Defender Wheel Sizes

Calf re-hydration tablets (well, half of one!) taken with a small glass of water before going to bed is, I'm led to believe (by a Vet friend!) the way forward in that department!!

Whereabouts in Scotland, it's a big place? Nene Overland have an outlet near Huntly (on a "B" road between Huntly and Inverurie) that do good deals on tyre and wheel packages. I got a set of 4 31-10.5x15 radial A/T's fitted and balanced on new white 8-spokes for £300 just over a year ago, they're wearing very well with good wet weather grip and braking.

Is it a 90 or 110? I'll assume from the tyre size fitted it's a 90, in which case you can fit 235/85x16's on the wider rims (or disco steel rims), they'll fill the arches a bit better and give it a slightly more purposefull stance. As for snow, they'll give a little more under-diff clearance, but they'll spread the vehicle's weight better and help it to drive over the snow as opposed to digging into it. I run my 110 on 31-10.5x15 A/T's and they suit it really well on snow, the wide footprint giving it the ability to "float" nicely on it, but with pretty good traction. As for the alloys, pain to keep clean and damage free if you do much off-roading or driving on salted roads, but no real benefits other than looks, IMO. Happy new year when it comes, etc. Badger. B.H.Engineering, Rover V8 engine specialists.

Badger wrote: but no real benefits other than looks, IMO.

Less weight could be usefull in terrain as well more economic at the gas station. Steel rims are stronger though. Kind regards and an happy New Year, Erik-Jan.

Suggest you go weigh them, that's a popular misconception I'm afraid. There tends to be very little weight difference, in fact there are a lot of vehicles that have alloys heavier than their equivalent steels.

Indeed, and easier to straighten too.

And may I wish the same to yourself, Erik-Jan.

Badger.

There are a few advantages to larger tyres - better floatation, better ground clearance, better approach angle, departure angle and breakover angle... In snow thay CAN have some disadvantages as a tyre with a smaller footprint will somethimes dig through the snow and get more grip.

7 inch wide rims are pretty much standard as far as 8 spoke steel wheels are concerned and they have the benefit of a deeper dish which gives you a better turning circle over a standard LR steel wheel and especially over a Disco steel wheel.

Fitting alloys rather than steel gives some benefits and some problems...

The main benefit (other than looks) is the range of sizes available, particularly if you want to go for some wide tyres and stick to 16 inch rims. (15 inch steel rims give you a larger range of widths "off the shelf" than 16 inch). Any tyre over around 235mm wide (wider than a 235/

85 for example) should really be mounted on an 8 inch or wider rim, 8 inch steel rims are a pain to get hold of so most people compromise and use 7 inch rims. Alloy 16inch wheels are "easy" to get hold of in wider fittings with widths up to 12 inch. I have my 35/10.5s mounted on 16x8 steel rims which is as narrow as you should go for a tyre that is 10 inches wide or more.

The problems with alloys come down to their susceptibility to damage, both superficial and structural. Any slight graze against a rock will mark an alloy. Alloys CAN shatter or crack when subjected to high shock loads (the sort of thing that would bend a steel rim). Alloys designed for 4x4 use shouldn't shatter but for serious off road use or if you are the type of person likely to clip a kerb at high speed it is something to consider. I've seen a saloon car shatter an alloy wheel when it hit a lump of wood on the motorway. 4x4 alloys SHOULD be made to absorb that kind of an impact but there's only one way to find out for sure !

cheers

Dave W.

Thanks to all for the advice, it's very much appreciated. Badger, I live just north of Aberdeen so will be checking out the Nene Overland outlet near Huntly in the not to distant future. Again, many thanks to all for the advice, hope you all had a good New Year and are well recovered. Brom.

So tell me, what is the reason they use them in motorsports. The only thing I can think of is the less unsuspended weight. My own experience b.t.w. is, lifting an alloy with mounted tyre comes easier then a steel rim. Kind regards, Erik-Jan.

A properly designed steel wheel and alloy wheel with the same strength should be very close to the same weight. But an alloy wheel, because it is cast, allows a freer hand in the design and generally as a result will be either stronger or lighter than a steel one. The other advantage is better cooling of the brakes. This is because the alloy wheels can more easily be designed with better ventilation, and because the thicker section and greater heat conductivity of the alloy allows it to conduct heat away from the hub (and hence brake) better. This gives alloy wheels a clear advantage in motor sports, but their advantages in ordinary cars are much less clear, and even less clear in off road vehicles where wheel damage is more likely. JD

Cheapo 'boy racer' alloys can easily be heavier than steels - just crap design, cheap manufacture and stupid punters....

