Cross ply Motorcycle Tyres
The term ‘cross-ply’ denotes a particular way to construct a tyre. On four wheeled vehicles, it has almost entirely given way to ‘radial’ constructed tyres (except on vintage and heavy commercial vehicles) but on motorcycle tyres, it is still a common tyre choice, especially for classic motorcycles, mopeds, scooters and cruisers.
What are Cross-ply tyres?
Cross-ply tyres are also called ‘bias-ply’. They were invented long before radials, by Dunlop in 1888. Radial construction was first developed by Michelin in 1948. A key difference that led to radials becoming standard on cars is the fact that cross-ply were intended for use with inner tubes, whereas radials can dispense with them.
The main difference in construction is that a radial is built on a stiff central belt that gives the tyre less flex and therefore more stability. A cross-ply relies on a woven mesh of interlocking cords instead, and typically has thicker and more-supportive sidewalls.
A variation of cross-ply tyres is called bias-belt. This is a cross-ply tyre with Kevlar belts added to support more weight. They are popular on cruisers. There is also a variation of radials called a “zero-degree” radial which is even stiffer than a normal radial and intended for supporting extra weight.
When building up a cross-ply tyre, each layer of ply is lain down at an angle of up to 75° relative to the direction the tyre rotates and alternating from side to side as each layer is applied. In a radial tyre, the ply is applied at 90° to the direction of rotation.
How to Choose Cross-ply Motorcycle Tyres and Comparison with Radial tyres
Unless you fully understand how different types of tyre will affect your motorcycle, we recommend that you stick with the type of tyres specified in your motorcycle manual. If you are not the first owner of the motorcycle, never assume that the tyres currently fitted are those originally recommended. Always compare each actual tyre with the specifications.
That said, you can often optimise or tailor the performance of your motorcycle to suit your riding preferences by making a careful selection from your tyre options. To do that, you need to understand how the tyre construction may affect the motorcycle’s behaviour in different road conditions.
There are some basic handling differences between cross-ply and radial tyres. In general, cross-ply tend to be nimbler whereas radials tend to hold the road in a straight line. Whether those differences matter depends a lot on the motorcycle and on your riding style. In practice, they are often designed-out by the choice of tyre compound and tread pattern but should still be considered if you are choosing between a radial, cross-ply or hybrid combination.
The central belt helps a radial retain its shape even with heavy luggage or when cornering at speed and this can give the motorcycle more precise handling. On the other hand, a cross-ply can make a motorcycle lighter to manoeuvre and more comfortable.
A cross-ply is also lighter and for that reason they are popular for off-road sport motorcycles and scramblers. Their stiffer sidewalls are resilient to impacts and under muddy riding conditions let you lower their pressure for more grip.
Cross-ply tyres are also more inclined to distort under load – whether due to weight or due to manoeuvring forces. Occasionally this can be to your advantage: for example, it can result in a more comfortable ride which is important for heavy motorcycles like Triumph Bonneville and Harley Davidson cruisers. On the other hand, it can lead to less reliable performance under heavy torque so fast riders are safer with radials.
Although radials are becoming more common, riders can still choose cross-ply to get the performance improvements they want, provided that the tyres match the Load Rating and Speed Rating Index prescribed by your manual.
Combining Different Types of Tyre
Front and rear motorcycle tyres are usually different sizes and although they do a different job (steering/traction) they are usually shipped from the factory gate with a matching pair that carry the same brand name and range. By choosing matched tyres in this way, you can be confident they work well together.
However, it is perfectly possible for different branded tyres to work well. When buying a new tyre there is no guarantee that the exact tyre you are replacing is even still available, so clearly you are at liberty to consider alternatives. In fact, it is often possible to improve a motorcycle by carefully choosing a different brand or even a different type of tyre.
Mixing radials and cross-ply on the same motorcycle can be problematic. Manufacturers strongly recommend against mixing a radial on the front with a cross-ply on the rear. Their different behaviour in those locations is potentially dangerous. The reverse is safer – offering improved stability at the back and nimbleness at the front. In fact, race motorcycles often choose the cross-ply front/radial rear combination.
Safe tyre combinations
| Front tyre | Acceptable rear tyres |
|---|---|
| Cross-ply | Cross-ply, bias-belt, radial or zero-degree |
| Bias belt | Bias-belt, radial or zero-degree |
| Radial | Radial or zero degree |
| Zero degree | Zero degree |
Remember that whatever kind of tyres you choose, they must both match or exceed the Load and Speed ratings prescribed by the manufacturer for your particular motorcycle. Not all motorcycle tyres are marked, but you may see the parameters imprinted on the sidewalls of your current tyres or on the packaging of a new one. If the tyre is metric, the specification may look like the following:
130 / 90 – 16 67 H
In the above example, 130 is the section width in millimetres, 90 is the aspect ratio, 16 is your rim diameter, 67 is the load rating and the final letter ‘H’ is the speed rating. The first three designate the physical dimensions of the tyre so that it will fit your motorcycle. The Load Index denotes the maximum weight that tyre is designed to carry and you must only fit a new tyre that is equal to or greater than the Load Index specified in your motorcycle manual because it is motorcycle specific and vital for your safety. Similarly, the Speed Rating denotes the maximum speed at which the tyre can safely travel and you must choose one equal or greater than the maximum your motorcycle might ever reach. This is specified in your manual.
