ADV TIRES FOR YOUR ADVENTURE BIKE

Tire Pressure

Bike OEM vs Tire OEM tire pressure recommendations.

Unless you are running OEM tires it is recommended to refer to the tire manufacture for recommended pressures. Although most tire manufactures will refer to the OEM pressures this is not always the case. Pressure recommendations are normally solo, with a passenger or load and in some cases off-road. I did a video here about tire pressures and how they relate to contact area. The results coupled with manufacture recommendations showed that on the front tire we are normally 10%-15% below the maximum pressure and on the rear we are at the maximum load pressure or down 10%-15%. It was also discovered that below 20% often results in a severe lack of rim protection, decreased stability and increased deflection. In short when the tires are engineered the amount of pressure inside the tire is calculated. We are actually riding on a cushion of air and if it is reduced too far the tires can no longer function as they were designed. Be careful about the “air down” advice that is so prolific on the internet and amongst riders. Your goal is NOT to air down but rather to create the most efficient air cushion of air to maintain tire stability, control tire temperature and provide rim protection.

Pressure for maximum load vs optimal pressure:

On heavy ADV bikes it is common to see the maximum load pressure be the pressure that is recommended however you will seldom see the maximum load pressure recommended for the front tire. The maximum pressure is not the maximum pressure of the tire but rather the pressure at which the tire what tested for it’s load rating. Increasing or decreasing the air pressure alters that maximum load. As a general rule there are seldom advantages to running pressures beyond the maximum load pressure. I normally recommend not reducing tire pressure more than 10%-15% from the maximum load pressure assuming you have no guidance from the tire manufacture. If you are planning on running lower pressures you should contact the tire manufacture for their guidance.

Tube type vs tubeless type tires:

Generally speaking you choose the tire type that matches your rim type. This is most critical with a tube type rim but is also consideration if you want to use a tubeless type tire on a tube type rim.

Tube type tires:

If you have a tube type tire you must run a tube in the tire even if you are running it on a tubeless rim. Tube tire are not designed to seat on the bead the same as a tubeless tire. If you have a tube type rim and seal the spokes to create a tubeless option this could be unsafe as the bead on a tubeless rim is designed differently than a tube type rim where the pressurized tube is used to hold the tire on the rim whereas as a tubeless rim there is a raised lip to assist in keeping the tire seated on the bead in the case of a flat tire.

Pros: Tube tires are most often on spoked rims which handle the abuse of rough terrain better than cast rims. Spokes are also often lighter than cast rims giving an unsprung weight advantage however it is becoming far more common on large adventure bikes to see tubeless spoked rims.

Tubeless type tires:

These tires generally have the advantage of being lighter, running cooler and being safer in the case of a flat tire. Tubeless tires are more likely to deflate slower than a tube tire when being punctured. You can safely run a tube in a tubeless type tire if you need to but is doing so you lose all the advantages of the tubeless tire over a tubed tire. Running a tube in a tubeless tire can be done safely if you have a spoked rim that is not a tubeless type rim and the only (or preferred) tire is a tubeless type tire. If you do run a tube in a tubeless type tire it is recommended to treat the tire as if both the load and speed rating are one below the sidewall ratings. This is primarily due to the extra heat that is created through the extra friction and material. When possible run tubeless tires on tubeless rims and tube type tires on tube type rims.

Pros: Tubeless tires are generally lighter, run cooler and can be safer in the case of a flat tire.

1. INTERNAL DESIGN

Internal design is another adventure motorcycle tire design consideration that isn’t visible to you as the buyer. The materials, layers, and other engineered factors may give the tire a stiffer sidewall (making it more resistant to rim damage) or a more compliant sidewall (giving you pliability that can enhance performance features at the risk of sacrificing protection).

1.a. BIAS PLY TIRES

Bias ply tires still exist heavily in the ADV tire world and for good reason. Bias ply tires have cords banded in a crisscross pattern of 30 degrees to 45 degrees, creating a uniform thickness around the tire. This may have the disadvantage on the street of creating a rougher ride, but offer the advantage off-road of exceptional strength in the sidewall and a high resistance to punctures. Although bias tires are more resistant to damage, this is exchanged for increased weight.

Bias tire pros: Strong sidewall, puncture resistant, handles high loads well, improves lifespan, sidewall stability is greater at lower tire pressures.

1.b. RADIAL TIRES

Radial tires use cords or belts running perpendicular to the tire giving the ability for the sidewall and tread to have different properties. These are more common on wider tires and higher speed rated tires. Although radials can reduce unsprung weight and offer higher street performance, they are more susceptible to sidewall punctures and are often (not recommended) to be used with tubes.

Radial tire pros: Lighter weight, improved wet weather properties, excellent all around performance

In general, bias ply tires get the nod if your goal is to ride off-road.

Radial tires and bias ply tires can be mixed safely on a motorcycle; many bikes are sold with OEM tires that are mixed. The grandfather of ADV tires, the Continental TKC 80 Twinduro as well the more modern designs of the Bridgestone AX41 Adventurecross, come mixed as both radial and bias ply depending on the tire size. This is also common amongst other manufactures such as Metzeler, Michelin and Dunlop.

To easily identify if a tire is radial of bias ply, look at the tire sizing and it will be listed between the aspect ratio and rim diameter. A radial tire will always be marked with an “R” whereas a bias ply will have a “B” or nothing at all.

Example: 160/60ZR-17 is a high speed rated radial tire as indicated by the “R”. 150/70-17 or 150/70B-17 would be a bias ply construction as indicated by the “B” or absence of a letter.

2. TIRE COMPOUND

Tire compound is independent of tread gap and certain tire compounds may be used to improve the tire’s resistance to “chunking” in rocks, more soft for cornering on the street or climbing slick rocks, or more resistant to rounding off the sharp edges needed for traction off-pavement. There is no way to know this other than manufacturer claims, reviews and experience. Sometimes the names may give it away, but that can be misleading.

As an example the Dunlop D908RR and the MotoZ Tractionator Rallz are both long-wearing 50/50 tires with hard wearing compounds that do well in deserts and rocky environments and offer longer life on the pavement than the average 50/50 tire, but they are dangerously compromised on surfaces that do better with friction traction over thrust such as slick rock or wet roads. On the other hand, the popular Michelin Anakee Wild is a fantastic performing tire on pavement, in sand, rock and dirt but is a premium-priced tire that wears quickly. So, what is most important to you?

3. TREAD DEPTH

Tread depth is also a factor in off-road traction by allowing tires to dig into soft surfaces in order to increase grip or thrust. Most ADV tires have shallow channels compared to dirt bike tires because the tire manufacturers need to balance the off-road performance with on-road performance. After all, we are on adventure or dual-sport motorcycles, not dedicated dirt bikes. The manufacturers must also meet DOT Guidelines for traction, speed ratings and stability while balancing off-pavement grip. A tall, narrow traction knob may be ideal in deep mud but when you reach a hard surface such as asphalt, rock, or even hard-packed gravel, it can become dangerously unstable.