One of the most exciting things about riding a motorcycle is shifting gears. Exiting a long curve, rolling on the throttle, and shifting up a gear is one of the best parts of the motorcycling experience. All of this would not be possible without a clutch.
Clutches are necessary because the engine is always rotating as it goes through the combustion process, but your wheels are not always moving. When your motorcycle is stopped, you need to have the crankshaft disconnected from the wheels otherwise the engine will stall. The clutch is the device that disconnects the engine from the transmission.
Electric motorcycles produce 100% of their torque at 0 rpm. Because of this, they have no need of a transmission. Gas engines are different, they can’t produce massive torque at low rpm, so a transmission is needed. Motorcycles utilize a multi-plate clutch pack design.
This clutch pack is made up of 5 to 6 plates. These plates are a combination of steel plates and friction plates. The friction plates have material on them similar to brake pads. These friction plates are sandwiched between steel plates.
When the clutch is not engaged, all of these plates will squish together and the whole multi-pack will rotate together. The engine’s power will be transferred to the rear wheel through the transmission.
When you pull in the lever on the handlebars, you are separating the friction plates from the steel plates. Disconnects the engine from the transmission, allowing the engine and transmission to spin at different speeds. During this time you can shift up or down, and releasing the clutch will re-engage the engine to the transmission.
Recognizing a Bad Clutch can Save You Money
Recognizing a bad clutch or the signs that it will malfunction is very important because it could leave you stranded. It could even prevent you from shifting into gear, and requiring you to pay for an expensive tow. Noticing the warning signs of failure can help you avoid becoming stranded.
Another reason is that most people buy their first bike on the used market with minimal riding experience. Usually beginner riders buy beginner bikes. These motorcycles could have extensive wear from learning to ride. Recognizing a bad clutch is very important when shopping for a used motorcycle or trading your bike in.
How to Tell if You Have a Bad Clutch
There are quite a few ways to tell if your clutch is going bad or starting to fail. Whether it be high engine revs, missing gear shifts, or even slipping we’ll cover it in this article.
1. High Engine Revs After Releasing Lever
If your bike revs to the moon after releasing the lever, it could be because the clutch is not engaging fast enough. In other words the friction and steel plates in the clutch pack are not being squished together quick enough, so not all of the engine’s power is transferred to the transmission. This will result in high rpm while the bike won’t accelerate much at all.
2. Hard Gear Shifts
Hard gear shifts can make for a very unpleasant motorcycle ride. If you experience hard clunking sounds and jerkiness while shifting during your ride, it could be the clutch.
These noises and jerkiness can be caused by a lack of separation between the friction and steel plates. This lack of separation can prohibit the bike from changing gears. The plates are designed to separate a specific distance apart from each other when the lever is pulled in. When there isn’t enough clearance between the friction and steel plates, a clunking sound or jerkiness will be the result when trying to change gears.
This issue can be caused by a loose clutch cable. This looseness would reduce the amount the plates are pulled apart when the lever is fully pulled in. The other cause for this issue is worn/malfunctioning springs in the clutch assembly.
3. Stuck Clutch Lever
A stuck lever can actually tell you if your clutch itself is bad or not. Your lever will either be stuck pulled in or it will be stuck out. Occasionally the friction and steel plates can stick together or be stuck apart, due to dirt and contaminates in the clutch assembly. This could also be caused by malfunctioning springs in the assembly, since the clutch relies on springs to push and pull the plates together.
If the plates are stuck apart, they could have deformed or bent jamming the clutch. If the plates are stuck apart your motorcycle will not be going into gear anytime soon.
4. Motorcycle Won’t Go into Gear
Its best practice to start a motorcycle in neutral. Generally I leave my Honda Shadow in first gear when I turn it off, and then shift it into neutral before starting the bike up.
If your bike is unable to shift into certain gears, and your gear shift lever moves up and down the ladder freely but doesn’t engage, you have a bad clutch. A lot of times this can happen because the whole assembly is seized, prohibiting gear changes altogether.
Generally this failure happened because of overheating. The overheating of the clutch probably happened because of a lack of lubrication. The clutch utilizes friction to transfer power, so it will heat up. An assembly that is not properly lubricated with oil could warp or even fuse together.
How to Extend Clutch Life
Its a good idea to know what you can do to increase your clutch’s life and more importantly what not to do.
- Use quality oil recommended by the manufacturer
- Be religious about oil change intervals
- Avoid clutch-less shifting
- Limit stop and go riding as this generates lots of heat
- Don’t overheat your engine
- Keep the chain at an appropriate tension per manufacturer
- Avoid partial clutch engagement while riding (especially common at slow speeds)
- Limit burnouts
With proper care your clutch can last a long time, without it and you could be in for some costly repairs. There’s no set standard for how long a clutch should last in a motorcycle but 20,000 to 50,000 miles seem to be standard numbers. However it is not uncommon for motorcycles to exceed 50,000 miles without any repair or replacement.
Is a Clutch Repair a DIY Job?
Before you start disassembling your motorcycle in the hope to repair a faulty clutch, inspect your cables. A lot of times a simple tightening of the cable can resolve clutch issues. You can tighten the cable on the lever on the handlebars or on the location where it enters the engine.
If tightening the cable didn’t work, you could try changing the engine oil as motorcycle engine oil is used to lubricate the clutch. That is why most motorcycles are considered wet clutches because they are lubricated by oil. Sometimes an oil change is all that is needed.
When I bought my 1998 Honda Shadow, it had been sitting in storage for several years. The shifting was somewhat rough and a little bit noisy while riding the bike home. After a fresh oil change the clutch felt great! The noise was gone and the shifting was much smoother.
How to Fix the Clutch
Clutches are usually located on the side of the engine. You may have to remove the rear brake pedal in order to access it. Once the cover is off you should see the stator (basically a motorcycle’s alternator). There will also be a gear in the center and then the clutch.
Here’s where things get tricky. You’ll have to remove the timing chain from the stator and the clutch. The timing chain will have to be reinstalled in the exact position it came back on or it will cause timing issues with your motorcycle.
You may need a special tool to remove the clutch assembly. For the amount of work you’ll have to do to access the parts, it makes since to do a full rebuild of the clutch with new friction and steel plates.
For more specific instructions, refer to your owners manual. Also see if you can find a repair or maintenance manual for your motorcycle. If you plan to keep your motorcycle long term, these manuals will easily pay for themselves.
