X85 & X86 Motocross Tires 2026: The Complete Buyer and Fitment Guide

Quick answer: The KingTyre X85 and X86 are 100% off-road motocross tires built on a multi-ply reinforced carcass with reinforced sidewalls and heat-resistant rubber compounds. They are published in three sizes — one front and two rear, on 18- and 19-inch rears with a 21-inch front — and they carry no road certification: no ECE or DOT approval, no speed rating and no load index are published for them. The X85 is the soft-terrain pattern, with an aggressive knobby tread and a wide void ratio for mud clearance; the X86 is the hard-terrain pattern, with closely spaced reinforced tread blocks for rock and hard-pack.

Last updated: November 14, 2026. Written and reviewed by the KingTyre technical team. Tread, construction, size and application figures come from the current KingTyre X85 & X86 product page; company figures come from the KingTyre about page. Where KingTyre has not published a figure — including certification, speed rating, load index, tire pressure and rim width — this guide says so rather than estimating it.

What are the KingTyre X85 and X86 motocross tires?

The KingTyre X85 and X86 are a complementary pair of 100% off-road motocross tires, engineered as the soft-terrain and hard-terrain halves of the same race programme. They share the same carcass platform — multi-ply reinforced construction, reinforced sidewalls and heat-resistant rubber compounds — and they differ only in tread geometry, which is what decides which one belongs on your bike.

Il X85 is the soft-terrain tire. Its aggressive knobby tread is laid out with a wide void ratio, meaning more space between the blocks relative to their size. That spacing is what lets mud fall out instead of packing into the tread, and it is why the X85 is the pattern for woods riding, muddy tracks and loose soil. The compound is formulated to stay flexible at lower temperatures, which matters on an early-morning race start when the track is still cold.

Il X86 is the hard-terrain tire. Where the X85 opens up space between the knobs, the X86 packs them closer together, putting more rubber in contact with the ground at any moment. More contact area means more traction on hard-packed soil, and more bite points across irregular rock. The X86's knob bases are reinforced, which directly targets the failure mode that ends most hard-pack races: knobs folding over under sustained cornering load, cracking at the base and eventually separating from the carcass.

For the deeper engineering behind both patterns — how knob geometry and compound interact under race load — our guide to the engineering inside the tires that decide who finishes the race is the companion read, and the engineering decisions that separate a serious off-road tire from a cheap one covers what the off-road category demands of a carcass in the first place.

KingTyre X85 and X86 motocross tires at a glance

Everything KingTyre publishes for the X85 and X86 is in the table below. It is deliberately short, because these are two focused race-oriented off-road patterns sold as one range with a shared size list.

Both patterns are built with the same manufacturing discipline across the range: computerized curing systems, precision moulds and automated testing, with the same compound development capability that supports KingTyre's race tyre line. Our guide to what ISO 9001 really means for a tyre manufacturer explains what the quality system covers and what it does not.

X85 vs X86: which pattern your terrain actually needs

Both are multi-ply, reinforced-sidewall, heat-resistant off-road tires; the difference is how much contact patch you want and how quickly you need the tread to clear itself. This is the single question that decides between them.

One honest note on competition claims. The product page states that these sizes have been tested extensively in motocross and enduro competitions, and it lists both models for competition use — but it publishes no test protocol, no race results and no independent validation data for the X85 and X86. KingTyre's documented competition record sits on its race tyre line instead: the K00 slick and K01 rain tyre have run the FIM Endurance World Championship at the 24 Hours of Le Mans, and our field report from seven years at Le Mans 24H covers what that record involved. The X85 and X86 are the pair to quote for off-road and motocross programmes; the K00 and K01 are the pair with a documented race result.

Every published X85 and X86 size, and how it fits

Three published fitments: one front and two rear, covering the standard motocross and enduro geometry. KingTyre publishes the X85 and the X86 as one range with a shared size list, so a pair is assembled from the front plus one of the rear options.

Two practical points that matter when you quote a fitment.

First, the front is narrower than the trail tyre front. The X85 and X86 front is published as 80/100-21, while the K81 and K83 off-road tires use a 90/90R21 front and the K82 dirt bike tire adds a 120/70R19 front. The narrower motocross front is correct for MX and enduro machines, but it means a 90/90R21 front rim will not take these tyres — and the X85/X86 range publishes no 19-inch front at all.

