Category Archives: Suzuki

A return to the bike build.

Posted on by Soulcraftcandyman
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Minimal fuel tank!

In the last installment of the bike build, which was let’s face it, too long ago and must be wrapped up soon, the exhaust was coming together. In order for me to be able to hear the results as the pipe came together a small tupperware container got a makeshift outlet fitted into its base and was then mounted to the main frame spar with a cable tie. With a bit of fuel onboard the engine could be started and run without the fuel tank in place and the exhaust listened to. The tank meanwhile was being prepped for painting.

The “silencer” that had been ordered came with an internal baffle already, if that’s what you could call it. You see these pipes everywhere on custom modified bikes so it will come as no surprise to anyone who’s ever had one that internally they are rudimentary to say the least. There was a piece of glass fibre packing inside the pipe but this was as good as useless. It would have disintegrated if you’d held it behind you and broken wind, frankly. So, first job was to get some proper packing material and firmly wrap the baffle so at least some of the noise could be absorbed. It was still too loud.

After a quick discussion about exhausts with the guys who’s workshop I was borrowing it was decided that the best thing to do was make a smaller secondary baffle that would fit into the end of the main pipe. Reckoning that the area of the holes in the internal cylinder should match that of the outlet it was time to have a go with the MIG welder. Not having used one much before, a quick session on the net provided some basic guidance to supplement the rather sketchy instructions contained in the user manual.

So a few hours later we had a finished baffle piece that fitted into the end of the main one that could be secured with three self tapping screws. Easy to remove and modify if need be and pretty much hidden behind the reverse cone end cap of the silencer. A couple of coats of aerosol heat resistant paint and the job was a good ‘un. This made a real difference to the sound and would be easy to remove if greater fruitiness from the pipe was wanted.This was the last fabrication job to do before the final build. What was up next was the biggest job of all, painting the bodywork.

 

Before moving on to that episode here are a couple of thoughts about MIG welding. Never having done any before, the thought of using the welder was a little daunting. Welding in all its forms has always come across as a bit of a black art, a deeply skillful craft practiced by wizards of metalwork with years and years of experience. This is all true but, it is also not as scary as it would seem. They say that every journey starts with the first step and so it is with MIG welding. Taking the plunge and having a go can lead you, with patience and concentration, to a thoroughly satisfying learning experience and hopefully a new found skill, and a finished part that you can be proud of.

 

My own introduction to this skill took me from making a simple baffle on the first day to knocking up a small paddock stand for the bike, to use during routine maintenance as I’d seen fit to remove the centre stand as part of the weight loss program. All within a week.

 

As mentioned before the manual that came with the welder was a little thin and searching the internet for tips and tricks threw up some really useful information and some tips which I never would have considered in my inexperience. Here are a couple of links to the two most useful websites found. The first one was the best: Firstly Tips and tricks and the second one here. Sadly the need for welding anything in my everyday work is rare but it hasn’t stopped me from wanting to buy a welder and start making something.

 

Although my skills remain relatively basic I’m no longer reluctant to consider using a welder for smaller jobs. Welding bike frames is something best left to experts for now but, with a new skill in the back pocket, the options available when making more complex ancillary parts has now grown and that can only be a good thing for when the next project comes along.

 

The welder used was a small portable unit with up to 150W of power, switchable. It had a variable speed wire feed, a small remote gas bottle (Carbon Dioxide/Argon mix worked best) and nice hefty earthing clamp.


 

Don’t buy it, build it.

Posted on by Soulcraftcandyman
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A couple of years ago I came to the end of a long term contract which had seen me running a modelmaking and prototype workshop for a small Industrial Design company in west London. I’d had, and in fact still do have, a very good relationship with the guys at the company and had often been able to work on small personal projects after hours over the course of the contract. Before I headed out into the world again to look for more work I had a desire to make something substantial for myself. After not much thought I decided I’d like to build a motorbike, or at least modify one to my personal spec. This is something that I’d actually been wanting to do for years but never had the time or opportunity to have a go.

Over the course of an evening, armed with three of my favourite creative tools, a pint of beer, a pencil and a pad of paper I sat down to plan my project. I had managed to persuade the guys to let me use the workshop for an extra month before going, so that set my timeframe. But what bike was I going to modify? I wrote many lists covering capacities, bike type and performance criteria in an effort to get a clear idea. I’ve always had a soft spot for 250cc bikes and after rejecting many other larger alternatives (I’ve already got a big bike anyway) I settled on the idea of creating a small runabout for town use based around a single cylinder 250.

I wrote a little brief for finding the donor bike in the form of a list. It had to be light and manoeuvrable, cheap to buy, run and fix but, most importantly it had to have potential. With only a month of workshop time available I knew I wouldn’t have time for complex frame work or to farm stuff out, I had to do whatever I could myself and quickly. I set myself a budget and dived into the web in search of a likely candidate. I finally settled on Suzuki’s GN250, an oft maligned little commuter custom like a Yamaha SR250, but better looking and with more appropriate geometry. Although they turned up on ebay fairly regularly the prices were high and condition questionable. I tracked a good one down in Gloucester – lady owner, low mileage, big rear rack. Perfect. I took the train down, and rode it home the same day.

I was as excited about going to get it as I’d been some years ago when I went to pick up my new Triumph. It was everything I wanted it to be. The dealer had serviced it for me and put in new oil etc. It started easily and coped admirably with everything I threw at it on the ride back to London. Assuming an “aero” tuck with my nose buried in the clocks we hit an indicated 80 mph, the brakes worked ok, and despite minimal suspension damping, floppy steering and a totally square rear tyre I stayed out of all the hedgerows. It was 120 miles of fun. And it did the whole lot on less than a tank of juice.

Once my mate Richard and my girlfriend had stopped laughing at my new purchase it got a good clean and I took some quick photos outside Rich’s garage so I could chop the thing about in Photoshop and sketch out my planned mods.

Ever since I’d decided that I wanted to create a little roadster for town I’d not stopped thinking about a retro styled scoot with a single seat and so this was my start point for mucking about very roughly in Photoshop. Without much work it turned out that I could get close to what I had in my minds eye quite quickly. One of the reasons I’d gone for the GN was that geometrically it already possessed the right kind of stance, not too high at the front end, with a short wheelbase. As a result I could leave the wheels where they were, and the frame too for that matter and just chop the rest around, creating mudguards, seats etc as I went. This was a Sunday, so I gave myself until the end of the day to reach my final idea.

Inspired by classic bikes of the 50’s and 60’s I’d very much latched onto the “Bobber” style, though I had no intention of giving the little 250 a hard tail, really not a practical solution for London riding. Other details would be changing though, like suspension, fenders, handlebars and exhaust but, for now these simple visuals gave me enough information to get on with the task of planning the build.

Next up, where to start and where to get the bits I was going to need.