For those starting out in motorcycling the type of tyres you choose is usually based on aesthetics rather than purpose or function. That’s fine, but here at Sol Invictus we thought we’d shed some light on understanding tyres and explain how to find the right ones for your motorcycle.
We know it’s easy to be overwhelmed by the jargon and marketing, but to make the right decision it is a matter of understanding how you ride, being honest about your use and abilities, and most importantly, being safe.
Let's start with the basic tyre construction terms:
Tread: This is the part you see that hits the road, and the part most people think about. In general, smoother tread works better on smooth, dry surfaces, and “chunkier” tyres work better off-road. Some street tread patterns are designed to do better in the wet and off-road tyres come in a wide variety for different surfaces, from hard-packed dirt to sand.
Bead: This is the part of the tyre that mates to the wheel. It is typically steel wire covered heavily in rubber. The bead has a snug fit to the wheel to prevent the wheel from slipping rotationally in the tyre.
Carcass: In simple terms, this is the “body” of the tyre under the tread. Motorcycle tyres are typically bias-ply or radial, which refers to how the tyre is constructed.
Sidewall: The area of the tyre that bridges the tread and bead. A small part of the tyre, it is vitally important. It gives the tyre much of its handling and load transfer characteristics. This is the part of the tyre we’re talking about when we reference height, profile, or aspect ratio. Typically, a shorter sidewall yields a stiffer sidewall, which tends to flex less. To a rider, this means better handling and turning, worse bump absorption, and more difficult mounting. This section greatly contributes to the tyre’s role in the suspension.
Cracking the code
First there is the tyre code, with two forms of measurement SI and Imperial it can seem confusing. Imperial is the older way of sizing tyres, using tyre widths in inches followed by the rim size, as in 3.00x18. The modern and more common way is the SI measure.
As an example our Mercury 250 uses a front 110/70-17.
The 110 represents the width across the face of the tread in millimetres. This may not be exactly identical from one brand of tyre to another. Each manufacturer varies slightly, and the curvature of the tyre’s profile can affect the overall measurement, but the tolerances are close enough that one will fit where another goes, as long as you’re sticking to stock sizes.
The 70 represents the aspect ratio. The aspect ratio is the height of the sidewall expressed as a percentage of the width. So, the Mercury stock front tyre has a side wall height of 70 percent times 110 mm or 77 mm.
The next figure you’ll see is the rim size expressed in inches. Our Mercury’s run a 17” rim on both front and rear.
Now that you understand sizing we can talk about tread patterns. This is the more interesting part of choosing a tyre because you can see exactly what the tyre looks like and know that basically the smaller the tread the better it is on-road – the bigger the tread the better off-road.
Below is a selection of tyres we use across our entire Sol Invictus range.
From left to right: Shinko E804/805, Shinko E705, Avon Safety Mileage MkII, Vee Rubber Classic, Shinko E240/270, Bridgestone BT45.
Shinko’s E804/E805 adventure tyre utilises the latest in dual sport tyre technology. These adventure tyres are ideal for situations where a rider spends 40% on-road and 60% off-road.
The Shinko E705 has a versatile tread pattern that provides excellent wet and dry weather adhesion and smooth running on the highway. Designed for 80% road and 20% trail riding.
The Avon Safety Mileage MKII is a classic ribbed front tyre for a vintage style bike and is a perfect match to the Avon Safety Mileage Rear Tyre.
Vee Rubber's VRM 418 is perfect for the classic vintage Cafe Racer look with the zig zag tread pattern.
The Bridgestone BT45 features high grip performance for fun winding road running and good durability.
The matrix below gives you an indication of which tyres will fit our motorcycles.
We hope this will help you decide which tyre you'd like fitted to your motorcycle, but if you're still unsure we are always happy to guide you on your choice to ensure you get the right tyre for your bike.
For pricing on tyres download our custom catalogue.