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big tyres and off sets


gelf

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since i fitted 35-12.5-15 tyres on the 90 they of course catch on the radius arms on full lock.

the wheels they came with are just standard white spokes 8x15 from craddocks.........any idea what off set these would be??

also what off set i need to stop the tyres rubbing.

of course theres wheel spacer but i heard alot of bad things about these.... and at £160 it nearly the price of 4 steel wheels.......or can i tell kazi that the only way to sort it is to fit Mach 5's.

graham

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Be careful of going for too much offset, that gives you more steering lock, I know that's what you are trying to achive, but it means you will end up busting more CV's with tyres that size. Limited lock gives a bit of a safety margin with regard to the CV's.

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Be careful of going for too much offset, that gives you more steering lock, I know that's what you are trying to achive, but it means you will end up busting more CV's with tyres that size. Limited lock gives a bit of a safety margin with regard to the CV's.

I've got 75mm off set Mach 5's with 35" simex and I've had to limit the turning circle, blew a CV to bits the other week and I do mean bits, the only thing left was the shaft :o

Going backwards up a bank with rear winch, but with a lot of front lock, gentle blip of the throttle to give a a bit of drive assist BANG.....B*&$%R :(

if I did'nt have as much lock it might have been fine, but only time will tell if happens again, now I've reduced it

They don't call Simex.."Fault Finders" for nothing.... :lol:

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Going backwards up a bank with rear winch, but with a lot of front lock, gentle blip of the throttle to give a a bit of drive assist BANG.....B*&$%R :(

Les,

only front locker engaged?

no steering-going backwards in a straight line?

and! gentle blip?

(assuming your "gentle" is " as "gentle" as I mean :rolleyes: )

Whoa...!

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Les,

only front locker engaged?

no steering-going backwards in a straight line?

and! gentle blip?

(assuming your "gentle" is " as "gentle" as I mean :rolleyes: )

Whoa...!

Michele,

Front lock......NOT...Front Locker.... :lol:

Blimey if I had the front locker in both would have gone :blink: as the torque would have been 70% front 30% rear....BIG BANG !

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Guest diesel_jim

My 35" simex's are mounted on a set of discovery steel rims that have had the middles cut out and re-welded (Bryn Hemming did them).

they give a nice offset (but they do stick out slightly... almost too far as the first puddle you go through the side windows instantly become "tinted" :rolleyes:

HPIM0429.jpg

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Michele,

Front lock......NOT...Front Locker.... :lol:

Blimey if I had the front locker in both would have gone :blink: as the torque would have been 70% front 30% rear....BIG BANG !

AWW!

Sorry,I was a bit in a hurry,my mistake.

:rolleyes:

But!

If you write "front lock" do I assume you also may have a rear?

4 wheel steering then?

:P

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Guest diesel_jim
no ones mention spacers so i assume stay well clear? :)

I've got spacers on my 110 SW (with factory alloys and 235/85 BFG MT's)... i just fitted the spacers for that "better" look... no hassles or issues at all, although on mine i got a little bit of steering shimmy, but it think thats down to the axle swivels, not the spacers themselves.

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My 35" simex's are mounted on a set of discovery steel rims that have had the middles cut out and re-welded (Bryn Hemming did them).

they give a nice offset (but they do stick out slightly... almost too far as the first puddle you go through the side windows instantly become "tinted" :rolleyes:

HPIM0429.jpg

A bit OT but I'm going to make up arches out of the rubber stuff the rally guys use for mudflaps. Its nice and flexible and you can get it in loads of colours. If I can make them for a reasonable price I might make them to order (any width).

Les, your CV may well have been damaged a few minutes earlier. I've had them let go doing fairly normal things after a few minutes of abuse.

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The offset values that have been quoted in the posts above are hard to believe! What definition for offset are you all using?

My understanding (and the only definition that makes sence to me) is that offset is the distance from the centre of the rim to the wheel mounting surface.

And backspace is the distance from the inside lip of the tyre bead seat to the wheel mounting surface.

Then an 8" wide rim with 4" backspace would have zero offset. A 7" rim with 4" backspace would have - 1/2" offset. A 10" rim with 4" backspace would have 1" offset.

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Les, your CV may well have been damaged a few minutes earlier. I've had them let go doing fairly normal things after a few minutes of abuse.

Will,

That might have explained it, just mins before thrashed the pants off it on special stage 2 :lol:

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The offset values that have been quoted in the posts above are hard to believe! What definition for offset are you all using?

My understanding (and the only definition that makes sence to me) is that offset is the distance from the centre of the rim to the wheel mounting surface.

And backspace is the distance from the inside lip of the tyre bead seat to the wheel mounting surface.

Then an 8" wide rim with 4" backspace would have zero offset. A 7" rim with 4" backspace would have - 1/2" offset. A 10" rim with 4" backspace would have 1" offset.

....and with your calcs Jon W does have 6 inch ofset, I know we welded them up and they are er...."Impressive" :unsure:

Nige

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....and with your calcs Jon W does have 6 inch ofset, I know we welded them up and they are er...."Impressive" :unsure:

Nige

That would give a large scrub radius!

We drive a lot of different terrain here (Aus) and that much offset could be dangerous on rock steps - lift 1 wheel and the offset would pull the wheel in contact around to full lock :rolleyes:

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broke one of mine in the same manner all the weight on the front wheels

tried to reverse and snap went the CV, the other one went in Putham lane (going up) on M/T's both time snapped the shafts off leaving the bell intact.

hopefully this problem has now gone away

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The offset values that have been quoted in the posts above are hard to believe! What definition for offset are you all using?

My understanding (and the only definition that makes sence to me) is that offset is the distance from the centre of the rim to the wheel mounting surface.

And backspace is the distance from the inside lip of the tyre bead seat to the wheel mounting surface.

Then an 8" wide rim with 4" backspace would have zero offset. A 7" rim with 4" backspace would have - 1/2" offset. A 10" rim with 4" backspace would have 1" offset.

Bush65 I'm with you on this. Bandying arround numbers but not using the same reference is just confusing. THere is some good stuff here on backspacing and the issues with too much or too little.

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Presume it was dry enought then on Wed to fit those shinny new cv then ????

No I got very wet as it started when I had stripped the old one off and was rebuilding in between showers.

all done now hopefully I won't be re doing that job for a while.

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Most people are taling backspacing - thats what means most to most people and is easiest to measure. I do have 6" of backspacing on my rims (7x16) which I suppose amounts to 2.5" of positive offset by your calculation.

Jon

By my calculation your offset is 7" / 2 - 6" = -2.5" Since the offset is negative, your track will be reduced by 5".

Increasing backspace will reduce track and clearance to radius arms. Reducing backspace will increase track, clearance to radius arm and may increase scrub radius.

I suspect as LR90 said, we dont have common definitions for offset and backspacing and don't state what we use in the posts, which makes them missleading or meaningless to others.

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By my calculation your offset is 7" / 2 - 6" = -2.5" Since the offset is negative, your track will be reduced by 5".

I suspect as LR90 said, we dont have common definitions for offset and backspacing and don't state what we use in the posts, which makes them missleading or meaningless to others.

I suspect what Jon really meant was he has 1" backspacing, not 6". :rolleyes:

Come on guys n gals, lets get our figures right. The info is then so much more usefull and we can start to make proper comparissons of how different wheel/tyre combinations efect basic things linke steering lock but also other factors like what clears the arches on articulaton and what doesn't.

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