Primary Chain Noise?

[brackenfel]

Dear All,
This may seem a daft question but I'm having trouble adjsuting the primary chain on my '62 A10.. I get the 1/2" slack right and tighten up the bolts & the chain tightens a little. Slacken off bolts, slacken chain a little , try again. 
I suspect that the chain is probably a bit worn but hey, the weather's good and this thing has been off the road too long to revisit the area just now - I'll do it in the Autumn! I've got it almost right now, although there is a tight spot..

My question - if it's too tight does the chain make a "whirring" noise??  It's been so long since I've had this thing running (and so much has been dismantled & reassembled) that I don't really remember what eveerything sounds like..

My mate reckons it's ok & that I'm worrying unnecessarily but thought I'd seek opinions here..

Thanks as always,

Adrian

[Rich]

I would make sure the tight spot is not to tight and you have oil in the case, then go for a run out and enjoy the weather, when you get back just recheck it and adjust as you may find the chain has sorted itself out a bit as you said it has been stood for a long time and it may just have a section that has seized a little and running it will loosen it up
I could be way off the mark but it can do no harm
Richard

[iansoady]

Does it tighten up when you've ridden it? This often happens as the gearbox can move back slightly due to the greater pull on the back chain, especially in lower gears. It's always a good plan to slightly overtighten the primary first, then use the adjuster to push the gearbox forwards to get the correct slack. This makes sure all the little clearances are taken up. If you adjust by tightening the primary only, these clearances are on the wrong side and will let the gearbox move back enough to end up too tight.

[Sidcar]

Odd you should mention that mine seems noisy as well. The adjustment is ok and it has oil (you can tell by the leak) but like you say the sun is shining why take it apart.

Sid

I've adjusted the dynamo chain as well but it still makes some noise.

[muskrat]

 I agree with Ian's method.
Chains will always make a bit of noise.
With a belt dynamo and primary all I need is a belt final drive. But then the tappets will drive me crazy(er).
Cheers.

[brackenfel]

Many thanks all.. I'll have another go as suggested. Went for a run with the AJS Club yesterday on the Velo (wonderful day for it here!) and a mate there has a '56 A10 which sounds quieter in the primary area (but has louder tappets!) so I'll see what I can do with mine.

As you say, the important thing is to get out and ride it!!!

All the best,

Adrian

[BSA_54A10]

To answer the first question, Yes.
Too tight & they make a whiring noise.
Of the two sins too loose is better than too tight.
If you are running a 6 spring clutch then be careful with a loose chain as it can & will jump off the sprocket if you declutch while changing back.

[brackenfel]

Thanks Trevor,
It's the 4 Spring clutch but point taken...

Thanks again,
Adrian

[RichardL]

I,  too,  have experienced this problem of the primary chain tightening-up when tightening the gearbox bolts. I think it is probably common.  First, I don't think it is well advised to run with the primary chain too tight (sorry if this contradicts other advice,  even more sorry if I'm wrong). A tight chain puts more lateral load on engine,  gearbox and clutch bearings. Though I won't swear from experience,  I believe this has strong potential for damage to the bearings,  particularly the engine main.

The technique I now use is to avoid loosening the gearbox so much that the gearbox has any potential to get twisted out of alignment when doing the tightening,  with the adjuster working against some friction from the snug plates. Then if there is still some tighten-up (not the song by Archie Bell and the Drells), I try to predict how loose to leave it before tightening. By feeling through the the oil filler hole, it should be possible to do this without dismantling .

Richard L.

[brackenfel]

Hi Richard,
Thanks for the insight that it's not just my bike..! I was loosening the bolts a fair bit so the idea of twisting is a very real possibility.

I've been out in the garage, wielded the spanners & Trevor is spot-on. Chain loosened a little and the noise disappears. I'll re-check at regular intervals just to be sure that it's all staying where it should.
So, that's one more thing solved, one step nearer the MOT. I've found a small oil leak where the mag fits the timing case but that's definitely case for a drip tray & a note to look at  next winter!!

Thanks again for all your help, what a wonderful place this Forum is!!

Adrian

[mike667]

remember -  a new chain is cheap -  but an old one with questionable mileage  may be much more expensive when it breaks and puts a hole though the primary or worse! ( yes i have had it happen and no it wasn't to tight...  though the aluminum welder might suggest not to worry about it much)

[BSA_54A10]

remember -  a new chain is cheap -  but an old one with questionable mileage  may be much more expensive when it breaks and puts a hole though the primary or worse! ( yes i have had it happen and no it wasn't to tight...  though the aluminum welder might suggest not to worry about it much)

All very true but it is a futile effort to place a new chain on a set of worn sprockets or you will end up with a new worn chain.

[dpaddock]

Replace roller chain when it gets 5% stretched because that's when it gets noisy.

David