Vibrac,
my remark about that Alton ESA being useless was meant to point to the photo showing some sprocket holes filled by poly bushes up to the top . You cannot compress rubber, only deform it . So for getting several degrees of rotation within the sprocket assembly there must be about a third of the volume in the holes free of rubber for it for deformation into this space. Either do a few cutouts in the polybushes or replace with o-rings. So when holes filled to the top with poly material the lot does nothing in smoothing the drive - so in this aspect it is useless like in being solid. But then it does not produce shock loads going into the chain like the original Vincent ESA does when that hits the end plate due to the hopelessly shallow lobe design with which the springs cannot possibly cope. I really believe it is better for the primary chain drive to have NO ESA at all than instead exposing it to the harsh shocks the Vincent ESA does to the chain.
It is a waiste of time trying to discuss pros or contras of the progressive action BMW lobe design as opposed to the flat Vincent shapes that lacks the progressive feature and in consequence hits its hard limit at the end plate. I cannot see a need for a linear action in an ESA but definitely for a more progressive design that does not rely on springs to fight a bang to the stops. I´d be interested to see that Australian design ESA which is said having been too firm at first try with all springs fitted. Remember, all these springs fighting to prevent the bashing at the end plate in the Vincent ESA put their total load onto the inner race of the main ball bearing via the triplex sprocket. Increasing spring preloads is simply the wrong way to achieve an effective ESA , the BMW type does it with the steeper lobes so forces stay in the ESA mainly and don´t wear the inner ring and sprocket face so badly.
Since the production days of Vincent post war bikes there is widely known experience about both types of ESAs: Millions of BMWs from fifties up to present types I think - no defects ever here in the gearbox ESA, most owners don´t even know about them, never had to deal with such. BMWs are all gear bikes, no drive chains to speak of, so no damping effect from said chains. So you bet these need an effective ESA for sure !!
Then at Vincents, a few thousand bikes produced - and many hundreds of snapped triplex chains, smashed cases and wrecked dynamos . . . . .
Vic
BMW type lobes:
BMW R 100 gearbox input shaft:
Kawasaki 1300 gearbox output shaft right side:
my remark about that Alton ESA being useless was meant to point to the photo showing some sprocket holes filled by poly bushes up to the top . You cannot compress rubber, only deform it . So for getting several degrees of rotation within the sprocket assembly there must be about a third of the volume in the holes free of rubber for it for deformation into this space. Either do a few cutouts in the polybushes or replace with o-rings. So when holes filled to the top with poly material the lot does nothing in smoothing the drive - so in this aspect it is useless like in being solid. But then it does not produce shock loads going into the chain like the original Vincent ESA does when that hits the end plate due to the hopelessly shallow lobe design with which the springs cannot possibly cope. I really believe it is better for the primary chain drive to have NO ESA at all than instead exposing it to the harsh shocks the Vincent ESA does to the chain.
It is a waiste of time trying to discuss pros or contras of the progressive action BMW lobe design as opposed to the flat Vincent shapes that lacks the progressive feature and in consequence hits its hard limit at the end plate. I cannot see a need for a linear action in an ESA but definitely for a more progressive design that does not rely on springs to fight a bang to the stops. I´d be interested to see that Australian design ESA which is said having been too firm at first try with all springs fitted. Remember, all these springs fighting to prevent the bashing at the end plate in the Vincent ESA put their total load onto the inner race of the main ball bearing via the triplex sprocket. Increasing spring preloads is simply the wrong way to achieve an effective ESA , the BMW type does it with the steeper lobes so forces stay in the ESA mainly and don´t wear the inner ring and sprocket face so badly.
Since the production days of Vincent post war bikes there is widely known experience about both types of ESAs: Millions of BMWs from fifties up to present types I think - no defects ever here in the gearbox ESA, most owners don´t even know about them, never had to deal with such. BMWs are all gear bikes, no drive chains to speak of, so no damping effect from said chains. So you bet these need an effective ESA for sure !!
Then at Vincents, a few thousand bikes produced - and many hundreds of snapped triplex chains, smashed cases and wrecked dynamos . . . . .
Vic
BMW type lobes:
BMW R 100 gearbox input shaft:
Kawasaki 1300 gearbox output shaft right side: