and many consider me to be somewhat knowledgeable on the bike, but there was a time when I didn't even know there were two kinds - the so called Standards or Roadsters, and the Specials. The bike across the road had cast wheels, a fat rear tyre, and a stepped seat but the one I'd bought had wire wheels, a skinny rear tyre, and a flat seat but that didn't matter. Either I didn't notice or didn't care. Probably both.

The '77 didn't run but I met another fellow at work who had an '80 Special which, this time, I did notice in the bike shed. I told him that I owned a derelict 650 which I intended making a chopper out of, but I'd never ridden one. He offered to let me ride his for an hour or so and after the first 5 minutes, I'd fallen hopelessly in love with it. That gave the "green light" to the project and it was full steam ahead. Incidentally, my mate later sold that bike and after passing through several owners, it finally fell into the hands of our very own Noel Beard of Springwood and whenever I see it, I get a little misty.

Next job was to do something else I'd not done with the Harley. Way back at the beginning of that project, I'd bought all the books on choppers I could find and one was the "Jammer's Handbook". As well as a catalogue of parts, it also contained many technical articles, one of which was about designing a chopper on paper. It had lots of line drawings of H-D motors, gearboxes, rigid and swingarm frames, different styles and lengths of forks, wheels, tanks, etc. These were all to scale and the idea was that you'd choose the parts you wanted, and using a pencil and tracing paper, assemble them into a drawing of your proposed bike. Even though I had that on hand, I never used it on the Harley, and look what happened. The pic below is just 1 page, there are several more.

I wasn't about to make that mistake again but the drawings in that book were only of Harley parts so I took the '77 outside and parked it on the centre-stand, stood as square-on to it as I could, and took a picture of each side. I had that processed (long before digital cameras), measured the distance between the axles, and compared that to the actual wheelbase. The idea was to have the pic either enlarged or reduced to make it 10% of actual size. Once I had that, I could work out any dimensions I wanted and proceeded to trace the new pic to end up with a line drawing of a 650 Yam in 1/10th scale. I could now design my new chopper on paper before I cut the first piece of metal. I decided on a swingarm frame, heavily modified, with hydraulic forks about 6" longer than stock. I can't find the original drawing but this is one I did a few years ago, when I briefly considered a girder fork and some fibreglass bodywork around the rear end. The original had great detail but this one only shows the major parts, the basic design having already been settled on. I've since decided to return to the original design.

Just to recap - The first time around I'd chosen a bike that very few people in Australia knew anything about, I did not buy a complete bike but a bunch of parts from here and there, I'd never ridden that make of bike, I didn't make any written plans as to it's look but did it all in my head, and I spent an absolute fortune having the motor and gearbox rebuilt and modified into an Earth-rotator long before I needed it to run. I also moulded and painted the frame and had bits chromed as I made them. Thousands of dollars and as many hours of my time wasted. This time, I chose a bike that was well known, I bought a complete bike with a ton of spare parts, I rode one before I committed to spending any money on the project after the initial purchase, I did some detailed drawings of the proposed bike, I took apart the motor and reassembled just the outer parts and the trans output shaft to put in the frame for fitting and fabrication purposes, and I have no intention of spending any time or money on making it look pretty until I've put some serious miles on it. If I'd done that with the Harley it might not have turned out the way it did but even if it had, at least it wouldn't have cost half as much or taken half as long.

So far so good, or so it seemed. Although the 650 was well known and quite common in Australia and was probably used as the basis for many choppers, they'd fallen out of favour with the chopper crowd who'd recently discovered Harleys (one of which was mine). The parts catalogues, which once listed parts for several British and Japanese bikes as well as Harleys, now listed parts for Harleys only. No longer could you buy a chopper frame and forward controls for a Yamaha 650. Oh shit.

I wondered if I'd jumped out of the frying pan into the fire and then, I happened across a fellow with a wild 650 chopper and asked where he got all the chopper gear.

He said he made all of it himself so I asked if he'd make parts to my designs, to which he agreed. He wrote his details on piece of paper and I went home to cut up the spare frame which, by the way, already had it's seat rails lowered by a previous owner.

I didn't like that but the fact that it'd been already modified made it the ideal candidate for further work. I went to the wreckers and bought the forks and triple clamps from a Yamaha TT-600 and the rear wheel from an '80 Special. This was in contrast to importing a 15" OS girder which I'd never seen in the flesh, and having a custom rear wheel cast for the Harley. The TT's front end had very chunky, aluminium triple clamps, and 43mm forks that were 6" longer than the 650's. No need to buy extended tubes.

