Trials Australia Forums

Hi Everyone,

David Lahey wrote:Here is a progress photo of a basket case that has been on the go here for a few years now.
My son Darcy has grown a bit too big for his modern GasGas 50 now and is almost big enough to ride this thing so there has been a flurry of activity around it recently
The frame, tank and seat are Sammy Miller High Boy TY175 made in the early 1980s and the donor bike was a (basket case) TY175JC. The engine has been rebuilt. The rims are AKRONT and were bought along with the frame kit from Sammy Miller Products in the 1980s
It is shorter in wheelbase than a TY175 (about the length of a mini-Majesty)

David, this piece of art really deserves the top of the page! Now how do I go about getting adopted?

Hi everyone,
Greg I am thinking that in keeping with a Spanish motor and the fact that you have never mentioned any other "spare" motor other than for a , my guess is a motor, but from what and from what year, I have no idea. What wheels are you going to use? Maybe something bigger from that era as I know you like to work on your brakes to work at their optimum and as big as possible.

I will post up some close up photo's of the 242 swingarm where the rear shocks mount for your information.

My Montesa cota 200 is progressing and I believe Darren Creswell may have recently aquired one as well. A few photo's Darren?

Chippy

Hi everyone,

Greg I have attached some photos for the rear shock mount on the 242 for your information.



Chippy

I should have known better.
For many years I looked at the slightly battered chain adjuster stops on a TY250 and decided that "one day" I would fit new stops.
Eventually the swingarm bushes wore out and while replacing them, I fitted new chain adjuster stops and repainted the swingarm.
It looked great until I went for a ride and then noticed that the brand new stops I had fitted, were already hammered even worse than the originals
I then worked out what had gone wrong . The TY250 uses a bush in each adjuster cam that has flats that fit into the slots in the swingarm, and on this bike, someone had fitted home-made bushes that were a bit longer than the original Yamaha bushes. This was probably why the original stops got a bit hammered. If the inner end of a bush touches the axle spacer on the inside of the swingarm end plate, it prevents the axle spacers and the adjuster cams from gripping against the swingarm end plates.
When I repainted the swingarm after fitting the new stops, the fresh paint was softer and probably thinner than what had been on the end plates of the swingarm, so the stops were hammered straight away.
Fairly disheartened, I shortened the adjuster cam bushes and tried not to look at the hammered stops. That approach lasted about a year until last weekend while I was preparing the bike for an upcoming event, and wanted to fit a nicer-looking sprocket guard, so while I was burning the paint off the swingarm welding a tab on for that, I replaced the adjuster stops for a second time. After all that I thought it looked good enough to post a photo up and tell the story.

Hi Everyone,

David Lahey wrote:Nice swingarm Greg.
Are those spherical bearings on the swingarm shockie mounts or just steel inserts?

David, yes they are spherical bearings as the top mounts are closer together than the bottom. There is surface rust as you can see in the photos but they rotate freely. There are a lot of parts missing and I will have to make adaptors for the bottom shock mounts, mine must be a different model to Chippys?

chippy wrote:Hi everyone,
Greg I am thinking that in keeping with a Spanish motor and the fact that you have never mentioned any other "spare" motor other than for a , my guess is a motor, but from what and from what year, I have no idea. What wheels are you going to use? Maybe something bigger from that era as I know you like to work on your brakes to work at their optimum and as big as possible.

I will post up some close up photo's of the 242 swingarm where the rear shocks mount for your information.

My Montesa cota 200 is progressing and I believe Darren Creswell may have recently aquired one as well. A few photo's Darren?

Chippy

Chippy, the motor is in the too hard Basket for now but I do want to keep this bike all Montesa! As you know the 242 motors have starting issues, namely kick start and kick start gears. This one has none of these parts and I am not sure what happened to the rest of the bike?

As for wheels, I am going to test some of my theories about rotating mass, a little like flywheel effect. Logic tells me to use lighter later model wheels, however that is not how I do things. With the 242 being around 1985 and close to the cut off date for components, I am going to go back in time to 1976 as I have these Montesa wheels:

The front brake is the same size and the rear is 20 mm bigger than standard, plus the spokes are Stainless Steel, but the main reason is simply that I like the look of them.

Big difference in rear sprocket size between the complete wheel and the spare hub?
Very envious of you guys collecting baskets and building bikes - I was out of room before I moved and now I have less!

Hi David. The chain adjuster lugs on my favourite TY250 have a similar disposition to yours prior to your repair. I have simply been making allowance for lopsidedness by eye rather than counting the number of recesses on the cam.

It's another I'll get around to it issue, but my question to you is ... Why did you completely replace them? I had planned to simply fill the eroded area with weld then tidy it up with a file.

Alastair

tat ty wrote:Hi David. The chain adjuster lugs on my favourite TY250 have a similar disposition to yours prior to your repair. I have simply been making allowance for lopsidedness by eye rather than counting the number of recesses on the cam.

It's another I'll get around to it issue, but my question to you is ... Why did you completely replace them? I had planned to simply fill the eroded area with weld then tidy it up with a file.

Alastair

Yamaha make them with the inside end of the stops lightly MIG welded. The stops are a neat fit in an 8mm hole so it is very easy to grind off the weld on the inside, tap the old one out and slide in a piece of 8mm rod and weld it on the inside

witch one is going to the twin shock masters ??

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