What’s the best tyre for my classic bike? How to choose motorcycle rubber…

The term ‘classic’ can now cover a huge range of motorcycles, from Nortons, BSAs and Hinckley Triumphs, to original Honda FireBlades and Suzuki GSX-Rs. With often unusual tyre sizes and older construction methods – not to mention spoked wheels – it can be hard to know what the best tyre is for your machine.

Technology has moved on, so we spoke to Gary Hartshorne, Senior Motorcycle Product Manager for Bridgestone North Europe, to find out how to choose the best rubber…

Gary Hartshorne is one of the most enthusiastic bikers you’ll meet…

How to choose the best classic bike tyre

If you’ve got a more recent sports bike, you’ll likely be looking at modern rubber – you can find advice by clicking here, but we’ve split the classics into two groups – these are Gary’s recommendations, and we’ll explain why in a moment…

Does my bike have cross-plies or radials?

Between 1986 and 1990, bikes went from cross-ply to radial tyres, so check in the handbook or with the manufacturer what it should have been fitted with when it was built. Don’t go by what it has now, as unless you’ve owned it from new, it could have the wrong tyres.

Cross-ply tyre are still used on many machines, like off-roaders, as well as modern Bonnevilles and others – they’re not an outdated technology, just a different construction.

Can I fit radial tyres to a bike that had cross-plies?

A cross-ply tyre is very pliable, while radials are stiffer – they were designed for bikes with much less power than we see today.

On a cross-ply, the body ply is laid at 75° or less relative to the direction of rotation, alternating from left to right as they overlap. There’s also a bias-belted cross-ply, which has a strengthening belt, making the carcass slightly stiffer.

A radial has the body ply at 90° to the direction of rotation, and is stiffer than a cross-ply; it’s sometimes called a cross-belt radial.

Stiffer still is the zero-degree radial, which also has the body ply at 90°, but a steel cord or strands (Bridgestone uses HTSPC: High Tensile Super Penetrated Cord) wrapped all the way around the circumference of tyre – from one side to another – to make it extremely stiff (there are alternatives to steel, though these can be more prone to punctures). Modern touring bikes might use a cross-belt radial on the front, for comfort, and a zero-degree on the rear to take the weight of luggage and a pillion.

The zero-degree radial (or mono-spiral belt) that uses steel is the least prone to expanding under high speeds, hence its use on modern race machines as there’s minimal change to the bike’s geometry when centripetal force tries to make the tyre bigger.

A tyre forms part of any bike’s suspension, so as machines built 30 or so years ago were designed to work with soft cross-plies, putting a stiffer radial on will create an ill-handling motorcycle as the additional forces that the suspension has to cope with will be transferred to the chassis. Unless the frame and swing-arm are braced, a bike designed to use cross-plies should not use radials.

Can I mix cross-plies and radials on a motorcycle?

Yes, you can fit a cross-ply front to a motorcycle, with a radial on the rear, but it’s illegal to do it the other way around. Basically, you can only put the more flexible tyre on the front, which gives you various options, but the safest answer is to take the advice of the tyre manufacturer.

Cross-ply and radial mixing options

What if my bike has awkward wheel sizes?

Bikes like the original Honda FireBlade have 16” front wheels, which reduces the options available, but there are still plenty of tyres to choose from, including Bridgestone’s Battlax BT-45 and the S21. Check the tyre manufacturer’s website for the recommended fitment, or give the company a call – any good tyre manufacturer will be happy to guide potential buyers towards the most suitable rubber in its range.

Will classic bike tyres grip well?

Yes – while the tyres recommended here by Bridgestone are models that have been around for a while, they’re were always designed to cope with the performance of these machines, including sports bikes. They’re also cheaper than the top-end sports tyres of today like the S22, but it’s generally not worth spending the extra money on rubber that your bike can’t take advantage off.

Does it matter if I have spoked or cast wheels?

If you have spoked wheels that don’t have sealed spokes, you’ll have to use a tube.

What’s important to know is that wheels rims have different designs, so while you can use a tube in a tubeless tyre on a tube-type rim, you mustn’t put a tube-type tyre on a tubeless rim, as the bead won’t fit securely.

What are the best classic tyres in the wet?

