PROX Aluminium Rear Sprocket for HONDA CR 80, CR 85 1986-2007

On HONDA CR 80, CR 85 from 1986 to 2007, the PROX aluminium rear sprocket fits in place of the original part. Bolted to the rear wheel, the sprocket takes all of the engine's force through the chain. An aluminium sprocket is the lightest option on the market: the suspension works better and the wheel picks up speed more easily, at the cost of faster wear than a steel sprocket.

Specifications

• Brand: PROX
• Manufacturer part numbers: 07.RA11086-50, 07.RA11086-52, 07.RA11086-53, 07.RA11086-55, 07.RA11086-56
• Available versions: 50 Teeth: ref. 07.RA11086-50; 52 Teeth: ref. 07.RA11086-52; 53 Teeth: ref. 07.RA11086-53; 55 Teeth: ref. 07.RA11086-55; 56 Teeth: ref. 07.RA11086-56

Choosing the right number of teeth

For the same bike, go for the number of teeth of your current sprocket (it's often stamped on it). More teeth on the rear sprocket shortens the gearing: more acceleration, lower top speed. Fewer teeth lengthens it. Even one or two teeth make a clear difference; if you change a lot, the chain length may need adjusting.

When to replace it?

• Teeth worn to a point or into a hook shape, worn down on one side only.
• Chain that lifts away from the sprocket when you pull it rearwards.
• Drivetrain noise, jerkiness or a chain that jumps under load.

Check the sprocket every time you service the chain. Always replace the rear sprocket, front sprocket and chain together: a new part running with worn ones wears out very quickly. Aluminium wears faster than steel, especially in sand and mud.

Fitting tips

1. Clean the hub and check that it isn't cracked or distorted.
2. Fit the sprocket the right way round (markings facing out) and tighten the bolts in a criss-cross pattern to the manufacturer's torque, with medium-strength threadlocker if the manual calls for it.
3. While you're at it, replace the front sprocket and the chain if they're worn.
4. Set the chain tension as per the manual, with the wheel aligned, then lube it with a suitable chain lube.
5. Recheck the bolt tightness and the chain tension after the first ride.

Why PROX?

ProX Racing Parts has been supplying engine and clutch parts to motocross riders since 1975, from its headquarters near Amsterdam. According to its catalogue, most of its parts are made in Japan, by manufacturers that also produce parts for the Japanese motorcycle makers.

Spare parts and items to plan

• Front sprocket : RENTHAL 259--420-15GP · RENTHAL 259--420-15P
• Drive chain : AFAM A420R1-G · AFAM A420MX2-G
• Chain lube : LIQUI MOLY 400 ml · MUC OFF

Frequently asked questions

Aluminium or steel?
Aluminium is lighter and works well for motocross and racing. Steel lasts longer: it's the best choice for enduro, sandy terrain or if you put in a lot of hours.

Should the chain be replaced at the same time?
Yes, if it's worn: a stretched chain wears out a new sprocket in a few hours.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
HONDA CR 80 2004
HONDA CR 80 2003
HONDA CR 80 2002
HONDA CR 80 2001
HONDA CR 80 2000
HONDA CR 80 1999
HONDA CR 80 1998
HONDA CR 80 1997
HONDA CR 80 1996
HONDA CR 80 1995
HONDA CR 80 1994
HONDA CR 80 1993
HONDA CR 80 1992
HONDA CR 80 1991
HONDA CR 80 1990
HONDA CR 80 1989
HONDA CR 80 1988
HONDA CR 80 1987
HONDA CR 80 1986
HONDA CR 85 2007
HONDA CR 85 2006
HONDA CR 85 2005
HONDA CR 85 2004
HONDA CR 85 2003
HONDA CR 85 2002
HONDA CR 85 2001
HONDA CR 85 2000
HONDA CR 85 1999
HONDA CR 85 1998
HONDA CR 85 1997
HONDA CR 85 1996
HONDA CR 85 1995
HONDA CR 85 1994
HONDA CR 85 1993
HONDA CR 85 1992
HONDA CR 85 1991
HONDA CR 85 1990