Cobra's tach, introduced in...
Cobra's tach, introduced in 2003, wasn't available when this test was conducted.
Don't ask us why most cruisers don't come with tachometers. We think every motorcycle needs a tach. Perhaps the manufacturers think that, because cruisers aren't constantly trying to wring the last bit of performance out of a bike's engine (like those sporty-bike types), we don't care what the engine is up to. Or maybe they think we find clutter on the handlebar so distasteful we'd rather not be bothered with how quickly the engine is spinning. Whatever the reason, the aftermarket has several tachometer options available for cruisers who want information about what's going on underneath the gas tank.
Recently, in our travels to events, several riders have asked us what tachometers we would recommend. Since we had heard of inexpensive tachometers that last for a few months before getting a terminal case of the jitters, we decided we would round up as many tachometers as we could find for our Vulcan Classic. Our methodology was to mount each tach, check its accuracy, run a simulated riding sequence on a dyno, and live with each one in everyday use on the street. The tachometers offered different levels of responsiveness, and we suffered none of the failures we had heard about. [Editor's Note: Since this was printed in 1998, at least one additional company, Cobra has introduced a new tach intended for cruiser use, shown above.]
Three of the tachometers arrived with brackets, one had no mounting hardware, one is a dash-mount item, and the other replaces the Classic's mirrors. The Auto Meter and Custom Chrome Harley tachs used a standard 4.25-inch Harley-Davidson accessory bracket which required that we have a bar clamp (Cobra part #05-0430 or Kawasaki part #K53020-130P) taken to a machine shop to be drilled and tapped to accept the tach bracket. The Fire & Steel bracket we used sports a Vulcan logo, which the tachometer bracket partially covers. We'd recommend a plain bar clamp for a cleaner installation. The Custom Chrome mini-tach mounts via a pipe clamp that wraps around the handlebar. The Drag Specialties mini-tach arrived with no mounting hardware. The Dakota Digital is a dash-mounted instrument which couldn't be mounted to the Classic. And the Maximum Products Gauge-Mirrors replace the Classic's mirrors, after some modification.
All of the tachometers required at least three electrical connections. For a switched power source, we spliced a connector into one of the two red wires with a blue stripe powering the front turn-signal running lights inside the headlight shell. Our ground was connected to one of the bolts inside the headlight shell. All the tachometers required a wire to be connected to the negative wire on the trigger side of the coil (the black wire on the Classic's left coil), which requires removal of the gas tank. When splicing to the coil's trigger wire, take special care not to damage it. Damaging the trigger wire could keep the coil from receiving the signal to fire, resulting in one cylinder not sparking. If this were to happen at speed...well, you get the picture. Consider yourself warned. We recommend running all wiring into the headlight shell and putting bullet connectors (female connector toward the hot side of the connection) on the connections for easy removal.
Auto Meter's tach was the...
Auto Meter's tach was the most responsive analog tachometer in the test.
Go to any racetrack for either national or club-level motorcycle races, and Auto Meter tachometers sprout from many bikes. The same responsive movement is incorporated into the company's street tachometers, although the needle's movement is slightly damped to keep the tachometer from registering every minute fluctuation in engine speed. According to the company, street riders tend to think something is wrong with the tachometer if they see variations of a few hundred rpm at idle.
We selected an 8000-rpm tach (model #19301, $285) in a chrome housing mounted to a Cycle Performance billet aluminum bracket (part #PP-9080) which bolted to the Classic's bar clamp. The Auto Meter tach is available with three face options: black, silver, and white. We opted for white, thinking it would be easier to read. But in retrospect, we should have chosen black to match the Classic's speedometer.
Installing the big, 3.5-inch tachometer was as easy as bolting it into position. We connected the separate wires powering the tach and lighting functions together to the switched power source (as we did with all the other tachs with separate wiring for the lights). The Auto Meter tach is shipped configured for two-pulse ignition systems. Since the Classic's ignition system only fires once per revolution, we had to clip the tach's brown wire to put it in ingle-pulse mode. Otherwise, the tach indicates half the rpm the engine is actually running. The Auto Meter's wires were not bundled together coming out of the tach housing, and required shrinkwrap to clean up their appearance.