Before I took a saw to the frame, I set it up on blocks with the rear wheel in place and leaned the TT front end with the wheel from the Harley (a 21" rim laced to a 650 Yam hub - the only one narrow enough for that girder) against it.

Having never cut up a frame before (the Harley's was modified before I bought it) I took a deep breath, cut the seat rails off, and cut the tubes that run upward from the swingarm pivot at a point intersecting where the new seat rails would finish if they were in line with the upper part of the backbone, and the entire rear end fell away. The tubes that run underneath the battery box were then removed, as they serve no purpose now. That done, the backbone itself was cut about midway between the top engine-mount and the steering head. The cradle was cut just forward of the bottom engine-mounts and the entire front end fell away. The engine mount was then removed from the remaining part of the backbone.

I then set the bike on blocks again but this time, with the front end suspended by a string from the ceiling as there was nothing to lean it against, a tank I'd bought from MCA, a rear mudguard off a H-D I'd bought from a H-D wrecker (such a thing didn't exist when I was building the previous chopper), and the seat which I still had from my Harley.

It would be a few months until I called the fellow with the chopper to arrange another meeting and by that time, I'd forgotten his name. It's a good thing he wrote it down - Peter Kommer - and as luck would have it, he lived only 30 minutes away from me. Together, we decided on a single down-tube with a gooseneck, and no cradle. Peter made and installed the new sections of the frame, turned up a new steering head to suit the TT's spindle, as well as axle spacers and several other small parts. This was done in just a few months but then he said he was moving house and so was unable to continue any further, at least for the time being.

While he was doing that, I was busy making up several minor parts. In the pics below, I'm making a bracket for the rear calliper, and cutting out some of the skirt on the rear 'guard.

This wasn't the end of the world as I'd recently bought an XD Falcon, which I wanted to rebuild into a mild street machine. I brought the bike home, parked it in a corner, and began work on the Falcon. This required taking it completely apart and so I needed alternative transportation. I pulled the '77 out of storage and after performing a few simple checks for oil, spark, etc., found the reason she didn't run was because she was out of fuel. I changed the oil, put fuel in the tank, and jump-started it from the car. She fired up after just a few seconds of cranking so I warmed her up, put air in the tyres, and took her around the block. I got her registered and took the Falcon off the road.

That little diversion took 15 months and once the car was back on the road, I let the '77 run out of rego. By this time, Peter had relocated and could resume work on my chopper. I took the bike over to his new house but not that much needed to be done and soon it was back at home again, where the pics below were taken in around 1992. Note that it has no stand and so is leaning against the wall. It also has no rear suspension and is held up by an axle or similar jammed between the swingarm and rear footpeg mounts. The handlebars are a short barbell (I used to lift weights, believe it or not) and there is also no steering stopper so I always had to position it just so, to stop the bars coming around to hit the tank.

During the time the car was off the road and I was riding the '77, my father was nearing retirement and wanted a project to keep him busy. Having owned an assortment of Royal Enfields, Triumphs, Nortons, and BSAs in his younger days, he decided to build a Triton (Triumph 650 motor in a Norton Featherbed frame in the café racer style). We looked at several examples but after riding Japanese bikes for over 20 years and nothing British in that time, he was shocked to discover just how agricultural they were. I suggested that a Yamaha 650 done in café style would be a much better bike, but he disagreed. A Triton was the fantasy bike of his youth and I suppose he'd wanted one for so long that nothing was going to sway him now. Nothing that is, except the stark reality of  40 year old British bikes. He did the intelligent thing and bought an XS and the story of it can be found elsewhere on this site but
suffice to say that soon after he got it finished, he died of liver cancer and the bike passed to me.

The only reason it gets a mention here is that it sent me off on another detour. I now had a café racer to ride and soon I'd have a chopper. Whilst these are nice bikes to own, they are what I call "fad" bikes - they look great but are totally impractical for everyday use, the T-bucket of the bike world.

It occurred to me that I should have an "everyday" bike so I again pulled the '77 out of storage. When my car was off the road, I didn't do any major work to the bike to improve it. As it was only used for local transportation and only for a short while, that it ran OK or indeed at all was good enough. Now however, I was considering using it as my main ride for a very long time. I decided a complete rebuild was in order to a standard a little better than stock. This should be fairly easy and not take too long. I'll knock that over, have a really nice bike to ride, and get back to the chopper.

