F: Frame UFM Dimensions

Pushrod Twin

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A question for Pushrod Twin, what happened in Australia with a cast aluminium steering head. The ones which I know of and which are being produced locally are LM25 heat treated. The casting shape is slightly beefed up in certain areas so is there evidence that there has been a failure somewhere?
Secondly, with regard to cleaning the inside of UFM. Good luck with the hot caustic soda but when I cleaned mine out I tried a variety of solvents and shaking a collection of nuts inside the oil tank and a pressure washer. I then cut a hole in the top for a manhole and there was about quarter of an inch of really solid black gunge in the bottom of the tank which required mechanical scraping to remove it. I could not have got that tank clean without the manhole. On another, I made the hole for the manhole and the tank was still completely clean inside. My guess is that it is a function of how the bikes have been used and what oils have been used as to how bad the problem is but you cannot see how bad it is without either a man hole or a fibre optic probe.
As far as I am aware, nothing untoward has happened with cast alloy steering heads, anywhere. I was offered one from Aus some years ago. Due to my aircraft background, I have an aversion to castings in structural situations. I understand that LM25 is good, and the added material probably negates the difference in modulus of elasticity, I guess you have done all of those calculations. It's a personal head-space thing for me, I am wary of cast structural items.
Re the oil tank cleaning, thank you. After the tank cleaning I will inspect with a borescope.
 

Gene Nehring

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Thanks David. Yes, it is the height above the engine which I really need. I dont have a "standard" (no such thing! :D) Vincent available to take the measurement from. I do have my loosely assembled B engine which helps. How long is the slot?
Can I assume that the theoretical datum is an horizontal line through the crank and drive sprocket?
Or the two FT3 holes horizontal?
I could level the engine & pass a bar through FT1-2 & apply an inclinometer to set the head angle at 30Deg. (or less, as you suggest, it could stand up 5 degrees with no harm! Welcome to Chopper City!)
That said, I have a pair of Girdraulic legs & some other associated parts, I would like to build this one with Girdraulics, rolling element bearings, modified bottom yoke, coil-over shock, 21" front wheel etc. and dont want the front guard getting to close to the mag cowl!
View attachment 31826View attachment 31827
I am moving back to NZ this feb and I hope to be able to join you all in Ngaruawahia. I am bringing my bikes plus spares. Might have a full set of girdraulics up for sale as I found a set of brampton's for my B.
Be good to meet you.
 

litnman

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My tool for cleaning the tank is a piece of outboard steering cable connected to a drill motor. The outer sheath doesn't turn. It is long enough to reach the far end of the tank and worked quite well.
Tank cleaning brush.jpg
 

Pushrod Twin

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I am moving back to NZ this feb and I hope to be able to join you all in Ngaruawahia. I am bringing my bikes plus spares. Might have a full set of girdraulics up for sale as I found a set of brampton's for my B.
Be good to meet you.
Very cool, we all look forward to meeting you! I will be there on the Home Made Egli Replica. :)
 

vibrac

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The last one I did was fairly easy. I used a 1/4" ball bearing against the plunger and a screw driver blade against the ball and gently levered against the opposite side of the hole for the big end quill. When it had move a little another ball and so on until the plunger popped out.
That will work but you have to ask if it takes all that effort does the damm thing do any good in operation at all?
 

greg brillus

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I can think of several cracking good uses for John's shiny red tool in the pics above, but have absolutely nothing to do with cleaning the innards of an oil tank............:):)o_Oo_O:eek::eek:.
 

vinhrd998

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