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ADV News10 Things To Know When Selecting Dual Sport Tires For Your ADV Bike

10 Things To Know When Selecting Dual Sport Tires For Your ADV Bike

Dunlop’s top dual sport tire tech answers all your burning questions.

Published on 05.06.2021
best dual sport tires

Dual Sport Tires have some of the most challenging requirements of any style of tire in motorcycling. They are expected to do a little of everything from sand and mud to wet pavement and gravel roads. But of course, no single tire can do it all. Manufacturers must consider the intended purpose during the design process, such as the time spent ‘on’ versus ‘off’ road, the type of terrain it will excel in, the size of the bike it will go on, and how long it should last. Fine tuning the performance characteristics at one end of the spectrum can often take away from the other. With so many different options available, a better understanding of the intricacies of Dual Sport Tire design can assist you in making more informed purchasing decisions.

To bring some clarity on this topic, we reached out to Dunlop’s top motorcycle tire tech — Ron Winkelman — who’s been working in the industry for 33 years in all facets of tire development. Previously, Ron shared his insights on how to get the most out of your dual sport tires. Now he sheds light on some of the common questions about tire selection that are prevalent in the adventure riding community.

1.) What can the tread characteristics tell you about the purpose of the tire?

selecting dual sport tires

Ron Winkelman: Typically, a good sand, mud and loose terrain tire will have a knobby lug pattern approaching a paddle design — large center lugs with a lot of open space between the lugs. The lugs may also be designed with a U or V-shaped pattern, allowing them to scoop more dirt with each rotation. Good rocky terrain tires will have a combination of large lugs with a deep pattern. You can also check the sidewall of the tire to see the number of plies and materials used in its construction. For example, the Trailmax MIssion 150/70B18 has 5 plies (3 Polyester + 2 Fiberglass) going across the tread, which give it a lot of puncture resistance, and it has 3 Polyester plies going down the sidewall, so the sidewall is very strong. A good pavement tire for both dry/wet conditions should have a closed pattern with a higher land-to-sea ratio (more tread area compared to grooves cut out), which will provide a larger contact patch. Those are just a few of the general characteristics to look for.


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2.) What design features make some dual sport tires noisier on asphalt?

RW: Noise on pavement is mostly caused by the tread pattern interacting with the road surface. Dual Sport tires with aggressive deep lugs will generate more noise than a smoother pattern. Tire engineers will want to design a tire with the optimal tread pattern for a specific tire usage or handling characteristics, and sometimes that may lead to a noisier tire. But there are ways to control noise by adjusting the number of pattern pitches, sequences and pattern depth.   

3.) Is it OK to deviate from the bike manufacturer’s recommended tire size?

RW: Anytime you decide to use a non-standard tire size, you are changing the tire’s profile, which changes the contact patch on the road. This will affect load and speed ratings, handling and performance, and even wear rate. In some cases, changing the tire size will require you to change the wheel width as well. Be extremely cautious when changing from the standard tire size the bike was designed for. 

If you do decide to go with a non-standard width, keep in mind that load and speed ratings follow tire sizing. Reducing the width will lower the tire’s load index. For example, a 150/70B18 TrailMax Mission Adventure Tire, with a load index of 70H, has a Max Load of 739 pounds at 41psi. If you go down to a 140/70B18, with a load index of 67H, the tire has a Max Load index of 677 pounds at 41psi. You just reduced your load carrying capacity by 67 pounds! 

Dunlop Load Index and Speed Rating chart
Dunlop Sidewall Codes

Increasing the width of the tire may improve traction by increasing the size of your contact patch on the road surface. Going up a size will also increase load carrying capacity, but you do need to be cautious about tire clearance issues. Adequate clearance of fenders and the swingarm need to be maintained. Also, be aware a tire will experience dynamic growth when driving down the highway, increasing in diameter so you need to account for this. 

4.) What’s Better? Radials,  Bias Ply or Both?

RW: Bias Ply tires generally have stiffer sidewalls. However, they can also be heavier tires and don’t dissipate heat as well. Radial tires have thinner sidewalls and typically offer better performance on the street at faster speeds. But, the Radial tire’s thinner sidewall is also more susceptible to punctures that are more likely to occur off-road. They typically have a lower profile and require wider rims as well. For this reason, Radials are more commonly found on larger, street-oriented adventure touring bikes rather than small dual sports.

