Offset of 'new' T25 alloys
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- 156silver
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Offset of 'new' T25 alloys
Good Afternoon,
I've been looking at all of the 'new' 14/15" T25 alloy wheels on offer from EMPI, JBW, FLAT4, SSP, etc and they all seem to have an offset of 20 or 23.
Having been doing the necessary reading on the subject I understand that the standard Et was 30 or 39 depending on fitment of alloys or steels.
So I don't understand why all of these new wheels have such a low offset, as I understand it this means the wheels will stick out further than the standard steels and the offset issue can't be rectified with spacers.
Am I missing something here, why would all of the manufacturers make them with an unsuitable offset and why are they being sold?
Thank you
Brendan
I've been looking at all of the 'new' 14/15" T25 alloy wheels on offer from EMPI, JBW, FLAT4, SSP, etc and they all seem to have an offset of 20 or 23.
Having been doing the necessary reading on the subject I understand that the standard Et was 30 or 39 depending on fitment of alloys or steels.
So I don't understand why all of these new wheels have such a low offset, as I understand it this means the wheels will stick out further than the standard steels and the offset issue can't be rectified with spacers.
Am I missing something here, why would all of the manufacturers make them with an unsuitable offset and why are they being sold?
Thank you
Brendan
- Titus A Duxass
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Re: Offset of 'new' T25 alloys
Project Zwo and Oettinger went out to 22 mm.
I think mine are below 30 mm.
I think mine are below 30 mm.
VW T3 GTi Camper 2,0l
- Titus A Duxass
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Re: Offset of 'new' T25 alloys
Just checked - mine are at 27mm
Oettinger went down/out to 23mm.
Oettinger went down/out to 23mm.
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- marlinowner
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Re: Offset of 'new' T25 alloys
The original VW alloys eg Carat are 6 inch rims, a lot of the aftermarket ones are 5.5 inch. This means that if both have offset of 30mm then the outer rim of the aftermarket wheels would be 6.5mm further in than that of the originals. So with an offset of 20mm they will be just 3.5mm further out. With an offset of 23mm they will be virtually identical to original in relation to the wheelarch.
To add - the VW original Atiwe pepperpot alloys on mine are ET30.
To add - the VW original Atiwe pepperpot alloys on mine are ET30.
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Re: Offset of 'new' T25 alloys
http://www.brick-yard.co.uk/VehicleSpec ... ltwhls.htm" onclick="window.open(this.href);return false;
- 156silver
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Re: Offset of 'new' T25 alloys
@silverbullet
It was the comment from the Brickwerks link that prompted my post:
"Wheels with a ET of less than 30 tend to stick out more and give the vehicle a feeling of not wanting to do much more than going in a straight line, wheel bearing load will be increased, steering will be heavy and the tyres will wear more on the inside edge and in my eyes are to be avoided."
The posts above clarify the ET is connected with wheel width and makes some sense of why the Et20 and Et23 are on the market.
Thank you all for your input.
Brendan
It was the comment from the Brickwerks link that prompted my post:
"Wheels with a ET of less than 30 tend to stick out more and give the vehicle a feeling of not wanting to do much more than going in a straight line, wheel bearing load will be increased, steering will be heavy and the tyres will wear more on the inside edge and in my eyes are to be avoided."
The posts above clarify the ET is connected with wheel width and makes some sense of why the Et20 and Et23 are on the market.
Thank you all for your input.
Brendan
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Re: Offset of 'new' T25 alloys
I have some period ARC 7" x 15" Penta style alloys, ET 21 iirc. I believe that they were a dealer option for T3's, along with the almost identical Ronals.
The reason for the diminishing ET with wider rims is because there is a balance to be struck between:
1. putting equal amounts of the wider rim both inboard and outboard (so the ET will reduce by half of the increase in rim width regardless)
2. Getting sufficient clearance for the tyre and/or rim from the top wishbone, which can require a reduced ET.
Regarding recent aftermarket wheels, they all seem to be T2 wheels and not optimized for T3...
The reason for the diminishing ET with wider rims is because there is a balance to be struck between:
1. putting equal amounts of the wider rim both inboard and outboard (so the ET will reduce by half of the increase in rim width regardless)
2. Getting sufficient clearance for the tyre and/or rim from the top wishbone, which can require a reduced ET.
Regarding recent aftermarket wheels, they all seem to be T2 wheels and not optimized for T3...
Last edited by silverbullet on 19 Aug 2015, 14:28, edited 1 time in total.
