The large debate to have with yourself when planning any expedition is "what should you take and what should you leave?". This inevitably encompasses spare wheels as they're bulky and heavy. If you're planning on going remote, then a spare wheel is absolutely essential in the event of a puncture. There are self-repair tyre kits available, but if you're in the middle of nowhere it's probably best to quickly change over a wheel and deal with it once you're back in a town. Although to be honest once you're in a town will probably have access to some kind of tyre repair shop, so the usefulness of these products is limited.
As a rule in Belize we used to carry two spares, one on the bonnet and one on the roof rack. Our operating procedure when out off road was to return to base if one tyre was punctured. The second wheel was there encase any more punctures happened on the way back. It worked quite well. In my first 7 months we had 8 punctures from 2 vehicles on our Hankook MT tyres. When these were replaced with Pirelli Scorpion MTs we never had a puncture in the next 9 months. That was probably something to do with them being new, although the tyre construction probably played a part also.
Your decision of how many spares to take should primarily be based on how remote you are thinking of going. I would say that taking 3 spares is probably overkill (unless your vehicle is 6x6...) - one is a must and two is a safe bet.
Where to put them
- On the back door
- On the roof rack
- In the load area
- On the bonnet
The back door is the standard place for all Land Rover Defender spare wheels. I have found there is a habit of the back doors breaking due to a combination of the weight of the wheel and rough terrain at speed. There are swing away wheel carriers from various brands which shift the weight of the wheel onto the rear crossmember, which may be a good investment. The post-2002 Td5 back doors are strengthened for carrying spare wheels so don't tend to crack as much. The back door is a great use of space.
The roof rack, if you have one fitted is another great use of space, although it can be a pig to get the wheel down. This would normally be the second 'back-up' spare. The main downside is that is drastically reduces the other loads you can take on the roof, as it's so big and heavy and eats into the recommended 75kg roof weight limit.
Putting the wheel inside is another option, but in reality it would take up a lot of space for sensitive equipment that either needs to be kept dry or secure. It would also be be buried under more day-to-day items which would have to be removed first. In reality this may not be such a good option.
The bonnet is another standard place for the spare wheel on a Defender. They were fitted as an option to 300Tdi Defenders only. The kit is a separate option for modification, STC7633 but is harder to find these days. You may be better finding the individual parts second hand and it's fairly straightforward to fit to your own bonnet. The main concerns with doing this are the weight of lifting the bonnet and visibility out of the windscreen. The bonnet is also liable to pop up on rough roads if the latch isn't robust enough.
The first 3 Land Rovers I ever drove had bonnet mounted spare wheels, so I don't have an issue with them at all. The weight of the wheel (if not a Wolf) is not unmanageable, albeit requires a snatch technique similar to a Olympic weight lifter. The visibility was never a problem as with my height (6ft) I was always able to at least see the opposite wing corner and therefore judge the width of the vehicle. In my opinion, this is another great use of space and an easy upgrade to make.
Type of tyre and wheel
Ideally, something similar to what you have on the main driving wheels already. The rim and tyre will need to be the same size, as running a single tyre of different diameter to the others will result in overworking the differentials.
I would go for a remould or a cheaper version of the tread pattern on the main tyres. For example if your main wheels are Wolfs with BFG Goodrich ATs (like mine) then I would go for an Insa Ranger tyre on standard wheels. Not only is the tyre the same tread pattern, but it is almost half the price, and the standard Steel wheels are a lot lighter than the Wolfs. But to be honest, if your main tyres are MTs and your spare is AT (or vice versa), then it's not the end of the world.
If you're able to afford 5 or 6 genuine good quality tyres then this is no bad thing. However having a cheaper spare tyre works on the principle that once the punctured tyre is repaired, this is placed back on the vehicle and the original spare wheel is used as the spare again. Once a puncture has happened once, you will probably more than likely be driving more cautiously than normal.
In summary, I would take 2 spares on expedition - cheap All Terrain tyres on standard Land Rover steel wheels, as they will reduce the weight, be less of an expense and bog standard tyres being more than adequate when you are limping along following a puncture. I will put one on the bonnet and one on the back door or roof rack, depending on the roof rack load. I'm not such a fan of swingaway wheel carriers, as there are a lot of cheap brands about that rust quickly, so I will be upgrading my back door to the later one piece type of newer Defenders to better take the weight of the wheel.