Dual Sport Tire ply rating

Typically you don’t want to mix Bias Ply and Radial tires because it can cause instability in the handling. Only do this if the vehicle manufacturer states the bike can be fitted as such or if the tires are the same brand and model. An example of this would be the Honda Africa Twin and the Yamaha Tenere 700 which both come standard with a Bias Ply up front and a Radial in the rear. Also keep in mind with Radial Tires on tube-type rims, you should only use Radial Tubes (look for the ‘R’ marking) that are of a matching size. Some riders may choose to use something different in a pinch when far from home. If you do, remember to reduce your speed and ride with caution until you can get the proper tube installed in your tire.

5.) How do Tubeless differ from Tube Type tires in their design?

RW: The beads are designed the same but a Tubeless tire is manufactured using a special inner-liner compound which prevents air from leaking out through the tire. Tube Type tires don’t have this compound and require a tube to hold air. If you try to mount a tube-type tire on a tubeless rim, it will hold air only for a short time before leaking out. And of course, you must also mount Tubeless Tires on a Tubeless style wheel (most spoke wheels are not Tubeless compatible) in order to have an airtight seal. You can fit Tubeless tires with an inner tube on a Tube Type rim. However when you do this, the tube adds weight and friction that creates extra heat in the tire. Therefore, it is necessary to reduce the speed and load rating of the tire by one step. For example, a tire with a ‘T’ speed rating (max 118 mph) should be treated as an ‘S’ speed-rated tire (max 112 mph). Likewise, if the Load Index of the tire is a 57 rating (507 pounds), it goes down to a 56 rated tire (494 pounds).

Best Adventure Tires

6.) What factors might significantly increase the cost of a dual sport tire?

RW: This is a difficult question to answer because many factors go into the cost of a tire. A single tire is made using many different compounds and materials. Those materials are made into the many components used to build a tire. Where the manufacturer purchases materials and builds the tire, also affects the price too. Changing just one aspect of the tire manufacturing process can have a significant impact on the price. One simple example would be reducing rubber thickness in the sidewall and tread. This might lower the cost while also resulting in a less puncture-resistant and lower mileage tire. Tire mold tooling can also be a factor. The type of mold material, how complex a tire pattern and design are, and how many tires a mold can produce all affect the price. 

7.) What are some of the challenges of designing a Dual Sport tire?

RW: When designing a motorcycle tire strictly meant for either off-road or pavement, you can concentrate on finding the best profile, pattern and compounds for that specific application. Designing a Dual Sport tire is extremely challenging because the tire needs to perform at some level on a variety of riding surfaces which can span off-road terrain that ranges from gravel, sand, rocks and mud to paved roads with dry, wet, icy or even snow. There is no magic unicorn tire out there that handles so many different types of terrain equally. This is why you find dual sport tires marketed as a percentage of road versus off-road use. However, this percentage is only a guideline and is open for interpretation. 

Dunlop Trailmax Mission adventure tires

8.) Is there a standardized street/dirt rating system for Dual Sport tires?

RW: It is important to note, there is no standard regulatory metric that tire manufacturers must comply with to call a tire 50/50 or any other range for that matter. The rating is up to the tire manufacturer. The 50/50 category is the most heavily debated for good reason – because it is the ultimate compromise position. but it’s up to the manufacturer to decide. 

When Dunlop is designing a dual sport / adventure tire, the rating 70 street and 30 dirt would be a tire that performs better on the pavement. A consumer looking for a 70/30 tire most likely rides more pavement and any dirt use would be non-aggressive areas like a fire road. You’ll notice the Tread pattern is what changes the most when looking at various adventure tires and what the manufacturer says the percentage is. Compound will also play a big roll. A tire meant to be ridden in the dirt 70% of the time needs to have a compound with better cut, chip and chunking resistance. A tire meant to be ridden on pavement 70% needs to have better wet, dry performance. The challenge with adventure tires is everyone wants that illusive Unicorn tire that works perfect in every riding condition. 

Best dual sport knobbies

9.) Does a ‘competition’ level knobby tire that is also DOT approved have to make some sacrifices to be given street-legal approval?