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Re: Offset of 'new' T25 alloys
I should just add that the above is with regard to maintaining broadly the same steering centre point geometry i.e. the actual offset remains the same.
e.g. when changing from 6" ET30 to 7" ET 21, approx. 12mm needs to be placed inboard as well as outboard, so the ET reduces by a similar amount. In this case, ET is reduced by only 9mm not 12, so the wheel is (E D I T) actually set out slightly to ensure that the inner shoulder of the tyre clears the top wishbone.
http://www.driverstechnology.co.uk/wheel-offset.htm" onclick="window.open(this.href);return false;.
e.g. when changing from 6" ET30 to 7" ET 21, approx. 12mm needs to be placed inboard as well as outboard, so the ET reduces by a similar amount. In this case, ET is reduced by only 9mm not 12, so the wheel is (E D I T) actually set out slightly to ensure that the inner shoulder of the tyre clears the top wishbone.
from here:The offset is described by the term ET, which is from the German word 'Einpresstiefe' translated as 'insertion depth'
http://www.driverstechnology.co.uk/wheel-offset.htm" onclick="window.open(this.href);return false;.
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Re: Offset of 'new' T25 alloys
Mine are 25 offset and been on at least 6 years now. Not noticed any adverse effects, inside tyre wear or heavy steering and it sticks like glue on corners. I have massive tyres (height-wise) too - bearings been fine. Mine are steel.
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Re: Offset of 'new' T25 alloys
I've just fitted 17" x J7s that bought from VW heritage (they're SSPs). The van came with 17 x 8Js with 225/45/17 94W tyres and 10mm spacers all round but one had a wobble another had a crack and they were all pretty badly chipped so I bit bullet and decided to replace them. I was also concerned about the proximity of the rim & tyre to the front upper suspension arms.
I measured the offset of the fitted alloys which I reckon was 40mm which is why I chose the SSPs (they were the same). Finding the correct tyre size is a minefield as neither VW Heritage nor the tyre suppliers would advise what tyres would fit these rims despite me stating their size. Trying to find the right size with correct loading was helped by the Brickwerks posting that gives a the acceptable tyres sizes for each rim but I was still dubious about them until I tested the first one that was fitted.
In the end I went for Dunlop 215/50R17 95Y SPORTMAXX because they had high grip and low noise levels. The van is now really quiet, and handles great.
Good luck with your search, the info is on the web somewhere you just need to take the time to do the research.
PS I'd attach a photo but I get this message "Sorry, the board attachment quota has been reached"
I measured the offset of the fitted alloys which I reckon was 40mm which is why I chose the SSPs (they were the same). Finding the correct tyre size is a minefield as neither VW Heritage nor the tyre suppliers would advise what tyres would fit these rims despite me stating their size. Trying to find the right size with correct loading was helped by the Brickwerks posting that gives a the acceptable tyres sizes for each rim but I was still dubious about them until I tested the first one that was fitted.
In the end I went for Dunlop 215/50R17 95Y SPORTMAXX because they had high grip and low noise levels. The van is now really quiet, and handles great.
Good luck with your search, the info is on the web somewhere you just need to take the time to do the research.
PS I'd attach a photo but I get this message "Sorry, the board attachment quota has been reached"
1986 2.1 petrol Caravelle GL camper conversion
1975 Triumph TR6
1975 Triumph TR6
- kevtherev
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Re: Offset of 'new' T25 alloys
Use a web host to post pictureshughzt wrote:
PS I'd attach a photo but I get this message "Sorry, the board attachment quota has been reached"
Photobucket is free
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Re: Offset of 'new' T25 alloys
156silver wrote:Good Afternoon,
I've been looking at all of the 'new' 14/15" T25 alloy wheels on offer from EMPI, JBW, FLAT4, SSP, etc and they all seem to have an offset of 20 or 23.
Having been doing the necessary reading on the subject I understand that the standard Et was 30 or 39 depending on fitment of alloys or steels.
So I don't understand why all of these new wheels have such a low offset, as I understand it this means the wheels will stick out further than the standard steels and the offset issue can't be rectified with spacers.
Am I missing something here, why would all of the manufacturers make them with an unsuitable offset and why are they being sold?
Thank you
Brendan
Hi Brenden did you ever get any further with this? Did you buy? This thread kind of petered out.
Like you I really like the 'new' classic wheels but concerned about offset. As you said all the major classic vw parts companies seem to sell these - I'm surprised they would continue to do so if they caused major issues on vans (or am I just being naive?)