Making a Cushier Cush Drive

[Guest ratchethack]

I might just drill a few small holes for the pucks that effect deceleration as nobody has indicated acceleration being a problem.

Nobody has indicated that Greg's well-documented, well-illustrated procedure is a problem, either, Dave.

 

Can't you simply do wot Greg and everyone else has recommended for 40 years??

 

You've been well off the fairway, well past the tall grass, beyond the weeds, the shrubbery, the woods, and now you appear to be in the middle of a swamp of confusion, thrashing about wildly. It reminds me of wildlife footage of a wildebeest attempting a futile crossing of the Upper Zambezi with a croc firmly clamped on its head.

 

This is not productive, Dave. Nor is it a pretty thing to witness.

 

Is this another fishing expedition to find something to do -- anything, regardless of any value -- that no one else has ever done before, just to satisfy some irrepressible compulsion to be different?

 

If it's possible to over-think, re-think, under-think, sideways think, and re-re-re-re-think, then ignore and contradict wot the Pro's and everyone else who's done wot Greg and other Pro's have suggested for 40 years, I reckon you've done it all here, including Photoshopping it -- everything but actually doing it yourself! -- and yet, contrary to wot the Pro's have said, you've made up your own (false) operating principles for defining driveline slack, then took it upon yourself to dispense advice on how to do a modification on something you've never as much as had a first peek at on your own bike.

 

If you weren't "afraid" (your word) to remove the threadlocked cush drive pie-plate retaining screws and actually have a look -- and dare I suggest actually service the thing the way Greg so clearly explained and illustrated with photo's in his opening post in this thread -- you might have some idea of wot it is you've been talking about so authoritatively here, as if you possessed any credibility or experience wotsoever with which to contradict the Pro's.

 

I was done with Greg's procedure in under a half hour (tops) three years ago, and I haven't given it much of a thought since, except to check on it at every other tire change. It's worked as well as expected, if not better, and it's been boringly satisfactory at every inspection, without a hint of a problem of any kind.

 

But instead of any interest in doing something that's been done and proven successful for so long, after thoroughly exhausting the idea of an entirely speculative and naively presumptuous junk science project to fabricate a urethane cush drive, now you're off speculating on providing more deceleration than acceleration cushion?! Has it occurred to you that, per Greg's opening post, it's the hard shock of hitting both ends of driveline slack (as occurs so often in everyday riding) that wears out drive splines and all the rest of the mechanicals in the driveline? I reckon that's why every cush drive I've ever seen on every motorcycle, including the Guzzi, has identical blocks for cushioning each end of the driveline slack.

 

Enquiring minds are well past curiosity now, well past hoping that you'll actually DO SOMETHING with your own cush drive (anything at all), and just begging you now to stop doing wotever it is you've been doing on this thread!??

 

It just [. . . sob . . .] makes NO SENSE wotsoever. . .

 

Cdr. Hatch Scratchracket, Curmudgeon

[TX REDNECK (R.I.P.)]

Hhmmmm , it's been awhile since I dropped by. Lemme see if I can help

[belfastguzzi]

Education takes time if it's done properly. 8-)))

A lifetime

 

Some threads may take longer

[Skeeve]

Oh for f*cks sakes! 9 bloody pages? God give us strength!!!!

 

Pete

 

C'mon, Pete, it's not like it's an oil thread or anything!

 

While I truly feel there's an opportunity lurking here somewhere for some Guzzisti working at Fermilab or some other zippy lab environment w/ access to all sorts of supercomputer free cycles & Finite Element Analysis software on which to run a simulation of the cush drive so that the exact location & [maybe even more importantly?] size of the holes to be drilled in the hardened-cheese wedgies should be positioned in order to deliver the maximum lifespan & necessary cush, I am inclined to agree with you that there's really not much more that needs to be discussed in this thread.

 

But let's not stop beating this dead horse until there's not even a red, muddy mark of it left!

 

 

just a thought. but is there a conversion to chain drive for guzzi, perhaps this could cure all problems of drive lash. i'm open to hear others thoughts on this.

 

Chain drive is a superior option for transverse engines, just as shaft drive is a natural choice for inline designs.

 

Change the Guzzi to a transverse V-twin, a la' Ducati or Harley-D, and it would naturally be a better choice to go w/ chain (or belt) drive. Otherwise, there's too much power losses associated w/ the extra 90deg turns required in the driveline.

 

But it sure would be nice to see the company exhibit some signs of new development. Not likely under Piaggio, but it would be nice...

[Ryland3210]

C'mon, Pete, it's not like it's an oil thread or anything!

 

While I truly feel there's an opportunity lurking here somewhere for some Guzzisti working at Fermilab or some other zippy lab environment w/ access to all sorts of supercomputer free cycles & Finite Element Analysis software on which to run a simulation of the cush drive so that the exact location & [maybe even more importantly?] size of the holes to be drilled in the hardened-cheese wedgies should be positioned in order to deliver the maximum lifespan & necessary cush, I am inclined to agree with you that there's really not much more that needs to be discussed in this thread.

 

But let's not stop beating this dead horse until there's not even a red, muddy mark of it left!

