To make an axle, what material ?

I use 4140 on my Featherbed spindle kits, for whatever THAT'S worth.

Different loads, so...
 
Most of the bolts in my Seeley are titanium. I have not got around to making the spindles. There is a lot of weight in steel ones.
 
4130 welds well. 4140 machines well.

more or less same strength/toughness/hardness etc.
 
Go down to the CAT heavy equipment sales/support desk and ask for a honkin' big long bolt. That's what I did for the Dreer Prototype monoshock bike. Chopped off the end and re-threaded it with finer threads.
 
Al
I would check your eligibility rules. I remember the replaced them on the Norths because they seized.
 
I thought they were illegal in classic racing here cos they snapped?
A Titanium spindle of the same diameter is weaker than steel.
And Brit bike spindles are skinny to begin with.
 
ACU road racing regs state
8.17 CONSTRUCTION
The use of titanium in the construction of the frame, the front forks, the handlebars, the swinging
arm spindles and the wheel spindles is forbidden. For wheel spindles, the use of light alloy is also
forbidden. The use of titanium alloy nuts and bolts is allowed.

But if you're just going to leave it in your shed and talk about on the internet, but never ride it, then Ti is fine. You can lighten it further by leaving the crank/rods/pistons etc out too
 
Bernhard said:
Great answer! Not!
Click to expand...
Well, it does answer the question.

Both alloys have the same (more or less for these purposes) properties, whether you keep them annealed or harden them.

The OP was not asking how to properly make an axle, he was asking what he should make an axle out of.
 
t ingermanson said:
yes.
Click to expand...
Your comment on the subject was neither here or there, nearly all metals can, to some extent, be improved when hardened and tempered.
The few exceptions that can't are not generally used on stressed components, or have their own practical use.
Wheel spindles, provided they are not titanium, which is too elastic, are, as a rule used in their natural state, but as they are usually 18mm or more in diameter, these are quite sufficient in lightweight motorcycles. But they will bend if, for instance, you hit something hard, full on. (Don't ask how I know)
One race bike I had used tubed spindles but, I belive, was h & t.
 
GRM 450 said:
Is bright steel 4130 ok to make an axle ?

Graeme
Click to expand...

Short answer is yes. 4130 is a pretty common material for race bike axles here in the US. 4140 is also pretty popular. 4130 is readily available in hardened, normalized bar with hardness around RC20, which machines well (with sharp tools). 4140 in hardened, normalized bar, is typically RC25 - RC30, and has higher tensile strength than the equivalent 4130. Either one will work fine for motorcycle axles. Both alloys can be had in higher hardness condition, with higher tensile strength, but the machining gets more difficult, and at really high hardness levels the material becomes too brittle for an axle that needs to be able to flex a little. Not sure what passes for "bright steel bar" down under. There's more than one definition of that term. But probably the same stuff we get here as pre-hardened, normalized bar. There are all sorts of other specifications for various 4130 conditions, but the stuff you usually get from a reputable metals supplier is likely to be what I've described here. If in doubt, ask what the specs are for the material before deciding.

If you just google "4130 motorcycle axles", you'll find lots of additional info, and some examples of currently available 4130 axles, although most of what you see will probably be for the Harley crowd.

Ken
 
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