Harley-Davidson XRTT750 – another winning legend ridden

Oxford (21 September 2012) - The attraction of Goodwood Festival of Speed (FOS) is simple: it’s the UK mecca for petrol heads. Since 1993, when Lord March, owner of Goodwood Estate, first opened the gates to a flood of motorcycle and automotive fans, every type of street and racing machine has appeared, and been gazed at in admiration by thousands. Many of these bikes are also ridden up the 1.16-mile Goodwood Hill Climb circuit.

Even though it only dates back to 1972, the XRTT750 is one of the most rare Harley-Davidson® motorcycles. It is rumoured only 18-23 of the bikes were actually produced by the Harley-Davidson® factory and most have disappeared into air-conditioned private collections.

This particular bike is owned by John Warr of Warr’s Harley-Davidson – Europe’s oldest H-D dealership – and it doesn’t reside in mothballs. John is a firm believer that bikes are built to be ridden and, as a former racer, he likes to get the XRTT750 on a circuit when he can… but not necessarily with someone else in the saddle! I feel privileged…

Despite full instructions and graphic detail on how and what the XRTT is like to ride, nothing prepares you for the first sitting. The seat is firm and narrow and the fairing bubble is plentiful, but to physically fit a relatively normal 14.5-stone rider in the gap between the two is the preserve of contortionists.

The foot pegs are of the rearset type, but painfully old school, by being placed so far back and high that boots never rest squarely on them with the first attempt. This is because the seat height is so low that hips and knee joints struggle to deal with a classic racing tuck on a very low classic racer.

Talking of racing tuck, clipped to the top of the fuel tank is a small leather pad to be used for resting the chin bar of the rider’s helmet while piling it down the straights. I now have thoughts that racers of the era were actually redundant jockeys. There is no physical, legal way I’m going to get myself in the right position.

Handlebars are of the clip-on variety, with the clutch and front lever mounting brackets welded solidly to them to prevent being broken in a crash. The bars are set so far forward that leathered forearms brush against the glass fibre fairing sides. It would be full contact if it wasn’t for the fact the steering lock is the smallest ever to be encountered. No wonder the Warrs’ technician made a big deal about being very careful to make my way out of the paddock, out of the holding area, out of the access road, out of…

It’s true. It takes umpteen leg paddles and bar movements to simply line up the XRTT in line with the remote starter rollers. To save weight there is no kickstart assembly, although the splined shaft is still visible.

Needless to say, the XRTT is prepared to a high standard. There are no scars, as such, to declare its former race life, and everything that is bolted in or around the frame is perfectly fettled to be light and smooth in action, and original. The clutch is feather light. Brake operation from the twin-leading-shoe drum front brake is grab-free and appears to work well, in and around the paddock.

In 1972 the famed 750cc XR motor was redesigned to be an all-aluminium affair. Cases, heads and barrels are all of the lightweight material and left bare to acknowledge this. To describe the engine as a tidy unit is an injustice. There isn’t a rattle or misfire or sound of old age from any part of it.

The cylinder heads are the archetypal two-valve and activated by pushrod. The main difference between this and a standard Sportster lump of the time is the lightened and blueprinted (everything fettled to exacting tolerances) innards and race spec valve timing with gasflowed heads. It’s powerful considering this V-twin is as basic an engine you could get in racing at the time. Still, cassette-type gear cluster and 80-odd-bhp were not to be sniffed at, especially when the bike led most races.

The most famous XRTT750 machine was ridden by Californian legend Cal Rayborn as part of the Harley-Davidson factory racing team. With Daytona wins and land speed records under his belt, Rayborn and an XRTT appeared in the UK as one of the American team to compete in the Trans-Atlantic race series. He promptly mopped up on unknown UK tracks with three wins from six outings. It was a special XRTT though, highly tuned with overhead cam drive.

Just blipping the throttle to link the two open mouthed carbs nets a sip of the potential from the growler below. It’s a mix of booming 2-2 exhaust-blowing waste gases, and clean air being sucked angrily through the carb bellmouths – positioned strangely to suck the right kneecap into the maelstrom downward of the carbs. Saying that, the high rise exhaust system is a puzzle too because I just know it’s going to warm my left upper leg.

Cramped and wobbling from trying to put my left boot on the rearset, we ride from the start line. There’s no doubting why the XRTT was competitive for its short life. There’s no need for mammoth clutch slip because the famed Harley® engine torque punches the XRTT from standstill. This is despite tall gearing of just four gears.

With the openness of the road circuit the XRTT gets moving, obviously not in the same vicious way of a modern four-stroke, V-Twin or otherwise, but in a solid delivery of ample torque compounded by the taller 8000rpm ceiling and the power it brings with it. It’s not all rosy though; a slight backing off of throttle for a shallow curve and then cracked open again reveals a slight stumble of over-rich carbs. It’s not a problem because the bike is obviously set to stretch its legs with flat stick runs at max rpm rather than a stroll along an estate road.

Suddenly the bike’s solidity shows its worth on a fast flowing bend. While it takes some hauling over into the turn, when it’s there the feedback is as rewarding as a modern day supersport bike. That large front drum brake isn’t all show. It could never be described as vicious with the amount of weight it has to slow, but slow the bike it does and with feel. A touch of rear brake – operated by the left foot because the bike is right-hand shift – makes late braking mentally more comforting.

Back in the paddock makes for a good time to look deeper at the XRTT. Ceriani forks, twin Koni rear shocks, wide-ish alloy rims for grippy rubber – all top notch for the time. Now dress it all with swooping glass fibre bodywork (even the fuel tank is glass fibre) and you have a bike that is as desirable as any Brit Iron with the same date stamp, or before.

Harley-Davidson’s XRTT750 is a classic motorcycle alright, one that fires up any motorcyclist who has lust for genuine race weaponry and Harley-Davidson® motorcycles: it does mine. Now, I’m never going to find a XRTT750 for sale, let alone afford one, but while the rage for building replica classic race bikes gathers momentum, my nagging urge to build something similar has taken a new route towards America and a replica XRTT750. Let Harley-Davidson UK know if you’ve beaten me to it. It could be your bike featured here.