RAKE

[vwbuild]

DOM tubing is the easiest and most common to use. It is mild steel. Chrome moly is not required for a plain application like this.
Steel (not iron) water pipe, EW (electric weld) tubing and DOM tubing are all plain carbon steel. Steel pipe is not very uniform in wall thickness and quality. EW tubing is much more dimensionally correct and better. Both of these have a weld seam to work around. You must turn the weld seam (visible inside the pipe or ew) to the inside of the bend and also watch which way the load forces will be. It can be done and used to be the only thing available to work with back in the day. Lots of welds, support plugs in the splices and fitting and grinding.
Now there is DOM (drawn over mandrel).
It is the same as EW but as the name implies it has been drawn. The weld is worked in and normalized. You now don't have to clock seams or even pay attention to the physical properties of the pipe/tubing anymore. You can just pick it up and start bending compound bends every which a way.

Square tubing is strong until you have to bend it. So for the most part it will need to be a lot of straight pieces instead of bends.

Many a trike has been built using the original vw design concept. Replace the tunnel with a large piece of square tube cut and angled up to the neck. Then add on running boards.
Just a thought.

Thanks for this. Was told chromoly was the way to go but DOM sound's better. Might combine square or rectangle tubing with round. Square for strength and round for looks. Any ideas on a fork neck? Was looking at one on ebay that is shaped like an hour glass at each end.

Doesn't leave much room to weld. Also found a rake calculator that say's I need a triple tree that is offset 10 degrees. Seems that finding a correct girder is getting to be difficult. I found one build where a guy stuck a broom handle down the neck and adjusted it for different front wheel axle centers so he could find the correct trail. Is this the best way?

[DeathBySnuSnu]

Typically chrome moly is used for weight savings. You can get equal strength with thinner tube. Racers use this to make a better hp to weight ratio.
I computer Draft my stuff and then make it by the numbers. But a straight edge through the neck will give you a start from number. I built mine on a 4ft x 8 ft 1/2" thick steel table.

What do you have a swing axle or an irs?

Offset trees on your hydraulic
long dog bones on your girder
Longer rockers on you springer
Length of swing arm on your leading link.
All are ways to reduce or adjust the trail.

[vwbuild]

Typically chrome moly is used for weight savings. You can get equal strength with thinner tube. Racers use this to make a better hp to weight ratio.
I computer Draft my stuff and then make it by the numbers. But a straight edge through the neck will give you a start from number. I built mine on a 4ft x 8 ft 1/2" thick steel table.

What do you have a swing axle or an irs?

Offset trees on your hydraulic
long dog bones on your girder
Longer rockers on you springer
Length of swing arm on your leading link.
All are ways to reduce or adjust the trail.

I have an IRS. I want a girder. The calculators I went to I believe are for hydraulics only. I haven't found a calculator for a trike build. So I keep punching in 19" tire and 26.10 for a diameter, a 42" rake, a 29" fork--measured under the neck and to make this work I have to punch in a 10 degree offset to come out at approx. 2" trail.

What am I screwing up? I came up with a 42 degree rake from other peoples builds I read about. Dog bones on a girder must be offset on a triple tree? Thanks

[DeathBySnuSnu]

Ok let's clear this up.
I have been assuming you mean raked trees when you say a degree offset.
What exactly do you mean to say?
Straight offset trees?
Angled by # degree trees?

It is easier to do the math for a straight offset.

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Do you have a donor bike?
If you have a bike with a swing arm and shocks........there's you a front end. A little different looking but would work.

[vwbuild]

Ok let's clear this up.
I have been assuming you mean raked trees when you say a degree offset.
What exactly do you mean to say?
Straight offset trees?
Angled by # degree trees?

It is easier to do the math for a straight offset.

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Do you have a donor bike?
If you have a bike with a swing arm and shocks........there's you a front end. A little different looking but would work.

I'm using this 1970 VW Beetle subframe or IRS for a rear axle. I don't care for the donor bike frame or fork up front. I want to use a girder because of how they look and because springers are so expensive. I won't be using a hydraulic fork for sure. Yea--the offset terminology came from a trail calculator that I was looking at and this would be a raked tree. I don't know if it is called raked tree on a girder. I've never seen a girder except on a pic on the computer. I'm ignorant as to lots of this stuff. Like I say, I've had two sportsters and some dirt bikes but never manipulated anything on these previous bikes so don't really know what is what.

[DeathBySnuSnu]

So in the end what you are looking for is the correct relationship between the neck and where the axle is. Sort of don't matter how you get there as long as the trail is there and the trail don't go negative during travel up and down.
I am in the process of building one for my scooter too. Mine is going to be short and stocky, made of stainless steel and look like a wishbone springer but with a hydraulic shock. It will mount in my honda trees.

[vwbuild]

So in the end what you are looking for is the correct relationship between the neck and where the axle is. Sort of don't matter how you get there as long as the trail is there and the trail don't go negative during travel up and down.
I am in the process of building one for my scooter too. Mine is going to be short and stocky, made of stainless steel and look like a wishbone springer but with a hydraulic shock. It will mount in my honda trees.

that's pretty much it in an egg shell. My son is a machinist but live 1000 miles away so no help there. I really don't have the talent for a build like this but can build anything out of lumber. Send me pics of your project when you get around to it? Thanks

[DeathBySnuSnu]

Keep at it. You will get there.


