OzVMX Forum
Marque Remarks => Yamaha => Topic started by: YZ250H on May 21, 2011, 10:51:44 am
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Mine is pitted, so will surely leak. Will be getting another one turned up and was thinking of getting it done in stainless steel. Will it work or should I just stick to mild steel? :-\
Thoughts ?
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Use 4140. It's high tensile and relatively easy to machine. It's what most axles are made from.
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Yup 4140 and you'll never have to think about again for as long as you have the bike.
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Excellent thanks lads. Want to create a stem that won't leak while I'm alive, so that sounds like the go 8).
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2011 or 2024 aluminium machines much better than 4140 and I'm 100% certain it will never rust ;)
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2024 has very poor corrosion resistance and is nowhere near as strong as 4140
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My main concern was Galvanic reaction. Possibly the reason for the corrosion of the stem in the first place :-\ Aluminium attached to steel - the steel will eat away ?
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Minimal galvanic reaction between steel and aluminium. Water retention would be the most likely cause of your initial problem.
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My main concern was Galvanic reaction. Possibly the reason for the corrosion of the stem in the first place :-\ Aluminium attached to steel - the steel will eat away ?
Paint it, anodize it, nickel plate it, galvanize it - many choices but tightass me goes for anti rust paint.
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Get a machinist to clean up steering head, braise stem, lathe stem to fit better than new and put back together with new seals....haven`t lost a drop since
Thats probably the reason i can`t sell a bike for half of cost price....haha
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Easier to start from scratch than root about brazing ?
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I'd have ago at brazing it unless it's really bad as long as you can get the seal surfaces back in good shape it should be fine.
What are you going to use for a bottom seal I hear their NLA now :o
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I got NOS seals from a former member of this forum. Came with a special message not to screw up the installation as they took a lot of finding ;D ;D
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I don’t believe the original shafts were of any high grade material.
If making a new shaft you can also consider making it to suit readily available seals if applicable.
You could consider 1020 mild steel which can be bought as hollow bar. This makes it easier to bore out the middle if any.
4140 falls into alloyed steel and is good stuff, if you’re after light weight you can use this and bore out the inside more to be a bit thinner in the wall thickness.
If you want to run with aluninium I would use a structural grade like 6061 T6 or something from the 7000 series.
I’m not sure how these shafts are set up for seals but I would probably consider stainless myself, but don’t outsmart yourself by having a stainless nut made. Stainless on stainless in regards to threads is one of the worst as the threads always bind and lock up.
You can polish the seal area for a good surface and I would probably consider making the thread section a bit longer if possible and making a new steel nut a bit longer so that it holds on more threads.
And then there’s Titanium….
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If making a new shaft you can also consider making it to suit readily available seals if applicable.
4140 falls into alloyed steel and is good stuff, if you’re after light weight you can use this and bore out the inside more to be a bit thinner in the wall thickness.
I’m not sure how these shafts are set up for seals but I would probably consider stainless myself, but don’t outsmart yourself by having a stainless nut made. Stainless on stainless in regards to threads is one of the worst as the threads always bind and lock up.
You can polish the seal area for a good surface and I would probably consider making the thread section a bit longer if possible and making a new steel nut a bit longer so that it holds on more threads.
And then there’s Titanium….
That's a bloody good idea regarding the seals Geoff. I would have blindly gone and made up a new one to suit the NLA seals (which when you think about it is pretty dopey)
Not concerned with weight really. The way I ride it would probably not make the difference between coming last and second last ::) ;D Mostly concerned with the damn thing not leaking.
All other comments taken on board. Have you got a lathe and what are you up to for the next few months ::) Someone said you were just bumming around the house with nothing to do ;D
I will post up a few pics on the week-end so you can see the set up and so people know what I'm on about.
I think I will leave the Titanium to Ji ;)
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I,ve machined Titanium.
Had to shorten an imported Prince Albert thingy for a mate ::)
Didn,t like to touch it in case it was second hand :o but it machined up real nice. :)
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If making a new shaft you can also consider making it to suit readily available seals if applicable.
You could consider 1020 mild steel which can be bought as hollow bar. This makes it easier to bore out the middle if any.
2 mighty fine ideas right there.