Diaphragm clutch Spring

[bodgerbloke52]

I recently fitted a new diaphragm clutch spring to my Commander. Result was that I had to have a left paw like Odd Job crushing Bonds golf balls. It was at least 30% heavier than the original spring which already bordered on the heavy but manageable. Has any one any experience of modifying a Commando spring to fit the Commander?? I am aided and abetted on this by the ever helpful RN who advises they are a softer spring.Roger in the Pacific NW

[Dell Boy]

Change your handle bar lever to one with with a better leverage ratio. Yamaha XJ900S diversion is quite good. I always thought the rotary clutch spring pressure was quite light.New one possibly not manufactured to correct specification?In over 300,000 miles on rotary`s I have never had cause to change any clutch component except the h/b lever to improve the lift.Derek.

[bodgerbloke52]

Thanks for advise Derek, appreciate it.From the get go this Commander has suffered from neutral selection problems..With recommended fluid it was a nightmare. The clutch has been pulled out so many times that I am considering wing nuts on the cover. It is hydraulic operated so first efforts were to experiment with differing fluids. The clutch is perfect when assembled dry so after extensive testing Amsoil ATF turned out to be the best. Next was to reduce the 18 plates down to 12 by substituting the thicker Commando steel plates which was another step forward. All the experimenting so far indicated to me that the clutch drum needed more ventilation in order to centrifuge out the fluid. Obtained a used clutch drum from RN, milled out some substantial slots to imitate modern drum design practice. Then obtained Cush rubbers and new spring from AN in order to eliminate other suspects. Wanting to go one step at a time I fitted the spring last week. Clutch pull was most excessive but the clutch did clear better than ever which tended to suggest the original spring was suspect.Lift at the slave piston is .093" so reducing that with more leverage at the control seemed not the direction to go in this case. Logic seemed to suggest a new spring with the same pressure, or less, than my original, hence the question re the Commando spring.I have one on the way which will be here in couple of days. Will see of I can machine the ID to fit the Commander.If that is not possible I will put back in the new heavy spring and try the lever assembly you kindly suggest.Roger

[Wayne]

Hi Allit was printed in the press at the time the rc and rcw used stiffer diaprham springs and 20 plates, i do have a few diapram clutch springs that came with the race clutch's but the look like std. I have spoken to several ex race team members and they confirm there were 20 plates in the clutch but they think the spring was stdIf these race springs exist i dont know how we would tell them appart from a standard one other than back to back trial ?

[bodgerbloke52]

I placed my new spring face to face with the old one. Put them in my press to see comparison. The old one was completely flat before the new one had hardly started to deflect. The new one was so much stronger.The new one was just .002" thicker than the old one so it may have been different steel???? The lever pull was completely unworkable in traffic.Roger

[Wayne]

Hi have you checked your clutch stack hight as richard pointed out as the plates wear the leaver pressure increasessticking plates, have you removed the burs that form on the plate teath the bur ocurs on the driven edge of the tooth, badly worn teath turn the plate round so the undriven portion of the tooth is now driven, burs on teath must still be removed.clean the plates to as new conditioncheck plates for flatnesscheck and dress burs on the teath on the hub and drum with a oil or slip stone i did 2 and 3 from the above and cleand the hydralic tensioner and it transformed the clutch on the f1, i moted the sport and f1 back to back and the tester could not believe the differance in the two clutches? the f1 has double the milage of the sport?the f1 uses the same clutch plates, spring and the pressure plate are the same dimentions apart from some taped holes. as a commander, richard informed me the lift differs a f1 has greater liftMy commander clutch dose not feel that differant to my commando, however commandos were very susepterble to the cable route and correct allignment of the leaver cam in the gear box cover.incidently the race bikes used a tz clutch leaver 87 to 90Regards wayne

[bodgerbloke52]

Thanks WayneBeen there done all that.With the reduction in plates I had to arrange stack height very carefully. I have it bang in the sweet spot of operating in the "flat" area.Steel springs are brand new Commando, they are much thicker than Commander and a flat as a pancake, likewise the friction plates. Clutch drum has no wear indents, only 1700 miles. My mods to date have rendered it a vast improvement over original, operation now perfectly acceptable with the new spring except for excessive lever pressure.Commando spring just arrived, off into the shop to see if I can cobble the ID to fit.Roger