WTF’s the Difference? Isle of Man TT Race Classes Explained

Welcome to the Isle of Man TT — the world’s most unhinged, full-throttle road race where danger’s part of the thrill and legends are forged one insane lap at a time.

Whether you’re a seasoned speed freak or just trying to figure out why people are launching 200mph missiles down country lanes, we’ve got you covered. Here’s your no-fluff, all-throttle guide to every class at the 2025 TT.

Superbike TT + Senior TT:

Big Boys, Big Power, Big Stakes

This is the top tier. The heavy artillery. If you came for power and chaos, you’re in the right place.

Bikes: 1000cc+ beasts pushing 200bhp or more
Tyres: Slicks, obviously
Laps: 6 laps / 226.38 miles / two pitstops
Lap Record: 135.970mph (Michael Dunlop, 2024)
Bonus: This class ends with the Senior TT — the GOAT of all road races

This isn’t your average superbike grid. If it’s fast and someone’s unhinged enough to ride it, it’s in. We’ve seen everything from a MotoGP-spec Honda to a screaming 500cc two-stroke Suter tackle the Mountain.

Pro tip: Superbikes rock white number plates — so keep your eyes peeled for those.

James Hillier will be going full send on his Honda Fireblade for Muc-Off Racing. Don’t blink.

Superstock TT:

The class that looks like your mate’s weekend ride—except it’s absolutely not. Superstock is where showroom-spec litre bikes get pushed to the absolute limit.

Bikes: 1000cc, limited mods
Laps: 3 with a pitstop
Tyres: Slicks
Lap Record: 136.358mph by Peter Hickman (2023) — yep, that’s the fastest lap ever at the TT

These bikes might look tame, but don’t be fooled — they’re razor-sharp and fast AF. Plenty of riders even choose to race their stockers in the Superbike class. And get this: the all-time lap record was set by Peter Hickman on a stocker!

Pro tip: Superstock bikes sport red number plates — easy to spot among the chaos.

James Hillier’s lining up in Superstock with Muc-Off Racing — reppin’ the squad and ready to fly on his stock-spec Fireblade.

Supersport TT:

Lightweights, Heavy Hits

Don’t sleep on the middleweights. Supersport races are savage, tight, and stacked with talent. These 600cc rockets are all about finesse, commitment, and being a stone-cold maniac in the corners.

Bikes: 600cc 4-cyl / 675cc triples / next-gen specials like the Ducati V2
Laps: 4, with one pitstop
Tyres: Slicks allowed (from 2023)
Lap Record: 130.403mph by Dunlop again — guy’s a freak.

Hillier’s reppin’ Bournemouth Kawasaki colours in Supersport — no messing around.

Supertwin TT:

The Underdog’s Playground

Born to be budget-friendly. Now? You need deep pockets and even deeper courage. Supertwins are 700cc twin-cylinder screamers that demand every ounce of your nerve.

Bikes: Road-derived 700cc twins
Laps: 3, pit after lap 1
Power: ~90bhp
Lap Record: 122.750mph by Dunlop (yeah, him again)
Tyres: Slicks

Originally a support class, now fully weaponised. Pure chaos in compact form.

Sidecar TT:

WTF Machines, Double the Madness

Two riders. Three wheels. Zero fear. Sidecars are the weirdest, wildest machines at the TT — and honestly, they’re awesome.

Engine Options: 600cc 4-cyl / 675cc triples / 900cc twins
Laps: 3, no pitstops
Tyres: Slicks
Lap Record: 120.645mph

The driver pilots the beast. The passenger hangs off like a human counterweight. It’s nuts. And for 2025, they’ve ditched the usual seeded start in favour of a qualifying-based grid. Fairer, faster, and more fire.

How to Follow Muc-Off Racing

Let’s talk about the guy rocking the Muc-Off Racing badge this year: James Hillier.

A TT veteran with 50+ starts and a rep for being fast, fearless, and frustratingly consistent. In 2025, he’s going full gas in both Superbike and Superstock — throwing everything he’s got at the biggest races of the week.

Check out our sick team announcement video below -