Trials Australia Forums

Hi Everyone,

David Lahey wrote:

Kurt wrote:One for the Yamaha TY80 Anoraks

What is the function of the Oil scraper No 17 in the parts manual?

It appears to me as if it would redirect oil flung from the clutch gear through a passage to the gear set on the other side of the crankcase but this would be in an oil bath anyway.

I don't remember seeing inside that casing when I had a ty80 but I'll have a stab at what it's for. Maybe the wiper is to limit the amount of oil thrown forwards by the clutch gear teeth.

Kurt, can I have a stab at this even though I only use my anorak when I am in Tasmania? Wouldn't the oil scraper divert the oil to maintain the oil level in the gearbox?

On another note, I was asked recently about weight distribution on my SQUEAMISH and I didn't have an answer. From memory the motor went forward 15 mm in the frame and that was achieved at the front at least by fabricating new engine mounts. Here is a unmolested RL 250 to use as a base measurement:

Using the centreline of front axle to centreline of crankshaft is 670 mm.....

And wheelbase is 1326 mm to 1352 mm, in other words 26 mm of axle adjustment.


Now just to show how I picked centreline of crank:

SQUEAMISH front axle to crankshaft centres are 660 mm which equates to 10 mm closer than standard. The headstem was not changed so you are probably wondering why there is a 5 mm inaccuracy? My thoughts are by elevating the back of the bike, the true length has changed by 5 mm. All dimensions were taken with suspension in full droop. If you look at photos, you can see a difference in bashplate heights.


The wheelbase is similar at 1330 mm to 1359 mm, so 29 mm of axle adjustment because of different swingarm. With the chain adjusted, the wheelbase is 1350 mm and this has only a slight variation as the chain stretches.

So to summarise, the crankshaft centreline location makes sense for working out the weight distribution for a static bike. However the nut holding the handlebars seems to move around quite a bit in every direction so that might be a very different equation?

David, in regards to the Chrome plated casings, have you tried using Hydrochloric/muriatic acid to dissolve the chrome plate?
Where I work we use Caustic soda and an electrical current to strip chrome but that is off steel, I believe this will have a rather deleterious effect on aluminium however.
I still think its a strange decision to chrome plate as the aluminium casings look pretty good as they are.

That gets me thinking though, has anyone ever anodised a set of casings?

Greg, last time you were in Tasmania I don't remember there being a use for an anorak.
The TY80 oil scraper is a mystery to me, what you say may have some merit though as the oil diverted to the gearbox would then setup a constant flow of oil between the clutch and gearbox sides of the casings.

Kurt wrote:David, in regards to the Chrome plated casings, have you tried using Hydrochloric/muriatic acid to dissolve the chrome plate?
Where I work we use Caustic soda and an electrical current to strip chrome but that is off steel, I believe this will have a rather deleterious effect on aluminium however.
I still think its a strange decision to chrome plate as the aluminium casings look pretty good as they are.

Yes Kurt, it was a very strange thing for to do and perhaps the strangeness was then hidden away for a few years until it burst forth in the form of the plated brake drums. At least with the plated brake drums there was the practical reason to reduce unsprung mass.
Sadly, hydrochloric/muriatic acid will eat the aluminium even without a voltage applied and even faster with a voltage applied.
Thinking about how cool an anodised casing might look, did you have a particular colour in mind that might not look too strange alongside the rest of a ?

I think you would follow the colour scheme wouldn't you?

For example, Blue for a 350 M199, Red for an M159.
Similar to Greg's colour scheme on the Squeamish.

Greg Harding wrote:Hi Everyone,

On another note, I was asked recently about weight distribution on my SQUEAMISH and I didn't have an answer. From memory the motor went forward 15 mm in the frame and that was achieved at the front at least by fabricating new engine mounts.
So to summarise, the crankshaft centreline location makes sense for working out the weight distribution for a static bike. However the nut holding the handlebars seems to move around quite a bit in every direction so that might be a very different equation?

So I guess that means that the Squeamish engine relocation was intended to go along with the use of a longer swingarm without lengthening the wheelbase?

Kurt wrote:I think you would follow the :Bultaco: colour scheme wouldn't you?

For example, Blue for a 350 M199, Red for an M159.
Similar to Greg's colour scheme on the Squeamish.

Like with Greg's Squeamish, it might look good if the whole bottom end was anodised one colour but if it was just the outer cases coloured, I think it might look odd

Could you anodise the bottom end of a Alpina case Gold and the outer cases Blue, or would that be too much?

For that matter we could keep going, Triple trees, fork sliders, hubs, brake plates, I've got a set of Blue Renthal Handlebars.

Kurt wrote:Could you anodise the bottom end of a :Bultaco: Alpina case Gold and the outer cases Blue, or would that be too much?

For that matter we could keep going, Triple trees, fork sliders, hubs, brake plates, I've got a set of Blue Renthal Handlebars.

For the replica Peter Paice "best ever" TY250 Yamaha I built years ago, to look right, it had to have authentic 1970s Blue trials Renthals. Trouble was, all the 1970s colour-anodised Renthals I had, had faded severely over time. I ended up removing the remains of the faded anodising from a set of 1970s Renthals and painting them with special paint that replicates the look of anodising when sprayed over shiny aluminium. Amazingly it really does look like anodising. I think it's made mainly for people who like to tart up the aluminium bits on their car engines.

Hi Everyone,

David Lahey wrote:

Greg Harding wrote:Hi Everyone,

On another note, I was asked recently about weight distribution on my SQUEAMISH and I didn't have an answer. From memory the motor went forward 15 mm in the frame and that was achieved at the front at least by fabricating new engine mounts.
So to summarise, the crankshaft centreline location makes sense for working out the weight distribution for a static bike. However the nut holding the handlebars seems to move around quite a bit in every direction so that might be a very different equation?

So I guess that means that the Squeamish engine relocation was intended to go along with the use of a longer swingarm without lengthening the wheelbase?

Yes David, from memory the SQUEAMISH engine cradle was much bigger than it needed to be. So the engine went forward 15 mm at the front and the swingarm pivot went forward about 35 mm. The swingarm is 50 mm longer than standard. This made the bike more tractable when climbing especially in low gears with very little run up speed.

On another note I am happy to say that all of the tweaks I made this year were a step in the right direction and I have thoroughly enjoyed riding it.


Time for a change so the SQUEAMISH has been stored for a while......









Now what do I ride next? Any suggestions?

I recently saw online a 123 Cota modified to fit a XL125 engine with a TLR200 barrel which brings the capacity out to 167CC.



Has anyone completed the 4 stroke dream for some of the other manufacturers?
Yamaha could have had the TXTY by fitting a TY250 with an XT250 engine.

Think I have seen a photo of Mick Andrews riding an XT500 modified to trials spec.