DIY! How to Clean and Lubricate the Speedometer Cable Taught by Professional Mechanic

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Recently, many motorcycles has been adopted the electrical system speedometer, but there are also many motorcycles that transmit the rotation of the tire to the speedometer by a metal cable from small to big bikes.

Regular cleaning and lubrication can be effective, as rust and poor lubrication of the metal cable can interfere with the smooth movement of the meter or cause cable disconnection.

In case of the motorcycle that is parked outdoors, you should be very careful as rainwater infiltrates often inside the cable.

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Table of Contents [Click the title to the part you want to read ↓]

 

POINT

・The layout of the speedometer cable is important.

・If the cable is bent at a steep angle or rusted, it will cause disconnection or needle fluctuation.

・Cleaning and lubrication are important to cable maintenance.

  1. Let's consider about how to layout the cable of the speedometer & tachometer.

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▲ Both speedometer and tachometer of the SUZUKI RG250 Gamma of the mid 1980s had been rotated mechanically by a meter cable. Cleaning and lubrication are also required to prevent response deterioration due to the increased friction.

The speedometer cable that connects the meter gear on the front wheel to the speedometer is a common component for mechanical meter-mounted models, from small bikes such as the MONKEY and SUPER CUB to 1000cc class big bikes.

Stainless steel and steel cables are also used for the clutches and throttles, while they transmit the force of the push and pull. By contrast, the speedometer cable transmits the rotational force, and the inner cable is rolled like a coil spring. The speedometer cable, which bends with the stroke of the front fork, is required to have flexible characteristics, and at the same time, the layout = method of connecting the meter gear and the speedometer, is also important in order to demonstrate its characteristics.

It is common to temporarily remove the meter when replacing the handlebar or maintaining of front forks, but it is required to note that if the meter cable is installed with a tight bend angle when reassembling, the inner cable is rubbed and the resistance increases, and it cause the cable disconnection or needle fluctuation. If the layout of the meter cable has a tight angle near the meter gear or the meter, it is better to remove the cable and reexamine the cable layout.

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▲ The cable take-out port of the meter and the outer cable fitting are connected straightly like in the photo. If excessive force is applied due to poor cable layout, it will adversely affect the inner cable.

By the way, the speedometer cable rotation speed is determined by the JIS standard, and in case of the motorcycle, the meter cable is designed to rotate by 1400rpm when the tire rotates at the equivalent of 60km/h.

Therefore, it is a nominal trivia that whether a meter is for small bike or big bike, the speed of the meter cable when riding at 60km/h at is the same 1400rpm.   2. Rainwater on parking and riding causes rust inside the cable.

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▲ Since dirt oozes out from the coiled part of the inner cable, it is good to not only flush its surface but also immerse it in a parts cleaner or washing oil. If the cable surface is corroded with red rust, the remaining use period is short, so it is better to replace it.

The speedometer cable is not as sensible as other parts like the clutch and the throttle cables, but it is indeed delicate as its function has influenced the layout, so regular maintenance is important. Along with its layout and lubrication, it is the penetration of water into the meter cable that requires special attention.

If you are doing outdoor storage or riding in rainy weather on a daily basis, moisture may come in from the meter gear or nut part that connects the meter main unit and the cable. At this time, considering the stroke of the front fork, if the cable near the connecting part with meter gear is below the meter gear, water will be kept inside of the outer cable, and the inner cable soaked in water will be rusted.

Rusting that way is not so common to on-road models, but trail models riding on the off-road are prone to splashing water around the wheel, then you should be careful of the moisture in the cables. This is easy to check, and it is a proof that the rainwater has infiltrated if rusty water drip out or the inner cable is partially rusted when the meter cable is removed from the meter gear section. The rust of the inner cable may compromise the flexibility of the cable itself and cause uneven rotation.

When the speed is fast, the cable rotation speed is also fast by force, so it will rotate with momentum, but in case that the motorcycle's speed is slow, the cable speed is also slow, so the needle of the meter may not be stable.

The rust can be a cause, of course, but it is needless to say that lubricating oil is necessary even if water does not infiltrate the meter cable, because the similar symptom may occur even if friction occurs due to insufficient lubrication of the contact part of the inner cable and the outer cable.

  3. Clean first before lubrication removing the outer cable.

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▲ After removing the outer cable, clean its inside through the parts cleaner. It is better to replace the meter cable because it will be easier for moisture to come in if the outer cover of cable is torn by rubbing somewhere with the body. In the case of end production model where repair parts are not available, protect the damaged part by a heat shrink tube at least.

