TR5mx Fork/Steering Stem

[johnu]

So sitting on my tr5 I could tell that something was awry with the forks. With the bars straight the wheel points slightly to the left. Loosened all of the triple clamp (yoke) bolts and tweeked it to more of less straight but still not quite right. Unassembled forks, triples and found that the stem is bent I have absolutely no idea how this could occur on this very stout piece. Are new stems still available? Right now I am even tempted to look for another set of forks, this stuff bugs the heck out of me.

[mlb50]

That can be straightened. Take to an engineering shop and ask that they cold work it. No heat. Should be able to press that true in 5 minutes.

[minetymenace]

Failing that, Mark Cook will make you one (might have one in stock), but he is the other side of the pond and all that entails....

[johnu]

That can be straightened. Take to an engineering shop and ask that they cold work it. No heat. Should be able to press that true in 5 minutes.

That's a good call but I just looked at the stem again and it is bent at the bottom as well so it looks like I'll just replace it.

[johnu]

Got an email in to PES regarding a new stem. I assume the old one just presses out of the yoke. Also do I need to heat the yoke at all before pressing out the stem?

[BasilF]

Its threaded both ends, a course thread into the bottom yolk and a fine thread into the bearing adjusted nut. Heating the bottom yolk will certainly help if it is tight.

[johnu]

Thanks Basil, it came out easy. About the only thing that has been easy on this build so far

[johnu]

Stem is a right mess, bent both ends and bearing surfaces worn. Not sure how it could be this bent! I would make a new one myself but I don't have the screw cutting gears that I need for my lathe.

[johnu]

Stem is a right mess, bent both ends and bearing surfaces worn. Not sure how it could be this bent! I would make a new one myself but I don't have the screw cutting gears that I need for my lathe.

IMG_6871.jpg

[SteveS]

Hi johnu

Last time I needed one I couldn't source one anywhere at a sensible price so a friend made one up from 3/4" solid mild steel bar. It was fairly simple to thread the end that goes through the bottom yoke 3/4" UNC. The thread at the top varies between early and late models:

early models - 3/4” UNF (16tpi) - stem top nut 97-4029, steering stem 97-4116
late models - 3/4" UNF thread form (24tpi) - stem top nut 97-4317, steering stem 97-4319

It would be helpful if you could post details of the overall length of the stem and how far the thread is cut at each end for future reference

[johnu]

Steve, here are the dimensions of of my stem. I think I will just buy a couple of dies and make the stem from 3/4" precision ground bar. I'm going to try to bore the middle out but that's a lot of drilling! It will be easier to get the 3/4 x 16 unf die so I'll probably do that then buy the earlier top nut. I dimensioned it in imperial as that's what it would have been originally.

[robtg]

You can get 4130 tubing the size in your drawing from Aircraft spruce By the foot.

https://www.aircraftspruce.com/

[johnu]

Thank you Rob, that is a big help Just ordered a piece

[beesa71]

And that nice fella ‘stainoifless’ on EBay sells a stainless steel stem top nut in the early version ie the coarse thread. They will ship worldwide.

It is cheaper to buy it, and the other listed items, through direct contact via this wonderful forum. As you would expect.

Regards to all OIF’ers.

Paul.

PS; if you haven’t realised it ‘stainoifless’ is my pal and I.

[johnu]

Got started on the stem today. My cheap Chinese 3/4-10 die did a pretty good job! Still waiting for the 3/4-16 die to arrive.

[johnu]

Done!

[Keefe]

Nice