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It is apart now. Gonna build a bigger stroker motor and go for a more chopper look and smaller tank.

[vwbuild]

Keep at it. You will get there.


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It is apart now. Gonna build a bigger stroker motor and go for a more chopper look and smaller tank.

I'd never be able to figure out a front engine build. hard enough with an engine in the rear. Looks good as it is. Thanks for the pic.

[DeathBySnuSnu]

I don't think I will get it back together this summer. To many things to do.
My little girl wants a new racing cart. Already ordered a new predator engine for it.

[vwbuild]

I don't think I will get it back together this summer. To many things to do.
My little girl wants a new racing cart. Already ordered a new predator engine for it.

My other toy is a Ditch Witch trencher/backhoe. Can't keep it running eather. I should be thinking about tearing up the driveway that the rainstorms dug big trenches in last summer. projects everywhere. But like the ol man said--You stop work'n ya die--and he was right.

[vwbuild]

Been running an add looking for a trike and got a response today. I'll try getting the pics up here asap. He want's $800. Haven't looked up the engine serial number yet but think it's a 1200. If it is a 1200, is this engine any good?

[vwbuild]

I just posted the above add for a trike that I found for sale. The engine serial number is B6277665. Can someone tell me if this is a 1970 1600 engine like the Samba website say's? The guy had told me it is a 1200. The exhaust is missing and the trike build is a mess. It used to be a sandrail converted to a trike. The tunnel is still attached and the shifter is in the tunnel. Battery was dead but will take charged up one tomorrow. Also, the beetle vin is under the seat but no title for that vin. The front fork is from a mid 70's cb750 and has a title with it.

Tell me what you think. Won't know till tomorrow if the engine runs. He said it was running last year. Any ideas or opinions? Thanks

[vw driver]

I can't see the engine very well but it looks like it has the old large body distributor and it looks to be a swing axle transmission which means it's all very old stuff. Those engines had a problem with #3 cylinder overheating because of where the oil cooler was mounted. Myself I wouldn't mess with it, I'd wait and find a dual port engine with IRS trans, much better unit and easy to find parts for.

[vwbuild]

I can't see the engine very well but it looks like it has the old large body distributor and it looks to be a swing axle transmission which means it's all very old stuff. Those engines had a problem with #3 cylinder overheating because of where the oil cooler was mounted. Myself I wouldn't mess with it, I'd wait and find a dual port engine with IRS trans, much better unit and easy to find parts for.

That's all I needed to know--thanks much

[vw driver]

Maybe I spoke too soon. That engine code does show a 1970 1600 single port so I guess it must be. It looks like they only made it for one year. If it runs good it might be worth $800. If it is a 1200cc it is really old or from Mexico. Check the shroud around the oil cooler. If the oil cooler is inside the shroud it's an old style engine which is not as good as the later ones.

[DeathBySnuSnu]

Well a couple hundred for parts maybe.
Looks to be a conglomeration of different year parts.
An early swing axle is going to be geared really low.
It has an irs torsion tube.
Might be a 1600 single port engine.

Meh.... pieces parts...not worth much as a viable vehicle....don't really know what your getting.

Unless you like building your own engines not really worth much to you.

[vwbuild]

Well a couple hundred for parts maybe.
Looks to be a conglomeration of different year parts.
An early swing axle is going to be geared really low.
It has an irs torsion tube.
Might be a 1600 single port engine.

Meh.... pieces parts...not worth much as a viable vehicle....don't really know what your getting.

Unless you like building your own engines not really worth much to you.

I think you guys are right--I'll pass on this one. Trikes are pretty rare around here. Didn't know swing axles are geared low. That may or may not be a good thing. I live at over 7300 feet elevation and the mountains are full of curves. BUT--lots of highway also.

[DeathBySnuSnu]

There is a massive amount of option combinations other than the USA options.
But if I remember my US VW history correctly..... The full syncro swing axle until 1966-1/2 had a 1.32 third and a 4.38 ring and pinion and we're 6 volt starter. They can be modified easily to 12 volt starter.
The last swing axles 66-1/2 and 67 were the newer 4.125 ring and pinion and longer axles. Most irs boxes are 4.125 ring and pinion and 1.26 third. Some of the very last boxes were 3.88. There are some other fourth gear ratios from not type one boxes.
It is common to put late model 3.88 ring and pinion in an early irs and call it a "freeway flyer". It is also common to put a .82 bus fourth gear in an irs and also call it a "freeway flyer".
So many of the different models and years have related components that it is common to mix and match parts to get a combination that fits your needs. For instance mine is a 65 short swing axle narrowed 12 inches, 3.44 ring and pinion, 1.26 third, .82 fourth, Splined shafts, Billet side plate, 4 spider super diff and internal machine work to make it run upside down.
So when you pick up a used box it is sorta pot luck as to what you may get.

[vwbuild]

This is crazy---Never knowing what your buying. is there a way to tell which transmission your buying with a model number anywhere on the case?