Any road tyre is designed to look aesthetically pleasing, but of course the grooves have also got to pick up water and throw it to one side, leaving a relatively dry patch of tarmac for the following ‘slick’ section of rubber.

The way the tread is designed will influence its ability to shift water, and that goes right down to the angle the grooves are cut into the rubber. These grooves also have to work as the tyre moves and deforms when it meets the road – it’s no good just having a slot in the rubber that looks pretty; it must be designed to maintain an efficient shape within its specified load and speed rating (that’s one reason why so much R&D goes into tyres).

Tyres are designed as pairs – if the front is engineered to disperse a certain amount of water, the rear must be able to cope with what it leaves in its path.

How long should my classic tyres last?

How many years or miles your tyres will last depends on many things, but the most important point is to regularly check the pressures; while tyres do have a liner built into the carcass, they’re still porous, so will slowly lose pressure – up to 2-3psi in a month.

How you ride also has a big influence – and not just whether you’re doing burn-outs; a smooth rider will see their tyres last a lot longer than someone who’s more aggressive on the throttle and brakes. Take a tyre used in short-circuit racing for example (let’s say Donington Park), the same one might be used at the same pressure and temperature at the Isle of Man TT. While Donington would have the riders on and off the brakes – hard – constantly, the TT sees fast and smooth riding. In 20 laps (50 miles), Donington would likely destroy the tyre, but six laps of the TT, covering 226 miles, would probably see it in far better condition.

How do I scrub in my classic bike’s tyres?

The industry guideline is a recommended 200 miles, but that is for the safest margin. Keep banking over a little at a time, so as you lean, your contact patch is half scrubbed in, half fresh; lean incrementally. And no sudden braking or acceleration; it’s not just the speed or the lean angle that can cause a problem on new tyres – it’s more the brake force or acceleration.

Of course, a tyre can be scrubbed in within one lap on a track with a fast rider, but on the road, just ride smoothly and gently while building up your lean angle.

A common perception used to be that scrubbing tyres in was about getting rid of the release agent that was used when removing the tyre from the mould, but not all manufacturers use this anymore; Bridgestone for instance has such precise moulds that there’s no need. But a tyre still needs its surface ‘roughing up’ (like a new pair of leather-soled shoes), and the plies within the carcass also have to settle into each other.

Another point to consider is that the tyre will likely have been fitted with ‘soap’ – it’s possible for a new tyre to spin slightly on the wheel during hard acceleration when it’s just gone on, which will throw it out of balance, though this should be less of an issue on lower-powered machines.

Finally, when you replace your tyres, the bike will feel very different as you’ll have been riding for a long time on rubber with a more worn, and hence different shape; you need to give yourself time to acclimatise to the new hoops.

What pressures should I run my tyres at?

While most modern bikes will likely have a sticker on the swing-arm stating what pressure to use, if that even existed on an older bike, the chances are it’s long gone now. Equally you’re far less likely to have the owner’s handbook. The best place to go is the tyre manufacturer – just select your bike on the website, or give them a call. You might get the right answer when asking on a forum, but there’s also a good chance you’ll get someone’s opinion, rather than the correct – and safest – figure.

Motorcycle manufacturers don’t randomly choose their own pressures – it’s dictated by the maximum load on the bike, so you’ll sometimes see recommended pressures based on solo riding, and when fully loaded, but that’s the only variable: the correct pressure is the one given to you by the manufacturer of the bike or of the tyre recommended for that bike.

In Europe the European Tyre and Rim Technical Organisation (ETRTO) stipulates what size of tyre goes on a certain size of rim, and what pressure goes in it under a certain load (in Japan it’s JATMA, the Japan Automobile Tyre Manufacturers Association).

Don’t drop your tyre pressures when riding in the wet either – this will cause the tyre to deform, reducing not only the contact patch, but also closing up the tread grooves when they meet the road, making water dispersal less effective. The leading tyre manufacturers – like Bridgestone – have spent years and years, and millions of pounds, developing tyres to work at specific pressures, so use them.

The only time you might drop tyre pressures is when riding hard on track; a newcomer should stick to standard pressures, but an experienced rider might reduce the pressure to take into account the higher temperatures that will be achieved, as this increases the pressure in the tyre beyond that of ‘normal’ riding.

How should I store my tyres, and how long will they last?

