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HunterGLS
Ireland
95 Posts |
 Posted - 31 Oct 2012 : 00:06:17
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I've seen a set of 7J x 13'' wheels with an offset of -7.
Will these fit a Hunter without any problems or would they stick out past the arches? |
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arrocuda
United Kingdom
501 Posts |
Posted - 31 Oct 2012 : 07:58:17
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You can work it out fairly easy cos the formula for calculating offset is..... Back spacing - Centerline = Offset. Where 'back spacing' is the measurement from the hub face to the inside flange of wheel and centerline is the overall width of wheel (flange to flange), devided by 2.
In your case.... if the offset is -7" ....they will definitely need arches, but if is -7mm... they will easily fit.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
Edited by - arrocuda on 31 Oct 2012 15:15:51 |
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turbinecol
United Kingdom
85 Posts |
Posted - 09 Nov 2012 : 11:23:26
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You need to check the typical Arrow/Rootes wheel offset, it's over -30mm (I have notes that states -38mm, but not sure how true that is). That gives rise to the very shallow dish look of the Rootes Rostyles when compared to Ford for example.
A -7mm offset will be very deep dish indeed therefore, so need to pay attention to your wheelhouse clearances, especially if you are adding rim width as well by moving to 7J. |
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arrocuda
United Kingdom
501 Posts |
Posted - 09 Nov 2012 : 14:37:13
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My project car is fitted with 7 x 13 Wolfrace slot mags, so I cast a ruler over them to work out the offset. The calculation for the wheels is...... (177.8 / 2) - 101.6 which gives 88.9 - 101.6 = -12.7mm offset.
The rims measure 3" from the hub face to the outer flange, and 4" from the hub face to the inner flange. This is how they look on the car.
They are fairly deep dished but TBH I'm not sure you could get much deeper without risking interference under standard arches. On american wheels they refer to the hub face to the outer wheel flange as the 'backset' and I would say that looking at mine that 3" is probably the safe limit if you want to keep the arches standard. I think Turbinecol is right, so check them carefully before you decide.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
Edited by - arrocuda on 09 Nov 2012 14:37:44 |
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arrocuda
United Kingdom
501 Posts |
Posted - 10 Nov 2012 : 20:21:26
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Was down at the lock up this afternoon so took the opportunity to measure the clearance of the rear wheels. At the widest point of the tyre there was just enough room to pass a 2mm thick piece of metal through the gap.
Closer than I thought, but it does suggest that a 3" dish from the hub face is the limit on the rear axle. Good news is that despite dropping the front by approximately 90mm, there is still plenty of clearance. Although I did fit lower profile tyres to improve the stance.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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Fastback Thomas
Belgium
423 Posts |
Posted - 23 Nov 2012 : 18:55:01
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Hi arrocuda
I've been thinking about a set of bigger wheels.
And the ones I think would look good on the car are 6.5" x 15" (smallest version)
So I've been calculating a few things in comparison to yours and have figured out that I'd have 34mm = ± 1" 1/3" to the rear arches... but I was also wondering how much room you have between the wheels and the front suspension and between the wheels and the inside of the rear arch...
Do you have any idea?
Many thanks, Thomas
'68 sunbeam rapier fastback {B341006846 OD/LHO}
I like a car that looks normal but really knocks your socks off!!
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arrocuda
United Kingdom
501 Posts |
Posted - 23 Nov 2012 : 20:21:07
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Hi Tom.... I was lucky in that I already had these wheels when I bought the car so could actually try them without worrying whether they fitted or not. Really is like turbine col was saying before about offset in that.... it's not so much how wide the wheels themselves are, it's where the hub flange is in relation to the width that is the crucial bit.
The Americans use 'backset' as a way to measure the outer rim clearance but it does not take into account caliper clearances on the inner rim, but with a 15" wheel is very unlikely you will have a problem there. So the best way to be sure that your wheel won't interfere with your arches is to measure the distance off the hub face to the outer edge of the rim. I've found that 76mm is really on the limit with only a 2mm clearance to the tyre wall. (Rear Arch)
I've lowered the front of my car substantially so it might not be relevant to yours, but as you can see in the pic, the front wheel (which is same dimensions as the rear wheel), is tucked further under the wing. Yours will have a slightly wider radius (maybe 50mm including tyre) but will be under a car that is 90mm higher. (My car has a 20mm lower profile than standard tyre on the front).
