How often should cush drive rubbers be replaced?

There is no single interval. Many riders check them at every tire or chain-and-sprocket change and replace them when there is noticeable free play or visible cracking.

Can worn cush drive rubbers cause chain slap?

They can add to driveline lash and clunking when you get on and off the throttle. Chain slack, worn sprockets and a loose chain are also common causes, so check those too.

Can I shim worn cush rubbers instead of replacing them?

Some riders do as a temporary fix, but shims can shift or chafe the rubber. New rubbers restore the proper fit and damping.

Do shaft-drive and belt-drive bikes have cush drives?

Many do, though the design differs. Shaft-drive bikes often use a damper in the final drive or the rear hub, and some belt-drive bikes have one in the rear pulley.

Motorcycle cush drive rubbers: wear signs and replacement

Motorcycle cush drive rubbers are the rubber blocks inside the rear wheel hub that sit between the wheel and the sprocket carrier. They absorb shock from gear changes, throttle on and off, and hard chain snatch, so the chain, sprockets and gearbox take less abuse. Over time the rubbers harden, crack and shrink, which creates slop and clunking in the drivetrain, and replacing them is usually a simple, affordable job.

Here is how a cush drive works, how to check yours, what worn rubbers feel like and how to replace them.

What a cush drive does

Every time you shift gear or snap the throttle open or shut, the drivetrain takes a jolt. Without some give, that jolt goes straight from the engine through the chain into the wheel.

A cush drive adds that give. In the most common motorcycle design, the rear sprocket bolts to a separate carrier. The carrier has lugs that drop into pockets in the wheel hub, and rubber blocks sit between the lugs and the hub. Engine power has to pass through the rubber before it turns the wheel.

That rubber damping:

Reduces stress on the chain, sprockets, gearbox and output shaft
Smooths out on-off throttle transitions
Reduces wear and fatigue on metal drivetrain parts

Some designs use coil springs instead of rubber. Those are more common in certain shaft-drive final drives and in some engine and clutch dampers.

Where cush drive rubbers are located

On most chain-drive bikes, you find them by removing the rear wheel and lifting off the sprocket carrier. The rubbers are usually in a ring of pockets in the left side of the hub.

Drive type	Where the damper usually sits
Chain drive	Rear wheel hub, under the sprocket carrier
Belt drive	Rear pulley or hub on many models
Shaft drive	Final drive or rear hub; sometimes in the driveshaft
Single-sided swingarm	Inside the hub or eccentric carrier assembly

Symptoms of worn cush drive rubbers

Clunking or a "knock" when you get on or off the throttle
Excessive driveline lash. The bike lurches as slack is taken up.
Jerky low-speed riding, especially in first and second gear
Rear sprocket that can be rocked back and forth while the tire stays still
Visible cracking, crumbling, or rubber dust in the hub
Rubbers that drop out loosely when you remove the carrier

Some of these overlap with other drivetrain problems. A worn chain, loose chain or hooked sprockets also cause clunks. Our guide to motorcycle chain noise helps narrow it down.

How to check cush drive rubbers

Quick check with the wheel installed

Put the bike on a rear stand with the transmission in neutral.
Hold the rear tire firmly so it can't turn.
Grip the rear sprocket and rock it back and forth.
Watch the movement of the sprocket compared to the wheel.

A small amount of movement is normal because the rubber compresses. Noticeable, clunky free play suggests the rubbers are worn. Compare it to another bike of the same model if you can.

Check with the wheel off

Remove the rear wheel following your service manual.
Lift off the sprocket carrier.
Inspect the rubbers for cracks, hardening, tearing and missing pieces.
Check how tightly the carrier lugs fit between the rubbers.
Look at the hub pockets and carrier lugs for wear or damage.

While the wheel is out, check the sprocket carrier bearing and the motorcycle wheel bearings. They wear out on a similar timeline and are cheap to replace at the same time.

Replacing cush drive rubbers

The job is usually straightforward:

Remove the rear wheel and lift off the sprocket carrier.
Pull out the old rubbers. Old, hardened rubbers can be stubborn; a little patience helps.
Clean the hub pockets.
Fit new rubbers. A light coat of soapy water or rubber-safe lubricant can help them slide in. Avoid petroleum grease, which can swell some rubbers.
Refit the carrier. It should be snug and require a firm push.
Reinstall the wheel and set chain slack and alignment to spec.
Torque the axle nut.

Some rubbers are directional or come in different shapes for drive and overrun sides. Match the new set to the old one and to the parts diagram.

OEM vs aftermarket cush drive rubbers

Option	Pros	Cons
OEM	Exact fit, correct hardness	Can be pricier; some older models discontinued
Aftermarket rubber	Often cheaper; available for older bikes	Fit and hardness vary by brand
Polyurethane	Long-lasting, firm	Can transmit more harshness to the drivetrain

For a daily rider, OEM or a quality aftermarket rubber with the same firmness as stock is a safe choice. Very firm rubbers reduce slop but give up some of the cushioning that protects the drivetrain. Our guide to OEM vs aftermarket motorcycle parts explains how to weigh fit, quality and price.

Cush drive rubber replacement cost

Costs vary by bike, region and shop:

Item	Typical range
Aftermarket rubber set	$20 to $80
OEM rubber set	$40 to $150
Sprocket carrier bearing and seal	$20 to $60
Labor (wheel off and on)	About 0.5 to 1.5 hours

If you are already replacing the chain and sprockets, the rubbers add very little labor. Our chain and sprocket replacement cost guide shows what the bigger job typically costs.

When to replace them

Good times to check and replace cush drive rubbers:

At every rear tire change
When replacing the chain and sprockets
When you feel new clunking or lash on throttle changes
On a used bike you just bought, especially a high-mileage one

Cush drive vs other drivetrain slack

Not all lash comes from the cush drive. Before buying parts, check these in order:

Chain slack. Too much slack causes snatch and clunks. Set it to the spec in your manual.
Chain and sprocket wear. Hooked teeth and a stretched chain make the drive feel loose and noisy.
Cush drive rubbers. Use the sprocket-rocking test described above.
Wheel and carrier bearings. Worn bearings let the wheel or carrier move side to side.
Gearbox and clutch. Lash that remains with everything else in good shape may come from inside the engine.

Working through the list from easiest to hardest saves time and money. Our guide on how to choose motorcycle sprockets shows what worn teeth look like.

When to see a mechanic

Have a shop look at it if:

The sprocket carrier is cracked, or the hub pockets are damaged
You hear clunks even with new rubbers, a good chain and fresh sprockets
The rear wheel or carrier bearings are rough or loose
You are not comfortable removing the rear wheel and setting chain alignment
The bike has shaft or belt drive and you are not sure where the damper is

A cracked carrier or failed hub can be a safety issue. A shop that offers motorcycle maintenance can inspect the whole rear drivetrain. You can find local options in our motorcycle repair directory.