1965 650SS clutch end plate ??

Checkout the attachment of Norton clutch. You can see under the pressure plate that the top clutch plate has friction pads on one side only. So the pressure plate acts on a plain surface.

On my 650 clutch there is only room in the basket for 4 single plain and 4 single bonded plates. Plus the half plate and clutch chainwheel half plate.

Previously Phil Hannam wrote:

Checkout the attachment of Norton clutch. You can see under the pressure plate that the top clutch plate has friction pads on one side only. So the pressure plate acts on a plain surface.

On my 650 clutch there is only room in the basket for 4 single plain and 4 single bonded plates. Plus the half plate and clutch chainwheel half plate.

Phil, In my 1961/62 650 Parts Book it clearly shows the 5 Bonded + 5 Plain plates. Perhaps you have an incorrect Pressure plate. To my knowledge there are 3 versions of this plate and your's should be the knife edge one to fit all the plates in.

I have several of these knife edge pressure plates spare if anyone needs one and also the other versions as well!

Bob Nicholas. E-mail - robert.nicholas987@btinternet.com

I think you'll find that the exploded diagram backs up Phil - 4 plain and 4 friction plates plus end plate. Gordon.

Previously Gordon Johnston wrote:

I think you'll find that the exploded diagram backs up Phil - 4 plain and 4 friction plates plus end plate. Gordon.

Gordon, I agree the diagram does only show 4 of each plate (that's because they were saving money by not re-drawing it!). Look at the parts list on the opposite page and it reads E14 - 5 : E15 - 5. Closer attention needed, to the detail, I think.

Bob Nicholas.

Everybody that has added to this thread is totally correct. The 650 SS clutch should have 5 + 5 plus the end plates. The diagram does not match the notes. My own 650 clutch was sold to me as a standard 1961 Norton 99 item and I assumed that by just changing the pressure plate to the correct thinner SS version there would be sufficient room for the extra plates. I have tried but the best I can insert is only 4 of each. Any more and the first full plain plates lifts clear of the basket.

My conclusion being that the baskets must differ between the 88/99 and the 650 models. My 1961/62 parts book does indeed show that the number of plates is different between the models but that the clutch centre and basket have the same part numbers. I do not understand what is going on. With all new plates I just can not make the clutch work with 5+5. The attachment shows the original pressure plate and the correct 650SS version.

Previously Phil Hannam wrote:

Everybody that has added to this thread is totally correct. The 650 SS clutch should have 5 + 5 plus the end plates. The diagram does not match the notes. My own 650 clutch was sold to me as a standard 1961 Norton 99 item and I assumed that by just changing the pressure plate to the correct thinner SS version there would be sufficient room for the extra plates. I have tried but the best I can insert is only 4 of each. Any more and the first full plain plates lifts clear of the basket.

My conclusion being that the baskets must differ between the 88/99 and the 650 models. My 1961/62 parts book does indeed show that the number of plates is different between the models but that the clutch centre and basket have the same part numbers. I do not understand what is going on. With all new plates I just can not make the clutch work with 5+5. The attachment shows the original pressure plate and the correct 650SS version.

I would add that the 3 Atlas clutches I have quick access to, all have the thin pressure plate...like in the RH side of Phil's photo.

So maybe the 650 clutch is the same as 750 atlas. It would seem to make sense. 5+5+1(1/2)

Interesting thread so far... I too have been having problems fitting the fifth steel plate into my 650SS clutch. There is plenty of room on the shock absorber centre for the fifth pair and the final half steel/half friction plate. I contacted Lawrence at RGM and he confirmed that the clutch chainwheel for the AMC Dominator and the 650s/Atlas is the same. Further research has revealed that the cluch shock absorber centre is deeper, the clutch spring studs are longer , the clutch springs are stronger and the pressure plate is narrower. Also the steel plates are the same... Therefore the only possibility is that the friction plates are thinner in the 650s/Atlas. Moreover because the steel element is the same (2mm) then the friction material must be thinner. In my parts book it does give a different part number ( 21259 for Dommies and ES2 ; 23308 for 650s ) . I am awaiting confirmation from Lawrence on actual thicknesses. Hope this assists. Regards to all, Howard

I purchased 5 new friction plates for my clutch and straightaway noticed that they were substantially thicker than the old set. Which seemed to exacibate the problem of getting them all into the basket. Which they will just about do, but on operating the clutch lever the top steel plate jumps out of the slots. If I take out 1 plain and 1 friction the thinner SS pressure plate bottoms out on top of the clutch centre. So I used an old Dominator pressure plate to get round that problem. I am convinced that the 650SS clutch basket is different to the standard 1960 Dommie version.

