Originally Posted by Tony H
Do spacers not increase the loads and wear on wheel bearings and struts (OK, maybe immaterially)? I suspect they must also have the opposite effect of fitting mud flaps! Just some other things that would concern me.
Fitting a spacer has the exact same effect on wheel bearings as just fitting lower offset wheels. There are a few things to consider, but essentially you would be hard pressed to tell the difference in life of them - the differences in loads are pretty small. Also who's to say standard offset is best on load for the bearings, lower offsets may be the centre of effort/load more in line with the bearings, reducing the length of lever - it varies by car.
But yes, for sure low offset wheels / spacers do not help with keeping the sides of the car clean!
With regards the safety of spacers, there are a few things to consider IMO.
First off make sure you get some which are a known brand, from a company that knows their stuff, so can advise you. If you get it from a bedroom trader on Ebay they may well sell the cheapest untested rubbish they can get their hands on - which actually can be a cause for concern where costs are cut on materials for example.
Next make sure when fitting them you have enough threads left when doing up the nuts. The most spacing usually on standard studs it around 5mm - you need at least 10 full turns when doing them up.
With any spacers you fit try and make sure they are hub-centric. With slip on spacers it's sometimes hard to find a spacer which matches the hub size of the vehicle - but this is preferable if you can find it to save them slopping about when fitting the wheels. Once done up of course they wont move. Bolt on spacers will tend to be more common in hub-centric form, and will also have an external spigot to seat the wheel - but it's always worth checking when ordering that this is the same as the vehicle - if you have OEM wheels they won't fit if that external spigot is larger!
When fitting bolt on spacers also make sure they sit flat on your hub - if they are 15mm or less sometimes the hub of the car can hold the spacer off the hub, as it bottoms out on the back of the spacer, and this will possibly or even probably lead to a failure in an exciting way. They should come with instructions outlining this - but it's something to think about for sure. Usually 20mm and larger this isn't as much of a problem, but does vary by car... a Nissan Juke for example has a hub height of around 30mm, so there's not way a spacer of less than that can sit flat on the disc - so a spacer would be needed with no spigot as the wheel can still locate on the car hub with a large spacer.
I hope that is some help - it's quite involved all things considered, but does change the look and stance of a car with a minimum of effort and no doom when done right
Edited by: Rarerims