Tall & skinny vs broad and not so tall??

[Gary Stockton]

I'm thinking of swapping my current Cooper STTs for something else. The OEM size on the 120 is 265/65x17 which gives an overall diameter of 30.56". I'm currently running 265/70x17 which work out at 31.61". I'd like to go to 33" or better without causing massive extra stresses or problems, primarily to get more air between the sump guard and the ground.

So I was wondering if I should go wider, thus higher. A 285/70x17 will give me OD of 32.71" and 295/70x17 gives 33.26"

Wary of too much width though.

So stay same width as OEM and go taller? I was looking at 265/85x17 which gives 34.74" or 265/80x17 at 33.69"

Slightly narrower at 255 gives 33.06" and 34.07" at the two profiles.

What of these is the better alternative?? Does increasing diameter per se add stress to bearings like going wider does?

Anyone got any reputable brands that does a decent AT or MT in an 80 or 85 profile in 17"? They seem to be a but like rocking horse poep!!

Cheers

 

[Gav Peter]

I think your last statement says it all - you'll probably have to make a compromise in what is actually available Gary...

JCS 4x4 Wheels & TyresThis guy seems tocarry quite a few tyres & was pretty helpful when I rang him trying to track sommat down

 

[Graham]

I'm thinking of swapping my current Cooper STTs for something else. The OEM size on the 120 is 265/65x17 which gives an overall diameter of 30.56". I'm currently running 265/70x17 which work out at 31.61". I'd like to go to 33" or better without causing massive extra stresses or problems, primarily to get more air between the sump guard and the ground.

So I was wondering if I should go wider, thus higher. A 285/70x17 will give me OD of 32.71" and 295/70x17 gives 33.26"

Wary of too much width though.

So stay same width as OEM and go taller? I was looking at 265/85x17 which gives 34.74" or 265/80x17 at 33.69"

Slightly narrower at 255 gives 33.06" and 34.07" at the two profiles.

What of these is the better alternative?? Does increasing diameter per se add stress to bearings like going wider does?

Anyone got any reputable brands that does a decent AT or MT in an 80 or 85 profile in 17"? They seem to be a but like rocking horse poep!!

Cheers

.
Hi Gary,

I kind of like this option,

So stay same width as OEM and go taller? I was looking at 265/85x17 which gives 34.74" or 265/80x17 at 33.69"
.
I really think 265 is wide enough.
More width is more drag.
My money, if I was going to buy, would go on 265/85x17.
The lift gives you lots space now.

Graham

 

[Paul]

What about the likely terrain/use they are going to be used on? This may limit some suppliers and sizes.

 

[Gary Stockton]

Yes definitely does seem to be a limiter. I can get BFG ATs in that sort of profile, but they're £££. KM2 in 17" are only available as 245/70 - pooh!

Cooper don't do the muds at that profile either. TBH, I think a decent AT would probably be just as good for me as the STTs are...

 

[Andrew Prince]

Gary,
Are you sure you can get 17" tyres in 80 or 85 profile? A quick glance at the major tyre places online suggests not. For sure your choice of tyre is going to be very small - and probably painful on the wallet
If the tyres are rare in the UK, how easy will they be to come by off the beaten track?

To answer your first question - I vote for tall & skinny. You get benefits of the height increase with a minimal increase in rolling resistance. In mud, thinner tyres dig better and you get good footprint elongation airing down with tall, narrow tyres for sand or rocks.

Cheers,

 

[Jon Wildsmith]

I'd go 285

 

[uHu]

I guess that the best and cheapest option is to get hold of some 16" rims. The selection is better in 16, and 255/85 is a classic. 16" means more rubber, which means a longer/larger tread (contact patch) when airing down.

- For increased strain on wheel bearings and brakes, and suitable gear ratio; the diameter counts more than the width. On a 100 series, these factors seem to be OK at least up to 33", depending on type of driving. Same on 120?
- When it comes to strain on steering, traction, and miles/gallon; the narrow is better than the wide.
- When it comes to floatation (glaciers and beach), the diameter counts more than the width. Width counts as well, but not that much, and gives more difficult steering and handling.

 

[Graham]

You haven't a snow balls hope in hell of getting a 16" rim onto your LC.
Well, thats not true, because you could remove your front calipers, then you would be OK.
Any way, to the issue, I even had to grind away some of the front caliper to get an aftermarket 17" rim on.
OK, it was only the casting seam on the caliper, but really, there is almost no clearance between the 17" rim, and your front calipers.
.

.

Graham

 

[uHu]

[strike:9int6h7z]I guess that the best and cheapest option is to get hold of some 16" rims. The selection is better in 16, and 255/85 is a classic. 16" means more rubber, which means a longer/larger tread (contact patch) when airing down.[/strike:9int6h7z]

- For increased strain on wheel bearings and brakes, and suitable gear ratio; the diameter counts more than the width. On a 100 series, these factors seem to be OK at least up to 33", depending on type of driving. Same on 120?
- When it comes to strain on steering, traction, and miles/gallon; the narrow is better than the wide.
- When it comes to floatation (glaciers and beach), the diameter counts more than the width. Width counts as well, but not that much, and gives more difficult steering and handling.

Thanks Graham
I started out thinking 100.
Earlier LC models always had 16", or even 15" for those who wanted more rubber.

There. I have edited the posting above.

Is there no alternative caliper for the 120? And is the disk to big as well? I know the later 80 changed calipers, or did like Graham did, in order to put 15" on.

 

[Gary Stockton]

Frustratingly, you can get BFG KM2s in 255/85x17 in Oz. Will drop BFG UK a line.

Edit: sorry, s/be 255/80x17 which gives a 33.06 tyre - perfect...

Won't be taking an 'angry grinder' to my calipers, that's for sure, casting waste or not

 

[Paul]

Have a look at Craddocks site, they seem to stock some of the more unusual sizes.