Second, the rear sizes are shared with the trail tyre line. Both 110/90-18 and 110/90-19 are the same rears used by the K81 and K83. That makes cross-fitting possible where the chassis allows it: an X85 or X86 rear on a 90/90R21-front machine, or a K81/K83 rear on an 80/100-21-front machine. It also means a distributor can cover the 18-inch and 19-inch rear demand from either line.

Always confirm fitment against the motorcycle manufacturer’s specification before quoting. The off-road trail riding guide explains why a manufacturer concentrates engineering on a small set of sizes rather than spreading it across configurations that rarely sell.

What KingTyre publishes for the X85 and X86 — and what it does not

For an off-road race tyre, the difference between a published figure and an assumed one is the difference between a tyre you can quote and a tyre you cannot. This is the complete list.

Where the X85 and X86 sit in the KingTyre range

The off-road, dual sport and race lines solve different problems, and shipping the wrong one is the most expensive mistake in this category. Here is the whole range side by side, with the certification status included because it decides what you can legally ship where.

Read it as a funnel. If the tyre must be road legal, it is a K60, K66 or K67 — never an X85, X86, K81, K83 or K82. If the tyre is purely off-road, the choice is between the X85/X86 competition pair, the K81/K83 trail pair and the wider-ranging K82. And if the programme is a race programme with a documented result, that is the race tyre line. The product pages for each of them carry the full published detail: the K81 and K83 off-road tires, il Pneumatici per moto da cross K82, il K67 90/10 dual sport tires, il K60 50/50 dual sport tires and the K66 80/20 ADV tires.

Construction and compound: what multi-ply and heat resistance actually do

Two construction decisions do most of the work in a race off-road tyre, and both models use them. Multi-ply carcass construction is the baseline for a serious off-road tire: layers of cord material are angled against each other so the carcass can absorb repeated impact loads without deforming. Single-ply construction is lighter and cheaper, but it cannot take the hits that a motocross track delivers — and the weight saving is worth far less than a finished ride.

Reinforced sidewalls matter because the sidewall is the most vulnerable part of any off-road tyre. It flexes through every corner and absorbs most of the impact energy, and a cut that reaches the casing is a retirement rather than a repair. The balance is delicate: over-reinforce and the tyre becomes harsh and transmits every rock strike straight into the rider, under-reinforce and it fails in the field.

Heat is the silent killer of motocross tires. Compound temperatures under sustained racing can exceed 80°C, and a compound that softens excessively loses knob integrity, accelerates wear and eventually fails through knob separation. A tire that performs in a 20-minute moto can degrade across a 90-minute enduro test on the same compound, which is why both the X85 and the X86 use heat-resistant rubber formulations that hold their physical properties across the operating range.

For the reasoning behind carcass geometry and compound behaviour in detail, the engineering inside the tires that decide who finishes the race covers how blocks, carcass and compound interact under race load.

Road legality: 100% off-road, and no ECE or DOT certification

This section matters most to importers and distributors, because it decides whether you can sell the tyre at all in a given market. The X85 and X86 are published for motocross and enduro competition. No ECE R75 approval and no DOT FMVSS 119 approval is published for either model, and no speed rating or load index table is published for them.

What that means in practice:

• Do not present the X85 or X86 as a road-legal tyre in any market. KingTyre has not published that approval, and the tyres carry no published speed rating to support it.
• Check the sidewall marking before you sell or ride them. Off-road competition tyres are normally marked for competition use only, and that marking is printed on the tyre itself, not in a catalogue. Request the marking from the factory if it is not legible on your stock.
• Local rules decide what is legal. In the United States, for example, off-road tyres are commonly used on unpaved public land but restricted on paved public roads. Europe and other markets apply their own rules and their own enforcement practice. Our country-by-country guide to slick street legality and the DOT and ECE tyre codes explained set out how the approval systems work in general.
• If the customer rides a road to reach the trail, quote a dual sport instead. The product page lists the X85 and X86 as part of KingTyre’s adventure knobby series, which is accurate in the sense that the tyres are fitted on adventure bikes for their off-road sections. For road-legal adventure touring the certified products are the K67 90/10, il K60 50/50 and the K66 80/20 ADV.

