bearings vs. trucks again

Rich Stephens · Post by **Rich Stephens** » Tue Feb 17, 2004 2:05 am

I know we were talking about bearings and spacers/washers months ago and I promised to do some drawings that would simplify the discussion of preload considerations and running bearings as radial pairs and what not. Rockin' Ron of California Bearing has mentioned on another forum that he will be creating some soon.

Today I read the following, from George Powell:

"Bearings are very precision parts, ground to tenths of a thousandth inch, but the truck axles they go on vary greatly in diameter, and more importantly, the truck casting is not usually square to the axle, nor is the nut always square to the axle. In order to use spacers and tighten up the axle nut, everything has to be perpendicular to the axle. If the casting, spacer or nut are not perpendicular to the axle, then when you tighten the nut, the inner races of the bearings will be unevenly loaded, and the clearance between the bearing and axle will allow a slight cocking of the bearing race, making the inner and outer races no longer co-axial. Ever tighten up a wheel nut and have the wheel not spin free, or get stuck in one place…this is the result of poorly made trucks or spacers (often both).

"In reality, most trucks are not made precisely enough to allow you to tighten up the nut with spacers in place, so skaters have merely adapted by backing off their nuts a little (the proverbial 1/4 turn) to allow the wheel to spin freely. This solves the problem of free spin, but when the skater turns, more friction is created than should be by the cocking that will happen when the bearings are side loaded."

====

more motivation to send our trucks to the machine shop. Do any of you go to the extreme of making the inner edge of the axle nut perpendicular!?!

Eric Wallgren · Post by **Eric Wallgren** » Thu Mar 04, 2004 8:16 pm

Yes.

Monkeywrench machine works, when doing our regular 8mm axle conversion, faces both the hanger casting and inner face of the axle nut square to the centerline of the axle. We also add a shoulder, so that washers or "speedrings" are not required. See pics in the MMW thread.

Jack Quarantillo · Post by **Jack Quarantillo** » Thu Mar 04, 2004 9:09 pm

GeezerX,
Does your mod work with Biltin bearings?

Q

Dave Gale · Post by **Dave Gale** » Thu Mar 04, 2004 9:41 pm

How could it not work!!?? The best of both worlds. Back-up system to allignment

Dave Gale · Post by **Dave Gale** » Thu Mar 04, 2004 9:45 pm

I'd save the life on the nyloks tho for when you don't use chris' killer biltins

Jack Quarantillo · Post by **Jack Quarantillo** » Thu Mar 04, 2004 11:07 pm

I'll explain my question:

I was thinking what with speedrings/washers built in to the Biltins, and built in to the MMW hanger and built in to the MMW nut, it would be the equivalent of 4 speedrings, and you might not have enough axle left to get the nut on.

I could be totally wrong, but the only stupid question is the one that goes unasked...

Q

Dave Gale · Post by **Dave Gale** » Thu Mar 04, 2004 11:33 pm

Point taken!
While I have yet to put a micronometer to Geezers trucks and nutz..I believe the buikt in speed rings are factored in to the over all width! IE: instead of adding on to the lock nut, he shaves away from, leaving the original depth etc.. It'd be a shame not to be able to marry the two outstanding products due to 2 or 3 mm over size!!
Eric is the answerer to this dilema.

Rich Stephens · Post by **Rich Stephens** » Fri Mar 05, 2004 3:02 am

For what it's worth, I have some of the tracker slalom trucks (not modified yet) and there is tons of thread left on those babies when mounting turner and fiberflex wheels on them. I suppose some other types of wheels may have the bearings further apart but for me, I could run a million washers in there and be fine. (I've seen some of the offset trucks people make and some at least have really long axles too - longer than stock).

Glenn S · Post by **Glenn S** » Fri Mar 05, 2004 7:11 pm

Jack Quarantillo wrote:I'll explain my question:
I was thinking what with speedrings/washers built in to the Biltins, and built in to the MMW hanger and built in to the MMW nut, it would be the equivalent of 4 speedrings, and you might not have enough axle left to get the nut on.I could be totally wrong, but the only stupid question is the one that goes unasked...Q

Jack,
I've used Biltins with trucks that Eric has reworked for me. Works fine. Eric does not skimp on the threading, there are plenty threads. But I did not take notice if the Biltins were sitting on more of the thread now because they stuck out more due to possibly being a tad wider than a stock bearing setup. I'll look next time though just for kicks. But if they are it is not by much. The thickness of two speedrings is probably just over 1/16".

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