Aermacchi Harley-Davidson 350 Sprint

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The Yamaha R5 350 Twin.
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Advertisement for the Aermacchi Harley-Davidson 350 Sprint SS.
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The Honda CB350.

Aermacchi Harley-Davidson 350 Sprint
Years produced:
Claimed power: 25hp @ 7,000rpm (1969)
Top speed: 92.49mph (period test)
Engine type: 344cc air-cooled OHV single
Weight: 323lb (w/half-tank fuel)
MPG: 47-58mpg
Price then: $795 (1969)
Price now: $1,000-$4,000

It made perfect sense in 1960. With the Japanese invasion taking hold, Harley-Davidson needed something competitive in the small bike segment. The options: further development of their 165cc two-stroke single or a completely new design — or buy a turnkey business. Aermacchi, of Varese, Italy, fit the bill to a tee: they built a sturdy and competent 250cc bike (derived from Alfredo Bianchi’s futuristic 175cc Chimera of 1955) with good performance and lots of development potential. Better yet, Aermacchi’s parent company, Aeronautica Macchi, wanted to focus on its airplane business, and was keen to divest its bike operations. Harley bought a 50 percent share.

The sporty Aermacchi Ala d’Oro (Gold Wing) featured a four-stroke overhead-valve single with horizontal cylinder and four-speed transmission, with the engine suspended from a spine frame. It looked like a good fit: overhead valve four-strokes were something H-D dealers were familiar with — no fancy overhead cams or ring-ding oil smoke haze.

The first Aermacchi Harley-Davidson Sprint went on sale in the U.S. in 1961. The speedy 250 quickly became popular in production racing, and was gradually improved over the years.

A 350cc version proved potent in GP racing, too, culminating in the 1968-1970 race seasons, when Aermacchis made up four of the top 10 places in the Isle of Man Junior TT each year and grabbed a pair of second place finishes in 1969 and 1970.

Unfortunately, little of the race technology (such as the five-speed transmission and short-stroke cylinder dimensions) made it to the street bikes, although H-D did boost the Sprint to 350cc for 1969.

Meanwhile, the engine got a cosmetic makeover, with the cylinder, head and rocker box blended together. Two versions of the Aermacchi Harley-Davidson 350 Sprint appeared: the SS with a one-into-two exhaust and low pipes, and the offroad oriented SX with a high pipe, high fenders and knobby tires.

This was a time of rapid change in the motorcycle market, however. The race for power and performance was well underway, led by hi-tech cammy Hondas and increasingly frantic two-stroke twins from Bridgestone, Kawasaki, Suzuki and Yamaha. Race versions of Yamaha’s 350s were already challenging the big four-stroke Grand Prix bikes — and winning. Could a 350cc pushrod single with its roots firmly in the Fifties hold its own? Mid-size four-stroke singles had pretty much disappeared from the streets, and offroad riding was dominated by lightweight European and Japanese strokers.

In 1970, Cycle magazine lined up a six-way comparo that included the  Aermacchi Harley-Davidson 350 Sprint SS, Honda CB350 and Yamaha R5 350. In terms of performance, the SS was outclassed by Honda’s twin and the strokers, turning the standing quarter-mile at 15.9 seconds/80.6mph, compared with the Honda’s 15.2seconds/85.4mph and the R5’s 14.7seconds/87.8mph. The fastest bike in the test was the Kawasaki A7, with 14.4seconds/91.6mph. The Sprint was also slowest around the test track, although it did return the best gas mileage, 47-58mpg depending on conditions.

The Sprint’s equipment was disappointing, too: just four speeds in the gearbox (not five, contrary to the ad at left), no turn signals, cheap suspension components and, until 1973, no electric starter. The lack of electric start wasn’t helped by the reversed placement of the kickstarter on the left side of the bike, and the kickstand (and gear shifter) on the right.

Other problems showed up in street use, too. Power pulses were intrusive at low revs, and vibration made it almost impossible to keep feet and hands in place on the pegs and bars at highway speeds.

The buzzing also highlighted some assembly issues, with fasteners backing off and parts coming loose in use.

So why would you want one now? In spite of their shortcomings, the Aermacchi singles are actually quite well made. They’re mechanically durable, easy to fix and frankly just about bulletproof. And because so many were (and still are) raced, parts availability is surprisingly good, and there’s a sound knowledge base on the Internet. Basket-case Sprints aren’t too hard to find, and even restored bikes still seem like good value. MC 

350cc rivals to the Aermacchi Harley-Davidson 350 Sprint

1968-1973 Honda CB350
• 36hp @ 10,500rpm/90mph
• 325cc air-cooled SOHC parallel twin
• 5-speed
• Drum brakes front and rear
• 371lb (wet)
• 46-55mpg
• Price now: $800-$2,500

It’s fair to say the Honda CB350 was Honda’s first “American” motorcycle. Engineered and styled specifically to U.S. tastes, it instantly made the Dream and Superhawk look clunky and dated, while upstaging Honda’s own awkward and over-sophisticated CB450. Styling cues were plainly lifted from the popular British twins, though the engine was brand new, combining performance, sophistication and ease of maintenance.

The short-stroke, SOHC, 180-degree parallel twin featured a 10,500rpm rev limit for high performance, dual gear primary drive for mechanical quietness and efficiency, eccentric rocker arms for easy valve adjustment, Keihin CV carbs for fuel efficiency, rubber-grommet top engine mounts to quell vibration — and electric starting. The price for all this technology was just $735 in 1971.

From a modern perspective, the CB350’s success was its downfall. The CB350 and its variants sold in such large numbers (more than 600,000 in the U.S. alone) they became ubiquitous. They were often ridden to high mileages with little or no maintenance, and then unceremoniously dumped when they expired. And because they had little or no residual value, few were afforded space in collectors’ garages; finding one in good condition now can be a challenge, and prices continue to rise.

1970-1972 Yamaha R5
• 36hp @ 7,000rpm/91mph
• 347cc air-cooled two-stroke parallel twin
• 5-speed
• Drum brakes front and rear
• 306lb (dry)
• 28-46mpg
• Price now: $1,000-$2,500

Piston-port predecessor of the reed-valve RD350, the Yamaha R5 350 twin was still a big improvement over Yamaha’s first full 350cc machine, the YR1of 1967. For one thing, the R5’s power band was much broader than that of the peaky, race-derived YR1, making it much more pleasant to ride. It also featured Yamaha’s Autolube system, pioneered on the 1964 YDS3.

Even with Honda’s CB350, two strokes still dominated the 350cc market, and the R5 was arguably the best of the bunch. Cycle magazine liked its ease of starting (kick only), quietness, sweet-working clutch, supple-though-firm suspension and lack of vibration.

In Cycle’s 1970 six-bike 350 shootout, the R5 was close to the equal of its two-stroke competition in performance terms, and was considered the best all-rounder mostly because it was lighter, and therefore quicker, than the CB350. Summarizing, Cycle’s testers wrote, “… if you think that a motorcycle should combine the best from the maintenance, performance, detailing and transportation points of view, then your overall pick will be our overall pick: the Yamaha R5.”

R5s were — and still are — less numerous than the six-speed, reed-valve, disc-braked RD350s that came along starting in 1973, but they’re also typically less expensive to purchase. MC 

Read about other motorcycles mentioned in this article:

Yamaha R5 350 Twin

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