I have never built a chopper before. I have built a cafe racer from a Triumph 900 triple and I have built a couple of cars but never a chopper. I’m struggling to think why I haven’t really, I guess work and other projects have always left me short on time, energy and inspiration.
Those of you that read the introductory piece will know that this is just a fun challenge – the idea being to build a decent chopper from whatever we can find in our respective junkyards. Our being Scott and Ian at www.motorbike-breakers.com and me, Dave at www.bostonbikebits.co.uk. We are not going to use any new parts, where we do have to buy stuff it will be used and will be procured as cheaply and meanly as possible. What we hope to do here is to inspire people and to show that it doesn’t cost a fortune to build something decent. Yeah, I know it helps when you have a yard full of stuff but what will be using will be at the cheap end of the scale to keep everything sensible.
So at first we had no idea what we were going to build – we just knew we were going to build something and let the junkyard finds guide us. We were having a damn good mooch but nothing really inspired us until Scottie proclaimed that he had found the perfect thing – an old hardtail chopper frame – GET IN THERE!! We just knew it had to be done.
Ian remembered he had a really cool rear wheel from a Suzuki VZ800 Marauder with a nearly new tyre on so that went in the pile. We then looked for the longest pair of forks we could find. I don’t know what they are from = possibly a Yam trials bike. We then found the tank and seat that we think came in with the frame and the yokes as well – bonus. I grabbed a couple of other minor parts as well that may or may not get used – I am making this up as I go along so what you see now may not end up on the final build either due to practicalities or just if something comes along that looks better.
vAs far as the power plant is concerned I had a couple of Suzuki GSX600F engines lying about and thought one of those would be ideal so I set about working out how to fit it. First job was to get rid of all the unwanted brackets that held the old engine.
Next job was to raise the frame and position the new engine so that I could work out where the new brackets needed to go – careful planning is needed at this stage as you have to make sure everything fits and that it is possible to remove the engine should the need arise. It’s also got to be mounted very securely as it produces a fair old bit of power and you don’t want it ripping itself out of the frame. Some of the welding on the old brackets was hideous, it’s getting done properly with my old faithful arc welder.
The mounts were just tacked to start with I will weld them fully when it all gets taken apart for painting but I will build it fully first to make sure I don’t miss any bracketry or whatever.
You can’t see the jack holding up the back or the one under the engine but it was a pretty shonky arrangement that probably wouldn’t satisfy even the most lay of health and safety inspectors. I did pull it over once but no harm was done and anyway I hadn’t had the opportunity to swear at anything all day so it was quite welcome really.
Inevitably things went downhill for a while, I welded in a bracket without realising the engine had moved slightly so that had to be cut off and done again. I had checked the frame was all square, which it is but the front uprights are not bent exactly the same, which threw me when I tried to use them as a datum point. It’s just one of those things you have to expect really, especially when you use somebody else’s home built parts.
With the engine in place I trial fitted the rear wheel, there is not much gap between wheel and frame for the chain to fit but there is enough so that was a relief. I will have to make spacers up as I don’t have any that will do the job – I looked through dozens. I have a decent lathe so it’s no big deal, I quite like doing stuff like that.
As I need to move the bike around it seemed like a good idea to test fit the forks so I bunged the yokes on and fitted the bits – it all went together splendidly. While I had the bike level I measured the height of the front wheel spindle center and scampered off to find a wheel that was 22 inches overall diameter with a 15mm spindle hole. I found a Lexmoto one that fitted the description perfectly so for now at leas that is our front wheel.
Only other jobs for today were to weld on a side stand that I cut from an old EXUP frame – it was ideal as it had a bracket with the spring on it so it made the job incredibly simple. I welded it on and will weld it on some more when it all comes to bits. It works perfectly for this application, it’s just the right length. I also bunged some temporary handlebars on it just to make it easier to move about.
Not bad progress for one day.
Article provided by David Powell of Boston Bike Bits.