Erics yammie 250/650 chopper#1

[Prof]

Latest project is Eric's first bike. He's been working on and off at The Chopper Shed over the last year or so, and had fun riding a variety of bikes that are here including the chopped 750/4 that Steven rode for a while.

Well, he's caught the bug and frequently has been a pillion, but we've worked out a deal where he can get his own bike for small bucks and "it has to be a chopper" so a chopper it is going to be.

I bought a demolished 250 yammie from Jeff a year of so ago in case of an eventuallity just like this. The original frame had been chopped to heck and other bits added, so we have decided to use the steering head and front end and rear wheel of something else that came with it and build the rest from scratch.

Eric has been coming around when he can to work on the project and so far has built a cradle for the motor and a jig section for the rear end.

Here he is testing out the front end last week (quite a bit done in the last few days)... will have 40 degree rake and still be 30mm within regs, though that may change as we proceed...


We'll give periodic reports of the project... not sure how much detail I'll be able to go into as I am way behind on workshop jobs as well as choppers australia stuff... also building three rooms onto East end of our house an hour or so a day... so a fair bit to fit in...

Anyway Eric is pretty chuffed so far and we are hoping to have lot done in the next few weeks as he passed his bike licence two weeks ago and is keen to get on the road with the rest of us chopper jocks...

[Prof]

Tried out the steering head with some of the original tube left on to save a bit of work. But steering head would have to be too high to get backbone to clear top of engine...


So all tubing cut off and we start from scratch. This angle to shows you the method I use for holding the steering head in place for fabrication of frame. Welding always pulls as metal heats and cools and I like to keep things aligned with a minimum of fuss. This set up allows fine adjustment in all planes. The aparatus in the steering head is my laser alignment tool made from a .22 barrel and a laser pointer with a couple of machined cones. The suspened pliers? It is counter balancing a plumbob that I use to ensure head stem is central...


Have backbone tubing ready to cut and should have 2mm wall tube for rest of frame this week...

[Prof]

Work has progressed steadily on this bike. Frame is almost complete with sissy bar, tail lights fabricated in the last couple of days.

Some pics coming, but flat out geting bike done and producinig a 'Chops'nBobbers' magazine as well as building the second to last section of our house... Rilda reckons that after 8 years she should have an inside laundry... I mean for goodness sake I gave her an inside toilet last year!

[Prof]

Gave Eric a push down the drive tonight... sorry a bit blurry.



A final set of engine mounts and brake reservoir mount to be welded and time to pull down, finish welding, paint and assemble.

An xs 650 motor will fit in the frame we have built, so once Eric has gotten used to this and gotten some money together he can upgrade and have a nice cruising machine.

[Cromag]

Thats the buissness there young Eric!

See you on the road...

[Bearcx]

Awesome stuff. Good to see a "younger" fella interested in choppers. Way to go, Eric.

[jsalt]

Saw this bike on Sunday, looks killer, you guys get it finished enough to ride Sunday? Get a photo of it on here, Eric look so happy with it . Great job
catch ya

Jon

[Prof]

Thanks Jon. Been working on it flat outfor a week in the hope of having it ready for Sunday. The 250 motor we initially put in it was smokey and gutless and Eric has recently gotten a well paying job and has been able to purchase an xs650 to replace the little motor. When I initially built the frame I made it big enough for a 650 as i figured he'd want a bigger motor if he got serious about riding... which he has.

The bike has needed more mods than we expected... major redo of swing arm position and shocker top mount due to the small (32 tooth) rear sprocket which runs on a Harley spoked wheel. Eric also wanted the footpegs a bit further forward as he is very tall.

So it is currently an xs650 motor in a TCS frame, HD rear wheel, CB750 front wheel and forks, xj1100 triple trees and steering head, I think tank was a yammie trail bike but with a new tunnel and front mounted filler.

As of today, we have only to set up a throttle cable, finish mounting the forwards (will be done tomorrow), time the ignition and set the points... then see it it will run... we had the motor in Steff's frame and got it running roughly, but thought the carbs were being a problem... the points plate was also dodgy and the advance springs too week.

I'll get some photos up shortly. Have held off until now as I have been getting a patent for the rear suspension... now patent pending in Australia as of end of December 2012 and being patented in US and Europe... and its costing a fortune!... been over 6 years in design and development. I actually was working on the solution to a suspended rigid look in the mid seventies before a change in direction and then work and family stopped serious chopper riding and building for a number of years, but I picked up the idea again some time after I officially started The Chopper Shed.

All being well, it will be running in a by Friday.

[Bearcx]

Good news about the patent, Andrew. I know its expensive, but should all be worth it. Your rear suspension design is awesome.

[Prof]

Well long story on this one. Eric and I worked absolutely flat out to get his bike ready for my birthday run and midnight ride... all to no avail. Tank split at rear due to a massively vibrating motor when we started it and the tank sealer failed to cope... so now have a messy welding job with a tank filled with water. In the mean time we fitted another tank but...

After first efforts to get motor to run... problems with both valve and spark timing... As I didn't have time, Eric pulled it apart one night with a mate and when put back together but timing was still crazy. He then took it home so he and his dad could work on it. They notified me valves were bent and timing chain was stuffed and jumping teeth... and then he accidentlaly got sand in the motor when sandblasting the casings... and they'd had enough of the whole thing.

Result... I agreed to buy the bike back off him so he could buy something modern that he didn't have to work on and actually get some riding under his belt.

Brian came up a couple of days and after going right through the motor and calling Dave Taylor (xs officiando) in Melbourne we worked out that the previous person who rebuilt the motor (750 kit and new everything) had one link too many in the timing chain... and as Eric found out, was jumping a couple of teeth each time the motor was shut down! Valves were checked and not bent and timing chain was perfect (just too long). In this process we did learn that 447 (74-78) motors have a metric timing chain and 17 and 34 tooth sprockets. 256 motors (69-73) have an imperial timing chain and 16 and 32 tooth sprockets. 447 motor enging numbers begine with 447. Camshaft is stamped with 447... just a case of counting teeth on bottom sprocket with bottom plate removed. Also pin sizes on different brand chains vary, so make sure you match the connecting link to the chain.

Anyway the motor is back together and ready to be put back in the bike... which I hope to do tomorrow.

Sorry still can't load pics.

PS. Eric rocked up a couple of days ago on a 650 Star. Quite a nice comfortable cruiser, but front end is very saggy... He's happy to be back on the road.

[jsalt]

That's great you got it fixed. Its a cool bike.
Jon

[Prof]

Jake (lad who is working for me after school and during holidays) and I started the bike yesterday... 2nd kick! Runs well with plenty of get up and go. Took it for a couple of short rides. Just needs to be tuned. I'll use it as a demo of the TCS 'rigid' suspension until I get my shovel set up with it. Currently building jigs in between working on a couple of other customer's bikes... pics when I can finally load them again.

[nozila]

Keep us updated with the rigid suspension. May be interested for one of my bikes.

[Prof]

TCS rigid suspension X1...



XS 650 motor, CB750 forks and front wheel, Yamaha 250 steering head, Yamaha 1100 rear brake caliper, Harley rear wheel... rest built in house. Patent pending in Australia and being applied for in other countries... these applications breaking the bank!

[Neo Dutch]

When the rear wheel moves up, the "swingram" translates that movement into compression of the shock absorber mounted slightly forward of the rear guard?

That's clever.