Thunder Road Comparison of the 1999 Harley-Davidsons

A look at the Harley big twins that stole Americas heart.

This article was originally published in the June 1999 issue of Motorcycle Cruiser.

Harley uses two different (though quite similar) engines to create three families of mainstream cruisers (plus touring machines). Left: The Fat Boy represents the Softail line. Center: The FXR2 is a temporary revival of the FXR-series machines which were displaced by the Dyna series, represented by the FXDX (right).Dean Groover

With the recent introduction of the twin cam 88 (a.k.a. Fathead), Harley now has two big V-twin engines. The new Fathead powers the Dyna and touring families, and the Evolution engine—which was introduced 15 years ago—supplies power for the Softails and the two recently revived FXR machines.

With more than one million copies minted since its debut in 1984 models, the 1340cc Evo is the most popular motorcycle engine on the planet. Although it retained its prede­cessor’s air-cooled, 45-degree single-carb design and pushrod valve actuation, it got a significantly revised top end with aluminum cylinders, new valve and port arrangements, automotive-style hydraulic lifters and other improvements.

The bottom end was largely unchanged from the iron-barrel Shovelhead that came before it, with Harley’s traditional knife-and-fork connecting rods running on a single crankpin. Initially served with four speeds and chain final drive, the Evo was eventually converted to five speeds and belt final drive. The Evo’s popularity means an unmatched selection of accessories and hop-up parts, prompting Harley to offer a factory rebuild service. For $2000 or so you can make your Evo engine showroom fresh.

The Twin Cam 88 is an entirely new design, even though it shares the Evo’s basic design parameters: air cooling, 45-degree V, single crankpin, knife-and-fork rods, single carb and hydraulically adjusted pushrods operating two overhead valves per cylinder. The twin-camshaft setup is the largest basic change in terms of configuration, but there are virtually no interchangeable parts. The design permits easier assembly and service in addition to greater durability. Shafts are no longer supported by the engine’s side covers; clearances are tighter and more precise; there is more lubrication; components are brawnier; and there is room to grow. It also starts out at 1450cc, achieved with a bigger bore and a shorter stroke. Like the Evo, the Fathead has a separate transmission case. The case itself is new, though the shafts and gears are the same.

The only straight-cruiser series using the new engine is the Dyna line, which uses the newest Harley chassis featuring rubber engine mounts to isolate vibration. To represent this family, we requested a FXDX Dyna Super Glide Sport, the newest and most sporting Dyna family member. The FXDX features longer, high-performance suspension, dual discs on the wire-spoke front wheel and a speedo and tach atop the fork crown. The front end is raked to a steep 28 degrees for responsive steering. The engine and other components, such as the flattrack-style handlebar, are blacked-out. It has a dual saddle and, in keeping with its sporting flavor, provides footpegs for both rider and passenger.

To represent the Evo-powered Softail line, we got an FLSTF Fat Boy, the most popular streetbike in America. The softail chassis mimics the clean, hardtail look with a triangular swingarm suspended by two shocks placed horizontally under the engine. The Fat Boy carries its weight with solid-disc wheels wearing fat 16-inch tires under wide fenders, a seven-inch headlight, covered fork tubes and floorboards. Distinctive touches include the dual shotgun-style exhaust and a leather tank panel atop the twin-cap 4.2-gallon tank.

As we were organizing this ride, Harley announced the return of another chassis family—the FXRs. The Dyna series superceded the FXR family (which also mounts the engine in rubber) but Harley recently announced two versions would be produced on a limited basis (900 units each). The FXR3 and the bike we rode, the FXR2, are both Evo-powered and feature a variety of custom touches, such as special paint and an array of accessories and chrome. Our FXR2 includes a 21-inch wire-spoke front wheel with a single disc, chrome slotted-disc rear wheel, billet footpegs, chrome fork lowers, a small passenger backrest, chromed swingarm, blacked-out cylinders with polished fin edges on a heavily chromed engine, and other head-turning touches.