 

Chain drive is a superior option for transverse engines, just as shaft drive is a natural choice for inline designs.

 

Change the Guzzi to a transverse V-twin, a la' Ducati or Harley-D, and it would naturally be a better choice to go w/ chain (or belt) drive. Otherwise, there's too much power losses associated w/ the extra 90deg turns required in the driveline.

 

But it sure would be nice to see the company exhibit some signs of new development. Not likely under Piaggio, but it would be nice...

 

I'm missing something in your theory. First, my understanding is that an "in-line" engine has its driveshaft along the longitudinal axis of the bike, and a transverse would by like the Guzzi's. I figured out what you meant when compared to H-D/Ducati. Second, Guzzi's have a 90 degree in the final drive anyway, so moving the 90 degree change to the transmission in order to use a chain or belt might be almost as efficient, given the relative efficient of belts and chains as compared to gears and elimination of U-joints and drive shaft.

 

What would the performance advantage be? I've been told, although only by one "expert" to date, that there is an interaction between the u-joints and suspension which does not exist with belts/chains. It's clear to me, since MG does not use constant velocity joints, that there could be some interaction, but it seems to me the deflection angle of the drive shaft would have to be pretty extreme.

 

I'm interested in comments on this.

[mike wilson]

I'm missing something in your theory. First, my understanding is that an "in-line" engine has its driveshaft along the longitudinal axis of the bike, and a transverse would by like the Guzzi's.

 

This is a whole new box of worms. Suffice it to say, for the purposes of this thread, that some people (primarily in the USA, I think) define the layout of an engine by the line of its crankshaft and others define it by the disposition of its cylinders.

 

Thus a Guzzi V-twin can be defined as transverse because the cylinders are splayed across the frame, or inline because the crank lies along the centreline (ish) of the bike.

 

Back to cush drive modification.......

[Ryland3210]

This is a whole new box of worms. Suffice it to say, for the purposes of this thread, that some people (primarily in the USA, I think) define the layout of an engine by the line of its crankshaft and others define it by the disposition of its cylinders.

 

Thus a Guzzi V-twin can be defined as transverse because the cylinders are splayed across the frame, or inline because the crank lies along the centreline (ish) of the bike.

 

Back to cush drive modification.......

 

Thanks for the clarification. Seems to me the crankshaft orientation is unambiguous regarding driveline configuration and is a better definition, as used by Skeeve, than my previous understanding. Of course others may argue the way the cylinders are oriented is more apparent to the eye. Perhaps we need another subforum on discussions like this.

 

As you say, back to the topic.....

[Dan M]

This is a whole new box of worms. Suffice it to say, for the purposes of this thread, that some people (primarily in the USA, I think) define the layout of an engine by the line of its crankshaft and others define it by the disposition of its cylinders.

 

Thus a Guzzi V-twin can be defined as transverse because the cylinders are splayed across the frame, or inline because the crank lies along the centreline (ish) of the bike.

 

Back to cush drive modification.......

 

 

It is the orientation of the crankshaft. Across the frame: transverse. Along the frame: Longitudinal.

The cylinder layout is described as "in line" or "V" or "opposed" or even sometimes "radial" or "square"

 

So our beloved Gooses are longitudinal Vs.

 

And please, no more bu, er, cush.

[dlaing]

Nobody has indicated that Greg's well-documented, well-illustrated procedure is a problem, either, Dave.

 

Can't you simply do wot Greg and everyone else has recommended for 40 years??

 

You've been well off the fairway, well past the tall grass, beyond the weeds, the shrubbery, the woods, and now you appear to be in the middle of a swamp of confusion, thrashing about wildly. It reminds me of wildlife footage of a wildebeest attempting a futile crossing of the Upper Zambezi with a croc firmly clamped on its head.

 

This is not productive, Dave. Nor is it a pretty thing to witness.

 

Is this another fishing expedition to find something to do -- anything, regardless of any value -- that no one else has ever done before, just to satisfy some irrepressible compulsion to be different?

 

If it's possible to over-think, re-think, under-think, sideways think, and re-re-re-re-think, then ignore and contradict wot the Pro's and everyone else who's done wot Greg and other Pro's have suggested for 40 years, I reckon you've done it all here, including Photoshopping it -- everything but actually doing it yourself! -- and yet, contrary to wot the Pro's have said, you've made up your own (false) operating principles for defining driveline slack, then took it upon yourself to dispense advice on how to do a modification on something you've never as much as had a first peek at on your own bike. homer:

 

If you weren't "afraid" (your word) to remove the threadlocked cush drive pie-plate retaining screws and actually have a look -- and dare I suggest actually service the thing the way Greg so clearly explained and illustrated with photo's in his opening post in this thread -- you might have some idea of wot it is you've been talking about so authoritatively here, as if you possessed any credibility or experience wotsoever with which to contradict the Pro's. huh2:

 

I was done with Greg's procedure in under a half hour (tops) three years ago, and I haven't given it much of a thought since, except to check on it at every other tire change. It's been boringly satisfactory every time. - _ -

 

