Harley-Davidson FL Panhead

The 74-cubic inch (1,200cc) OHV Harley-Davidson Panhead was launched in 1948. It was the post-war successor to the very worthy 48hp, 74 cubic inch OHV FL Knucklehead. Indeed, the Panhead's engine was built upon the Knucklehead's tried-and-tested bottom end, but with new cast iron cylinders, aluminium heads (as opposed to cast iron), and inverted pan-shaped rocker covers; hence the "Panhead" epithet.

But Harley-Davidson didn't launch the bike as the "Panhead". As with the "Knucklehead" sobriquet, that name was coined post-launch by H-D aficionados seeking a more "friendly" moniker for the bike that was officially designated simply as the FL.

Panhead engine

The new engine produced only an extra 2bhp, or thereabouts, but it ran smoother, quieter, cooler, and it boasted more simplified modern styling (as opposed to the aircraft engine inspired look of "The Knuck").

Top-end feed and returns oil "pipes" were now incorporated into the cylinders (as opposed to being routed externally). Hydraulically-operated valve lifters (located at the top of the pushrods) were introduced (said to be the first on a production motorcycle). Redesigned rocker arms helped reduce the mechanical noise. And the physically bulkier engine (largely as a result of the inverted pan-shaped rocker covers) necessitated a new "wishbone" or "dogleg" frame.

Hydra Glide front fork

For the first year of production  (1948), the front fork offered was Harley-Davidson's traditional springer/leading link unit. But the following season saw the introduction of new telescopic tubes that would soon be badged as Hydra Glide suspension. And very soon, the Hydra Glide name would be applied to the bike as a whole.

It wasn't, however, Harley-Davidson's first flirtation with a telescopic fork. Between 1942 and 1943, the firm built 1,000 shaft-drive XA (Experimental Army) bikes for the US military. The majority of the motorcycles featured a conventional springer fork. But subsequent examples sported telescopic units (as per the BMW R71 upon which the XA was based).

In the event, the XA was rejected for battlefield use, and production came to an end. Instead, the now iconic Willys Jeep became the preferred option (and the US military already had plenty of WLA sidevalve motorcycles in the field for despatch work; bikes that were well understood and respected by riders and mechanics alike, and had spares stockpiled).

But those first telescopic forks showed the way ahead, and Harley-Davidson was keen to give its new FL every chance of becoming a sales hit in the marketplace.

Handling & equipment

To that end, larger (split) fuel tanks were created. Deeper fenders appeared. The front brake was enlarged. Taper-roller steering-head bearings sweetened the handling. And the quintessential H-D headlight cowl arrived along with the teles.

This bike was to set the tone for generations of Harley-Davidsons. It was said to be good for 100mph (but we've ridden these, and we wouldn't try that unless drunk).

That said, the "Pan" was never envisaged as a sportster. It was always a touring mount, and with a screen, saddle bags, luggage rack, spot lamps and footboards, this 45mpg heavyweight could traverse continents in what was then state-of-the-art comfort (and is today still considered very laid back and relaxed).

But at around 565lbs (256kg), handling was always a little ponderous and more suited to freeway than back road. That said, the FL carried its weight like a fit fatman, and experienced FL pilots will tell you that they're well accustomed to the idiosyncrasies of this motorcycle and rarely complain.

Foot shift transmission

As with the Knucklehead, the transmission was always a four-speeder. Changing gear was originally by a hand lever on the left side of the fuel tank. It was, typically, slow and klunky. Meanwhile, a traditional H-D clutch rocker pedal, which had served the firm for so long, was deployed to feed the power.

If you haven't tried this system, you might be surprised at how well it works. Unlike a modern clutch lever, that pedal is counter-balanced and can be positioned throughout its arc of movement allowing you to pull away with both feet down if needed.

Just dab the pedal, get the bike rolling on a slipping clutch, and feed in the rest of the power as and when you need to.

Beyond that, if you adapt and accept the mechanical limitations of a slow revving cruiser, shifting up or down can be fairly smoothly handled. It works.

In 1952, foot-change, via a clumsy "mousetrap" servo linkage, became optional. And almost as soon as the mousetrap appeared, mousetrap eliminators followed.

When the mousetrap works, it works. But it doesn't find favour with everyone.

Solid/hydraulic lifters

In 1955, the FLH appeared; a higher performing FL with new engine cases, a beefed up bottom end, and refinements all round.

The original pushrods with hydraulic lifters (see image immediately below) were scrapped. When fitted new, these devices operated reasonably well. But dirty oil, engine heat and general wear & tear issues caused them to bind or fail. So H-D rethought the set up and put hydraulic lifters in the timing chest and fitted solid pushrods above.

It was a far more reliable arrangement, and it needed little, if any, maintenance during the life of the engine. However, the hydraulics sapped a little power. Nothing to get excited about in normal use. But speedsters, ever on the lookout for more muscle, took umbrage.

Consequently, many such hardcore Harley-Davidson FL riders have retro-fitted solid lifters. It's a cheaper set up, but it requires more maintenance.

Swinging arm frames

In 1958 swinging-arms appeared. This represented another great leap forward for Harley-Davidson—and revealed just how far behind the rest of the world the company was as far as chassis technology was concerned.

Handling was not significantly improved, if at all. In fact, many riders preferred the direct feedback offered by the earlier rigid frames. But it was clearly time to move with the times, and swinging-arms were the natural way to go.

Duo Glide - Electra Glide

Now dubbed the Duo Glide, the 74-cubic inch FL rolled on without huge changes until 1965 when the first electric starters were fitted.

These starter motors were a little ponderous and needed a good battery to strut their stuff, but for many riders they were a great improvement over H-D's kick-starter technology which demanded accurate ignition, clean plugs, good fuel, a well tuned carburettor, plenty of leg muscle, and a lot of carefully technique.

But the kickstart pedals were retained, which suited the traditionalists fine (many of whom removed the electric starters, anyway), and it would be another generation or so before the Big Twins were electric only.

These final Panheads were therefore badged as Electra Glides. "Electra" for "electric".

In 1966, H-D took another step forward and the FL Panhead breathed its last. This was the dawn of the FL Shovelhead with around ten more horses, and another new and interesting Harley-Davidson tale to tell.

FL Panhead prices

The 1948 launch price of the FL was $650. Within a couple of years that rose to around $720. The foot gear change models of 1952 cost just shy of $1,000.

By 1965, when production was running at around 7,000 bikes per annum, the price was almost $1,600 by which time fibreglass panniers had been introduced along with 12-volt electrics.

In 2015, Mecum Auctions sold a mostly original and very clean 1948 Panhead for $39,000.

In 2016, Mecum sold an "original" 1965 Electra Glide Panhead for $17,000.