Which grooved axle design works best?

[texasengineer]

My question is which design of grooved axles is best? I have seen them with multiple grooves, and then ones with a single groove that is right in the middle of the bearing surface so the portion of the wheel nearest to the nail head and nearest the body are supported (this is the design we used). The other design has 2 grooves (one near the axle head and the other near the body). This design seems like it would be most likely to cause wheel wobble, so I avoided it, but have not tested it.

Any pro's care to comment. Which design seems to work best?

The setup I plan to use them in is:
+2.5 deg camber in rear
-1.5 deg camber on FDW
standard wheel base
COM 3/4" to 1" in frnt of rear wheels
outside wheel diameter trued in a lathe

Thanks in advance!

[roosclan]

Feb 5, 2010 9:34:31 GMT -6 texasengineer said:

My question is which design of grooved axles is best? I have seen them with multiple grooves, and then ones with a single groove that is right in the middle of the bearing surface so the portion of the wheel nearest to the nail head and nearest the body are supported (this is the design we used). The other design has 2 grooves (one near the axle head and the other near the body). This design seems like it would be most likely to cause wheel wobble, so I avoided it, but have not tested it.

Any pro's care to comment. Which design seems to work best?

The setup I plan to use them in is:
+2.5 deg camber in rear
-1.5 deg camber on FDW
standard wheel base
COM 3/4" to 1" in frnt of rear wheels
outside wheel diameter trued in a lathe

Thanks in advance!

If you are canting your axles, I don't think you want the grooves, as they may cause some binding with the wheel bore. The basic idea with the grooves is to get rid of the burr and crimp marks. A properly prepared axle will do the same thing. The "reduces friction" claim is a bunch of hooey, as the same amount of friction is now concentrated into a smaller area. I've seen tests done online that shows running graphite with straight axles vs. grooved axles gets better results with straight axles. Oil tends to do better with the grooved ones over extended races.

[texasengineer]

Hi Roosclan,

I understand that it does not reduce friction, and it ticcks me off when I see sites that say they are no zero-friction or no-friction. My point is that these grooved axle designs holds graphite longer than straight axles, and at race #5+ a grooved should be faster than a straight all else being equal. I don't see how binding would be a problem with grooved axles, it actually seems less likely than with straight axles, especially with the 2 groove (what I would call the wobbly) design.What tests did you see? Do you have a link? I would love to see them! I think I need to get a test track, cause I know all of the theory, but some things just need testing to prove out.

Thanks!

[blizzard]

I don't know if this is the experiment page he recommended, but this is one I found helpful.

members.cox.net/pinehead/expres1.html