In all situations, the Auto Meter tachometer showed its racing heritage by being the most responsive tach we tested. It was accurate at all rpm. The needle registered instantaneous response to changes in engine speed; snapping up to match the engine's speed at every downshift. While the Auto Meter was the most expensive tachometer in this test, the price to performance ratio and the high-quality appearance make this a good choice. We're not the only ones that feel this way about Auto Meter. Kawasaki and Auto Meter are currently developing a 2.5-inch tachometer based on the same movement, which will be sold as a Kawasaki Fire and Steel accessory beginning in early 1999.
The Custom Chrome Harley tach...
The Custom Chrome Harley tach looks as good as it works.
This replacement tach (model #CCI26-708, $180) for Harley-Davidsons looks, as one might expect, exactly like an original-equipment Harley-Davidson tachometer. It measures 3.5 inches in diameter and has a black background with white numbers. The tach has a 6200-rpm redline printed on it. When combined with the included chrome housing and bracket, the tach assembly will fit any standard 4.25-inch Harley handlebar clamp, or a drilled and tapped Vulcan Classic clamp. Installation was simple. The tach and bracket bolted together then attached to the bar clamp. Testers felt that the bracket, with its integral visor, made this one of the best-looking tachs in our test.
The tachometer worked consistently throughout our tests without a glitch. The tach was accurate from idle to 3000 rpm. From 3000 rpm to redline it became progressively more optimistic, with a 300-rpm error at 5000 rpm. In our dyno test, the needle didn't drop as quickly as the more responsive tachs, which we interpreted to mean the needle was moderately damped to avoid fluctuations. When we ran the Classic up to redline in first gear, the tach accurately indicated the 5500-rpm starting point of the rev-limiter. Out on the street, the tach's responsiveness was never an issue, and it provided the information we wanted.
Custom Chrome Mini-Tachometer
Custom Chrome's mini-tach...
Custom Chrome's mini-tach mounting system allowed several tach locations.
Measuring only 2.5 inches in diameter, this imported mini-tachometer (model #CCI27-821, $66) mounts to the handlebar via a pipe clamp. Since this tach could be mounted in just about any position on the handlebar, it offered the most placement flexibility of any in the test. The rubber cushions kept the tach almost vibration-free, and the white numbers and needle over the black background were easy to read. In order to utilize the internal instrument light, the blue and black wires exiting different holes in the tach housing must be connected to the power and the ground, respectively. Since the wires exit from different places on the tachometer, we recommend shrinkwrapping them together to clean up the appearance.
The needle vibrated noticeably at idle but smoothed out at other speeds. On the dyno, the tach was 100 rpm optimistic at idle and 200 rpm optimistic at 5000 rpm. Under acceleration on both the dyno and the street, the tachometer lagged to the point where the needle didn't start to slow until after the rev-limiter kicked in. Overall, the tachometer didn't appear as responsive as others in the test.
Dakota's dash-mount digital...
Dakota's dash-mount digital tach would be a good choice for a custom project.
This digital tachometer (model #ODY-02-7, $170) requires a dash mount, so it is ideal for custom projects where it would be inset into the tank or other bodywork. Measuring 2.7 inches wide by 1.8 inches high, the tach belongs to a line of mini-gauges ranging from oil pressure, to speed, to cylinder head temperature. (The company also sent us its just-released Mini-Bargraph Tachometer, which sells for $199. But it arrived too late to be tested.) The tach offers a variety of installation options, such as a warning indicator (shift light) and switched dimming feature to tone down the display at night. We'd take the time to hook up a switch for the dimmer. This was the only tach with a fused power wire.
Setting the functions took only a few minutes. First, the number of cylinders needed to be set using a button and a knob. Second, the flashing rpm warning was set to 200 rpm before redline in a similar fashion, causing the display to flash when the rpm exceeded the rpm setting. This gives a visible shift point.
