individual wheel rolling resistance test

[parallelevan]

Lately i have been trying to find some lrr tires and that got me thinking why don't i check out the resistance of each wheel to see if maybe i have a bearing that's about to go bad and fix that while I'm at it. Never doing this before I thought id run my hypothesis past you guys. Which idea do you like better.
1. Jacking the car up tires off the ground tranny in neutral.
use a torque wrench to check the force required to turn the wheel and compare to the other side (front and rear will be different because of cv shaft
2. Create a jig to set one tire on at a time. Using electric motor bring the wheel speed to set point and disconnect power and time the wheels movement till it halts

Ones really easy but the other would test it under normal load. Ideas guys?
P.s. I work on convayers all day a jig would only take 3-4 hours to build with parts already on hand

[arcosine]

Usually when a wheel bearing goes bad it makes noise, a whining grinding noise when driving. You will be measuring brake drag most likely with your set up.

[ksa8907]

The torque wrench sounds like an easy test, you might want one measuring inch-pounds.

[MobilOne]

This has been my experience. The first sign of a wheel bearing starting to go is uneven wear on the inside or outside edge of a tire. Every two or three inches or so around the tire edge you will see some cupping. The next step will be that if you turn the wheel by hand gently, with the car jacked up, you will feel a slight clicking. Next, you will hear a slight clicking as you go at idle speed down the road. Much, much later you will hear a squealing; just before the bearing seizes up. The torque wrench is a waste of time, way too insensitive.

[MobilOne]

what kind of vehicle is this? Are the bearings easily available to be inspected? What signs, if any, are you getting that you have a bad bearing? If they are the kind that need to be packed, then take the wheel off and repack them. If they are sealed bearings, then leave them alone unless you are getting some indication of a bearing problem (see above post). A torque wrench won't tell you anything, necessarily, too many other variables at work (temp of bearing grease, dragging brake, play or no play in differential, your skill at using a torque wrench, etc.).

[parallelevan]

The vehicle is a 07 honda fit. Currently I am not having any wheel bearing issues. Im just figuring since im going to have the car jacked up anyways to check a few things if one tire is harder to turn either from a bearing or brake rub It causes unnecessary friction.
A well maintained car is an efficient car

[MetroMPG]

Have you done any other efficiency mods yet?

If not, testing for wheel drag would be pretty far down my to-do list if there's no obvious problem.

Typically you can feel drag when coasting to a stop with the transmission in neutral. If the car comes to a perceptible halt at the end, I know something's dragging. If things are working well, the car has no "stickiness" to its coasting stops. (Not sure if I'm essplaining that well enough.)

[MobilOne]

Hi Parallelevan,

I didn't communicate very well. What I meant to impart is that using your hands to turn the wheel will give you more information than a torque wrench. You can feel a brake drag. You can feel a c.v. joint click or a drive shaft c.v. joint click. You can feel a dry bearing click. That's what I meant to impart. I didn't mean to imply that you should skip maintenance and inspections. Sorry for the miscommunication.

[MobilOne]

Hi again,

just for the fun of it, you might want to try using a torque wrench and also just your hands to see what, if any, difference you can detect.

[Frank Lee]

I've thought of using an electric motor to bring the wheels up to speed, then rig up a bicycle computer to count down the revolutions and/or use a stopwatch. The reason for the emotor is to get exactly the same rpms each time.