Any chance you can try them first.... and more importantly.... any chance of some pics? A rapier on 15" rims? This could be another first! 
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
Edited by - arrocuda on 23 Nov 2012 20:27:55 |
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1922
United Kingdom
549 Posts |
Posted - 23 Nov 2012 : 20:26:30
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I've got 7x15 rims on mine - I think the offset is 30mm.
Using 195x50x15 tyres.
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Edited by - 1922 on 23 Nov 2012 20:29:12 |
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arrocuda
United Kingdom
501 Posts |
Posted - 23 Nov 2012 : 20:31:55
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Too bad Tom.... Derek's beat you to it. Looks the dog's dangly's as well! Are they aftermarket or is there a Ford running around on it's hubs somewhere Derek? 
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
Edited by - arrocuda on 23 Nov 2012 20:33:22 |
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Fastback Thomas
Belgium
423 Posts |
Posted - 23 Nov 2012 : 20:35:30
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Well correct me if I'm wrong but the wheels I'd be able to buy have a 38 offset.
and only 6.5" wide so they shouldn't cause any trouble if those 7" on Derek's don't rub...
this is one I found earlier.. also big wheels...
'68 sunbeam rapier fastback {B341006846 OD/LHO}
I like a car that looks normal but really knocks your socks off!! |
Edited by - Fastback Thomas on 23 Nov 2012 20:37:11 |
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arrocuda
United Kingdom
501 Posts |
Posted - 23 Nov 2012 : 20:39:58
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Comparing Derek's pic with mine you can see the difference quite clearly in that the large dish that mine have, has the effect of pushing the outer rim further away from the hub and nearer to the arch even though both sets of wheels are 7" wide.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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arrocuda
United Kingdom
501 Posts |
Posted - 23 Nov 2012 : 20:42:25
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quote:
Originally posted by Fastback Thomas
Well correct me if I'm wrong but the wheels I'd be able to buy have a 38 offset.
and only 6.5" wide so they shouldn't cause any trouble if those 7" on Derek's don't rub...
I would concur Tom.... I think you will be Ok. Isn't that Martyn's (UMU's) car in the pic?
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
Edited by - arrocuda on 23 Nov 2012 20:43:05 |
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Fastback Thomas
Belgium
423 Posts |
Posted - 23 Nov 2012 : 20:49:01
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I was hoping for it! ;)
I believe it's david atherton's car..
no it's not martin's car.... he has modern dunlops...
this is martin's
'68 sunbeam rapier fastback {B341006846 OD/LHO}
I like a car that looks normal but really knocks your socks off!!
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Edited by - Fastback Thomas on 23 Nov 2012 20:50:30 |
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1922
United Kingdom
549 Posts |
Posted - 23 Nov 2012 : 20:54:18
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They are TSW Stealth, put them on this one (when it was still Argonaut's car) and my previous Rapier years ago (10 I'd guess).
I had some Ford RS style Compomotive 7x14 rims before this.
Like this:
I was told at the time they were a very common offset typically used on Fords.
The offset is stamped on the back - but my spares are tucked away in mum's spare room ten miles away at the moment so I cannot look easily.
I use a 3mm spacer on the front to stop the tyres rubbing on the suspension tower and anti-roll bar (they still do a little on full lock).
The car is also lowered 25mm all round.
The rear tyres are close to the wheel arch but never actually touch.
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Edited by - 1922 on 23 Nov 2012 21:06:02 |
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1922
United Kingdom
549 Posts |
Posted - 23 Nov 2012 : 20:58:27
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Here's a pic of my old Rapier (now Jon's) in the company car park - back in 1998.
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Edited by - 1922 on 23 Nov 2012 21:08:30 |
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arrocuda
United Kingdom
501 Posts |
Posted - 23 Nov 2012 : 21:04:49
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Is that colour wardance red?
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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Topic |
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7'' x 13'' wheels
