The rear wheel stay didn’t work out quite as I had planned as it didn’t give me enough clearance from the wheel without looking a bit crap. I decided to still use the rear part from the bandit bit but cut a length of ¾ inch square box to extend it to the mounting point. I still have to weld on end caps to the pieces of tube but it looks a lot better than the first attempt. All the minor fettling will be dealt with when the bike gets torn down for paint, nothing will be finalised until I know everything fits. In a build like this things can change quite quickly so I don’t want to waste loads of hours on something that ends up on the scrap pile.
Next job to attend to is the front footpeg mounts, I have at last received the hex steel bar that I ordered nearly 2 weeks ago so I have what I need in stock to get the job done. I will be using two lengths of the hex and some flat steel sheet to complete the hob. The hex bars will have 6mm tapped holes in their outer ends for the footpegs to bolt to – these were found in Scottie’s infamous scrap pile and will be ideal for the job. The steel sheet will be used to stiffen it all up and make sure they are very securely fixed to the frame, last thing you want is the right hand one falling off when giving the rear break a good dose of size 11 boot. To make absolutely sure I am going to put a brace right across the frame and weld it all together so there is no chance of it coming apart. I still have to finalise how I am going to do that so in the mean time it’s on with the sissy bar.
The builder of the frame had made provision for a sissy bar to mount on the frame down near the rear wheel spindle so that saves me a job. The challenge is to build one that looks decent but doesn’t cost very much money so chrome plating is out. Fortunately my local metal fabrication place always has a fine selection of offcuts so this one is going to be ¾ inch square box steel, I will paint it either black or silver when it is done. The method I like to use for such constructions is the same method I used to build the spaceframe chassis for the little race car I built – furniture blocks. Yes, those little plastic blocks that have screw holes in them that are supposed to be used for holding cheap shit furniture built out of chipboard together. I use a sheet or two of chipboard or similar on a flat surface, I carefully measure and draw the outline of the piece I want to make and then cut each individual piece to the pattern. The plastic blocks are used at strategic points to hold it all together. I can then stand back and have a check to make sure it looks like I want it to before welding it all together. It’s very simple but very effective, as I said I once built a whole car using this method and it came out perfectly square.
First thing is to establish the critical dimensions – the width at the mounting points, the height of the back wheel, the width for the seat rear mount, the overall height, that sort of thing. I also need to establish where the rear light and number plate will fit so I can incorporate the mounts – it’s much easier to design this all in from the beginning and make it while it is flat on the floor. Where I can I like to make each piece of metal serve more than one purpose eg the seat support may also be the rear light support or something – I’ll see how it shapes out when I get on with the job.
As I started to draw it out I made a couple of changes , which iis far better done now than when you are cutting or welding. I love doing this sort of stuff, just starting out with an idea and evolving it in to something you really like. I tack welded it when all the parts had been cut and then fully welded it to make sure it is good and strong. It won’t be taking any real weight apart from the lower seat support which will have the full weight of the pinion on it. Now is a good time for a word of warning. When I was building my car I was a member of a web group where all things to do with the cars would be discussed at length. One lad spent forever and a day welding his chassis and then spent equally as long grinding it all down so it was all super smooth. He also ground all the strength out of it, something he noticed when it literally fell in half. Just worth bearing in mind.
Anyway here’s the fully welded article complete with the really cool chrome light that Ian found.
It still needs the mounts welding on to it, that will have to wait until next time.
Article provided by David Powell of Boston Bike Bits.