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- 1/10 JConcepts Outdoor Tyre Guide -
by Ray Munday
One of the appeals / challenges of outdoor off-road racing is the variation in track conditions that occur (even on the same day). Tyre choice is critical to get the best lap time and enjoyment out of your buggy, but with so many tyres available it can be overwhelming to stay in front of the track conditions.
With many racers experiencing outdoor 1/10 for the first time recently due to covid, I have put together a guide on how we choose our #JConcepts tyres for outdoor off-road here in Australia (where pretty much every track is outdoors dirt of some kind) based on countless hours of testing. Many of our race days start wet, then start to dry out, then groove up, then cool off again in the evening so you need to be prepared for these situations.
Through our testing, we have narrowed down the tyres we carry to 4 tread patterns. There are other patterns in the range which sometimes work in specific conditions but the 4 patterns in the guide below should cover almost every condition you will experience in racing.
4 step process:
I have broken the selection into 4 steps in the order I follow when choosing tyres:
- compound selection
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rear tread selection
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front tread selection
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setup changes
Compound:-
Compound is generally more important than tread pattern, especially on harder surfaces. The ideal compound varies depending on temperature, track moisture and abrasiveness.
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Generally if it's wet, green is the go to compound. Blue is used if it's dry. Black if it's very cold, R2 if it's very hot or abrasive. We use green and blue 90% of the time here in Melbourne.
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There has been a trend to oiled dirt surfaces (using vegetable oil such as canola). When the surface has been freshly oiled, you can use a very soft compound even if it is very hot as the oil takes away the abrasion of the surface. But once the oil has dried, you will need to run a slightly firmer compound again.
Tread Pattern:
- Tread pattern is chosen based on how hard or soft the surface is. Soft surfaces need a sharp pin to dig in (FlipOut). Wet surfaces need open spaced pins to minimise clogging of the tread (DoubleDee). Hard based surfaces with loose or dusty tops need dense pins (Sprinters). And grooved / dust free surfaces like lots of surface area and bars (Ellipse).
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The Sprinter is a great all round tyre which I usually start with unless it's very wet. If you can only have one tyre in your bag, it's this one!!
As soon as the track looks to be grooving, switch to Ellipse. We use Sprinters and Ellipses most of the time, but I keep some Flip Outs and DD on hand in case the day starts wet.
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Rear tyre choice is most important. Front tread pattern is chosen to give a good balance to the rear. The narrower tyres (Rips) tend to be most stable, while a wider tyre like the Ellipse gives the most steering when the track is grooved.
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The insert is generally chosen to match the tyre carcass. The Sprinter and Ellipse have a thinner carcass and give more traction with closed cell inserts. The Flip Outs and DD carcass generally works better with open cell. At the front, closed cell will give more precise steering and more exit steering, whereas open cell will feel a little less responsive on turn in but then feel more stable on exit. I usually match inserts front and rear.
Setup changes:
- Each tyre/surface behaves differently and you need to adjust your setup and driving to compensate. The most common changes we make when we change tyres are to weight bias, rear toe and rear roll centre. This is a complex subject so I encourage you to try some of these changes on your own track and see what you like.
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