What Grime Bike Tire Dimension You Have [& Which Is Best]

Attempting to determine what dust bike tire measurement you’ve or which is finest to your particular bike? Whether or not you’re struggling to decipher the numbers or simply need a step-by-step information on understanding dust bike tires, you’ve discovered the appropriate article!

Selecting the best tire could make a HUGE distinction in your confidence whereas dust bike driving off-road as a result of traction is so essential – it’s simple to put in the flawed tire for the kind of driving that you simply’re doing, making you slide out extra rapidly, which is frightening!

On this article, you’ll study:

• Tire measurement – tips on how to establish what you’ve or want
• Tube measurement – An easy conversion chart
• Sort of tire – Selecting one of the best tire to your particular wants

The right way to know what measurement your dust bike tires are

The simplest solution to discover out is to have a look at the tire’s sidewall- it reveals its diameter, top, and width. For instance, if it says “80/100X21”, which means it’s a 21” inch diameter tire.

What do the numbers and letters on dust bike tires imply?

For off-road use solely tires, you normally see numbers, corresponding to 80/100×21 with no letters. A road authorized dust bike requires DOT-legal tires, so it is best to see DOT letters on the tire.

Right here’s what every quantity means on a dust bike tire, corresponding to (120/90 – 17):

• 120 (First quantity) – Tire width in millimeters (120mm). 
• 90 (Second quantity) – Tire sidewall top as a share of the width [90% of 120 = 108mm sidewall height]
• 17 (Third quantity) – Tire diameter in Inches that goes on the rim/wheel

What does the arrow on a dust bike tire imply?

An arrow on a dust bike tire merely signifies that’s the supposed set up route. You need the arrow to be rolling ahead when it’s on the bike transferring ahead if you need it to work correctly.

For instance, the knobbies are positioned in a sample that works finest in a sure route if the entrance or rear tire has an arrow on the sidewall. When you set up it backward, you received’t have as a lot management as a result of the tire received’t grip or monitor as effectively.

On a knobby tire – if the width is 120mm, does that embrace the complete a part of the knobs?

It actually will depend on the model of dust bike tire you purchase. For instance, you may need a Metzeler 130/90/18 rear tire that measures 140mm together with the width of the knobs, however the tire carcass width is just about 115mm.

My advice is to purchase the precise tire measurement that got here in your dust bike from the producer.

Commonest dust bike tire sizes

Whereas this record doesn’t embrace all the variations of tire sizes (widths, sidewall, and many others), these are the most typical measurement tires and rims primarily based on the scale and sort of dust bike:

Grime Bike Dimension	Tire & Wheel Dimension (Entrance/Rear)
50cc 4-stroke path bike	2.50-10” / 2.50-10”
50cc 2-stroke MX bike (mini)	2.50X10” / 2.75X10”
50cc 2-stroke MX bike	60/100×12” / 2.75X10”
65cc 2-stroke MX bike	60/100-14” / 80/100-12”
110cc 4-stroke path bike	2.50X14” / 3.00X12”
85cc 2-stroke/125cc 4-stroke (Small wheel)	70/100×17” / 90/100×14”
85cc 2-stroke/125cc 4-stroke (Huge wheel)	70/100×19” / 90/100×16”
200-250cc 4-stroke path bike	80/100X21” / 100/100X18″
125 2-stroke/250 4-stroke MX bike	80/100X21” / 100/90X19”
250cc 2-stroke MX bike	80/100X21” / 110/90X19”
250cc+ Enduro bike	80/100X21” / 110/100X18”
350-450cc 4-stroke Enduro bike	80/100X21” / 110/100X18″
450cc 4-stroke MX bike	80/100X21” / 110/90X19″

Grime bike tire & tube conversion measurement chart

It’s complicated in case you’re attempting to determine what measurement tube you want to your tire measurement, which is why I made this straightforward chart. Tube sizes are sometimes proven in inches, so there’s a easy conversion wanted when going from a metric tire measurement to a U.S. customary tube measurement.

The straightforward equation is “X (tire width) / 25.4 = tube measurement/width”. 1-inch = 25.4 millimeters, which is why the width is split by 25.4.

So when you’ve got an “80mm” large tire, then the equation is (80 / 25.4 = 3.15). That’s why you’ll use the three.00/3.25 large tube. 

Entrance tire to tube measurement conversion:

Entrance tire measurement	Appropriate tube measurement
60/100	2.50/2.75
70/100	2.75/3.00
80/100	3.00/3.25

Rear tire to tube measurement conversion:

Rear tire measurement	Appropriate tube measurement
80/100	2.50/3.60
90/100	3.60/4.10
100/100	4.00/4.10
110/100	4.00/4.50
120/100	5.00/5.10

Do you want a brand new tube when changing the tire?