RW: The decision to make a tire DOT approved is a marketing decision made by each manufacturer. For any tire to be street-legal DOT, it needs to go through various dynamic and static tests in a lab. A tire manufacturer has a list of test requirements that it must meet in order to supply tires for use on public roads. Sometimes sacrifices in performance are made to make a knobby tire meet DOT standards. One example might be reducing the knob height in order to pass the DOT high-speed test.

street-legal knobbies

10.) Sometimes you see Adventure Tires that are in the 80/20 (street/dirt) range that look like a normal street tire. What makes them any different?

RW: The rubber compound of the tire tread being used is probably the biggest design difference. While they may look similar, the compound used may improve the cut, chip and chunking resistance in the dirt. But it all depends on the tire.

BONUS QUESTION: Why do some smaller tires use inches (e.g. 3.0×21) instead of metric sizing?

RW: Tires with the sizes stamped in inches or alphanumeric are just an older way to ID the tire size. As larger sizes and radials became the norm, it required a more complex ID system, which is why most tires use metric stamping now (e.g. 150/80B16). You can use Dunlop’s size converter chart to help determine the correct conversion from Metric. For example: 80/90 Metric is MH90 Alphanumeric for 2.5 to 2.75 Inches.  

Dunlop tire size conversion chart.

Photos by Sam Bendall, Stephen Gregory, Jon Beck and Alfonse Palaima

Author: Rob Dabney

Rob Dabney started a lifelong obsession with motorcycles at the age of 15 when he purchased his first bike – a 1982 Honda MB5. Through his 20’s and 30’s he competed in off-road desert races, including the Baja 250, 500 and 1000. Eventually, his proclivity for exploration led him to dual sport and adventure riding. Rob’s never-ending quest to discover what’s around the next bend has taken him on Adventures in Mexico, North Africa, Europe, and throughout the American West. As a moto journalist, he enjoys inspiring others to seek adventure across horizons both near and far.

Author: Rob Dabney
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15 thoughts on “10 Things To Know When Selecting Dual Sport Tires For Your ADV Bike

  1. Great job, Rob and Ron. I learned a few things I didn’t already know — things that will enable me to make better choices when choosing and using tires.

  2. The Africa Twin can roll along nicely on a flat Kenda Big Block. I rode about 25 miles on a flat rear tire a few months ago because I was just a step ahead of a nasty winter thunderstorm. The AT was able to roll along at 50 mph on the flat rear Kenda and the tire never tried to roll off the rim. I think I could have gone faster but I didn’t want to push my luck to much. The tire was still firmly seated to the rim when I got home. That is a very desirable characteristic in a tire.

    • Sounds like a harrowing experience! You are lucky that experiment worked out. That is definitely not something anyone should try but interesting to know the tire held up.

      • There was nothing harrowing about the flat. I’ve been riding for 50 yrs and I’ve ridden many bikes on flat tires. I expected the weight of the AT to overwhelm the flat tire but it didn’t. That was unexpected.

  3. I believe I am one of the first to obtain and use the (relatively new) Dunlop Trailmax Missions, on my 2016 Yamaha Super Tenere. I posted this information on the Yamaha Super Tenere forum, but stuff like this kind of feedback can quickly get “lost in the noise”. Since I believe RW may be interested, I will provide my user experience for these tires. I am a conservative rider by nature, and a missile SW engineer by profession (think: Conservative). The Missions replaced the OEM Bridgestone tires, front and rear together, at March 2020. I now have 3500 miles on them. I am a 90/10 rider (street/offroad) on this cycle, and I fitted these because I have 1/2 mile (1 mile round trip) of graded sand / gravel / small rock mix from pavement to my house. I believed these would help me prevent a “drop” getoff while driving home that last bit. I normally inflate cold (morning check) to 33 PSI front, 36-38 PSI rear (single rider, no luggage load). On pavement, I experience a howl from the front, onset beginning at about 50 MPH, and the howl is basically drowned out by road noise above 65 MPH. The rear gets very hot and the inflated pressure goes up pretty dramatically with even small amounts of freeway speed (70-80 MPH). Rear inflation checked after a ride will typically show around 48 PSI. I was astonished by this at first, and put it down to “tire break-in”. But, this “feature” has not changed. I tried increasing the rear cold pressure to 40+above PSI in small increments, (believing low inflation = higher temps). This did not help. The cold-to-hot differential stayed pretty constant. So, for me, anything much over 38 PSI cold for the rear, was a non-starter. My .02, for Mr. RW. Again, my thanks. I will likely be looking elsewhere for my next set because of these conditions.

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