Well, something went terribly wrong. As I'd take a part off, I wasn't happy to just rebuild it, I had to make it look pretty too. Say it was a wheel, the intention was to clean it, tighten the spokes, and replace the bearings but no, I couldn't leave it at that. Since the spokes are a little rusty, why not get new ones? Since I'm getting new spokes, why not get stainless? If I'm having the wheel taken apart, why not polish the hub and get a wider rim? Apply this line of thinking to every last part and we come up with the bike pictured below.

This is hardly an everyday bike that can be ridden in all weather, parked anywhere and left for long periods, loaded up with tons of luggage, etc. Yeah, I screwed up. By that, I mean I didn't end up with what I set out to have. An uncountable number of parts were custom designed and made, and a lot of it had never been done before. Throw in a relationship break up (thankfully, no kids), new girlfriend, father dying, 2 kids, Ian Irving, moving house twice, etc., and we arrive at 2009. Time sure gets away when you're having fun. So, to cut a long story short, it took many years more than I anticipated and cost....don't even ask.

However, it's not all doom and gloom, as I now own a custom 650 in the "fat bob" style. The fat bob, with it's shorter-than-stock forks and fat front tyre, was the bike that came into vogue when the chopper fell out of favour around the mid '80s. I disliked them and I stopped going to shows and buying magazines because there were no longer any choppers to be seen. With about as much planning as I put into my Harley (almost none), I wound up with a style of bike I thought I'd never own. The funny thing is that as I was building my Harley, choppers were disappearing to be replaced by the fat bob and as I was getting my fat bob finished, choppers were making a comeback. As usual, my timing was spot on.

In any case, I love the way my '77 has turned out and it seems most other people like it too but like my Falcon, the only reason it gets a mention here is because it's impacted heavily on the chopper. Many of the parts I'd bought for the chopper, head and taillights, brake calliper, etc., found their way onto the '77. Not only do all those parts need to be bought again, but to my mind and as much as I love my '77, a chopper is still the ultimate custom and for as tricked out as the '77 is, the chopper must be even more
so or to put it another way, the '77 has raised the bar which the chopper must now clear.

During periods of inactivity on the '77, I occasionally bought a part or two for the chopper to keep the interest up but just recently, I dusted her off and have begun taking stock of what I have, what I need, and what I have to do.

I decided a few years ago that I couldn't live with the look of the TT's forks. Like all modern dirt bikes, the axle is forward of the legs, and the legs extend way below the axle. This is to allow extra long travel, something very useful on a dirt bike. Not only do I not like the look of that on a chopper, but also I began to question if having 13" of travel on a bike with only 5" of ground clearance was a good idea. I imagined that if I ever had to slam the brakes on hard, the forks would compress so much the frame could scrape on the road. I sold the TT forks to someone who'd crashed their TT.

I was given the front end off a Yamaha XS-750 about a year ago. I knew the spindle was the same diameter but shorter than the 650's, but I took it anyway. To my surprise, the spindle is the same as a TT-600, so it fits the chopper. Trouble is that the tubes are only 36mm and way too short. Of course I'll now have to buy extended tubes and not only do I like the look of thicker tubes like the TT's, but the longer any piece of tubing is, the easier it is to bend. Thus, 41mm tubes of any given length should be way stiffer than 36s. I know people use 35mm and even 34mm tubes on 650 choppers but I wonder how much they flex. So in the pic below, I've installed the 750 's front end and pulled the forks down to the bottom clamp to get the length I want.

One thing is for sure and that's that all telescopic forks twist when raked to any great extent, and this bike has 45 degrees. The reason is that the more rake there is, the more the front wheel falls over when the steering is turned, and the wheel's weight twists the forks. Thus, a fork brace is mandatory and the only place these forks can have one is where the dust covers go. You can buy clamp-on braces quite cheaply but my café uses a one-piece item machined out of billet. It's front-end came off the '77 before I put the wide item on. The chopper will have to have one the same or better and that one cost $200 about 10 years ago.

However, the Suzuki forks now on my '77 have tabs for a brace that any dope with a hacksaw and file could make out of flat stock. Of course, I wouldn't know anyone who's actually made a fork brace that way. Also, when I had the billet triple-clamps made for the '77 a few years ago at 10" wide, I also had a similar pair made at 9". I got them at a good price and they've sat on a shelf ever since.

So, I must now buy a set of 41mm forks off a late model bike of some kind (preferably a Yamaha and possibly an R-6) because I'll need the brakes as well and the discs bolt up to a 650's front wheel. If I subtract the cost of having a billet brace made from the cost of used (and hopefully bent, to keep the cost down) R-6 forks, and given that I already have the triple clamps, and that I have to buy extended tubes whether I use the XS-750 forks or some other, it shouldn't be too painful. Not only that, but having similar front ends on my '77 and chopper would indicate they're from the same stable. A family resemblance, if you like.

