Knobby Shop Tire Fitment Center
Find the Right Tire for Your Bike and Your Riding Style
Understand tire sizes, tread patterns, riding styles, and eventually find verified tire fitments for your exact motorcycle.
Find Tires for Your Bike
Bike Fitment Database — Coming Soon
We're building a verified motorcycle tire fitment database so you can eventually select your exact bike and see compatible tire sizes, popular setups, and rider-tested combinations.
Find the Right Tire Style
Work from how you actually ride. Pick your riding style and terrain, compare tread families, learn how tire sizes are written, and get a tread-style recommendation you can bring to us.
Step One
What Kind of Riding Do You Do?
Tap a riding style to see the tread characteristics, carcass traits, common size examples, terrain strengths, and tradeoffs that usually go with it.
Full Dirt / Enduro
These riders prioritize maximum off-road traction over pavement performance. Tread is tall and open, and the tire is built to bite in loose terrain rather than last on asphalt.
Tread style
Tall open knobs with wide voids and aggressive shoulder knobs.
Carcass
Light, flexible dirt carcass that conforms to terrain. Usually tube type on spoked dirt wheels.
Typical characteristics
- Tall knobs
- Large void spacing
- Strong shoulder knobs
- Self-cleaning tread
- Maximum loose-terrain bite
Common front size examples
Common rear size examples
Terrain strengths
Loose dirt · Mud · Sand · Roots · Technical single track
Tradeoffs
- Short tread life on pavement
- Vague feel and reduced braking grip on asphalt
- Knobs can tear or overheat during sustained road miles
Terrain breakdown
- Sand
- Paddle-like scoops or tall widely spaced knobs that push volume instead of digging a hole.
- Mud
- Very tall knobs with huge voids so the tread clears itself as the wheel spins.
- Intermediate terrain
- The all-round knobby — medium knob height and spacing that works across most trail conditions.
- Hardpack
- Shorter, more closely packed knobs with more edges in contact so the tread does not squirm.
- Rock
- Softer, gummier compounds and flexible carcasses that wrap the rock instead of skating off it.
- Roots
- Soft compound plus supported knobs for grip on slick wet wood, usually run at lower pressure.
- Extreme enduro
- Gummy compound, flexible carcass, very low pressure, and usually a mousse or heavy-duty tube setup.
Sizes listed are common examples for this riding style, not verified fitment for any specific motorcycle.
Tread Pattern Guide
How Tread Families Compare
A side-by-side look at the five tread families we work with most, rated qualitatively across the conditions riders ask about.
Open Knob / Full Dirt
Tall widely spaced knobs built to dig and clear themselves.
- Loose dirt
- Excellent
- Mud
- Excellent
- Sand
- Excellent
- Rock
- Good
- Gravel
- Very Good
- Wet pavement
- Poor
- Dry pavement
- Fair
- Tread life
- Poor
- High-speed stability
- Fair
Aggressive Block ADV
Deep reinforced blocks for heavy bikes ridden hard off-road.
- Loose dirt
- Very Good
- Mud
- Good
- Sand
- Good
- Rock
- Very Good
- Gravel
- Very Good
- Wet pavement
- Fair
- Dry pavement
- Good
- Tread life
- Fair
- High-speed stability
- Good
Dual-Sport Knob
Moderately open knobs with supported blocks for mixed use.
- Loose dirt
- Very Good
- Mud
- Good
- Sand
- Good
- Rock
- Good
- Gravel
- Very Good
- Wet pavement
- Fair
- Dry pavement
- Good
- Tread life
- Good
- High-speed stability
- Good
50/50 Block
Large stable blocks balancing gravel bite and road manners.
- Loose dirt
- Good
- Mud
- Fair
- Sand
- Fair
- Rock
- Good
- Gravel
- Very Good
- Wet pavement
- Good
- Dry pavement
- Very Good
- Tread life
- Very Good
- High-speed stability
- Very Good
Road-Biased ADV
Closely spaced siped tread aimed at pavement and touring.
- Loose dirt
- Fair
- Mud
- Poor
- Sand
- Poor
- Rock
- Fair
- Gravel
- Good
- Wet pavement
- Excellent
- Dry pavement
- Excellent
- Tread life
- Excellent
- High-speed stability
- Excellent
Ratings are general comparisons between tread families. They are not mileage claims or guarantees for any individual tire.
Terrain
What Terrain Do You Ride Most?
Pick the surface you spend the most time on and see what tread characteristics generally help there.
Mixed trail
The all-rounder. Pick tread that never excels but never falls apart across the day.
What generally helps
- Balanced knob height
- Even void spacing
- Good shoulder support
Tire Guide
How to Read Motorcycle Tire Sizes
A size like 140/80-18 tells you the nominal width, the sidewall proportion, and the rim diameter. Here is what each part means and what else is stamped on the sidewall.
Tire width
The first number, in millimetres, is the nominal section width of the inflated tire. In 140/80-18 that is 140 mm. It is a nominal figure — the measured width varies by brand, rim width, and tread design.
