Wheel offset, how does it work?

[Munchbox 100]

I understand that a wheel with offset, usually in mm, means that the hex hub inside is set off to one side of the center.

But which side is it? In thinking about how to ask this question I realize there are many confusing ways to ask and answer. So I'll ask the simplest way I can think of; if you use a set of 6mm offset wheels will the track width be wider or narrower than with 0 offset wheels?

[Jason1145 3986]

It will be 12mm wider overall, because each wheel is now sitting out 6mm wider than the zero offset wheels.

[Kingfisher 1171]

In 1:1 car terms, +6mm would mean that the wheels stick out 6mm more towards the fenders and -6mm would mean that the wheels are 6mm closer to the chassis inside the fenders.

[Munchbox 100]

So it would be a safe assumption to make that a car that has stock 0 offset wheels will be fine with aftermarket wheels with an offset of 6mm and simply that the car will be, overall, 12mm wider?

Does this mean that all positive offset wheels should be ok on most 0 offset cars, and that anything with a negative offset could be problematic due to rubbing?

[speedy_w_beans 4272]

A few thoughts:

• A model that starts with 0 offset wheels will be fine with some positive offset wheels until the outer edge of the tire starts to rub on the body.  Certain TB03 and TA05 kits ship with +2 mm offset wheels already; sometimes you can use a +3 mm third-party wheel successfully without rubbing on the kit body shell.  I don't think I've ever seen negative offset wheels offered.
• Just to make it confusing, a positive offset for a 1:1 car wheel means the face of the wheel is more outboard; the inner lip of the rim is more inboard.  A positive offset for an RC car wheel means the face of the wheel is more inboard; the outer lip of the rim is more outboard.

There are other ways to fine tune offset as well.  You can buy third-party wheel hexes in different thicknesses, such as 4 mm all the way to 7 mm.  5 mm is the usually the default hex thickness.

There are also third-party 0.5 mm and 1 mm spacers you can install between the hex and the wheel.  So, between wheel offset, hex thickness, and spacers/washers you can get anywhere from -1 mm offset to +12 mm offset per side (I'm sure someone can find an exception such as the 9 mm hexes included on some TT01 parts sprues; I'm referring to the most common thicknesses and offsets available.).

[mastino 1085]

If you build  scaler models can be useful wheels that reduce the track width. Unfortunately also the producers contribute to confusion.

 

For example:

 - Tamiya CR01 wheels, #54116, offset +5mm, are 5mm wider than the original 0 offset wheels

 - GMade SR03 wheels , offset +2mm, are 2mm narrower than original 0mm offset wheels

Many people think that the interpretation of gmade description is more correct, but everything is very confusing

[TurnipJF 9192]

On the subject of hexes, it is also perhaps worth noting that when stating thickness, Tamiya seems to ignore the little bit that stands about 1mm proud of the inner face of the hex to engage the inner bearing race. However most aftermarket manufacturers don't ignore it.

 

Thus if you want an aftermarket hex that is a direct replacement for the so-called 5mm plastic hexes supplied with most kits, you'd probably want to order 6mm ones.

[Munchbox 100]

See this is why I asked. I thought positive offset would mean that as the wheel sits on the car the closer you push the wheel hub towards the car, the more offset it would have and the more track width you would have.

It seems like thats what you guys are saying but the graphic that mastino posted looks the other way around. To me that graphic says that positive offset means the hub is further away from the car meaning that the wheel is pulled in closer (less track width). Logically speaking it seems to me that this means the wheels and tires would be more likely to rub on some part of the chassis (c hub, spindle, etc.)

So which is it?

I know that my Blackfoot wheels have the hubs almost at the inner edge of the wheel. My Lunchbox wheels are much closer to the middle of the wheel, which is why they wont fit on the Blackfoot (they rub the Blackfoots comically large c hubs). So do the Blackfoot wheels have positive or negative offset in relation to the Lunchbox?

[Kingfisher 1171]

16 hours ago, Kingfisher said:

In 1:1 car terms, +6mm would mean that the wheels stick out 6mm more towards the fenders and -6mm would mean that the wheels are 6mm closer to the chassis inside the fenders.

I just want to correct what I said as I don't want to post false information. I may have had the wording a bit wrong here. This website explains offset on 1:1 cars better than I could.

 

http://www.wheelpros.com/page/offset-explained/9

Quote

 

ZERO OFFSET
The hub mounting surface is even with the centerline of the wheel (dashed line to left).

POSITIVE
The hub mounting surface is toward the front or “wheel side” of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.  An example of a positive offset wheel is the Polaris RZR 1000 which comes stock with a +38mm offset.  Higher offsets restrict design and leave the wheel looking flat, with little to no depth in spoke design/lip.

NEGATIVE
The hub mounting surface is toward the back or brake side of the wheel. “Deep dish” wheels are typically a negative offset and benefit the design process by allowing sharp angles, deep spokes and incredible layering.

 

 

[StrokerBoy 772]

This drove me f.batty when trying to get the right look on my Lowride Pumpkin.  I know how offset works on proper 1:1 cars, but you can't trust the RC lot to follow the same rules, sometimes they mean the opposite.

[Percymon 2184]

Anyone know if all the Tamiya M chassis wheels are zero offset ?

I know the likes of Active Hobby and Ride wheels can be purchased at different offsets, but are all the various Tamiya M chassis neutral ?