What Would Be the Standard Practice in This Situation? - 1

He's going to need to shrink it quite a bit more than that.

With the lathe available, I'd anneal the very end and put it in the collet with just a half inch sticking out, turn on the lathe, and use the back of an old lantern toolholder to spin a much small neck on the tube. Then put it over a mandrel and push it through something.

Without the lathe you get it started driving the annealed end of a short unannealed piece into a chamfered hole or draw ring, then anneal and finish by pushing it through with a mandrel.

Ok, before you proceed any farther with th' steering neck OD difference, you've got to measure th' offset of both those top triple trees. It makes a huge diference in rake and trail if they're not exactly th' same... and my naked eyes say they're not.

Offset is th' diference between th' fork tube hole centers and th' steering neck hole center. Do a google search on motorcycle rake and trail for more info. This is very important for you to know and factor in prior to doin' anything else. There's at least a couple of sites that have free calculators for this.

Next logical questions are; will you be using th' stock dia. wheel, tire, and stock length forks? Offset, rake, trail, fork length, wheel and tires all need to be factored in. Once you get all that figured out, we'll go from there.

Snarl

Thank you for the additional information. I held off on ordering some shim stock. Your point about it being hard to curl made me want to find SOMETHING .030 to test fit in there.

Thank you for the one over suggestion. I have been wondering how much larger it needed to be.

I forgot about the heating tricks. I have been meaning to get a little toaster oven from a thrift store for such projects. Another thing I have used is to put the other piece in a Zip-Loc bag, then set it in the freezer for a few hours. Sometimes that will help things like bearings slip in better.

I found out why some micrometers on eBay have a blade on each end! A regular one can't measure pipe wall thickness. My pipe I had laying around was not close enough anyway.

McMaster-Carr will have to keep it at that price. :-)

Thanks for the additional information, gentlemen.

Offset, rake and trail won't be much different. No need to worry.

Find an industrial heat gun. That's what I use, when I'm not using the kitchen oven. To keep the tang of 90wt gear oil out of the food, a Reynolds Roast-In-Bag works wonders.

Basically aluminum alloy has a much larger thermal expansion coefficient than steel. This is a good reason to make your bushing from steel, you can remove it again by heating the clamp.

Jim

As before, thanks again for the information. I had never heard of putting something in a Roast-In-Bag. Great tip!

Think: entire bmw gearbox in the oven. Sure the 90 wt has been drained out of it, it still stinks!

Jim

Drained does not equal oil free. :-) Like Aqua Vela (I think), MMMMM, the smell of it! :-)

I bought mine for the same reason ... and it's saved me *hundreds* of dollars . Pretty sure it's paid for itself in less than 18 months on parts savings .

Snarl , I axed him pretty much the same questions and got a similar answer . He ain't worried about it . I'm not sure I'd ride this bike when he gets it together ...

I know of folks who have died from issues like this.

In one case it was an improper weld on a sidecar conversion, on the front forks.

Looked good, but there was no penetration. And they ground the surface nice-n-smooth.

Especially for front end stuff, it has to be right.

Jim

A mandrel is a device for mounting an object on a lathe or other machining tool where the mandrel is a rod machined or purchased to have an interference fit with a hole in the part to be machined. It allows parts to have their entire od machined at once. Once the machining is finished, the mandrel is removed and the part is ready. A chamfered hole is sort of like a radius, but it is an angle rather than a curve. Straight | | to Chamfer | | |-------| \-------/ This is important whenever press or interference fits are involved because it allows the part to seat and center itself in the hole. To anneal a part is to heat it up and let it cool slowly. When cool, the part is at its softest state. Most metals can be annealed, but the temperature should be controlled according to published tables for the particular material. Some are much more forgiving than others.

You won't find me welding something that my life will depend on , at least not until I get a lot better . I will , however , turn some worn (springer forks) rocker studs to a smaller od and turn bushings to match . In fact , I was doing just that this afternoon for the '39 WLDD I'm rebuilding . I ain't restoring it , I'm rebuilding it . Too much of the original is gone ...

According to woodworker88 :

Or -- converting the ASCII drawing above to a fixed pitch font to eliminate the distortion on my screen (select a font like "Courier" to view properly):

Straight | | to Chamfer | | |-------| \-------/

Agreed!

Again agreed. And some can *only* be annealed by heat treating, and cannot be hardened again except by work hardening (brass is an example).

Enjoy, DoN.

The bike is disassembled to the frame currently, so measuring rake and trail is not possible right now. I haven't checked offset, as it is close to the same, and if it were any different, it would be for the better. The tire OD is the same. I'll have to get it all bolted up before worrying about fork length (travel is the same, but axle to clamping area may be different). I am thinking any slight height difference can be taken up by sliding the fork tubes up in the clamps. Right now, I am just worried about how to get one metalworking issue solved. I have to take care of "first things first". :-)

Thanks.

Well I'm positive my ass wouldn't be on such a frankenstein abomination! Not without performing some due dilligence and triggin' it all out just right.

Yeah, and about all we can do is sit here and wait for th' kid to self destruct I guess. Oh well.

Snarl

From an earlier post:

The bike is disassembled to the frame currently, so measuring rake and trail is not possible right now. I haven't checked offset, as it is close to the same, and if it were any different, it would be for the better. The tire OD is the same. I'll have to get it all bolted up before worrying about fork length (travel is the same, but axle to clamping area may be different). I am thinking any slight height difference can be taken up by sliding the fork tubes up in the clamps. Right now, I am just worried about how to get one metalworking issue solved. I have to take care of "first things first". :-)

Thanks.