Wheel spacers. Does wider mean better?

  • Author: OPONEO.CO.UK

When taking a closer look at tuned sports cars, we can often notice that many vehicles seem to utilise a wheelbase that is wider than the factory-produced model. This is achieved by the use of spacers, helping to push out the wheel and car tyre. Here, we will look at the various benefits and changes that come with the use of wheel spacers.

As a result, this changes the car’s profile and proportions. Many feel such a change makes a vehicle appear much more compact and aggressive. From an aesthetic point of view, certainly, the use of spacers ensures a car stands out from its peers.

From a driving perspective, an extended wheelspace also improves the car’s handling. In other cases, you may also find that spacers are a necessity. For instance, when you need to install larger brakes, spacers are used to generate this extra room. They can also be useful when the offset of a selected wheel is too high or deep.

In these cases, the spacers help provide a safe distance between the braking system, specifically the calipers and discs, and the suspension system.

wheelbase-comparison-standard-and-spacers

An example of how a vehicle can look with the addition of wheel spacers.

How to check the maxium spacer width?

The easiest and most effective method is to measure the distance between the edge of the wheel arch and the tyre. This provides us with the maximum safe distance between the car tyre and the hub, thus giving us the maximum size of the spacer.

However, you should also consider leaving some gap between the tyre and the car’s bodywork. As a result of this, spacers with the exact same width as the distance measured - using the formula above - should not be used. Because of this, you should always consider the tyre width and size of the models you are using. 

 

maximum-spacer-width-measurement

How To Calculate The Maximum Spacer Width Available.

Tips  for spacer installation

The spacer diameter must be adjusted to the diameter of the hub, as the hub sidewall and the side of the spacer must form a coherent whole that is flush and smooth. Consequently, the formation of visible indentations in this area, resulting from a difference in diameters, is unacceptable.

Similarly, the bolts of the spacers screwed into the hub must not protrude above the surface of the rim. When screwing longer bolts into the hub, make sure that there is no risk of damaging the elements already inside the hub, such as the ABS sensors.
 
Ultimately, the spacer must be fitted loosely to the hub and no significant levels of resistance should be evident.

spacer-mounting-tips

Once installed, the spacer diameter must be flush with the diameter of the existing hub.

  What kind of  bolts should be used for installing spacers?

When installing spacers, you must ensure that the bolts are correctly screwed to the hub, thus fitting the wheel on the spot. Many experts claim that this condition is only met if at least 10 to 12 mm of the screw thread is screwed into the hub socket. If the bolt is not screwed in this way, there will be a risk of thread failure.

The recommended screwing depth, as well as the number of turns for a range of screws with different thread pitches, is present below. Please remember that the number of turns also applies to any nuts used.

  • M12x1.25 = at least 8 turns = approx. 10 mm of thread
  • M12x1.50 = at least 6.5 turns = approx. 10 mm of thread
  • M12x1.75 = at least 6.5 turns = approx. 12 mm of thread
  • M12x1.25 = at least 9 turns = approx. 12 mm of thread
  • M14x1.50 = at least 7.5 turns = approx. 11 mm of thread

According to various automotive experts, the selected bolt length for pass-through spacers should be longer, by 50% of the spacer’s width, than standard variants.

selection-of-proper-bolt-length

New bolts need to be longer than your existing ones.

How to choose the right spacer type

When considering the wide range of spaces currently available, they can be installed in virtually any car, as long as the individual needs of the vehicle owner are taking into account.
 
The car width, for instance, can be increased from 5 to 90 mm on each side. For such a wide selection of sizes, various solutions can be applied.
 
Here, we will go through the various types of spacer constructions, which may help you in making the correct decision when looking for a solution appropriate to your given car.

Type 1 - Pass-through spacers without a centring collar.

Known as “pass-through spacers”, these options do not have a centring collar. Due to their low thickness, the rim is centred on the centring collar of the hub. Such spacers should be fitted with the use of bolts which a longer than the standard options.

spacer-without-centring-collar

An example of installing pass-through spacers without a centring collar

Type 2 - Pass-through spacers with the centring collar.

If you decide to extend the car’s wheelbase by 6 mm or more, a spacer with a centring collar should be used. This is necessary because the hubs’ centring collar gets covered by the spacer itself.
 
It is essential to use adequately longer bolts during this installation. In terms of length , these bolts should have an additional amount equal to 50% of the spacer width. Do not use standard bolts, as these will not be long enough!

spacer-with-centring-collar

An example of installing pass-through spacers with a centring collar.

Type 3 - Spacers fastened to the hub.

Spacers fastened to the hub offer more opportunities for wheelbase extension. This product is supplied with the bolts needed to mount the spacer to the hub, rather than relying on the standard bolts.
 
Apart from the bolt sockets, the spacer has threaded holes which are used to mount the wheel - this time using the standard bolts.

spacer-fastened-to-the-hub-with-wheel-sockets

An example of installing typical spacers fastened to the hub.

There is also an alternate, more developed version of this spacer type. In this variant, the threaded holes (normally used for bolts) are replaced with pins which the car wheel is then mounted on. Such solutions can be used to extend the wheelbase by up to 90 mm.

spacer-fastened-to-the-hub-with-pins

An example of installing alternative spacers fastened to the hub.

PCD changing spacers.

You should also be aware of a specific type of spacer known as PCD changing spacers. Due to the ability to change the spacing of the bolts, these spacers are used on wheels with a non-standard pitch circle.
 
The installation and design, however, does not differ much from the construction of a normal hub-fastened spacer, as already discussed in this article.

What are spacers made of?

The most typical materials used for the construction of spacers are aluminium alloys, similar to that used in car rims, alloy wheels and hubcaps, as well as magnesium alloys.
 
Additionally, the surface of a spacer is also hardened via anodisation. This is a surface treatment for metals, involving electrolytic production of a thin oxide film, significantly increasing the hardness and scratch resistance of the material. The use of light allows also reduces the weight by up to 70%, when compared to traditional steel counterparts.

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