Custom motorcycle bobber build

Junkyard Dog Part 14 –

battered motorcycle mudguardThe mudguard that I found last week was definitely the right size and shape but it had been badly knocked about and had several deep gouges that did nothing to improve it’s appearance. It looked like somebody had attacked the poor thing with a flap wheel or something so before I could do anything I had to repair that and fill the unwanted holes, of which there were several.

There was nothing for it but to break out the P38 and fill, sand, swear, fill,sand. Swear , repeat until it looked about right. I hate doing bodywork, mainly because I am just not very good at it and it seems to take me forever and I am incredibly impatient. I have found that I hate it slightly less if I do it in short bursts and get on with something else while waiting for filler to dry etc. I had a bike in that needed the carbs cleaning so I multiplexed and that made the day considerably more bearable.

re-sprayed motorcycle mudguardNow the – paint. Paint is something I have had nightmares over recently, it started about 2 years ago when I painted a tank and side panels for a Triumph triple. It came out really nice, I used Halfords rattle cans and the finish was just what I hoped it would be. Then I got petrol on it, which literally just washed the paint off – I was furious. It had looked so nice but now several days work had gone down the pan and I was miffed. I have since found that the only paint that is truly petrol resistant is 2 pack but it’s nasty stuff – very poisonous. For this project I am trying some acrylic stuff. It smells hideous when it’s going on but the manufacturer insists it is petrol proof. I have put on the first couple of coats using the mudguard as a test piece, I have to say after putting 3 coats on it looks really good. It has dried to a pretty high gloss without any polishing and it went on very smoothly. I shall give it the petrol test after it has been on there a few days and if it’s all good that’s what I will use on the frame etc.

Before I painted it I added a plate to the rear seat support and drilled for a bolt to hold the mudguard. I welded on a nut to the underside of the guard to make assembly and removal a lot easier. A quick test fit showed that everything was fine and dandy so I could proceed with the rest of the work.

custom bike seat frameAt some point soon I need to look at the seat. The one I have is pretty much useless, it’s had a hard life and it’s just wrong. I need to incorporate a back rest for the pillion in to it and I need to form a seat pan that will be rigid. I have a big old sheet of alli that I bought when I was building a car, it’s been tucked behind my lathe for 4 years or more and I think it will be perfect for this job. I am thinking I shall make a wooden former so I have something to beat the sheet material over, that way it will have a return and be rigid as well as light. It will be quite well supported by the brackets that are now formly welded to the bike so I think it will work out ok. I may have to add a couple of tabs to the sissy bar to make assembly and removal easy, I will cross that bridge when I come to it. This will be the last job I do before everything comes apart for paint and cleaning.

My mate Grub just popped round to see if I had an exhaust that would fit on his Harley, while he was here he cast his expert eye over the dog. Although he seemed reasonably impressed he had a couple of observations and suggestions that shouldn’t be ignored when they come from somebody with his experience. Mainly his concerns regarded the chain. Firstly he pointed out that a tensioner probably wasn’t needed on a run as short as on the dog, secondly the spring is nowhere near strong enough and thirdly it still runs too close to the ammo box and the frame upright.

I kind of shared his concerns but was less concerned than he was so we had a quick chat about what could be done. The first thing he suggested was kinking the upright out so the chain didn’t need to run through it. Then he came up with a brilliant idea – he said “have you got an old pair of handlebars?” I did – the ones that came off when I put the new ones on there. Out came the hacksaw and angle grinder and the handlebars simply fell to pieces. A bit of crafting with a hand file or two and they fitted perfectly. When I take it all apart the part will be fully welded before the old upright gets cut right out of the way. I will deal with the tensioner spring issue later, Even though I probably don’t need it I kind of like it.

I might even weld a third upright in the middle of the frame just to make sure it is really strong as these parts form an important part in the rigidity and therefore handling of the bike.

Article provided by David Powell of Boston Bike Bits.

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