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▲ After cleaning inside the outer cable by a parts cleaner, blow it by an air compressor. Because the oil will be cleaned away if the parts cleaner remains inside.

As with other cables, maintenance of the speedometer cable is performed as a set of “cleaning” and “lubrication”. When rust is generated on the inner cable, you can imagine that the rust also adheres to the inside of the outer cable, and even if there is no rust on the cable, since the dirt due to friction attached to the part where the inner and outer parts are rubbed, first remove the outer cable from the meter, and remove the inner cable next.

The inner cable is often possible to pull out from the meter gear side and the lower part of the vehicle, but, o-rings, oil seals, and washers may be installed at the end of the cable depending on the model, so carefully pull out the cable to avoid losing those parts. After that, spray the parts cleaner to inside the outer cable to clean it. When the red rust powder comes out with internal dirt, you can judge that the rust has stuck inside as it is, so it is a good idea to replace the cable to a new, if you want to keep riding your motorcycle for a long time.

Also, if the parts cleaner component continues to remain in the cable, the oil will be cleaned away, so let’s blow it off by using an air compressor after finished the cleaning.

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▲ The grease of the inner cable is applied thinly and evenly so as not to get stuck in the gap between the outer cable and the friction loss.

The cleaning of the inner cable also uses the part cleaner, but in order to bring out the intruding dirt from the coiled cable, it is effective to store the slow drying cleaner in the shallow tray and soak the cable for a while. Once the dirt has removed sufficiently, wipe it off with a waste cloth, and if there is a compressor, blow the remaining parts cleaner inside the cable by an air blow.

The grease on the inner cable is good for rust prevention if you apply it a lot, but since it causes friction loss when the cable rotates and causes to roll up a new contamination, you should apply a material that is suitable for metal lubrication and not too thick to the surface of the cable uniformly and thinly. Insert the inner cable applied grease into the outer cable, and turn it with your fingers to ensure that the cable turns smoothly even if you bend it, and then reassemble it to the vehicle.

POINT

・Cable maintenance is done by cleaning and lubricating as a set.

・There is a possibility that rust and dirt have accumulated on the inner cable.

・It is recommended to replace the new cable according to the condition of the rust.

・The grease to be used after cleaning is applied thinly and evenly on non-viscous objects.

 

Click Here for Meter Cable

  4. Align the cable end and the meter & gear carefully when assembling.

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▲ If you forget to put the washer or o-ring on the meter gear side, the ratio of the length of the inner and outer wire may change and push the meter gear. If you have a used vehicle with traces of removing the meter cable in the past, you may check the configuration of the part in the parts list.

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▲ Insert the cable from the meter gear and the position of the minus groove of the inner cable. When the groove does not fit, adjust by turning the front wheel, never push it by force. In addition, since the nut of the outer cable may crack when tightening, it is kept to the extent that it is lightly tightened with a plier.

When setting the speedometer cable coated with grease, check the way of the outer cable so that it does not cause unreasonable bending as described in the above photo. As a checkpoint on the meter side, it is important to make sure that the outer cable is obediently straight forward or that the cable does not bend suddenly underneath the meter. The meter gear part of the wheel is also the same, let's take it around so that the outer cable does not stick and does not sag too much. When inserting the inner cable, do not forget to set if the washer or oil seal is built in the meter gear side. Moreover, the meter body and the meter gear part are aligned properly.

For this motorcycle, the inner cable must be set in the correct position respectively because it has a square cross section on the meter side and a slit on the meter side gear side with a minus groove. If you force it in a position where it doesn't fit, it leads to an increase in friction and the inner cable also causes trouble by pushing the drive part of the meter.

By performing the cleaning and lubrication, you can prevent trouble such as cable disconnection while the meter moves smoothly, so sometimes you should remove the speedometer cable to check the inner.

POINT

・When assembling, do not bend abruptly, do not overstrain, or loosen too much the outer cable.

・Remember to reset when a washer or oil seal is built into the meter gear.

・Cleaning and lubrication make the meter move smoothly! It also prevents cable disconnection problems.

 

Rust is the inner cable's greatest enemy! Regular maintenance is effective to make it last longer.

If you feel the needle of the meter shake or unusual noise, it is too late! Maintain smooth operability for the cable of mechanical meter as well as the clutch cable and throttle cable by cleaning and lubrication.

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See SUZUKI Moto Index Page
See HONDA Moto Index Page
See Accessories for SUZUKI RG250
See Accessories for HONDA MONKEY
See Accessories for HONDA SUPER CUB 50 (C50)

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