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A guide to fitting aftermarket wheels

4K views 0 replies 1 participant last post by  AZZA 
#1 ·
Just been searching around due to my recent rim problems, I found this guide, i hope it can be as much use to people who dont understand the fittings of aftermarket wheels as it was to me. Maybe some of you guys could make it a sticky:)

When equipping your car with aftermarket wheels, there are many things to look at:

Wheel Diameter:
This is the size of the wheel, such as 18". Bigger wheels are usually heavier and thus will make your car slower. If you get a bigger wheel than stock, you must get lower profile tires. More on that later.

Wheel Width:
This is the width of the rim, such as 7.5" or 8", as if you were looking at it from the back of the car. Wider wheels require wider tires and various offset adjustments. More on this later.

Bolt Pattern:
The bolt pattern of the wheel is key in determining whether or not it will fit on your car. Toyotas have a bolt pattern of 5x114.3 which means there are five lugs with spacings of 114.3mm. Some cars have 5x100, others have 4x100, etc. The point is, you have to get a wheel that matches the bolt pattern on our cars, which is 5x114.3 (sometimes listed as just 5x114). If the bolt patterns do not match, the wheel will NOT go on your car. I have seem some bolt pattern adapters, but I don't know how safe or strong they are.

Hub Size:
The hub size is basically the diameter of your hub in mm. Solaras have a hub size of 60.1mm. This is important when choosing spacers or hub centric rings. More on that later.

Center Bore or Hub Bore (on wheel):
Every wheel in the back has something called the hub bore or center bore. This is the space in the back of the wheel where you hub inserts. It is where your wheel 'sits' on your hub. Therefore, as you can imagine, it is important that the size of the hub bore on the wheel and the size of the hub on your car match up, else your wheel will wobble. f the hub bore on the wheel is too small, you are generally SOL unless you want to pay a lot of money to get the wheels bored out larger, but I don't know how safe this is. But if the hub bore on the wheel is too big, then there is an option: hub centric rings. More on this later.

Offset:
The next thing to look at after the size, is the offset. The offset determines how far off the hub the wheel sits on your car. A lower offset means the wheel sits further away from the hub, causing it to stick outwards more from the body. A higher offset moves the wheel in towards the body more. Offset is measured in mm, and you may think a few mm here and there don't matter but they do. Move the wheel too far out and you'll rub the fender, too far in will rub the strut. As far as an lowered Gen1-1.5 Solara goes:

-18x7.5 - 45 offset
-18x8 width - 42 offset

The offset can be lowered more, to around 35mm, for a more agressive look, however you will have to get your fenders rolled so the wheels don't rub. Also keep in mind, each wheel and tire is slightly different, so your offset may vary but not by more than 1-2mm. In general it is better to have a offset too low (rub the fender, which can then be rolled), than a offset that is too high causing the wheel to rub the strut.

Spacers:
Oftentimes, when you buy a wheel, they dont have the correct offset. If the offset is too low, lets say around 35, then I think the only option you have is to roll your fenders. However, if the offset is too high , spacers can be used to bring the wheel out further from the hub, i.e. decrease the offset. Spacers usually come in increments of mm, but sometimes inches. So if you have a 50mm offset wheel, and you employ a 8mm spacer, you will decrease your offset to 42mm, thus enabling you to use a wheel that would otherwise rub your strut. It is important however, when buying a spacer, to buy a spacer that fits the hub of your wheel. Genreally, if the spacer is made for Toyotas it will be fine. Otherwise, try and look for the diameter and get one that matches the Toyota hub diameter of 60.1mm

Hub Centric Rings:
The job of a hub centric ring is to close the gap between your wheel and your hub. For example, madza wheels have a center bore of 67mm (which is the hub size on most mazdas). Toyotas, as stated earlier, have a hub size of only 60.1. That means, when you sit a mazda wheel on toyota, there will be a 6.9mm gap between the wheel and the hub on your car. So what you do is get a hub centric ring that has an inner diameter equal to the size of your car (60.1mm) and an outer diameter equal to the size of the hub bore on the wheel (67mm in this case). This will close the open gap between the wheel and the hub, thus eliminating an wobble at high speeds.

Tire Sizes:
There are three important measurements on the size of a tire, the width of the tire, the height of the sidewall, and the diameter of the wheel. For example, the most common size here is 225/40/18 for 18 inch wheels. This means the width of the tire is 225mm, the height of the sidewall is 40mm, and the diameter of the wheel opening is 18". If you increase the width, lets say to 235mm, you will have to run a different offset to prevent rubbing. If you increase the height of the sidewall, you will get more cushioning, but you might rub your fenders. If you decrease, you may get a more jarring ride. The last number can't really be played with, it has to match the size of your wheel.
 
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