Interesting Clutch Friction Plate

Status
Not open for further replies.
Starvingphotog

Starvingphotog

VIP MEMBER
Joined
Jan 1, 2021
Messages
356
Country flag
Check out this interesting friction plate I found on the 850. Have you seen these before? Very different from the Barnetts. It looks to be brass plate with the friction material one piece and adhered to the brass plate. There's a groove that's off centre on the plate, and it's on all the friction plates in the same orientation. Very cool looking plate compared to the cheap looking Barnetts kit friction plates. I'm wondering if I should reuse these or go with the Barnett kit I bought to renew the clutch.
 

Attachments

  • Interesting Clutch Friction Plate
    65837017310__8BF87F25-F009-452E-BC31-43EF0D13183B.JPG
    289.8 KB · Views: 144
whoops! I didn't realize I started a new thread. I thought I was in the What Did You Do With Your Commando Today thread.
Anyway, yes, there's five of these bronze friction plates and 4 of the steel plates. So, I'm thinking that this bike could actually be quite original and "new" I can't imagine the original plates being in there from '74. Who knows. These bikes have a life of their own it seems and many secrets, which they won't give up too easily:)

Thanks for the eye to spot the details behind these original clutch plates Les.

Cheers,
Rob
 
  • Like
Reactions: baz
The plates are long lived .
My 74 still has the std plates in very good order .
 
  • Like
Reactions: baz
Starvingphotog said:
whoops! I didn't realize I started a new thread. I thought I was in the What Did You Do With Your Commando Today thread.
Click to expand...

I started the new thread as you posted on an "Ignition light" thread and not the "What Did You Do..." thread, however, don't worry about it.
:)
 
  • Like
Reactions: baz
Starvingphotog said:
I'm wondering if I should reuse these or go with the Barnett kit I bought to renew the clutch.
Click to expand...

As mentioned, one good point about the bronze plates is they hardly ever wear out.

The not so good points are they can become coated in a black residue that needs to be periodically cleaned off to prevent slipping and dragging.
The tangs of the plates eventually notch the (hardened) clutch centre (although any type of steel-backed friction plate is likely to do that) as shown in the pic below, resulting in drag and poor neutral/1st gear selection.

Interesting Clutch Friction Plate
 
Been running them since new in 76 and with 46 years use have only replaced the clutch centre once and the pressure plate once.
 
Hey there LAB. I have a query for you, if you're up for it. I remember you helping me with my work I was doing replacing the clutch on my Combat. I recall you telling me to make sure the pivot arm inside the transmission doesn't drop when I replaced the clutch cable. Well, I'm doing the same thing on the 850 and this time the pivot arm did drop when I was taking too long to remove the old clutch cable. Did I put myself in a very bad situation with the arm falling? I'm going to finish my clutch assembly today and also the cable installation so I just wanted to ask in case there's something I should be doing other than trying to just wiggle the arm back in position and attaching the end of the clutch cable and testing it out once the pressure plate and diaphragm are back installed.
 
Starvingphotog said:
I recall you telling me to make sure the pivot arm inside the transmission doesn't drop when I replaced the clutch cable. Well, I'm doing the same thing on the 850 and this time the pivot arm did drop when I was taking too long to remove the old clutch cable. Did I put myself in a very bad situation with the arm falling?
Click to expand...

If you slacken the pushrod adjuster then you should be able to click it back into position with a screwdriver or similar.

Edit: For the actuator arm to have dropped in the first place then the pushrod adjuster must have already been slackened off.
 
Last edited:
Wow! FAST!
Well, the clutch plates aren't back in yet, so the pushrod is just floating back and forth in there now. So, I'll get the clutch stack back in there and diaphragm and then work on the pivot arm. See how that goes.
 
By the way, I didn't have any of those notching that you mentioned earlier in this thread. I guess that's one of the reasons whey the Barnetts are some sort of softer metal, perhaps aluminum, so as to prevent that notching on the centre sprocket.
 
Starvingphotog said:
By the way, I didn't have any of those notching that you mentioned earlier in this thread. I guess that's one of the reasons whey the Barnetts are some sort of softer metal, perhaps aluminum, so as to prevent that notching on the centre sprocket.
Click to expand...
That, and it's easy to work with and cheap. I replaced my measured-near-new-at-0.124" sintered bronze plates with Barnetts.
The perfectly linear, no-grab, no-slip, no drag clutch is a joy to operate. Some of which is attributable to being bathed in lots of ATF.
1636811393393.jpeg
 
Last edited:
Starvingphotog said:
By the way, I didn't have any of those notching that you mentioned earlier in this thread.
Click to expand...

Good.

Starvingphotog said:
I guess that's one of the reasons whey the Barnetts are some sort of softer metal, perhaps aluminum, so as to prevent that notching on the centre sprocket.
Click to expand...

Yes but then the soft metal plate tangs can wear away instead of the clutch centre so you'd end up replacing the plates instead of the clutch centre although that should take a considerable mileage before either course of action would be necessary.

Surflex plate example in a dry clutch so the wear rate is likely to be faster.

Worn Surflex clutch plates

Hi All. Here´s a photo of one of the Surflex clutch plates from my MKIII. I´ve fitted a Norvil beltdrive a number of years ago, together with new clutch center and 4 new Surflex clutch plates. I guess the kit has less then 50.000 km/30.000 miles. I´d say a set of clutch plates should last a...
www.accessnorton.com www.accessnorton.com
 
Looks like everything worked out well with my clutch renewals. I put in the Barnetts and also a Venhill cable. Feels marginally better than it was before. The same setup I installed on the Combat feels lighter to pull and more positive. I might mess about with the 850 a little more over the winter to get the cable position on the lever right and the pushrod adjuster screw positioned accordingly.
 
These 850 bronze plates last forever , but clutch center notching has to be considered.
I'm wondering about the oil dispersal spiral groove and how each plate's direction of the cut spiral would fit , to throw off the oil properly. Perhaps it doesn't matter .
I drilled out 2 holes into one of these plates to bolt together a clutch locking tool. Works good to loosen or tighten drive train nuts.
 
Torontonian said:
These 850 bronze plates last forever , but clutch center notching has to be considered.
I'm wondering about the oil dispersal spiral groove and how each plate's direction of the cut spiral would fit , to throw off the oil properly. Perhaps it doesn't matter .
I drilled out 2 holes into one of these plates to bolt together a clutch locking tool. Works good to loosen or tighten drive train nuts.
Click to expand...
The CNW hardened center.
 
Starvingphotog said:
Looks like everything worked out well with my clutch renewals. I put in the Barnetts and also a Venhill cable. Feels marginally better than it was before. The same setup I installed on the Combat feels lighter to pull and more positive. I might mess about with the 850 a little more over the winter to get the cable position on the lever right and the pushrod adjuster screw positioned accordingly.
Click to expand...
You need to get the stack height dead right on a commando clutch for light operation
 
Status
Not open for further replies.
Back
Top