If your bike’s being stored for a while without being ridden, you should ideally use paddock stands to get the rubber off the ground. As all tyres slowly deflate over time they’ll start to deform a little with the weight of the bike on them in one spot; getting the motorcycle up in the air will cure this.

If you can’t lift the bike up, check the pressures every week, and rotate the wheels through 90°. Also keep some carpet under the tyres, to insulate them from cold concrete – in a very harsh winter, the freezing temperatures can push the rubber to its ‘glass transition point’ and it will start to become brittle.

If the bike’s not on stands, you can also pump the tyres up to the maximum pressure indicated on the sidewall, but you must leave a note on the tank to remind you to drop them back down to the correct pressure before you ride.

If you’re storing loose tyres, or wheels with tyres on, keep them laying on their side in the loft or under the bed. The main thing is to keep them out of the cold and away from sunlight.

To check how old a tyre is (as long as it was made after 2000), look at the last four digits that appear after the DOT code – the first two are the week it was made, the second pair are the year; for instance, 1518 would be a tyre made in the 15th week of 2018.

What if I don’t like the OE tyres that came with my bike?

During development, motorcycle manufacturers don’t test their bikes with every set of tyres available – some brands might use just one, others might use several. From this data will come the bike maker’s recommended fitment, but all tyres are made to conform to European Tyre and Rim Technical Organisation (ETRTO) specifications, so within the axle weights, maximum speed and sizes, there will be other options that can safely be recommended by other brands.

Some top-of-the-range motorcycles, like the BMW S1000RR, will come with top-spec tyres, but others might have rubber that’s been designed specifically to be sold with the bike when new. These could look the same as similarly-named tyres, but might have one or two extra letters at the end if their name.

Just one example of this is a pair of sports tyres that might be single-compound for the bike that they come with (like the Bridgestone RS10G on the Yamaha R1), but multi-compound when bought after-market (the Bridgestone RS10). A single compound tyre is of course less costly to produce, so a bike manufacturer might specify that as part of its requirements when developing the machine, but they could last fewer miles than the after-market versions.

No bike manufacturer can tell you that you must use a specific brand of tyre – what matters is that you stick to the correct sizes and load/speed ratings, and that you run them at the correct pressures. Each tyre manufacturer will offer a list of recommended fitments, then you can choose which best suits your riding style.

Bridgestone’s choice.

Bridgestone’s Gary Hartshorne explains how to choose the best bike tyres

What about other brands?

We worked with Bridgestone to explain how to choose the best tyres for your classic motorcycle bike – once you understand how and why they’re made the way they are, you’ll be better equipped to buy the right rubber. We also asked the other most popular manufacturers for their recommendations. Of course, these are a general recommendation, and not specific to a particular bike, so always check the fitment for your motorcycle…

Bridgestone recommended classic bike tyres

I have a classic that takes cross-plies: Battlax BT-45

I have a classic that takes radials: Battlax BT-023, or BT-016 Pro for a sports machine

Anlas recommended classic bike tyres

I have a classic that takes cross plies: NR,NF

I have a classic that takes radials: Not available

Avon recommended classic bike tyres

I have a classic that takes cross plies: Speedmaster, Safety Mileage

I have a classic that takes radials: Not available

Continental recommended classic bike tyres

I have a classic that takes cross plies: Conti Go or City

I have a classic that takes radials: Classic attack

Dunlop recommended classic bike tyres

I have a classic that takes cross plies: TT100 / K82 / K70

I have a classic that takes radials: Not available

Maxxis recommended classic bike tyres

I have a classic that takes cross plies: C6501/2 Magsport  /  Promaxx

I have a classic that takes radials: M6029 Sport/Touring

Metzeler recommended classic bike tyres

I have a classic that takes cross plies: Pilot Activ

I have a classic that takes radials: Road 5

Michelin recommended classic bike tyres

I have a classic that takes cross-plies: Pilot Activ

I have a classic that takes radials: Road 5

“The named tyres are in general one of the most appropriate tyres for the stated type of bike and use. These generalisations are not Michelin recommendations. The law, the specific bike and the intended use are all factors that must be considered when determining the correct choice of tyre. Always seek expert advice if in doubt.”

Pirelli recommended classic bike tyres

I have a classic that takes cross plies: Sport Demon

I have a classic that takes radials: Phantom Sportscomp