The green LED readout was easy to read in almost every lighting situation. Only when the sun was reflecting directly off the gauge could we not read the display. On the dyno, the gauge was spot-on accurate up to the gauge's resolution of 50 rpm (i.e. the tach would read 2200 rpm if the engine ranged anywhere from 2200 to 2249 rpm). Although we were concerned the tach would be difficult to read under hard acceleration because it only updates the display twice a second (the external warning/shift light feature updates 16 times a second for increased accuracy), the tach didn't have any trouble keeping up with the engine speeds. The flash-warning feature helped with high-rpm shifting. The tach returned to idle speed instantaneously when we pulled in the clutch.
The Drag Specialties mini-tach...
The Drag Specialties mini-tach vibrated enough to be difficult to read.
The Drag Specialties 2.5-inch mini-tachometer (part #DS-243910, $70) looks remarkably similar to the Custom Chrome version. However, the Drag Specialties tach has four wires bundled together in a common harness. It arrived with a flat mounting plate that severely limited the options for installation. We used one of the threaded holes in the handlebar clamp, but the rigid mount caused the tach to vibrate, making it difficult to read at high rpm. A U-shaped clamp (DS-243803), similar to the one used on Custom Chrome's mini-tach, is available for $6. A billet bracket (DS-243803) and cup (DS-373525) will add $235 to the price.
The Drag Specialties tachometer was accurate at all engine speeds. Under acceleration on both the dyno and street tests, the tachometer lagged behind the engine to the point where the needle didn't start to slow until after the engine was well into the rev-limiter. Overall, the tachometer didn't feel as responsive as others in the test. Although the white numbers on the black dial were translucent and easier to read at night, we suspect it utilizes the same movement as the Custom Chrome mini-tach.
Maximum's Gauge Mirrors feature...
Maximum's Gauge Mirrors feature a tach as part of their full complement of instruments.
The most unique product in this comparison, Maximum's Gauge Mirrors, contains all the instrumentation a rider would normally need (odometer, oil pressure, speedometer, tachometer, tripmeter and voltmeter) within a pair of chromed, billet-aluminum mirrors. This test only addresses the tach function of the Gauge Mirrors. However, the mirrors could not mount directly to the Classic's stock mirror attachment points. Maximum Products is working with us to develop a mounting system. The red LED readout was easy to see in daylight. And when the full system is installed, the LEDs dim automatically through four levels of brightness for varying light conditions.
Since the Mirror Gauge is a digital tachometer, we were not surprised to find it to be perfectly accurate at all engine speeds. However, the tachometer ramped-up slower than the other digital tach on the dyno. According to the manufacturer, the tachometer updates every 100 rpm on acceleration and every 200 rpm on deceleration. However, we found that when accelerating hard on the dyno in first gear, we had to upshift as soon as the tachometer reached 5000 rpm or the engine would bump the rev-limiter. This was only an issue in first gear. The rpm picked up just slowly enough in the other gears for the tach not to lag. During the street test, the lag was never a problem. The $875 suggested retail price would be expensive for a tachometer alone, but the mirrors are a complete instrumentation package -- containing indicator lights (high beam, neutral, oil pressure and turn signal) plus performance features like 0 to 60-mph elapsed time. These are ideal for riders who want to eliminate their conventional instruments. A new style of Gauge Mirrors is also available from Maximum for $695.
Auto Meter Products, Inc.
413 W. Elm St.
Sycamore, IL 60178
Cycle Performance Products, Inc.
2724 Spring Garden Road
Winston-Salem, NC 27106
Dakota Digital, Inc.
3421 W. Hovland Ave.
Sioux Falls, SD 57107
(800) 852-3228, (605) 332-6513
For additional evaluations of, comparisons of, and shopping advice for motorcycle gear and accessories, see the Accessories and Gear section of MotorcycleCruiser.com.