Race alloys will often be split rims. The spokes take compressive loads whilst the rim takes torsional and flex loads. Thus different materials are optimum for each component, and thus the best weight / performance trade off is obtained by split rims with different materials, or the same materials with different manufacturing methods (e.g. cast, forged, spun etc).

One reason is the proposed purpose. When you say they use them in motorsports I have to ask, what percentage of vehicles taking part in off road motorsports use them ? Motorsports encompasses a far wider spectrum than those who go round and round on a piece of tarmac. ISTR reading somewhere that, in the UK, off road motorsport is actually the largest, numbers wise, form of motorsport.

Were you to design a wheel for "roundy roundy" racing then alloys make sense, you need very little in the way of shock and impact protection, even suspension items are built to the lightest specification and will fail if they are in an impact. Alloys for this kind of use can be made as light as possible. The problem comes when you want to use alloys in more punishing environments. In order for an alloy wheel to absorb the same amount of punishment as a steel wheel without failing you have to make the alloy wheel much thicker in materials, any weight loss in materials is soon put back on again by the sheer quantity of material that has to be used. The average steel 8 spoke uses 4 to 6mm thick steel, an equivalent alloy needs to be over an inch thick. Even then it is still not unknown for the heaviest of alloy wheels to shatter or crack in an impact. Road biased alloys can be made extremely light, especially when produced to high specification and quality control, cheaper road alloys are made with much heavier and thicker materials in order to compensate for variations in the alloy and manufacturing tolerances.

IMV you should match the wheels to the vehicle and it's use. I would not fit 16 inch 8 spokes with 35 inch Simex to a circuit racer any more than I would fit 19 inch alloys with wafer thin low profile slicks to an off road racer.

cheers

Dave W.

On or around Mon, 03 Jan 2005 01:23:01 +0100, Erik-Jan Geniets enlightened us thusly:

I suspect the ones used in motorsport are made of more exotic materials and cost mucho dinero.

Correct, Austin. If anyone cares to weigh an alloy from a classic rangie and a steel rostyle from the same vehicle they will understand. The difference is as small as won't make any odds. If you are prepared to spend a LOT of money on exotic alloys then you CAN save weight, but most alloy wheels fitted in this day and age are for aesthetic reasons only and hence the weight is no longer a consideration by the manufacturers. Their brief is to spend the money not on exotic alloys, but exotic styles, so to keep within budget they utilise cheaper alloys and make the wheels thicker to maintain suitable strength. Look at the genuine BMW alloys for an M3 and compare them with aftermarket replicas, the replicas are thicker but weigh the same!!! What does that tell you?? For those interested, price up some of M J Lee's off-road alloys and try and get a delivery forecast..... last I checked it was a case of "join the queue!" BTW, his alloys are very good, but still not as resilient as decent steel rims for comp safari use, at least you can attempt to straighten the steels with a hammer whereas the alloys buckle off-centre easily - and they are designed for rough use. Badger.

I do totally agree on the strength of a steel rim. It won't be easy to distroy one to a point you can't move on. Still in some situations, like sand beaches, you could gain a little in less weight. The change of damaging an alloy on such a beach seems very slight. So maybe it just depends on where you are driving. And still in lifting these: I've only had the experience with a BMW steel rim and a much wider alloy rim for the same car. Tyres fitted. Much easier to lift the alloy rim. Maybe this won't compare to LR/RR Kind regards, Erik-Jan.

"Austin Shackles" wrote> I suspect the ones used in motorsport are made of more exotic materials and

It's funny but the Alloys on my Kangoo 4x4 (15" 5.5j) are MUCH lighter than the Steels I keep the MT (ish) tyres on and I dont think its tyre weight. They are 15" 6.5j so its not quite the same but when changing them there is a very noticeable difference. I can go out and weigh the Spare(Steel but still 15"x5.5 - same tyres as alloys) and an Alloy if anyone cares enough to ask.

Of course its not a Land Rover - just thinks it is, But it's not exactly a high performance sports car either. Esp as we traded in the petrol on a brand new Diesel.

John.

-- Chasing Landies in a converted French Van since 2002.

I had Italian BWA alloys on my previous RR (classic). By heck, they were light and common enough not to be expensive.

Ron Beckett Emu Plains, Australia

1995 P38A Range Rover HSE 4.6 Litre V8