Evolution Rigs

Why four Wheels

In the last ten years I have been involved in the sled dog sport, things have evolved. It is clear that dogs are getting faster and with the introduction of hounds in to the UK race scene there is a need to make the sport safer where ever possible. In addition to this teams are looking for every advantage to close those final few minutes, seconds and tenths of a second.

Four wheelers are undoubtedly heaver (by a kilo or two) than some of the top end three wheeled rigs around. This is no reason to suggest that they are slower, it is fact that the dogs are pulling more weight but this is not everything. Things to consider:

Weight

This is a factor in sled dog racing where no weight class restrictions or handicaps exists and only really applies to those who are light and can’t lose anymore weight. As it is the total weight we need to consider not just the rig. The key factor here is that the dogs will use more energy to get the rig started and then again up hills. Once at speed and with good rolling resistance (we cover this later) the dog should be able to maintain this for some time.

During a race there are mainly two times when we lose speed and the dogs need to bring the rig back up to speed. These are approaching hazards (corners, tight bends, and complexes trail sections) and up hills. Unlike three wheels, four wheels give you far more stability in corners and on complexes trails which reduces braking, maintaining speed and allowing the dogs to keep running.

Hills pose problems for all rig types, however if you are approaching an up hill after several corners you will find your dogs are tierd after slowing and having to speed up again. with four wheels you will have kept the speed in the corner and your dogs will be fresh to get up the hills.

Safety

On a number of occasions I have seen and heard of three wheel rigs rolling with bad consequences. This is due to one thing, three wheels. Like a three legged stool these rigs are very good at finding stability on uneven ground when standing still. Four wheels are not so good at this unless they have active suspension that allows them to adjust to the terrain.

One thing you should try if you get a chance (without a team and not moving) is to stand on your three wheeler and lean forward to the left or right and un-weight the opposite back leg. Be careful as it will at some point tip over. Now you may say that you never get into this position when racing, however if you are moving at speed and brake whilst standing you will be trust forward. In a corner this will be forward left or right and may possible resulting in a roll. if you are old enough you will remeber Robin Reliants and understand why we don't make three wheel cars now, if not look at this. Click here

Growth Sport

In the last few years so many people have commented on the amount of new teams coming into the sport. This is good and we should do everything to encourage this growth. One of the comments I have heard and read on forums is how some people are buying up big teams and going out without the experience to run such a team. This is no different from any other sport I have been involved; with fresh attitudes and new approaches these people should be encouraged and not trodden down. This is all fair and well until something goes wrong and with the pushing of boundaries it inevitably will.

EVR four wheels provide greater margin for error with added stability and braking power that can bring a world class six dog hound team to a stop within a hundred meters. This is not something I have ever heard a three wheeler doing. Clearly this is an advantage if you are still learning about running big teams, and lets face it most of us are.

Braking

Most three wheelers have two brakes on the back wheels. This is the best place for them as the misuse of a front brake on a three wheeler can extenuates the rolling problems. Very few use disc brakes with most using drum brakes. Whilst these are ok they were never designed to be used off road in the condition we use them in. You only have to look around the bike market to find this out with no off road bike fitted with them.   

EVR fit all four wheels with a hydraulic disc brake system. Discs work better in wet condition as the rims get wet and prevent pads working, discs are not normally in contact with the wet mud. Even when wet the holes allow the pads to clear and the brakes to work. Having four brakes provide power unrivalled by any other system on the market.

Rolling Resistance

This is a since in it self and refers to how the wheels / tyres roll over the ground. Broadly speaking your tread, tyre pressure, side wall profile and tyre width will alter the efficiency of the rig over the ground.  If you have ever been involved in cycle racing then you will be aware of the amount of tyres you need to be competitive. A rough rule of thumb is if your tyres are thin, smooth and high pressure they will roll better. However they will give you less grip in corners and will be more prone to puncture. You will also fin the ride loess comfortable. Four wheel will prove more grip in corners and  the active suspension will make the ride more plesent.

This applies to both four wheel and three wheels rigs.