Wheel spacer/ smaller offset engineering

Wheel spacers/smaller offset wheels
I always hear people say spacers or less offset will wear bearings faster. Some claim they have gone thousands of miles with no issues...others have bearing failures within a few thousand miles.

I have yet to see real numbers run...so I took a stab at with a napkin calc.
From what I see...even a half inch spacer will load your outer bearing with 50% more load. If your wheel centerline lines up with the outer bearing, it will see all the load.

Questions:
1. Does anyone know the bearing load rating in these assemblies?
2. Anyone know the exact spacing between the bearings?

Assumptions:
Bearing spacing, if someone has better numbers I'll update.
Truck weight to make numbers cleaner.
Only vertical static load, no dynamic or turning loads.

CONCLUSION: even a small spacer will significantly change bearing load, bearing wear, but until we know the bearing spec, we can't quantify the loss of bearing life.

 

Far right column should be negative 25

 

3 tacomas with over 750k total miles all lifted, all ran a 285 on a min -10 offset wheel never replaced a single wheel bearing front or rear.

 

Ahhhhaha didn't take long for the anecdotal retort to the cold hard math.

 

Remember. L10 definition.

Paraphrased.... 10% of the bearings will have spalls, pits......on a bearing component; race, balls

This means the bearing will continue to run, although it will begin generating noise. The bearing is considered on a path to a catastrophic failure.

So, L10 is a very conservative life calculation.

 

he isnt disputing the math. Just sharing experience which in the end is one of the greatest teachers

 

You're right, I misread his post. It wasn't so much a retort as much as just sharing his experience. My bad.

 

Yea exactly!

 

Nice work! I’m curious how tire & offset combinations would factor into your calculations.

i.e., 65lb-285mm-factory offset vs 45lb-235mm-1”spacer

Which would wear out bearings faster?

 

Good question. I would bet the spacer would wear the bearings out faster than a heavier tire. Since this calc is independent of tire weight, it's hard to factor that in.