jumping chain

[derek taylor]

had a run out yesterday flash run well until coming home, stopped at some lights going up hill wife on the back when we set off the bike jerked twice as if the rear chain jumped teeth.
the chain does seem a bit slack, but if that's not the problem what else could it be ?

[Topdad]

Hi derek, was the chain  loose without either of you on board ? Or just with you ? I think two up that could make it looser. what are the teeth like and the condition of the chain. Just adjust the chain and try it then decide what do do, regards bob

[muskrat]

Could it be the cush drive jumping? If so you both need to lose weight .
Cheers

[derek taylor]

had a quick look tonight chain is a bit slack wile an center stand

[Brian]

Derek the chain will be loose while the bike is on the centre stand. There is a thread here that deals with how to adjust your chain.

You need to have the bike sitting on its wheels and get someone to sit on the pillion seat and then check the chain, it tightens as the suspension compresses.

If the chain was jumping while you where riding the bike the chain would have to be horribly loose or the sprockets totally worn out.

You also need to check the cush drive, it can not actually jump unless it has come loose and if that is the case it needs fixing immediately.

[derek taylor]

was ok when riding jumped when we set off

[BSA_54A10]

Checked the primary chain reciently ?

[wilko]

Broken driveshaft on the crank  or sheared keyway on mainshaft.

[bsa-bill]

Could it be the cush drive jumping? If so you both need to lose weight

or the cushdrive nut is bidding farewell and adieu to it's neighbours 

[derek taylor]

have added a pick to first thread

[bsa-bill]

Good one, that looks all in reasonable  order

[WozzA]

Wheel spin ????   

[wilko]

Checked the primary chain reciently ?

   I allus have one at eleven!

[derek taylor]

just been thinking its only done it since i fitted the new clutch plates.

[muskrat]

G'day Derek.
Other things to check. Primary sprocket alignment and clutch basket bearing wear. Under load like you described the basket could cock off a bit causing momentary slip.
Cheers