ALIGN THOSE AXLES - Derby Tech - February, 1986


(Reprint from Jerry Bryan's Jan 76 Derby News)

Align those axles --- is it really necessary??? Does it help??? How much faster will it make it go??? These plus many other questions must be asked by everyone at some time or another. DERBY NEWS has always felt that a well aligned and well balanced car is necessary to win races. Ok, now how do we do it???

Well, first we have to explore the many different ways that we have seen axles aligned. We will also discuss some ways that we have heard of but never seen. Let's start off by saying when you get a set of axles you should treat them like glass. They should always be stored "upright" , never "laid down" and not on a flat surface - "they will warp".

If you've got someone who will do it for you it's nice to know and have checked to see if the axle journals are parallel. This will have to be done by a machine shop. In this article we are not going to discuss how the axles are attached to the car, or suspension, etc. So let's say the car is done and axles installed .... it's time to race.

The type alignment bar we are going to discuss is used by more racers than anything else used; its accurate, portable and cheap. Some call it a "wish bone" Here's a picture of a sketch of a alignment bar. Also an actual racer being aligned.

 

You will note that the driver must be in the car why? Well, we want the weight on the axles. We want to check camber under racing conditions. Camber is the angle or degree the axle is off center. Maybe this sketch will help.

Ok, now how should we bend our axles up, down or straight? Most all derby "pros" feel it should be "straight ahead". The stock derby axle is made of a soft steel it's not known to hold alignment even when it's "handled good". So you can see when it's going down a hill with 250 lbs. spread over two axles, it's going to bend. So some people bend their axles down .005 to .01 0 to allow for this. (maybe more if the track is rough)

Last year for the first time, Akron allowed the champs to realign axles after their "test run" on Thursday. Some champs took advantage and at least checked them, some didn't, some had fancy guages, some crude. Our experience has found that the axles WITHOUT the radius will lose about .001 on each run on an average track. On a rough track you could lose .004 - .005 per run if you figure it takes about 4 to 7 runs to be "champ" in a local rally or All-American. The next step is to set the axles on what you feel you will run. If for example the number of entries will mean it will take 5 runs to be champ .... bend them down .005. One problem is if you draw a tough competitor the first time and he set his at .000 , your down .005 you might get beaten. Look at it this way, if he was a tough competitor, chances are he like you was also down .005. It's those "sleeper cars" that some time upset the "hot ones".

So far all we have talked about is camber (up and down). Now lets talk about toe in and toe out. This is the angle the axle is "bent in or out" when looking down at the axle. Here again lets look at our drawing.

Some old derby "Pros" feel that as a Derby Car reaches the bottom of the hill, with a speed of around 30 MPH, that the wheels tend to "toe out". So they "toe them in". . centrifugal force will straighten them out. Our experience has found that a straight ahead position to start with should be used. :

Some people allow the driver to get out of the car when they check toe in. Since there is no weight to compensate for on toe in ... we don't do it this way because we still like to check camber "one more time".

This about concludes our alignment article. We wish there was a secret we could pass on to you on alignment. One of the other means of alignment is thru a series of mirrors. It's a complicated arrangement plus it's NOT PORTABLE, in other words, when you go to the rallies, etc. you can't take it with you. I understand that one, maybe two champs at Akron in '75 used this system.

Good luck to you. Maybe we'll see you in Akron in '76.


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