Motocross tire pressure: how to set the X85 and X86

KingTyre does not publish a pressure table for the X85 or the X86. Anyone who gives you one figure for a motocross tyre is guessing, because track temperature, surface hardness and rider weight all move the answer. This is the method instead:

1. Start from the sidewall and the owner's manual. The sidewall carries a maximum load and pressure rating — a ceiling, never a target. The bike's manual gives the baseline for that machine.
2. Set pressures cold, and lower them for technical terrain. A larger contact patch is what grips in mud, ruts and soft soil and what absorbs rock and root impacts.
3. Raise the pressure for hard track and speed. On hard-packed circuits and on the long straights between sections, higher pressure reduces heat build-up, which is the dominant failure risk in a long race.
4. Adjust by feel and by the tyre's behaviour. A sidewall folding over the rim means the pressure is too high for the terrain; a sidewall that never touches the rim and a bike that feels vague and bouncy means it is too low.
5. Re-check after every race or session. Off-road pressures run far below road pressures, and a setting that was right at the start of the day may not be right by the end of it.

For the reasoning behind off-road pressure, including how terrain and rider weight change the target, read qual è la migliore pressione degli pneumatici per una moto da cross?.

When an X85 or X86 needs replacing

On a race tyre, the wear pattern tells you what failed before the tread depth does. Four signals matter, and they are not the same for the two patterns.

1. Knob tearing on the X86. This is the signature hard-pack failure. Knobs fold over under sustained cornering load, crack at the base and eventually a section of the tread separates from the carcass. If the X86's knob edges are rounding and the bases are showing cracks, the tyre is finished for hard-pack use even if the tread still looks deep.
2. Packing on the X85. The X85's wide void ratio is its whole mechanism. If mud is staying in the voids rather than falling out, the knob edges have worn past the point where they can clear it, and the tyre will skate where it used to bite.
3. Cuts that reach the casing. A cut into the ply is a retirement, not a repair, however good the rest of the tyre looks.
4. Lost edge. Across both patterns, a rounded knob has lost the ability to shear through soft ground or hold a line on hard ground. That is the signal to change the tyre, and on a race schedule it usually arrives before the tyre looks obviously worn.

Because the published figure for this pair is in hours rather than kilometres, condition is the honest replacement trigger. For a broader view of the current off-road shortlist, see quali sono i migliori pneumatici per bici da cross.

Ordering X85 and X86 motocross tires: wholesale, OEM and ODM

For distributors, the X85 and X86 are the simplest product to quote in the whole off-road range: two patterns, one size list, three fitments and an unambiguous certification position. They also cover a demand most import ranges leave unfilled — a pair of genuine competition-oriented off-road tyres rather than a road dual sport with a knobby tread pattern.

The manufacturing background is verifiable. KingTyre (Tianjin Kingtyre Group Co., Ltd.) was founded in 2015 in Tianjin and is one of the few Chinese manufacturers producing motorcycle tyres at scale. The Tianjin plant runs an annual capacity of more than 300,000 radial tyres across 150-plus sizes and five product categories — racing, adventure, off-road, cruiser and commuter — and KingTyre currently exports to more than 45 countries across Europe, South America, Asia and the Middle East. The company is certified to ISO 9001 for quality management, and the range is certified to DOT for the United States, ECE R75 for Europe and CCC for China.

KingTyre also runs OEM and ODM programmes for teams and resellers, including private-label moulding and branding — our private label and OEM motorcycle tyre manufacturer guide explains how that works in practice, and the wholesale importing guide covers the logistics and documentation side.

Two points for importers specifically. First, the X85 and X86 are not in KingTyre’s race tyre specification sheet, which covers the K00 slick, K01 rain tyre, K06 semi slick and K97 classic racing tyres only. Any specification you need for the X85 or X86 — tread width, overall diameter, rim width, cold and hot pressures, load index, the 80/100-21 section width — has to come from the factory, not from the race tyre data. Ask for it in writing before you publish it in your own catalogue.

Second, treat any capacity figure you see quoted for this product with care. The X85/X86 product page carries a production-volume claim that does not reconcile with the company’s own published plant capacity, so the number to quote in a supply agreement is the one you get in writing from the factory against a dated figure.

For a supplier assessment rather than a single SKU, read how to choose a motorcycle tyre manufacturer in China, and browse the complete KingTyre product range to see how the X85 and X86 sit alongside the trail, dual sport and race lines.

