Tech Check: Offset

Wheel Offset

Offset is the distance the hub mounting surface is away from the center of the wheel. You can see what I mean by writing 'hub mounting surface' on the photos below (greenish area). I chose this surface as a reference point because it is easiest to measure when you calculate which offset fits best to your body-chassis combination.
Please note that most manufacturers specify offset for two wheels, not one. Yokomo's 12mm offset wheels have 6mm on each side.
Negative offset means that he hub mounting surface is closer to the inside, the overall width becomes wider. This results in deep dish wheels.
If you have problems distinguishing which side is negative and which is positive it might help to think of the flat minus character "-" as the deep flat surface the negative offset creates on the outside of the wheel.

measure measure measure

Step 1: Get the middle

To get a reference or zero point we have to find the middle of the wheel. Measure how wide the wheel is and divide by 2 to get the middle. In the example below, the wheel is 26mm wide. Divided by 2 gives us 13mm. If the hub mounting surface would be 13mm from the inside or outside of the wheel, offset would be 0mm (= no offset).

measure

Step 2: Measure more

Put something straight, which does not bend (a strip of plywood here) over the backside of the wheel and measure the distance from there to the hub mounting surface. In this example it is 11.5mm. Now get the thickness of the plywood (in this case 2.5mm) and deduct it from your first measurement. 11.5mm (depth of hub mounting surface) - 2.5mm (thickness of plywood) = 9mm.
measure measure

Step 3: Get the offset

We got the middle of the wheel (13mm) and we got the depth of the hub mounting surface (9mm). Since the depth of the hub mounting surface is smaller than the middle, we have negative offset. Now just get the difference and you have your offset for one side of the chassis:
13mm - 9mm = 4mm

Offset Chart

A chart of the brands and their width and offset per side:
Brand Width Offset
Yokomo 4mm 26mm +2mm
Yokomo 8mm 26mm -2mm
Yokomo 12mm 26mm -6mm
Mikuni 3mm 26mm +1.5
Mikuni 5mm 26mm -0.5
Mikuni 7mm 26mm -2.5
Mikuni 9mm 26mm -4.5
Surging 3mm 26mm +2mm
Surging 6mm 26mm -1.5mm
Surging 8mm 26mm -3.5mm
Surging 9mm 26mm -4.5mm
Street Jam 3mm 26mm +1mm
Street Jam 6mm 26mm -2mm
Street Jam 10mm 26mm -6mm
Speedway Pal 7mm 26.5mm -1.75mm
Speedway Pal 10mm 26.5mm -4.75mm
RC Art 6mm 26.5mm +0.25mm
RC Art 8mm 26.5mm -3.25mm
Kazama 8mm 26mm -2.5mm
Kazama 10mm 26mm -4.5mm
Top Line 5mm 26mm +1mm
Top Line 7mm 26mm -1mm
Top Line 9mm 26mm -3mm
Top Line 12mm 26mm -6mm
HPI 3mm 26mm +3mm
HPI 6mm 26mm -1mm
HPI 9mm 26mm -3.5mm
HPI LP29 3mm 29mm +3.5mm*
HPI LP32 6mm 32mm +1.5mm**
HPI LP35 9mm 35mm +0.5mm***
* final width is same like a 26mm wheel with +2mm offset
** final width is same like a 26mm wheel with -1.5mm offset
*** final width is same like a 26mm wheel with -4mm offset

Please note, that we can not guarantee that this data is 100% correctly.
Please let us know if you find an error.

/trHPI LP32 6mmneg
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