Aspect ratio
The second number is sidewall height as a percentage of section width. In 140/80-18 the sidewall is roughly 80% of 140 mm. A higher number means a taller, more cushioned sidewall; a lower number means a shorter, more direct one.
Wheel diameter
The final number is the rim diameter in inches — 21, 19, 18, or 17 on most of the bikes we service. This must match your wheel exactly.
Tube type vs tubeless
Tube-type (TT) tires require an inner tube. Tubeless (TL) tires are designed to hold air without a tube when mounted on a compatible tubeless wheel. Some tubeless tires may also be used with an appropriate tube on a tube-type wheel when specifically permitted by the tire manufacturer. Always follow the tire and motorcycle manufacturer's fitment requirements—don't assume TT and TL setups are interchangeable.
Load rating
A coded number on the sidewall indicating the maximum load the tire can carry at its rated pressure. On loaded adventure bikes this matters as much as tread choice.
Speed rating
A letter indicating the maximum sustained speed the tire is rated for. Many aggressive off-road tires carry low speed ratings — check before long highway stretches.
Bias vs radial
Bias-ply tires use multiple carcass plies laid diagonally across one another, creating a structure where the crown and sidewall work more closely together. Radial tires use carcass cords running roughly 90° to the direction of travel, typically with a separate belt beneath the tread. Radial construction generally reduces heat buildup and performs well at sustained road speeds, while bias construction is common in many off-road, dual-sport, cruiser, and load-oriented applications. Construction alone does not determine how stiff or compliant a tire will feel—carcass design varies significantly between tire models. Always use the construction type and front/rear combination approved by the motorcycle and tire manufacturer.
Rim width
Every tire has an approved rim width range. Mount a tire on a rim that is too narrow or too wide and the carcass profile is wrong — the tire will feel odd on its side and wear unevenly.
Clearance
Wider or taller tires can foul the swingarm, chain, chain guide, fender, or fork brace. Check clearance through full suspension travel, not just at rest.
Common dirt bike sizes
Fronts are typically 80/100-21, 90/90-21, or 90/100-21. Rears are typically 100/100-18 through 140/80-18, with 110/100-18 and 120/100-18 being very common enduro choices.
Common dual-sport sizes
Fronts typically 80/100-21, 90/90-21, or 100/90-19. Rears typically 120/90-18, 130/80-18, 130/90-17, 130/80-17, or 140/80-18.
Common ADV sizes
Fronts typically 90/90-21, 100/90-19, 110/80-19, or 120/70-19. Rears typically 130/80-17, 140/80-17, 140/80-18, 150/70-17, 150/70-18, or 170/60-17.
Tire Width
Is Wider Always Better?
No. A wider tire changes far more than the contact patch, and on the wrong rim it can make a bike handle worse.
Wider — potential advantages
- Increased flotation on soft surfaces
- Larger footprint on the ground
- Potential straight-line traction benefits
Wider — possible disadvantages
- Slower steering
- More rotational mass
- Incorrect carcass profile on narrow rims
- Possible chain or swingarm clearance issues
- Different lean behaviour
Narrower — potential advantages
- Easier direction changes
- Better penetration through some loose surfaces
- Correct fitment for narrow dirt-bike rims
- Lower weight
Wider does not automatically mean more grip. The right width is the one that suits your rim, your clearance, your terrain, and the way you want the bike to steer.
90/90-21 vs 90/100-21
90/90-21
- Lower profile
- Common enduro and ADV size
- More direct feel depending on carcass
90/100-21
- More sidewall volume
- More cushioning
- Potentially better impact absorption
- Slight geometry and steering change
Both are 90 mm nominal width on a 21-inch rim. The 90/100 has a taller sidewall — roughly 100% of the section width against roughly 90% — so it carries more air volume. Actual measured dimensions still vary by manufacturer and tire construction.
Size Reference
Popular Motorcycle Tire Sizes
Expand any size to see what the numbers mean, the bike category it usually appears on, and the rim and clearance checks to make first.
Popular 21-inch front examples
Popular 19-inch front examples
Popular 17-inch front examples
Popular 18-inch rear examples
Popular 17-inch rear examples
Find Your Tire Style
Answer Four Questions
This points you toward a tread category — not a specific size and not a vehicle fitment.
Answer all four questions and we'll point you toward a tire style.
Rider Setups
Real setups from real riders — bike, front and rear tires and sizes, riding style, terrain, pavement split, and fitment notes. We'll open submissions once the fitment database is live.
Still Not Sure? We'll Sort It Out
Tell us your bike and how you ride and we'll help you land on the right tire — then mount and balance it at your garage, office, or the trailhead.
Tire sizes shown in this guide are common examples and are not universal fitment recommendations. Always verify your motorcycle manufacturer's recommended tire size, wheel width, load rating, speed rating, clearance, and tube/tubeless requirements before installation.