Frequently asked questions

What are the KingTyre X85 and X86 motocross tires used for?

Both are 100% off-road motocross and enduro tires. The X85 is the soft-terrain pattern, with an aggressive knobby tread and a wide void ratio for mud evacuation in woods and loose soil. The X86 is the hard-terrain pattern, with closely spaced reinforced tread blocks that put more rubber on the ground for rock and hard-pack traction.

What is the difference between the X85 and the X86?

Both share a multi-ply reinforced carcass, reinforced sidewalls and heat-resistant rubber compounds. The X85 uses widely spaced knobs for self-cleaning and stays flexible at low temperatures, which suits mud and cold starts. The X86 packs its tread blocks closer together for maximum contact area and reinforces the knob bases against the tearing that hard-pack cornering loads cause.

What sizes do the KingTyre X85 and X86 come in?

Three published fitments: 80/100-21 for the front, and 110/90-18 or 110/90-19 for the rear. The front designation publishes two section-width options on a 21-inch rim, so confirm which moulding is available. KingTyre publishes the X85 and X86 as one range with a shared size list rather than a per-model split.

How long do X85 and X86 motocross tires last?

KingTyre’s product page states that riders typically achieve 50–80 hours of competitive use, depending on terrain. That is a rider-typical figure rather than a laboratory test result, and it is expressed in riding hours rather than kilometres, so a rough conversion depends entirely on the terrain and the pace of the riding.

Are KingTyre X85 and X86 tires street legal?

No. Neither model carries published ECE R75 or DOT FMVSS 119 approval, and no speed rating is published for them. They are 100% off-road competition products. Check the sidewall marking and your local rules, and quote a dual sport such as the K60, K66 or K67 if the customer needs road legality.

What tire pressure should I run in the X85 and X86?

KingTyre publishes no pressure table for these models. Start from the sidewall limit and the bike owner’s manual, set cold, lower for mud and ruts, raise for hard track and speed, then adjust by how the tyre behaves and re-check after every session. Off-road pressures run far below road pressures.

What is the 80/100-21 front size?

It is a dual-width designation on a 21-inch rim, publishing two section-width options — 80 and 100 — rather than a single width. It is the standard motocross and enduro front fitment on bikes from 125cc to 450cc. Because the two widths are different tyres, confirm which moulding the factory is shipping before you quote a set.

Are the X85 and X86 for motocross or for trail riding?

Both patterns are built and published for motocross and enduro competition, and they suit trail riding as well — the X85 on soft, wet terrain and the X86 on hard-pack and rock. For a dedicated trail and woods product line, the K81 and K83 off-road tires are positioned there, and the Pneumatici per moto da cross K82 cover the widest size range with a published service life.

Are the X85 and X86 competition tires?

They are the dedicated motocross and enduro models in KingTyre’s off-road range, and the product page states that their sizes have been tested extensively in competition. No test protocol, race result or independent validation data is published for either model. KingTyre’s documented race programme runs on the K00 slick and K01 rain tyre in the FIM Endurance World Championship at Le Mans.

Can the X85 and X86 be used on an adventure motorcycle?

The tyres are fitted on adventure bikes for their off-road sections, and the X85 in particular is a natural choice for loose dirt and mud on those machines. They are not road legal, so a customer who rides paved roads between trails needs a certified dual sport tyre such as the K67 90/10, K60 50/50 or K66 80/20 instead.

Find the KingTyre X85 and X86 motocross tires

The X85 and the X86 are one programme split across two terrain problems: soft ground and hard ground. The X85 is the tyre that stays clean in the mud and woods; the X86 is the tyre that keeps its contact patch on hard-pack and rock. Both are built to the same multi-ply standard, both are certified to nothing on the road, and both share a three-size list that covers the standard motocross and enduro fitments.

For a distributor, the decision is simple: quote the pair for motocross and enduro customers, keep the K81/K83 for trail and adventure work, keep the K82 for the widest size coverage, and route every road-legal enquiry to the K60, K66 or K67. For the full published specification, the current size list and the pressure and fitment method, start with the X85 and X86 motocross tires product page — or talk to the KingTyre team and ask for the technical data sheet and a dated capacity statement for the model you are quoting.