The XR750

22 Aug 2026

The XR750:

The most successful race bike in history

We love motorcycle racing here at North Coast V-Twins, it’s in our veins and our DNA from our founders, owners, and staff Team. We’re pretty confident that you do too! We can all watch overseas Harley-Davidson racing too, there’s King of the Baggers and Super Hooligan from the USA, and the Bagger World Cup with MotoGP racing.

But there are some older H-D racing events that truly give us the ‘feel’ of being trackside, in the pits, in the crowd and the dust… inhaling the fumes of methanol and the scent of Castrol R.

We’re talking about American AMA Grand National Flat Track racing, and our Sunday Run today looks at the most successful race bike in history. It’s a Harley-Davidson, it’s the XR750, first introduced 56 years ago in 1970. Mark Brelsford took the XR’s first AMA win in 1972, and went on to win the Grand National title that year… and the XR750 still managed a race win as recently as 2017.

The final part of the sensory experience for you is to imagine (or better, google and find out) the sound of Harley-Davidson 45-degree V-Twin race engines at about 8,500 RPM as they reach 140mph/225kph on the dirt tracks (with no brakes by the way). No V-Twin rumble here… these things howl!.

The XR750 flat-tracker has 37 Grand National Championships since its introduction in 1970, the last being in 2015, and 502 race wins… “the most successful race bike in history” tag comes from motorcycle journalists, and we wouldn’t doubt it.

Success came away from the long and short dirt track ovals too. An extended swingarm XR750 won the AMA Hillclimb Championship in 1989. And in the air… Evel Knievel used XR750s for most jump records, but note too that Evel’s bikes DID have brakes!

(As an aside, Evel Knievel set a record in 1972 jumping his XR750 over 21 cars. This record was finally broken in 2015 at Sturgis Motorcycle Rally by Doug Danger, using THE EXACT SAME XR750 that Evel jumped 43 years earlier! Danger accomplished this feat on Evel Knievel’s actual vintage 1972 Harley-Davidson XR-750, with no modification to the bike apart from relocating the foot pegs to suit Doug's height.)
That was an amazing feat for Doug Danger, but we’re equally impressed with that incredible 1972 XR750!

Because of its success, customers began asking for a street-legal XR right from the start, but the Motor Company waited until 1983 to introduce the Sportster XR-1000 street bike. The XR-1000 used XR-750 heads, with the eye-popping Dellorto pumper carbies on the right and 2-into-2 left side exhausts, but kept the Sportster engine, frame and other equipment. It was only offered to the public for 2 years.

The XR750 was born out of AMA rule changes after 1969, allowing both side-valve and overhead valve engines of up to 750cc to race together. Prior to this, side-valves could be 750, but overhead valve engines were limited to 500cc. At that stage, the KR750 side valve Harleys were almost unbeatable, but would be uncompetitive against 750cc overhead valve Triumphs and BSAs.

Harley’s response was to modify the Sportster-based XLR race engine which already carried overhead valves. The cast-iron heads and cylinders were modified, the generator was swapped to a magneto, and the entire new system including improved oiling was all dropped into a lightened frame (the backbone frame tubing diameter was reduced from 1.65” to 1”). The tank was a small fibreglass 2.5 U.S Gallon unit, wheels were spoked with aluminium rims and the bike had a low fiberglass seat... all for lightness.
The engineers took the 900cc XLR powerplant, decreased the stroke and increased the bore and brought the bike in just below the 750cc limit. But the iron cylinder heads proved problematic in the early days as they overheated. The new replacement heads from 1972 were alloy, with larger valves, twin plugs, and swapped the exhaust to the left, leaving the intakes to the right, mainly to keep the intakes and twin Dellorto carburettors cooler.
And suddenly the “look” of the XR750 was complete, and unique. And SO desirable!

Now, race fans, here are the riders who have won AMA Grand National Championships on the XR750, there are names you’ll already know, or if not, Google them! Mark Brelsford, Gary Scott, Jay Springsteen, Steve Eklund, Randy Goss, Mike Kidd, Ricky Graham, Scott Parker, Chris Carr, Joe Kopp, Kenny Coolbeth, Jared Mees, Jake Johnson, Brad Baker.
Parker was indisputably the greatest, and retired in 1999. He came back in 2000 for just one race…the famous Springfield Mile in Illinois…and (of course) he won it.

But here’s a surprise – a link to Australia - and surely some our V-Twins Blog readers will remember this. Parker was tempted out of retirement to race in Australia, along with H-D Team racer Rich King, and legendary race tuner Bill Werner.

For the 2001 Australian National HOG Rally at Southport on the Gold Coast, Harley Distributor at the time Mark Wacker put on a complete Flat Track exhibition meeting at Parklands trotting track, inside the HOG Rally venue.

What a gold-plated memory that is! But the best and unforgettable memory is simply the awesome 8,500 RPM sound of the XRs, and the astonishing speeds reached around the track. Of course the two Americans won everything on the night, despite King taking a gentle dive into the soft surface in one heat.

You can find plenty of AMA Grand National videos on You Tube, head back into the 1990s races to find Scott Parker at his best.