how to measure et (offset) on a wheel?? ideas?

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jimGTS
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how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

from where to where on the back off an alloy??
Mark Edwards
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Mark Edwards »

From the back of the mounting area to the centre of the rim.
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xxxx, AM TUNING, sbITs
DaMonsta

Re: how to measure et (offset) on a wheel?? ideas?

Post by DaMonsta »

Hi:

Wheel offset is measured from the centre of the wheel rim to the wheel mounting flange. Offset can be either positive or negative depending whether the face of the wheel mounting-flange is to the outside (positive) or to the inside of the wheel (negative). For example, an offset of zero would mean the face of the wheel mounting-flange would be aligned with the exact centre of the wheel rim.

Have read here:

http://www.yokohamatire.com/utcustom.asp

Regards,
Jim
Stef Derner
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Stef Derner »

If you want to measure the offset on an existing alloy wheel, you need to put a straightedge across the rim, inside and outside and measure the distance between them, then half it, giving the distance to the centre line of the rim. Then measure the distance from the inside straightedge to the mounting face. The difference between the centreline distance and the rim edge to mount flange distance is the offset.
jimGTS
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Re: how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

i understand how offset works, but unless i chop the wheel in half im not going to be able to actually measure the offset.

i thought markings on the back of the wheel might indicate the offset.

if i post some pics up of the rear faces, i asume this would help.
???
Adam_B

Re: how to measure et (offset) on a wheel?? ideas?

Post by Adam_B »

offset is usually printed or stamped on the back of the rim yes
Andy Jones
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Andy Jones »

Adam_B wrote:offset is usually printed or stamped on the back of the rim yes


Seconded - The majority of manufactures do stamp the offset on the rear of the wheel somewhere - Scrub off all the brake dust etc and have a nosey - will be 2 digits (may have "et" stamped before the 2 numbers)
Engine rebuilt by: Steve Horrocks & Andy Jones
Engine mapped by: Ryan@2bartuning (330 bhp & 325 lbft @ 1.4 bar)
Current Status: F****D :(
Andy Jones
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Andy Jones »



Looks like et45 - The first pic in your list right at the top in the middle - e45 in a circle
Engine rebuilt by: Steve Horrocks & Andy Jones
Engine mapped by: Ryan@2bartuning (330 bhp & 325 lbft @ 1.4 bar)
Current Status: F****D :(
jimGTS
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Re: how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

Andy Jones wrote:


Looks like et45 - The first pic in your list right at the top in the middle - e45 in a circle



these wheels are "MENT" to be both et 35.

i thought e45 on that pic would mean et45 as well.
thats why i asked if there was a way i could measure them.

to be quite honest, i am TOTALLY peed off with rota that send me these wheels.
not only did they arrive 4 days late, i was ment to get wheel locking nuts, ment to be fitment for a mr2 (they gave me 64.1 spiggot rings, mk2s need 60.1), and they also gave me the wrong center caps.

ive sorted the other bits out, but if i find out these arnt both et35s, im gona hit the roof!
:twisted:

could the e45 just be a coincidence, and not mean et at all.
find it strange thats not stamped on the other wheel.

need to send these pics to rota.
Andy Jones
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Andy Jones »

Sorry to hear that Jim, Could be a coincidence and mean nothing but if theres no other number on the wheel i would go off that - 100+/Team Dynamics use the same style stamp for offset (circle with line through middle and e number)

Unfortunately it does happen, We get sent wheels boxed wrong on a weekly basis which is very frustrating (PCD or offset not what it says on the box) in the time i've been in the trade incorrectly stamped offset on the wheel is very rare but does occur :(

I'd e-mail your photos to Rota to see what they say.

Not that at helps you much but i prefer et35 and run this on mine as they sit closer to the arch.
Engine rebuilt by: Steve Horrocks & Andy Jones
Engine mapped by: Ryan@2bartuning (330 bhp & 325 lbft @ 1.4 bar)
Current Status: F****D :(
jimGTS
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Re: how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

Andy Jones wrote:
Not that at helps you much but i prefer et35 and run this on mine as they sit closer to the arch.


thats why i ordered et35s all round :wink:

ive spoke to the comapny quite a bit through phone and email, so i shouldnt see it as a problem for them to help me out.
just that soon as they got my money, they didnt seem interested.
gona get onto them monday, see what they say.
disappointed, cause i was hoping to get these on today.
guess i may have to wait another week.

:cry:
ANT
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Re: how to measure et (offset) on a wheel?? ideas?

Post by ANT »

did u get the wolfrace octanes in the end?? :?:
jimGTS
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Re: how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

ANT wrote:did u get the wolfrace octanes in the end?? :?:



hell know mate!
:mrgreen:

these new wheels are 7.5j fronts, 8.5j rears. lightweight jobbies!
octanes are only 7j all round and probably weigh a ton.
now ive had 2 weeks on stock wheels, they scare me to death so its defo a great idea to get wider and bigger rims than this at least (but this is coming off the back of 16inch volks :-)).
the octanes wouldnt off been a good choice in the end. (for me anyway, not dissing anyone that has them).

all will be revealed when i have them on.
:mrgreen:
Andy Jones
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Andy Jones »

jimGTS wrote:
Andy Jones wrote:
Not that at helps you much but i prefer et35 and run this on mine as they sit closer to the arch.


thats why i ordered et35s all round :wink:


8) In the words of RedMR2 "I am a tool" :lol: Got confused somewhere along replying didn't i :)

Hope you get it sorted, I'm waiting to see the end results to :D
Engine rebuilt by: Steve Horrocks & Andy Jones
Engine mapped by: Ryan@2bartuning (330 bhp & 325 lbft @ 1.4 bar)
Current Status: F****D :(
jimGTS
Posts: 14024
Joined: Tue Dec 14, 2004 1:40 pm
Location: North Kent

Re: how to measure et (offset) on a wheel?? ideas?

Post by jimGTS »

Andy Jones wrote:
jimGTS wrote:
Andy Jones wrote:
Not that at helps you much but i prefer et35 and run this on mine as they sit closer to the arch.


thats why i ordered et35s all round :wink:


8) In the words of RedMR2 "I am a tool" :lol: Got confused somewhere along replying didn't i :)

Hope you get it sorted, I'm waiting to see the end results to :D



so do i mate, cause i was screaming like a little girl this morning when i got them!! look awsome!
however, due to the situation, they cant go on.
:cry: #-o
Stef Derner
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Re: how to measure et (offset) on a wheel?? ideas?

Post by Stef Derner »

Like I said earlier Jim, with a couple of bits of wood and a tape you can measure the offset. Get two straight bits of wood or metal that will reach across the rim. Apply one piece each side and measure through the hub centre hole. This will give you the rim width. Half of this distance is the rim edge to centreline. Measure from the wood across the rear face of the rim to the mount face and the difference between this figure and the rim edge to centreline will give you the offset, ET or Eins Tiefe (German for 'in depth').

The offset for a 7 inch rim, wont be the same as for an 8 inch rim as the distance from face to centreline of the rim will be 1/2 inch bigger on an 8 inch rim. On the rears this will affect how far the rim sticks out, but if you get the offset wrong at the front it can affect the steering geometry, as the wheel offset defines the offset from the centreline of the tyre's contact patch to the point where a line drawn through the steering axis hits the road.

If the contact patch centreline isn't pretty much in line fore and aft with the steering axis, then a bump/ridge or overbanding will make the car tramline/twitchy as more leverage goes into the steering on the side where the bump is.
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