When you’re not sure, it’s higher to be secure and purchase a brand new tube to exchange the outdated one while you’re putting in a brand new tire – it’s a ache to put in most tires, so that you don’t need to need to take away it twice in case the outdated tube fails with the brand new tire.

With that stated, I don’t at all times exchange my dust bike’s tube each time I placed on a brand new tire. If the tube has by no means leaked and it nonetheless appears to be like good, particularly if I simply changed it inside the final 12 months, I’ll attempt to hold utilizing it.

Indicators of an outdated dust bike tube that wants changing:

• Pin-hole leak when full of air – duh! 
• Effervescent – if one part of the tube is “swollen/enlarged”, it’s prone to fail quickly
• Corroded valve stem – The valve stem space can begin leaking simply from outdated age and corrosion
• Dry cracking – Rubber deteriorates over time

Tire measurement comparability – what’s the impact of various sizes?

Whereas it’s usually finest to stay with what tires got here in your dust bike from the producer, you may get some constructive results by switching to a barely completely different measurement. Nonetheless, there may be normally some compromise when going greater or smaller…

Here’s what you’ll usually really feel when altering the tire measurement in your dust bike:

Width:

• Wider is healthier traction
• Slim is healthier dealing with and fewer prone to get caught in a slender rut

Peak:

• Taller is extra plush
• Shorter is faster steering

Larger tire:

• Extra weight = extra secure
• Slower dealing with

Why do enduro bikes have an 18-inch rear wheel?

An 18” rear tire for an off-road enduro bike has the identical outer diameter as a 19” rear tire for an MX bike – the principle distinction is that the diameter of the tire that goes on the rim and the sidewall top is completely different. This implies the sidewall top is sort of a bit taller on an 18” enduro tire in comparison with a 19” MX rear tire.

The primary advantages of an 18-inch rear wheel are:

• Extra plush (acts as further suspension) – Softer sidewall
• Higher traction – softer sidewall compresses extra for extra contact floor

As compared, the advantages of a 19-inch MX rear wheel are:

• Can deal with large jumps with out feeling “mushy”, which may have an effect on the dealing with – Stiffer sidewall
• Higher high-speed cornering/stability – the tire is much less prone to “roll” resulting from a stiffer carcass/sidewall

Which is healthier for path driving?

For many varieties of path driving, an 18-inch rear wheel and tire setup is healthier for plenty of causes. Because of this nearly all full-size path and enduro bikes include an 18” tire from the manufacturing facility, however that doesn’t imply it’s at all times one of the best.

A 19” rear tire is healthier for path driving when:

• Using at excessive pace
• The paths have jumps and massive obstacles at average to excessive pace

An 18” rear tire is healthier for path driving when:

• Using at low speeds
• Traction is restricted (moist rocks, roots, mud, and many others)

Execs & Cons of a 21/18 vs 19/16 Setup (Full-size vs Mid-size)

Going from a mid-size large wheel 125cc 4-stroke or 85cc 2-stroke with 19”16” wheels to a full-size path bike with 21/18” wheels and tires is an enormous step up in measurement, top, and efficiency most often.

The 19/16” midsize wheel combo is unquestionably lighter, decrease to the bottom, and has higher dealing with in the case of simpler and flatter trails. Nonetheless, they don’t deal with obstacles, corresponding to roots, logs, and rocks as effectively resulting from easy physics (a 21” wheel rolls over a ten” log with much less effort than a 19” wheel).

The 21/18” wheels are heavier, which slows the dealing with down, however they’re extra secure and deal with average to aggressive and technical path driving higher as a result of they roll over obstacles extra simply.

Grime bike rim width – must you change it?

There aren’t many causes it is best to change the width of your dust bike rim. For instance, going from a 1.85 to a 2.15 18” rear rim on a YZ250FX enduro bike will assist you to run a wider rear tire, however there are drawbacks.

Sure, the broader tire may give you extra traction, however it is going to additionally gradual you down.

Execs & cons of wider rims

Give it some thought, you’re including significantly extra weight with extra rim, tube, and tire materials – these act as extra flywheel weight and unsprung weight.

The additional flywheel weight trigger the engine to rev slower and really feel like there’s much less energy (which might truly assist in circumstances with low traction). The broader tire and unsprung weight considerably have an effect on dealing with, making your dust bike tougher to lean & flip, and deal with slower however have barely extra stability.

Varieties of dust bike tires – the deciding issue

Okay, so that you’ve found out what measurement tires you want, however there’s an enormous distinction in the case of the kind of tire you want as effectively. It primarily will depend on the terrain you’re driving, however some folks get these sorts confused primarily based on their title, so I’ll break it down.

Mushy – no, the tire isn’t delicate, per se

A “delicate terrain tire” is made for delicate terrain, corresponding to sand. Some folks see the phrase “Mushy” when trying to find a tire and suppose the rubber compound is delicate, which is usually finest for rocky and slippery circumstances, however that’s not the case.

