The eagle eyed readers amongst you will have noticed that my last post was back in August! this is for 2 reasons. Firstly a broken wrist ...
and secondly i've been preoccupied trying to find a job of some description. Lucky the nice people at Nissan invited me into there plant to work as a graduate engineer. The move to Nissan meant that i needed to find a new work shop for the bobber. A bit of internet surfing and i had found myself a second home.
its got a toilet and everything! As you can see by the material sitting on the floor there's plenty to build to get it looking like a proper workshop which i'll be doing over the next few weeks. WATCH THIS SPACE.
Finally got around to posting a new blog entry. I've been busy trying to arrive at a final design for the frame. I've run into problems trying to make the frame look how I want but also keeping it strong enough to not collapse when am giving it full beans. The drawing below is what i have for now but i wouldn't be surprised if it needs some more small modifications :/
This is the working drawing for the jig i have designed through solidworks to mount the frame. Hopefully this jig will help maintain a high level of accuracy. I'm having to use a professional metal fabricator to machine some of the bits on the jig for me. Hopefully the next entry will have a picture of the real thing!
The engine is nearly rebuilt now so i am going to need a frame to mount it in before i can get it fired up. I've been reading Motorcycle Dynamics by Vittore Cossalter to try and get my head around motorcycle dynamics but it turns out its all hideously complicated. I took a few recommended dimensions out of the book and copied the original frame in a few places and this is what i got so far:
It turns out that rebuilding engines at actually very expensive :/ new crank bearing shells, big end bearing shells, full gasket set, gasket cement, torque wrench, oil seals, piston circlips, oil filter and a few other bits and bobs all add up. I've been using padgetts motorcycles (http://www.padgettsmotorcycles.com/) as a supplier who have always had the parts in and fast delivery so they get two thumbs up from me.
I've been storing everything that has come off the engine in Chinese take-away boxes. I thought i would share this with you because it works so well. Cheap to buy, they keep everything clean and contained, they are compact, easy to label and they can be re-used.
With all my spares to hand it wasn't long before it was looking like an engine again.
After re-installing the pistons to the connecting rods and getting all the piston circlips in i finished up last night trying to get the pistons into the cylinder block which i didn't have enough hands for so i called it night.
With the engine now in pieces i broke out the iron wool and got scrubbing. A few days later and every part is looking factory fresh again. Here's just a few bits and pieces...
I set about taking the engine to pieces. First I removed the engine from the frame
and then after knocking up an engine stand.....
I could start unbolting stuff!
The first problem i ran into came after trying to remove a tight cylinder head nut and ending up rounding it off. The position of the nut couldn't have been any worse.
The indent on top is were i tried to make a groove on top using a chisel then use a flat head screw driver to get it off which didn't work then the small hole you can see is the remains of my attempt to weld an Allen key to the top then use that as leverage but that didn't work either.
If anyone out thereneeds advise on how to remove a rounded off nut or bolt here's mine...
This may look like another cheesy American gimic but it got the nut off with ease and i couldn't be happier with my Grip Tites.
With the Cylinder head off the rest off the dismantling was all straight forward. Internally everything looked in good working order apart from one half of the crank casing which had a small crack and needed to be professionally repaired.
Building my own motorbike has been at the top of my list of things to do since I can remember and now with my Motorsports Engineering degree behind me I think its about time I started. This project has been inspired by the stunning bikes created at Falcon Motorcycles:
So where to start? .... In Ebay we trust.
Initially I wanted to use an old British motor such as a Triumph or BSA but after seeing rusty old engines which were in pieces go for quadruple figures (!) I had a re-think and decided Japanese was the way to go as they are cheaper to buy easier to find spares for. After a bit of searching a came across this beauty.
A 1977 Yamaha XS 250. To the untrained and trained eye is an absolute state. Needless to say it is non-running, needs a lot of TLC but it is just want I am looking for.
