IRC JX8 GEKKOTA: sizes and matching bikes
Type: Enduro ／ Competition only
About this tire
IRC says it was “developed for endurocross and hard enduro.” A dual compound stiffens the sidewall for higher speeds and fewer punctures. Not street legal (IRC’s own statement).
Across the six axes, Rocks sits at 5 and Pavement at 1. A tire set up to be good at some things and to give up others. Of the 23 tires in the Enduro group, 7 carry 5 for Rocks. 2 sizes, mostly 18-inch.
Our rating (1–5)
| Sand | 3 / 5 |
|---|---|
| Mud | 4 / 5 |
| Rocks | 5 / 5 |
| Hard-pack | 2 / 5 |
| Pavement | 1 / 5 |
| Life | 2 / 5 |
OE sizes can differ by model year and market — the sidewall of your own bike is the sure reference. This is a Japanese-market lineup; the sizes themselves are international.
Size lineup
Rear
- 110/100-18
- 140/80-18
Bikes whose OE sizes it fits
Of the 260 bikes on file, this tire’s size lineup fits the OE sizes of 21. Each link opens the tires you can pick for that bike.
| Model | Years | Front | Rear |
|---|---|---|---|
| KTM 125 ENDURO R / 390 ENDURO R | 2025 model | 90/90R21 | 140/80R18 |
| KTM 125 XC / 250 XC / 250 XC-F / 350 XC-F / 450 XC-F | 2020–26 | 80/100-21 | 110/100-18 |
| KTM 150 EXC TPI / 150 XC-W | 2020–26 | 80/100-21 | 110/100-18 |
| KTM 250 EXC TPI | 2020–22 | 80/100-21 | 140/80-18 |
| KTM 250 EXC-F | 2020 model | 80/100-21 | 140/80-18 |
| KTM 250 EXC-F | 2025–26 | 90/90-21 | 140/80-18 |
| KTM 250 XC-W / 300 EXC (formerly XC-W TPI) | 2026 model | 90/90-21 | 140/80-18 |
| KTM 300 EXC TPI | 2020 model | 80/100-21 | 140/80-18 |
| KTM 350 EXC-F | 2020 model | 80/100-21 | 140/80-18 |
| KTM 350 EXC-F | 2025–26 | 90/90-21 | 140/80-18 |
| KTM 390 ADVENTURE R | 2025 model | 90/90-21 | 140/80-18 |
| KTM 450 EXC-F | 2020 model | 80/100-21 | 140/80-18 |
| KTM 450 EXC-F | 2025–26 | 90/90-21 | 140/80-18 |
| KTM 500 EXC-F | 2020 model | 80/100-21 | 140/80-18 |
| KTM 500 EXC-F | 2025 model | 90/90-21 | 140/80-18 |
| KTM 690 ENDURO R | 2026 model | 90/90-21 | 140/80-18 |
| Kawasaki KX250FX | 2027 model | 80/100-21 | 110/100-18 |
| Triumph TF 250-E / TF 450-E | current as of Aug 2026 | 90/90-21 | 140/80-18 |
| Honda CRF250RX | 2020 model | 80/100-21 | 110/100-18 |
| Yamaha YZ125X / YZ250X | 2022–present | 80/100-21 | 110/100-18 |
| Yamaha YZ250FX | 2019–present | 80/100-21 | 110/100-18 |
Where to buy
How to read this
- The 1–5 ratings are our own estimates. Not manufacturer figures, not measurements.
- Within one model, character and street legality both change with the size and the spec. Confirm with the manufacturer or a dealer before you buy.
- Shop links go to search results rather than product pages. Other sizes and older models will be mixed in.
- “Narrower” means one or two steps below the OE size. The “rim width OK” badge means the tire maker's published rim widths line up with the OE rim width; no badge means unconfirmed.
- Competition tires may not be used on public roads.