A delicate terrain tire is commonly barely tougher, however extra importantly, the tread sample works finest in delicate sand/terrain. For instance, a delicate terrain tire may need greater “knobbies” in a sample much like a paddle tire, providing you with higher traction.

Intermediate – the good compromise?

An “Intermediate terrain tire” is normally an excellent compromise between delicate and laborious as a result of it provides you with one of the best general traction and management in case you’re driving in all types of circumstances, corresponding to sand, rocks, hardpack, and loamy dust all in in the future.

For instance, my favourite rear tire for path driving in all circumstances is the IRC VE33 (Amazon) as a result of it will get good traction if the terrain is dry, moist, rocky, or sandy.

Onerous – is it truly laborious?

A “Onerous terrain tire” is commonly delicate or referred to as a “gummy” tire within the off-road enduro world as we speak. The softer rubber, such because the Bridgestone Battlecross X40 (Amazon) “grips” the laborious dust or rocks higher than a tougher compound tire.

Nonetheless, some laborious terrain tires even have a tough carcass (rubber), making them last more, however the knobby tread sample works effectively in laborious terrain.

What if there’s a mixture tire (e.g. delicate/intermediate)?

You’ll typically see a tire that claims Intermediate/delicate or Intermediate/Onerous terrain, such because the Dunlop Geomax MX53 tire (Amazon) or perhaps a Multi-terrain tire. This simply signifies that the tread sample and rubber compound is a combination of the 2.

It received’t work fairly in addition to a tough terrain tire within the rocks and hardpack, however it is going to work a little bit bit higher within the dust and barely softer terrain.

What’s one of the best dust bike tire for you?

Greatest entrance tire for informal path driving:

Greatest rear tire for informal path driving:

Greatest entrance tire for laborious enduro driving:

Greatest rear tire for laborious enduro driving:

Least expensive dust bike tires:

Tire Strain – The right way to get probably the most traction with out getting a flat tire

There’s a nice line between getting extra traction and getting a flat in the case of the “proper dust bike tire strain”. Nonetheless, it’s not at all times the identical quantity for everybody, and it additionally will depend on the place you’re driving.

For instance, 11-13 PSI of strain is an effective start line, but it surely additionally will depend on:

• Bike weight
• Rider weight
• The tires you select
• The tubes you select
• Sort of terrain
• The pace you’re driving

How lengthy do dust bike tires normally final?

You may normally get 20-50 hours on a set of dust bike tires as a result of they begin dropping vital traction, however there are various variables that have an effect on how lengthy they’ll final for you.

For instance, in case you’re racing a tough enduro course with numerous rocks and also you’re on a 300cc 2-stroke or 450 4-stroke, you may solely get 3-5 hours earlier than the knobs begin ripping off.

These elements have an effect on how lengthy your tires will final:

• Bike energy – extra energy = much less tire life
• Terrain – Tougher terrain = much less life
• Tire choice – Softer rubber = much less life
• Bike+rider weight = extra weight = much less life
• Using model – aggressive throttle (spinning) = much less life

When you’ve 120/70-17 entrance and rear is there a distinction in width? (4.25-4.5 vs 4.5-4.75)

If the tires present the identical measurement with the three numbers (120/70-17), then they’re the identical measurement whether or not you utilize them on the entrance or again. For the tube measurement, you simply use the easy conversion of (120 / 25.4 = 4.72).

This implies you’ll need to use a 4.5-4.75 tube with a 120mm large tire, however a 4.25-4.5 tube will work if that’s all you’ve and it is advisable get house or again to camp.

Tube vs Tubliss vs Mousse Bibs

There isn’t any “good selection” in the case of what it is best to use for dust bike tire inflation – all of them have execs and cons.

Standard Interior tubes (execs & cons):

• Least expensive choice
• Best to exchange
• Completely different thickness tubes supply higher or worse flat prevention
• Can barely change tire strain for various really feel & traction
• Almost certainly to get a “pinch flat”
• Usually require the least upkeep

Tubliss (execs & cons):

• No standard interior tube to “pinch”
• Can run very low PSI for higher traction (good for laborious enduro/gradual speeds)
• Much less weight (unsprung weight)
• Require excessive PSI for high-pressure interior tube (seals to the rim)
• Dearer

Mousse bibs (execs & cons):

• Just about 100% flat-free resulting from full foam development
• Most troublesome to put in
• Can not change “tire strain”
• Wears out faster at greater speeds
• Ought to be changed each 1-2 years resulting from foam deterioration
• Costliest

The right way to have extra management whereas path driving

A recent set of dust bike tires is likely one of the finest methods to have extra confidence, however in case you’re attempting to show your self tips on how to journey then you definately is likely to be forming habits which can be inflicting you to slip out or lose stability and fall over.

I need to present you tips on how to construct your confidence 5X sooner by forming constructive driving habits. As a thanks for studying this far, I need to give it to you as a present – obtain it right here for FREE as we speak!