Part # 2121-70-80-R50-75
Clutch Service Kit R50-R80 up to 1980

Boxer2valve's clutch service kit contains all the parts you will need to replace the clutch components on your R50/5, R60/5, R60/6, R60/7, R75/5, R75/6, R75/7, R80 models up to 1980.

Part Name	Part #	BMW Part #	Quantity
Diaphragm Spring Standard	2121288	21 21 1 250 288	1
Clutch Disk up to 1980	2121332	21 21 1 236 332	1
Compression Ring for Clutch	2121666	21 21 1 231 666	1
Pressure Plate Clutch	2121801	21 21 1 251 801	1
Clutch Bolt	2121463	21 21 1 231 463	6

Diaphragm Spring, Standard

This is the standard clutch Diaphragm spring that was used in /5 and /6 models. With the introduction of the R90 S a stronger spring was used and it was retained through the 09/80 production. The stronger spring places more tension on the clutch plate, important with the more powerful motor.

The heavier spring is not needed on a stock /5 or /6 but is can be used instead if desired. The clutch lever pull will increase with the heavier spring.

If you have installed a Siebenrock Power Kit on your R75 then we do suggest that you instead use the heavier spring, part number 2121288. Also if the harder lever pull is not something that concerns you, in that case you might also rather choose the heavier spring.

Mark + Swiss Clutch Disk

This clutch disk features a highly reinforced construction, superior to the original. The hardened spline is attached to both the clutch disk and a steel reinforcement plate with 8 rivets and the reinforcement plate is attached to the disk with an additional 8 rivets, 16 in all, making this the strongest clutch that we have ever encountered. The organic lining has a special metallic compound that will offer many years of reliable service.

Important Note: When replacing your clutch, it's not enough to just replace the disk! It is a good idea to also replace the pressure plates and the diaphragm spring.

it's also important that your clutch cable is properly adjusted. This is important so that the clutch actuation mechanism has full movement. Failure to perform these tasks may result in premature failure, wasted effort and money.

Fits /5 /6 /7 models up to 9/1980

Comparable to 21 21 1 236 332

Compression ring for clutch

This part should always be replaced when installing a new clutch disk. Even if the old one "looks good", wear patterns have been established and the replacement disk will wear out prematurely if it's re-used.

Replaces BMW part number 21 21 1 231 666

This part may appear to be different than the one removed. If the original part has spacers between it and the pressure plate, those spacers are not re-used. This part has been machined to incorporate the spacers and they can therefore be discarded. Always use new bolts when installing this part.

Pressure Plate for clutch

This part should always be replaced when installing a new clutch disk. Even if the old one "looks good", wear patterns have been established and the replacement disk will wear out prematurely if it's re-used.

Replaces BMW Part Number 21 21 1 251 801

Always also replace the diaphragm spring, compression Ring and 6 bolts. Fits all models from /5 to 09/80 production except R45/65

Bolt for clutch disc

Replacing the clutch bolts every time the clutch is removed or replaced is the right thing to do.

These are the replacement bolts for all clutch assemblies from /5 through 09/80 production. 6 are required.