Stupid me cut the footpeg mount bolts off years ago, thinking I'd use forward controls. I now intend using a belt-driven cam like the '77's, which would be very hard to get my leg around. So, I've temporarily fixed a pair of stock pegs and their brackets into place to see if I can sit in that position, given that the seat is so low. It turns out that I actually prefer to sit with my knees bent and now that I think about it, when I'm driving a train I often sit with my feet right up under the seat. Now, I have to make the bolts and weld them to the frame. At least I own a welder now and can use it for simple jobs like that. The lesson here is never cut anything off
until you're absolutely sure you won't need it. Also on the bike at this time is a 16" rear wheel on the front, like on my '77. I briefly considered running it but decided against it because deep down, I still believe a chopper should be long and slender. A chopper is a chopper and a fat bob is a fat bob. The 18" wire wheel on the rear in the pic above is a spare I'm using to hold the bike up. The 16" wheel on the front will go on the rear, and I have a 19" cast wheel for the front.


The plan is to finish the frame, and I've gone off the idea of no cradle so that'll have to be made and welded in place. Until I buy some 41mm forks and some extended tubes from Forking by Frank, I've taken the tubes out of the 750's forks and replaced them with ordinary black tubing that I had cut to the correct length. They go right to the bottom of the lowers and there is no suspension in there at all. I did that so they would run through both triple clamps so I could move the bike around and I've also welded a tube
between them so they don't twist.

Because it'll have a belt drive, the swingarm must be a little wider on the left side but instead of having one custom made as on the '77, I looked around the wreckers and found one to suit. It's off a Kawasaki GPz-750 and is asymmetrical. I don't know what purpose that serves on the Kaw, but it'll allow me to run the belt drive, which I've already bought most of, and a disc brake on the left. This gives an uncluttered view of the right side of the wheel, which I like. I've already done the drawings for all that. The
swingarm had to be shortened across the pivot tube and luckily, Kawasaki had machined the bearing bores deeper than they needed to be and I could push them in further, allowing the tube to be cut to the required length. Because the rear of the swingarm is much wider than a 650's, I'm using an axle from an XS-1100. Because of the gear-set at the rear wheel, shaft-driven bikes use longer axles. It's 20mm in diameter but the Kawasaki's is only 18 so the axle slots had to be enlarged to 20mm.

 The rear of the frame is too low for any shocks in the usual location so I'll run a short mono-shock off a sports bike in front of the tyre. It won't be a rising rate system, just straight swingarm-to-frame. Shocks like this are now common at the wreckers so it's just a matter of taking the bike there on a trailer and trying them on until I find the right one.

In the pic above, it's still sitting on blocks with the steering straight ahead but I've fitted an old exhaust just to for fun and I've also made a wooden seat so I can sit on it to position certain things, relative to me.

Tired of always having to sit it on blocks, I recently made a dummy rear suspension unit, a temporary steering stop, and welded on an old stand I had lying around. Now I can push it around the garage, which makes it much easier to work on.

The motor will be much the same as the '77 but with a few minor changes. The ignition housing will be see-through so you can watch it turning, the clutch will have a window over it for the same reason, and I'll probably source the cam drive off a car instead of making it all from scratch. Other than that, it'll be a 90 degree 750 with rods from a Honda CR-500 and pistons made by Ross to my design. Valve gear is Kibblewhite/Porsche. Intake is one like you've not seen on a bike before and I'd prefer to keep that to myself for the time being, but suffice to say that I won't be able to ride wearing loose fitting shorts.

Paint is something I really get off on (that, and radical engines). In fact, I used to be a painter but have not worked in the industry for many years now. I saw a paint job on a bike featured in Street Chopper of September 1972 (I was 12 at the time) that's been stuck in my head all these years. It's a multi coloured candy-over-flake job featuring ribbons and scrolls, and I wonder if I have the balls to put something like it on a bike today.
We'll see.

It's been 20 years so far and I hope to have it running by say, the end of 2010. I still have to fabricate foot controls, handlebar risers, rear suspension mounts, intake system (minus the carbs), exhaust system, seat, rest of the belt drive, and that's just off the top of my head.

Dimensions;
Length - 8' or 2440mm.
Wheelbase - 5'11.5" or 1810mm.
Rake - 45 degrees or 45 degrees.
Trail - 6.5" or 165mm.
Bottom of Neck to Front Axle - (measured horizontally) 510mm (550mm allowed by RTA).

