I finally received my Simex Extreme Trekker copies. OK, all my off-road friends ones are about 36in tall and mine only 4in. But size does not matter. What counts is how they perform on the field, and they do, big time.
 
I got those 1.9 Trail Buster scale tyres from RC4WD in the USA.
 
The company started several years ago in a garage with one employee. They used to make small run of parts for several trucks on the market especially the monster truck. About three years ago things got more serious and a few more employee's got hired. At about this time the focus really shifted from monster trucks to crawlers. Slowly they have evolved into the company they are today. Very small and fast moving, they try and focus on what the customers are asking for, this has proved to be a good choice.

Have a look at their website (www.rc4wd.com) and you will be amazed by the choice of parts, kits, accessories for your RC vehicles.
 
I chose the Trail Buster as I want to create a good looking and capable scale off-roader that look similar to what is being used on the full-size market at the moment. And when it comes to tyres, the Simex and similar copies are almost running the show for extreme mud-style pattern.
 
Their specifications are as follow:

• Outer Diameter: 104mm (4.09in)
• Inner diameter: 48mm (1.9in)
• Width: 29mm (1.14in)
• X3 Compound (soft and sticky)
• reinforced sidewall

Trail Buster (right) compared to original SCX10 tyre

I asked Tom Allen (RC4WD Promotions and R&D) to give us a brief overview on how a tyre is created:
 
"Since we are still a small company some of our customers provide us with CAD drawing of tires, other times we have our own internal engineer draw a tire for us. What you normally see is a tire with a likeness to the 1.1 world. There are all kinds of designs that work out there, and once again these are what the customers want.
 
On some tires we actually have a prototype tire made with a 3D modelling machine. This process can be expensive so we do not use it everytime. This helps us check and make sure that the CAD work was correct and that the tires shape, size, and design is good. Then its off to the mould makers.
 
Once the mould gets made for the tires, we make some test tires from the mould and check these for fit and finish. Some tires have a more extensive testing period than others. Some we just know they will do okay. Now that we have been making tires for a little while our compounds are better than ever and our tires are performing very well.
 
Then its off to the races. Make tires as fast as we can so we can start shipping. The faster we can get the tires made and out the door in our customers hands. From start of a prototype to a completed and ready to ship tire is about two months. We have been getting better with this time and are still making improvements to our process. "
 
In addition to the tyres, I also ordered a set of steel wheels. I choose the RC4WD OEM Steel stock beadlock (Black Edition) as they are very similar to the black modular and triangular wheels that you see on our off-roaders.
They have what I call an internal beadlock, meaning that the tyre is blocked from the inside on the wheel instead of using an outer ring.

 
I initially mounted the tyres on the wheels using the provided internal foam without cutting it, but I found the tyres to be too hard. It was like running your Simex at road pressure, you just don't do that when you go off-roading. I decided to cut half of the foam, only keeping a thickness of about 1cm. With the beadlock wheels, it feels like I am running internal Staun Beadlock. The parts are so well made that you can actually think like your are using full size equipment.

If you do not want to cut too much or not at all, you can drill a hole in the wheel or make a small hole in the tire that will allow air in and out of the tire. This too will cut down on the hardness I experienced.
 
I fitted the wheels to my Axial SCX10 scaler and went for a test in the garden.
 
The initial look and feel is just right. The tyres are thiner that the original ones and give more a scale look to the overall vehicle.
 
On rock or bricks you can really see the tyre working hard, it deforms well without collapsing and has a fantastic grip. When it comes to a more slippery terrain, the thread pattern does its job as expected. If the Simex pattern has been working so well all those years in the real off-roading world, there was no reason why it was not going to perform as well in the RC market.

In conclusion, it is no turning back for me. When it comes to make a scale looking tyres, RC4WD have done a fantastic job. The only drawback is that I have been on their web site and I saw some other parts that I want. The pricing of all their parts is not "cheap", but when you think about the very high quality of the products, you realise that it is not actually "that" expensive.
 
Now, what next for my scaler ?