Author Topic: Clutch chainwheel studs questions  (Read 135 times)

Online bakerlonglegs

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Clutch chainwheel studs questions
« on: 15.04. 2019 20:59 »
Hi, I’m rebuilding an A10 plunger from a collection of parts. I have questions about the captive studs for the cover fixings on my clutch chainwheel. Most of the threads on the studs are damaged or the studs are snapped short. I also don’t have all the corresponding nuts.

With a mind to fitting a replacement nut and hex head bolt, I’ve tried to drill out one of the captive studs which had snapped. It seems to be brazed in place so it’s not coming off easy. I’d like to ask two questions, potentially dumb but hey ho.....  *whistle*

Firstly, stupid question but is the cover really necessary? I’m assuming it’s there to protect the clutch plates from oil off the chain drive. For example, could I use a modern waxy chain lube instead.

Secondly, if I have to fit the cover, before I hack at any more studs am I doing the right thing? If the chainwheel is scrap in this state it would handy to know before I spend hours working on it.

Ta muchly!


Online muskrat

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Re: Clutch chainwheel studs questions
« Reply #1 on: 15.04. 2019 21:20 »
G'day bll.
I think duTch runs his without the cover.
I'd try to fit the cover with the remaining studs/nuts and use a good gasket goo (silastic OK in the primary).
Without the cover you will still need oil in there. The chain and slipper will wear quickly without.
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'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
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Online morris

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Re: Clutch chainwheel studs questions
« Reply #2 on: 15.04. 2019 21:44 »
I run my plunger’s clutch without the cover (bike came without). No issues.
Springs need to be tight though or it will slip, but I don’t really think this has anything to do with having no cover.
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Offline Swarfcut

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Re: Clutch chainwheel studs questions
« Reply #3 on: 15.04. 2019 23:05 »
 BL   I have come across chain wheels where the studs have  a narrow spiral flute at the none threaded base end, and are simply "nailed" into the chain  wheel rim from the rear. You might find cutting the bad ones flat will enable them to be simply knocked out. Support the rim to prevent distortion. If yours are brazed, soften the braze with heat and push them out.

 The threads are 2BA. I made my own nuts, tapping a thread in a hex bar, then parting  each one off in the lathe  with a small cutaway to clear the raised rim of the cover, just like the originals, they looked better than new.

 The cover is not essential, as long as the oil level just kisses the chain, no higher, the plates will remain reasonably dry, but the cover also adds rigidity to the clutch basket. Even held on with a few Loctited nuts is OK, you won't notice any imbalance compared with the rest of what goes on within those crank cases. If a clutch adjusting nut loosens, you will hear it grinding the clutch cover rather than the primary cover before it drops off to do major damage.

  Swarfy.

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Online duTch

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Re: Clutch chainwheel studs questions
« Reply #4 on: 15.04. 2019 23:14 »
 
Quote
.....I think duTch runs his without the cover. ........

 Yes, that's correct. I'm kind lazy so (aka- like to streamline/shortcut) left it off until I knew the clutch adjustment was going to work for me (and didn't have nuts anyway, but have since bought some), but as time passed I figured I don't need a cover, but did need to do lots of adjustments.
    The plates don't seem to oil up significantly, and my theory is that oil flings out and the cover flange inhibits any oil flowing in when at rest..... I've done about 16K miles like that thus far....I do have some clutch slip when I give a extra big handful, but I think that's due to the springs too short or sagged ( ~ 37-38mm) or too many winds for the length, (about 8,1/2 or 9 I think) so can't garner any more adjustment without binding.

  I also am only using 4  friction plates, because five made it too thick and the adjusting nuts constantly came loose *pull hair out* - but saying that, maybe the cover would hold them in place- nah bad idea metinks *eek*

 Swarfo conveniently arrived with the reason why ^^ while I was tapping *smile*;
   
Quote
........If a clutch adjusting nut loosens, you will hear it grinding the clutch cover rather than the primary cover before it drops off to do major damage......



Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
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Online bakerlonglegs

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Re: Clutch chainwheel studs questions
« Reply #5 on: 17.04. 2019 10:14 »
Thanks very much for all the replies and advice! That really helps.