Previously Phil Hannam wrote:

I purchased 5 new friction plates for my clutch and straightaway noticed that they were substantially thicker than the old set. Which seemed to exacibate the problem of getting them all into the basket. Which they will just about do, but on operating the clutch lever the top steel plate jumps out of the slots. If I take out 1 plain and 1 friction the thinner SS pressure plate bottoms out on top of the clutch centre. So I used an old Dominator pressure plate to get round that problem. I am convinced that the 650SS clutch basket is different to the standard 1960 Dommie version.

i too had trouble with slipping or draggin clutch on my 650ss and on my es2.after fiddling around with them i found the nearest hedgerow and threw them over as far as i know they are still there causing no more trouble.

i then fitted a bob newby belt drive on both bikes.

i,ve been using them for a few years and never had to touch them again.i did over 200mls on my es2 last sunday so they are used.i think they are still in there but i,ve never had to look.

happy riding[or fiddling] tony

Dave - My parts book that I used to check these items is the official Norton Spare Parts List for 1961/62 from Bracebridge St. - Publication PS214. Cost 4s.6d.

Models covered ES2, 50, 88, 99, 650 Std and Deluxe. With supplementary List for Models 88SS, 99SS and 650SS. (pages 75 to 87).

Phil - hello again....On page 34 it lists part number 21249 as the cluch sprocket with applicability for all models. Incidentally the dimension measured by me, and confirmed by RGM, for the inside depth of the drum portion of the clutch sprocket is 32mm. As each steel plate is 2mm there is a maximum of 22mm avalable for the 5 friction plates. ( The half and half plate does not engage in the sprocket of course. ) Regards.

Howard -Thanks for the info.....The maths makes sense as each of my new friction plates was about 4mm thick. So 5 x 4 = 20mm which leaves just enough room for the last plain plate. Until the clutch is lifted. I guess, like many others, my thoughts were clouded by the belief that the new thicker plates would be much better than new thin plates ........which of course is nonsense. Cheap Ebay junk not made to the correct specification I suppose.

Hello again Phil and readers, I have now had confirmation from Lawrence McDowell at RGM that the replacement friction plates for the AMC 650 and Atlas clutch are 3.5mm thick. So that should do it - ( 5X2mm + 5X3.5mm = 27.5mm ) so even with the clutch lift there is sufficient room to keep the final steel plate in the basket slots. If you need further dimensions please look for yourself on the RGM website and search for item 82M11. Regards, Howard

Previously howard_robinson wrote:

Hello again Phil and readers, I have now had confirmation from Lawrence McDowell at RGM that the replacement friction plates for the AMC 650 and Atlas clutch are 3.5mm thick. So that should do it - ( 5X2mm + 5X3.5mm = 27.5mm ) so even with the clutch lift there is sufficient room to keep the final steel plate in the basket slots. If you need further dimensions please look for yourself on the RGM website and search for item 82M11. Regards, Howard

Hello Howard

Have just come across this discussion. Was that the answer to fit 5 of RGM 82M11 plates?

Speaking to an ex-speedway rider he advised removing just one friction plate. Sounds barmy; steel first plate against the chainwheel [drum] steel, but it works!

Regards

Tim S

hello Tim - In my experience with 650s and Atlases Norton fitted the eleven plate clutch for a reason. In those days of course these bikes were the fastest road bikes on the planet and the yufe at the time insisted on proving that. The constant slipping of a Dommie clutch when fitted would often end up in tears. Five of the RGM SS friction plates plus five steel SS plates plus the half steel/ half friction will fit satisfactorily on the SS centre and in the basket. Leaving out one friction plate may well satisfy your needs. It depends entirely on the use of your right hand and the condition of the mating face in your basket. Remember also that the the SS clutch spring studs are longer and the springs are stronger - so you may need to fiddle to get the adjustment correct. I prefer to use all eleven plates in my bikes but ho hum..... Kind regards, Howard

Previously howard_robinson wrote:

hello Tim - In my experience with 650s and Atlases Norton fitted the eleven plate clutch for a reason. In those days of course these bikes were the fastest road bikes on the planet and the yufe at the time insisted on proving that. The constant slipping of a Dommie clutch when fitted would often end up in tears. Five of the RGM SS friction plates plus five steel SS plates plus the half steel/ half friction will fit satisfactorily on the SS centre and in the basket. Leaving out one friction plate may well satisfy your needs. It depends entirely on the use of your right hand and the condition of the mating face in your basket. Remember also that the the SS clutch spring studs are longer and the springs are stronger - so you may need to fiddle to get the adjustment correct. I prefer to use all eleven plates in my bikes but ho hum..... Kind regards, Howard

Hello Howard

Thanks, I agree, from an engineering point of view it would be better to have the full set of plates.

Have not had chance to ride since Autumn. Last "spirited" ride A166 [from York] over the wolds to the E coast involves [the formidable] Garrowby Hill; a good test. Approx' 100 mls. No slip and no oil on the plates when stripped. As soon as I can get out on the bike again I'll see if it's still good.

Am trying to put together an article on the AMC clutch for the NOC mag, so part numbers [or any sugestions] are very useful.

Kind regards

Tim Stockdale [ t.stockdale123@virginmedia.com ].