The following charts show you exactly what each Index and Rating actually mean.
Motorcycle Cross-ply Tyre Load Index
| Code | Kg |
|---|---|
| 31 | 109 |
| 32 | 112 |
| 33 | 115 |
| 34 | 117 |
| 35 | 121 |
| 36 | 125 |
| 37 | 128 |
| 38 | 132 |
| 39 | 136 |
| 40 | 140 |
| 41 | 145 |
| 42 | 150 |
| 43 | 155 |
| 44 | 160 |
| 45 | 165 |
| 46 | 170 |
| 47 | 175 |
| 48 | 180 |
| 49 | 185 |
| 50 | 190 |
| Code | Kg |
|---|---|
| 51 | 195 |
| 52 | 200 |
| 53 | 206 |
| 54 | 212 |
| 55 | 218 |
| 56 | 224 |
| 57 | 230 |
| 58 | 236 |
| 59 | 243 |
| 60 | 250 |
| 61 | 257 |
| 62 | 265 |
| 63 | 272 |
| 64 | 279 |
| 65 | 289 |
| 66 | 299 |
| 67 | 307 |
| 68 | 314 |
| 69 | 324 |
| 70 | 335 |
| Code | Kg |
|---|---|
| 71 | 345 |
| 72 | 355 |
| 73 | 365 |
| 74 | 375 |
| 75 | 387 |
| 76 | 400 |
| 77 | 412 |
| 78 | 425 |
| 79 | 437 |
| 80 | 450 |
| 81 | 462 |
| 82 | 475 |
| 83 | 487 |
| 84 | 500 |
| 85 | 515 |
| 86 | 530 |
| 87 | 545 |
| 88 | 560 |
| 89 | 580 |
| 90 | 600 |
Motorycycle Cross-ply Tyre Speed Index
| Index | mph |
|---|---|
| B | 31 |
| C | 37 |
| D | 40 |
| E | 43 |
| F | 49 |
| G | 55 |
| J | 62 |
| Index | mph |
|---|---|
| K | 68 |
| L | 75 |
| M | 81 |
| N | 87 |
| P | 93 |
| Q | 99 |
| R | 106 |
| Index | mph |
|---|---|
| S | 112 |
| T | 118 |
| U | 124 |
| H | 130 |
| V (&Z) | 149 |
| W | 168 |
| Y | 186 |
Don’t confuse the Speed Rating with letters in the name and model of the tyre. A letter ‘B’ here may just stand for “Bias” and an ‘R’ often means the tyre is “Radial”.
Choosing your Motorcycle Cross-ply Tyres
Although you can choose tyres to tweak the performance of a motorcycle to suit your riding style, there is a basic consideration you should not ignore. Vintage motorcycles that were designed when the flexible cross-ply tyre was the norm did not need as much suspension. If you swap in a stiff radial tyre, that suspension will have to work harder than the original designer anticipated and consequently you may accelerate the wear rate of its components.
Conversely, switching a motorcycle designed for radials onto cross-ply will likely make your ride more comfortable and actually reduce wear on your suspension. However, the handling will probably become a little more sensitive at speed.
If you want the benefits of a different type of tyre without the penalties, a good motorcycle mechanic can often make other minor adjustments to compensate (for example, bracing the swing arm). The tyre professionals at any approved garage will be happy to advise you whether the transition is likely to achieve the performance improvements you want.
The easiest way to choose your new tyre or tyres is to use our online tyre finder, which collects all the leading brand names in one place and makes it easy to compare their performance ratings with one another. You can also type in your motorcycle VRN number to get instant recommendations.
Many popular tyre ranges offer both cross-ply and radial versions. Examples include the Metzeler Roadtec and the Avon Road Rider family. Other popular cross-ply premium motorcycle and scooter tyres will be found in the Pirelli Sport Demon and Angel City ranges. We also recommend the Bridgestone Battlax BT-45, especially for classic motorcycles.
Choosing the ideal tyre that will optimise your motorcycle’s performance, safety and fuel economy used to be a difficult business, but today the internet makes it easy. You can easily browse the options online and find a local garage that specialises in motorcycle tyres, or call Oxford Tyre Centre on 01865 590523 for free advice.
