The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: orabanda on 01.09. 2010 08:41
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1960 Super Rocket; problem with rear drive chain rubbing on front part of 4 piece enclosed chaincase.
I have an issue with the drive chain touching the (engine) RH side of the front part of the enclosed chain case.
The rear sprocket has the correct spacer between the bearing axle and the swing arm, but the centre of the sprocket is about 1/8? too far towards the cast iron hub. The (front) gearbox sprocket also appears to sit off-centre in relation to the chain case shroud that bolts to the inner primary case (the chain touches on the gearbox side of the tinware).
The chain is the correct width, and the sprocket is the correct dimensions. Any ideas?
Rattled Richard
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Chain guards are only for when you have a girl with a long dress on the back. Get a girl with a mini. LOL
Will be looking at one on the weekend. See what differs.
Cheers.
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I had that problem. I unclipped the rear chain spring clip and put a few washers on the pins and put it in loose and the with the bike on the centre stand then ran the packed out link through the front part of the chainguard a few times to "adjust" the clearance. Took the washers out, re clipped the link and all was well. *eek*
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G'day again Richard,
can't sleep, too much back pain. Had another look at your post.
A stab in the dark, is the rear sprocket the right one? Could it be a "56-"57 Ariel type? I know they are different, not sure how.
Also, is there a spacer for the inner primary to frame fitted. If it's too thin or not there it will pull the primary outwards and cause the chain to rub.
Cheers
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G'day Richard,
I have a '63 S/R engine with the front part of the chain guard fitted, the gearbox sprocket is sitting about 6-7mm off that
gearbox side, nearly in the middlle of the guard. I can send a photo if you want. In your case it may have something to do with
the sprocket offset, is it a new one!
regards, Cus
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Hi Cus,
Thanks for the offer!
I will come back to you if necessary, but I think muskrat hit the nail on the head! (He is more than just a pretty face).
The spacer between the LH crankcase, and the inner primary case is about 1/16" thicker than my other S/A bikes, so I will investigate that over the next few days, and let you all know.
Thanks!
Richard
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Richard,
I think Muskrat is talking about the spacer/washer at the lower rear of the innner case where its bolted to the frame
I have come across different thickness spacers between crankcase and inner primary, if this is too thick the primary chain may also rub against the inner case *ex* *ex* *ex*
HTH
John O R