Measuring camber

[Beesza]

I’ve been incrementally modifying my Z4C leaving enough time between each to feel the changes. I’m beginning to start playing with wheel alignment.

I’m sorted for measuring toe but camber is a little bit more difficult. Does anyone have any experience using spirit level style gauges that measure off your brake discs? £10 off eBay seems reasonable but I’m concerned about the accuracy. Ideally I’d like to be able to measure to within 0.25deg.

I’ve tried the board and phone accelerometer method. That’s like pulling numbers out of thin air.

I’m tempted to make something like a post on a board which can be adjusted to be perfectly level and then take measurements from the top and bottom of the wheel rim. It’ll work but much more faff than the magnetic gauge.

 

[Spriteracer]

I use one of these. Need to make sure it picks up on the wheel rim not the tyre as the bulge will give an incorrect reading. It means you can check camber with the wheels and weight on the ground and the weights set up in the car as BMW spec. I do it with the wheels on thin, slippery magazines so the wheels can move as you adjust, and roll back and forwards between each adjust. I have a pit which helps access and speeds things up, but it would work jacking up for access then down again to measure.

 

[buzyg]

I use one of these.ada_castor-camber-gauge.jpg Need to make sure it picks up on the wheel rim not the tyre as the bulge will give an incorrect reading. It means you can check camber with the wheels and weight on the ground and the weights set up in the car as BMW spec. I do it with the wheels on thin, slippery magazines so the wheels can move as you adjust, and roll back and forwards between each adjust. I have a pit which helps access and speeds things up, but it would work jacking up for access then down again to measure.

This sort of Plumb line and Vernier gauge works great. Similar to how mine were checked and corrected.

 

[JamesClements]

What about a digital angle gauge? Something like this at the cheaper end https://www.machine-dro.co.uk/wixey-digital-angle-gauge-with-magnetic-base?gclid=Cj0KCQjw94WZBhDtARIsAKxWG-9srzX3Q9F8tUg1EsOtoAsWWTKHEED7HmQFSZOvL7Glfs3obTARCJcaAj83EALw_wcB

Good luck

 

[TheDan]

Both of those options will work as long as you make a decent jig to rest on the rim of the wheel and not the tyre as said above. Essentially all you are doing is measuring wheel rim angle relative to true vertical. Measuring the camber from the disc/hub like in the photos above is wrong and will give you an incorrect value once the wheel is reattached the the car lowered. Essentially you could make a jig similar to this:



The alignment place I used to visit always used to measure on their Hunter rig, jack the car up and make adjustments and then lower and re-measure. This was to not adjust the camber while the weight of the vehicle is pressing on the strut. But its up to you if you want to do that.

 

[Jellyfishfields]

I use one of these.ada_castor-camber-gauge.jpg

I've used an angle gauge in the past with a similar set up to the thedan, but that looks like a handy gadget.

Look to be just under the £100 mark, or can they be bought cheaper?

I think I might get one.

 

[Zikim]

One important thing to ensure, is that the floor that you are doing the measurements on is perfectly level and not on any angle. Otherwise that angle of the floor will be added to or subtracted from your camber.

 

[Spriteracer]

@ Jellyfishfields - yes about £100 from Demon Tweeks who are not always the cheapest! I bought mine 20+ years ago when I started racing. It has had new strings and new weights, but essentially nothing to go wrong. With a bit of trigonometry, you could make one.
@ JamesClements. I have one of those too, but harder to use but I'm sure it would be possible to make a frame for it as the other demon Tweeks offering here.
@Zikim. Absolutely - critical to accurate measurement. I tend to set up with bits of plywood and a water gauge to make sure they are all level.
@TheDan - that is why I use slippery magazines - you can buy slip plates but old magazines are much cheaper....
On the item in my first post I fix a length of stiff aluminium channel to the flange so it fits within the tyres on the Sprite - with 13" wheels. On the Z4 if I remember correctly the length as sold is ok with the 18" wheels.

 

[Jellyfishfields]

@ Jellyfishfields - yes about £100 from Demon Tweeks who are not always the cheapest! I bought mine 20+ years ago when I started racing. It has had new strings and new weights, but essentially nothing to go wrong. With a bit of trigonometry, you could make one.
@ JamesClements. I have one of those too, but harder to use but I'm sure it would be possible to make a frame for it as the other demon Tweeks offering here. bgr307-1.jpg
@Zikim. Absolutely - critical to accurate measurement. I tend to set up with bits of plywood and a water gauge to make sure they are all level.
@TheDan - that is why I use slippery magazines - you can buy slip plates but old magazines are much cheaper....
On the item in my first post I fix a length of stiff aluminium channel to the flange so it fits within the tyres on the Sprite - with 13" wheels. On the Z4 if I remember correctly the length as sold is ok with the 18" wheels.

Thanks for the info, much appreciated.

I was about to suggest shimming with plywood but you beat me to it

It's always worth checking as garage floors often have a slight built in slope towards the door opening, for water drainage I guess.

 

[JamesClements]

@ Jellyfishfields - yes about £100 from Demon Tweeks who are not always the cheapest! I bought mine 20+ years ago when I started racing. It has had new strings and new weights, but essentially nothing to go wrong. With a bit of trigonometry, you could make one.
@ JamesClements. I have one of those too, but harder to use but I'm sure it would be possible to make a frame for it as the other demon Tweeks offering here. bgr307-1.jpg
@Zikim. Absolutely - critical to accurate measurement. I tend to set up with bits of plywood and a water gauge to make sure they are all level.
@TheDan - that is why I use slippery magazines - you can buy slip plates but old magazines are much cheaper....
On the item in my first post I fix a length of stiff aluminium channel to the flange so it fits within the tyres on the Sprite - with 13" wheels. On the Z4 if I remember correctly the length as sold is ok with the 18" wheels.

That looks like a much better solution Spriteracer