How to measure your camber at home
In this guide I will show you how to get a pretty good measurement of your vehicles' camber, without having any special tools.
Keep in mind that you should probably still go to an alignment shop, but if you want to just get close, this guide will help. You should be on a level surface when you do this, otherwise it throws off the calculations.
This method does not replace that of a professional alignment!
Tools you'll need:
- Level
- Caliper (digital is best)
- Tape measure
- Flat edge
- Calculator
Step 1) Measure the wheel diameter. This is different than the wheel size that we typically refer to. For me, the 18" Forgestar wheels have a 19.5" diameter from top of lip to bottom of lip. I converted this measurement to millimeters with mm = (inch * 25.4)
Step 2) Place the bottom of the level against the base of the tire or wheel. The level's bubble being centered is important for measuring the proper angle.
For the most accurate measurement, cut a piece of wood to exactly the diameter of the wheel (19.5" in my case). Tape it to the flat side of the level, estimate how much space to leave at the bottom of the level for your tire sidewall. The newly cut piece should only touch the wheel, and not the tire edge. Allowing you to measure directly from the bottom lip to top lip of the wheel.
Keep in mind you may add a few mm or so if you're not going to use a straight edge to line up to the wheel exactly. Notice how my tire sticks out further than the wheel lip edge.
Step 3) Use the caliper, and measure the distance between the wheel/tire, and the level. Make sure that the little bubble in the level is exactly in the middle.
Typically, the tire sidewall will bugle out more than the wheel, unless you're stretching tire. This is an important idea to undertand when measuring. Remember: measuring from the tire edge and not the wheel lip will throw off your diameter measurement from step 1! Re-calucluate this as needed. I repeated step 1 with an extra 4mm of tire in the diameter, then I measured the mm gap between the level and tire.
Step 4) Use both measurements, and plug them into this formula:
arctan(mm between wheel and level / mm diameter of wheel)
That number is your degrees in camber. Keep in mind this will most likely be negative camber.
Example: tan^-1(12.21/499) = 1.40 where 12.21mm = distance from tire to level, 499mm = 19.5" wheel + 4mm of tire, 1.40 = angle of tire/wheel. I know my alignment is negative camber, if you want you can just put a negative in front of the tan^-1 if you want to.
For those with BC Coil overs or similar camber adjustment plates
A few extra pointers here for those with adjustable camber plates. Using the above method, is how I was able to measure my camber and adjust the top plates before I brought it in for a proper alignment. I wanted to get the camber as close as I could, because I knew the shop wasnt going to adjust the front camber for me.
This is particularly time consuming for the Volvo P1's because the strut hole is not large enough to change the camber while its on the vehicle. Without using a hole saw and cutting open the strut hole larger (comprimising the structural integrity), the strut has to be completely removed in order to set the camber.
This is why I wanted to write this up, because most alignment shops won't do this for you, or will charge you alot of money for their time.
Here's the top of the BC coil over camber plate. You can see that there are 4 hex key bolts that can be moved around to allow for the full -3* to +3* camber adjustment. I had to move two of them to the middle to get the adjustment I needed.
For the BC coil over plates on the Volvo P1's, each line represents 1/3* of camber adjustment. You want to line up the dimple on the black plastic surface with the painted lines. You may have to move the bolts around to get more adjustment.
Be sure to measure your camber before you take the strut off, so you know how much to adjust. Mine was measured at -2.7* while the dimple on the plates were set at 0!
