wheels and tyres

Technical questions and answers
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Andy
Posts: 20
Joined: Sun Nov 15, 2009 12:37 am
Location: New Zealand

wheels and tyres

Post by Andy »

Hi Guys.

Sorry for more questions, I am replacing the 16" wheels with 15" and want to go quite wide. I have been thinking about 31x10.5x15 but also 32x11.5x15. Does anyone know what works best and if I can even go as wide as 33x12.5x15?
map1275
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Post by map1275 »

What works best is to stay 16". The only reason 15" comes into play is the tightwad option.

Other than this you will have to adapt to the five different ways of assessing tyre sizes. The problems you have avoided are wheel offset; outwards or inwards.
Inwards for what you are suggesting will clip the inner arch. Central or outward should protrude well beyond the body line and void your WOF. Plus throw your speedo calibration out, another warrant fail point.
Regardless, that width will require some serious upper body strength so don't forget to fit a smaller steering wheel at the same time.
The hubs (if well maintained) can support that kind of leverage. But I would suspect that you will be needing to do more than just inspecting wheel bearing play at every service.

Side wall flex and the handling effects will also come into play, even from only a 1" increase in rolling diametre.

Do you have some particular swamp that you need to float across?
stirlsilver
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Location: Wheelers Hill, Victoria, Australia
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Post by stirlsilver »

I run 33x12.5x15 tyres. They sap a fair amount of power but have helped when offroad.

I'm not sure what the offset of my rims are because I bought them on ebay, but I know you will need 15x8" rims to fit those sized tyres.

The inside of the tyre does rub against the chassis at full lock, but I just put up with it.

Photos of when I first trialled the tyres on are here:
http://stage1v8.org.uk/phpBB2/viewtopic ... c&start=30
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gary_in_nz
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Post by gary_in_nz »

go for it, i run 33x12.5 mongrels left over from my nissan safari from when i put 35's on that.

the only lifting i have done is to level up the rear springs by having the right rear reset.

they do rub at full lock (pretty minimal) on the chassis but are very good other wise as the mongrels dont have the large lugs that go right to the outside of the tyre that say simex and silverstones do.

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"If it ain't v8, take it back"
Jamie_grieve
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Joined: Wed Dec 02, 2009 12:10 am

Post by Jamie_grieve »

I'd agree with map and stay 16". less chance of between the drums and wheels filling up with mud and better when you get a puncture and one less modification.
Why wide? You'll have less grip on wet grass and sideslopes. Better flotation by virtue of less ground pressure but tall and narrow in my opinion is the way to go. Unless for purely on road use of course.
I've run petlas 900x16's since 2002 and wouldn't go back to anything smaller. They're narrow so good grip on sideslopes, tall so good clearance and good contact patch and because they're narrow they don't rub the springs or body. They were also a factory option so although not standard, also not out of place.
Andy
Posts: 20
Joined: Sun Nov 15, 2009 12:37 am
Location: New Zealand

Post by Andy »

Hi, just want to get better on road handling as well as more s
traction when driving on sand or mud. Am happy to stay with 16" wheels if this is advisable but would like to go wider than 245x85x16. I would like to go to 275x85x16 so diameter will be the same but wider than current and I'd run these on the standard stage 1 rims. Will this option of 275x85x16 have any bad impacts on the mechanical side of the vehicle?
map1275
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Joined: Mon Jul 21, 2008 2:48 am
Location: Brisbane, Australia

Post by map1275 »

All of the problems you will encounter have already been covered. You may want to reread what has already been posted.

If you want to improve handling then buy a 110.

Otherwise the only simple and effective option is to buy a radial equivalent of a 7.50/16. As previously stated, you need to learn the five different ways of sizing tyres. A tyre that grips the bitumen with as aggressive a pattern as possible. The tyres also need to retain the correct load rating.

Otherwise the only other change would be to fit 110 standard wheels which have a slightly outward offset. This will increase track and make the car slightly more stable.
map1275
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Location: Brisbane, Australia

Post by map1275 »

Tyre profile is expressed as a percentage of width.

Therefore two different width tyres which both have 85 (%) profile, doesn't mean the side wall or rolling diameter will be the same.
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