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Locost owner confused about wheel offsets.
J222jra - 16/4/14 at 07:25 PM

Not sure if anyone can help me or not....I'm a little puzzled regarding wheel offsets.

Currently no original locost 7 (not Haynes roadster) has 13" Ford 4 spokes fitted that are 6j wide. I. Believe they have an offset of 19

I'm looking at fitting new wheels, ideally it want them a little wider so was looking at 7j. How do i know what offset I need though?

Thanks in advance.

James

twybrow - 16/4/14 at 07:33 PM

If you want it to give you a wider track, then you could go for a higher offset and keep the same width wheel. If you want a wider wheel, then if you keep the same offset, the inside of the wheel will start at the same point, and the outside edge will be further outside!

CRAIGR - 16/4/14 at 07:38 PM

This is a useful tool

http://www.1010tires.com/Tools/Wheel-Offset-Calculator

loggyboy - 16/4/14 at 07:41 PM

quote:
Originally posted by twybrow
If you want it to give you a wider track, then you could go for a higher offset and keep the same width wheel. If you want a wider wheel, then if you keep the same offset, the inside of the wheel will start at the same point, and the outside edge will be further outside!


Not true, if you keep the offset the same, half the additional width will end up on inside and half to the outside as offset is measured from the centre line of tge rim.

J222jra - 16/4/14 at 08:02 PM

What I need is for the back spacing to be the same as the current rim so it sits no closer to the chassis just sits further out in the arch.

Matt21 - 16/4/14 at 08:08 PM

in that case, if you want 7j rims, you need an offset of 0.5inchs (12mm) less than you currently have

so et7 will give you the same inside clearance

loggyboy - 16/4/14 at 08:57 PM

quote:
Originally posted by Matt21
in that case, if you want 7j rims, you need an offset of 0.5inchs (12mm) less than you currently have

so et7 will give you the same inside clearance


Exactly that, or retain a similar offset and add a spacer.

daniel mason - 16/4/14 at 08:57 PM

and a higher offset number will pull the wheel further inwards,narrowing the track. basically an offset of 0 puts the inside edge of the mounting face of the wheel in the middle of the wheel. +19 moves it 19mm towards the outer edge away from center bringing the wheel 19mm inwards -19 would move the mounting face 19mm inwards making it 19mm wider

chrism - 16/4/14 at 09:26 PM

quote:
Originally posted by twybrow
If you want it to give you a wider track, then you could go for a higher offset and keep the same width wheel. If you want a wider wheel, then if you keep the same offset, the inside of the wheel will start at the same point, and the outside edge will be further outside!


Not quite right there a higher offset will bring the wheels closer together reducing the track width, a smaller offset (And negative) will push the wheels further out.

And if you use wider wheels with the same offset then the outside edge of the 2 wheels will be further apart by the difference in width of wheels fitted, i.e. the center of the wheel would be in the same space so half of the extra width of wheel on each side of the car.

twybrow - 16/4/14 at 09:37 PM

quote:
Originally posted by chrism
quote:
Originally posted by twybrow
If you want it to give you a wider track, then you could go for a higher offset and keep the same width wheel. If you want a wider wheel, then if you keep the same offset, the inside of the wheel will start at the same point, and the outside edge will be further outside!


Not quite right there a higher offset will bring the wheels closer together reducing the track width, a smaller offset (And negative) will push the wheels further out.

And if you use wider wheels with the same offset then the outside edge of the 2 wheels will be further apart by the difference in width of wheels fitted, i.e. the center of the wheel would be in the same space so half of the extra width of wheel on each side of the car.


I stand corrected. Thanks for the explanation chaps.

Loco - 21/5/14 at 12:36 PM

So if my existing 6 x 13 capri laser alloys have an offset of 19, and I wanted to fit 7 x 13 alloys but didn't want the inside edge of the wheel any closer to the vehicle, what offset would the new wheels need to be?!!

loggyboy - 21/5/14 at 12:58 PM

Convert to metric - 1" inch difference = 25mm
so keeping offset the same will add 12.5mm to each side.
so to keep the outside position (ie smae disdtance from arch) the same you will need to add that 12.5 to the offset - so around 31or 32mm offset.

If you wanted to keep it the same on the inside (ie to avoid suspension/wishbones/chassis etc would would take the 12.5 from 19 = so about 6or7mm offset