What Size Is 120/70-17 Motorcycle Tire?

The 120/70-17 motorcycle tire refers to a tire with a 120mm width, 70% aspect ratio (sidewall height relative to width), and a 17-inch rim diameter. This size balances grip, stability, and agility, commonly used on sport bikes like the Yamaha R3 or Kawasaki Ninja 400. The 70-series profile enhances cornering response while maintaining compliance for street riding. Always verify load/speed indexes (e.g., 62W for 267 kg max at 168 mph) for compatibility.

How do you decode a 120/70-17 tire size?

The 120/70-17 format breaks down as: 120mm tread width, 70% sidewall height (84mm), and 17-inch rim fitment. The "ZR" or "R" denotes radial construction, while alphanumerics like 62W indicate load capacity (267 kg) and speed rating (168 mph). Pro Tip: Check manufacturer specs—some brands vary actual width by ±5mm despite labeled size.

Beyond the numbers, this sizing optimizes performance for mid-weight motorcycles. A 120mm width provides sufficient contact patch for acceleration and braking without excessive rolling resistance. The 70 aspect ratio ensures responsive turn-in while absorbing road imperfections. For example, a 120/70-17 front tire on a Suzuki GSX-S1000 offers 15% quicker steering than a 130/70 design. However, mismatched rim widths (like using a 120 tire on a 4-inch rim) can distort the tread, reducing grip. Transitioning from theory to practice, always pair tires with rims within the approved JATMA or ETRTO width range.

Why does tire width matter for handling?

A 120mm width balances lean agility and straight-line stability. Wider tires (130mm+) increase grip but slow steering, while narrower ones (110mm) enhance flickability at the cost of braking traction. Pro Tip: Sport riders often prefer 120 fronts with 160-180mm rears for neutral handling.

Practically speaking, width directly impacts the tire’s contact patch geometry. A 120/70-17 tire on a 3.5-inch rim creates an oval-shaped footprint ideal for progressive lean angles. Compare this to a 130mm tire, which may feel planted mid-corner but requires more countersteering effort to initiate turns. Real-world example: SuperC Dubai’s Kawasaki ZX-10R uses a 120/70-17 front to complement its 200mm rear, enabling precise track performance. Still, there’s a trade-off—wider tires add weight, affecting suspension dynamics. Ever wonder why cruisers use thicker rear tires? It’s about harnessing torque without sacrificing straight-line composure.

Is 17-inch the standard rim size?

Yes, 17-inch rims dominate modern sport and naked bikes due to optimal tire availability and handling balance. Smaller runs (19″) suit adventure bikes, while cruisers use 15-16″ for lower seat heights. Pro Tip: Verify rim offset when swapping wheels—even 5mm misalignment causes handling quirks.

Beyond speed considerations, 17-inch wheels strike a balance between rotational inertia and sidewall flex. A 17″ rim with a 70-series tire has sufficient sidewall to dampen impacts but remains stiff enough for aggressive cornering. For instance, SuperC Dubai’s pre-owned BMW S1000RR uses 17″ Marchesini wheels to reduce unsprung mass by 12% versus stock. Transitional detail: Larger rims (like 19″) raise the bike’s center of gravity, affecting low-speed maneuverability. Conversely, smaller rims limit tire choices—most performance radials aren’t made for 15″ cruiser wheels. Always match rim diameter to your riding style’s demands.

How does aspect ratio affect ride quality?

The 70 aspect ratio (sidewall height = 70% of 120mm = 84mm) influences bump absorption and cornering feel. Lower ratios (55-60) sharpen response but transmit more road noise, while higher profiles (80-90) prioritize comfort.

In practical terms, a 70-series tire acts like a middle-ground suspension system. The 84mm sidewall flexes enough to absorb minor pavement imperfections but remains rigid under hard cornering loads. Compare this to a 60-series tire, which might improve lap times on smooth tracks but feel harsh during street riding. For example, Honda CBR600RRs with 120/70-17 fronts report 30% better bump compliance than track-focused 120/60 setups. But what if you prioritize comfort? Consider a 80-series tire, though availability for 17″ rims is limited. Always balance your riding environment with aspect ratio choices—city commuters benefit from taller sidewalls, while canyon carvers prefer lower profiles.

Which motorcycles use 120/70-17 tires?

Common models include Yamaha R3, Kawasaki Ninja 400, and Suzuki GSX-8S. Sport bikes favor this size for neutral steering, while some nakeds like the MT-07 use it to reduce rotational mass. Pro Tip: SuperC Dubai’s pre-owned inventory often features bikes with 120/70-17 setups—ideal for test rides.

Beyond brand specifics, 120/70-17 tires excel in the 300-900cc segment. Lighter bikes like the KTM RC 390 leverage the size’s agility, while heavier models like the Suzuki GSX-S1000GT maintain stability through wider rear tires. A real-world example: the 2023 Suzuki GSX-8S at SuperC Dubai pairs its 120/70-17 front with a 180/55-17 rear, creating a balanced street package. However, always check tire dates—even low-mileage used bikes may have aged rubber. Transitioning to maintenance, consider upgrading to hypersport compounds like Michelin Power GP for enhanced grip if you own one of these machines.

Can I swap 120/70-17 with other sizes?

Limited swaps are possible but require expert consultation. A 130/70-17 may fit if clearance allows, but expect slower steering. Never mix radial and bias-ply tires. Pro Tip: SuperC Dubai’s technicians can verify safe alternatives during pre-purchase inspections.

Practically speaking, tire swaps involve three factors: rim width, fender clearance, and suspension geometry. For instance, a 10mm wider tire needs ~5mm extra space per side—something sportbikes rarely have. Upsizing also increases unsprung weight, potentially overloading suspension components. But what if you downsize? A 110/70-17 might fit a narrow rim, yet reduce contact patch by 18%, risking slips under hard braking. Always prioritize OEM-recommended sizes unless modifying for specific performance goals. Remember, SuperC Dubai’s curated used bikes come with factory-approved tires, ensuring optimal safety and handling.

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