Update 6/3/13

The steering head was made to suit the spindle of a TT-600 but since I sold those forks many years ago, I no longer need that. I could leave it there but I’d prefer one off a 650 as it’s quite a bit longer and when you increase the rake, you increase the load that’s applied to the steering head so the further the bearings are apart, the lesser the load is increased by. It’s all a matter of leverage. Anyway, I acquired a badly bent frame a few years ago and cut everything I could from it before scrapping it so since I have this steering head, I might as well use it. Here, it’s having all the bits of frame cut away. It’s pretty rusty but a week in a bucket of molasses will fix that.

Update 25/5/2013

Well, after I'd cut most of the excess metal away from the steering head I noticed a hole right through one of the bearing surfaces. Bugger. I'm not sure if it rusted right through or was done by a PO trying to change the bearings with a hammer and chisel. In any case, it's junk. Time for plan B. I actually prefer the look of chromed bearing cups as on my Harley (go right back to the beginning if you want to see them). It's lucky I discovered I couldn't use the 650 item before I cut the one in the chopper out because now, all I have to do is simply cut the end sections containing the bearings off. I wondered for a while about how best to do that and finally hit on the idea of doing with the mill. Not only does it make easy work of it, but as long as the frame is positioned so the steering head is perfectly upright, the cuts should be square to the centerline so the new cups will seat properly when they're pressed in. Clamping it to an angle plate took care left/right and raising/lowering the engine hoist until a digital leveler read 90° to the table took care of fore/aft. Simple, really.

Update 10/12/14

I went to a tube bending workshop recently to have some intake runners made for one of my other bikes. Since I was going there, it occurred to me to take the chopper frame to find out if the missing part of the cradle could be made.

Here is what’s there now.

That’s a slug pushed into the frame right at the bend under bottom motor mount. I did that many years ago and never got any further with it. You can just see that the slug has split the frame tube at the end of the slot I cut to increase weld area. That’s not good. Sure, it could be welded up but the whole idea of joining 2 lengths of tubing on a bend is a bad one. I didn’t know that back then.

The nice people at the tube bending shop gave me a few pointers about what can and can’t be done with tubing, and told me how to lay out a pattern or template for any length of tubing I needed, allowing for such things as the radius of their dies, minimum distance between two bends, etc. They told me to bend a piece of 1/4” solid round into the shape I needed, saying just one side would be enough as they could also make a mirror image of it.

I went home and thought about what I wanted and how best to make it. I marked out the start and finish of all bends in the cradle. TP is tangency point (where a bend begins), and MP is mid point of the straight sections. The frame has been dragged around the floor so the tape in the pic below has some of the marks worn off but I’d already gotten what I needed from this exercise before I took the pic.

If you turn an XS frame upside down, you’ll see the cradle has several bends that may not be apparent when the bike is all together and standing on its wheels. I made my cut at the mid point between the two marks which can still be seen on the tape on the opposite side.

Next job was to make something that would locate the solid round in the frame stub and keep it true. I machined this slug from a piece of solid aluminium I had laying around. The cut is so it could be a fraction bigger than the ID of the frame, yet still go in as it would collapse a little, and so be very tight. Any movement would lessen the accuracy of the template I’m making.

The hole going across it is to put a rod through to tap on when I want to take it out.

Here, the slug is in place and so is the solid round bar. In this shot, you can see why there is a bend under the motor mount. If it weren’t there, the frame would be too far away from the motor at the front and look ridiculous. Actually, I considered cutting the frame past the next bend, reshaping the swing arm brackets, and beginning the bend in the replacement tube a couple of inches higher up. That would run the cradle right on or maybe a little above the motor mount. It’d close up a rather large gap that, if you run high pipes and maybe I will, is now showing and not very pretty. But, that would require major surgery to the cross brace that’s at the bottom of the backbone. Way too much work. Just for once in my bike-building life, I let common sense prevail.

In this shot, you can see that the round bar doesn’t follow the centre line of the bike. If the frame tube followed this path but with the aforementioned upward bend, it would foul on the motor so another bend is necessary (which a stock frame has – see the slug in the opposite tube) to straighten it. If I can, I’ll try to achieve two changes in course with just one bend and rotating the tube. By comparison, the cradle of an RD-350 is straight in both planes. Doing this to one of those would be so simple and easy.

I should say that the reason all this needs to be done in the first place, going all the way back to when I cut this frame up more than 20 years ago, is because I want a swing arm. You can buy very nice rigid frames with whatever rake you want but I’ve ridden with enough people who have rigids and seen the way they bounce all over the road. No thanks, not for me.