can you measure a wheel offset with the tyres still on?

i got a set of wheels fitted with tyres and wanna know the et as they not what i thought

 

surely its stamped on the rim somewhere what the et is,fwd or rwd or foreign jobbys etc etc

 

it can be done but you need to get a flat bar across the back of the rim and make it level to the rim edge.then measure the distance down to the hub. after that really you need a conversion chart.

if you do these and tell me the diameter and wheel width i can ring someone on monday for you to find out

 

they aint stamped otherwise that would save me messing about with a tape measure and flat edge

 

dont you take the measure from where the tyre bead sits? inner rim

instead of outer lip

i know you measure the backspace and take off from wheel centre, just unsure where the wheel is measured from

 

first measure rim width

then back space the difference between the two is your et

 

is rim width measured from the outer lip tho?

or


from where the tyre bead would sit?

 

I would imagine the outer lips, usually always full or half inches 8", 8.5" 9" etc so wotever the measure is nearest.

 

the way i described is the way i had to do it for a customer of mine to find out what offset his racelines were on his jwrc kitted fiesta.mu suppliers converted it for me from the info i gave them

 

i dont know the wheel width tho

this is what im getting at

i know how to measure the offset (sort of) but need to know where / how to measure the wheel width first, with the tyre on

 

FFSake------DEAR 'O' DEAR-------JUST IMAGINE NO TYRE ON THE WHEEL!!!,the tyre got f-all to do with it-----
STRAIGHT EDGE ACROSS THE RIM AND MEASURE DOWN TO THE FLAT AREA BINGO!!.

 

who you shouting at!!!!!!!!!!!!!!!!!!!!!!!!


measuring from flat edge to hub will only give me the back space

i need to know if the tyre is measured from inner or outer rim lip so i can work out the wheel centre

 

It doesnt actually matter where the wheel width is taken from. Measure the complete width of the wheel. I usually find the actuall overall width is half an inch more either side than its official width so a 7 inch wheel would measure 8 inches. I use two sliding squares with the ruler part clamped together in the middle. This should get you the full width of the wheel. Now work out half this amount. Bare in mind wheel widths are usually measure in J ie inches. You need it in mm. Using your sliding squares again mark off this half way point. Now measure from the back face of the centre of the wheel to this middlepoint you have marked. This is your offset in mm.

 

cheers for that my man

yep got that

 

The lower the offset, the more pussy you get.