But instead of any interest in doing something that's been done and proven successful for so long, after thoroughly exhausting the idea of a entirely speculative and naively presumptuous junk science project to fabricate a urethane cush drive, now you're off speculating on providing more deceleration than acceleration cushion?! Has it occurred to you that, per Greg's opening post, it's the hard shock of hitting both ends of driveline slack (as occurs so often in everyday riding) that wears out drive splines and all the rest of the mechanicals in the driveline? I reckon that's why every cush drive I've ever seen on every motorcycle, including the Guzzi, has identical blocks for cushioning each end of the driveline slack. : huh2:

 

Enquiring minds are well past curiosity now, well past hoping that you'll actually DO SOMETHING with your own cush drive (anything at all), and just begging you now to stop doing wotever it is you've been doing on this thread!?? : huh2:

 

It just [. . . sob . . .] makes NO SENSE wotsoever. . .

 

Cdr. Hatch Scratchracket, Curmudgeon

 

Mike Wilson already cleared up the acceleration vs. deceleration so I don't know why you are going on about that.

Regarding drilling's effect on driveline lash, I think it depends on how you define driveline lash. I define it as slack and cushion. Earlier I agreed I was WRONG about slack and freeplay. Of course slack is only increased when slack is increased. Lash is increased when slack and or cushion is increased but perception of lash is minimized when the cushion is optimized.

 

Greg recommended drilling it as shown in the photo, because he said the pucks were too hard.

I suggested urethane because it can be ordered in various hardnesses.

And then I get attacked. WTF!?!

Drilling holes in cush drives has only been done in V11s for a few years.

As far as we know you are the longest going with such a drill job.

It may last 40 years, but I don't know.

I am not saying it is a bad idea, but the reaction I get as if I am calling you all idiots.

I am the only one here whose cush drive rubbers ever failed, and they failed quickly.

It is reasonable for me to have reservations about the drilling the cush drive rubbers.

I think if urethane is too much trouble, than drilling is likely a good idea, but there have also been more than 40 years of Guzzi making cush rubbers without drilling holes in them.

Are they so far off the mark that the rubbers have to be drilled as much as Greg did?

Maybe, but I choose to be more conservative with my drilling, if I choose that path.

And you say that is well off the fairway.

But I say it is lined up just right for birdie.

Drilling the heck out of it may be your perfect hole in one, or it may have rolled into the sand trap. But you may still finish better than par! It is difficult to see from here and I like to play within my ability.

 

Trust, but Verify.

[belfastguzzi]

As far as we know you are the longest going with such a drill job.

Lobotomy, is the technical term...

 

 

 

 

 

[Guest ratchethack]

. . . Lash is increased when slack and or cushion is increased but perception of lash is minimized when the cushion is optimized.

. . . It is difficult to see from here and I like to play within my ability.

Ma'am, it is with regret that we must now inform you that we've done all we can do. There appears to be little hope for optimism at this time. The boy has irretrievably lost control of his faculties, and continues to mentally inhabit an alternate reality beyond both his own ability to control and far beyond our ability to understand. After extensive analysis and consultation with the medical team, we have concluded that any further professional assistance from the field of medicine, rational thought, and behavior science is not only futile, but imminently life-threatening.

 

We have concluded that the patient will surely not survive without immediate and decisive intervention. There is a procedure that has been employed in such rare circumstances. We only make this kind of a recommendation when the life of the patient is at extreme risk. The procedure itself is very high risk, and it's success rate is low. Only two successes that we know of have been reported in the last twenty years with this depth of involvement -- one in a mountain village in Arkmenistan in 1989, and one deep in the jungles of Bolivia in 1992.

 

Yes, I'm afraid you must well understand where we're going with this. We're recommending Exorcism from demon possession.

 

Dr. Mack Chatwacket, GPh.D., Esq., CmN, BAA, TJM, YMMV, and Staff Clinical Evaluation Team, Guzzi Psycho Clinic

[docc]

With the drive apart it answers some questions for me , but begs others.

 

I can see now how Dave could suggest affecting deceleration without acceleration. I forgot there are cushes in front of the vanes as well as behind.

 

My rubbers are pretty pliable. I have had this apart before, but only once in 50,000 miles. I did grease every thing with BelRay waterproof grease and use copper anti-seize on the bolts. One of the heads still munted and required a Torx30 to come out.

 

I suppose you could use stainless fasteners in the rust prone application as it appears less critical than a brake rotor?

 

No one mentioned the friction disc between the vane plate and the retaining ring. I cleaned mine with Naphtha (lighter fluid). So, now, to lube: back with the BelRay, use some moly to really slick it up, what?

[Guest ratchethack]

I suppose you could use stainless fasteners in the rust prone application as it appears less critical than a brake rotor?

Yes indeed. Unlike Greg, I didn't find the 6 "pie plate" fasteners to be particularly rust prone. Actually, mine had no trace of corrosion wotsoever at 22K miles, even though the forged steel cush drive plate underneath was substantially rusted-up (again -- without grease) by the time I first got to it. There's no requirement for shear strength wotsoever with the retaining screws, only relatively weak tensile strength is required to retain a non-stressed part. I used common 302 (A2-70) stainless socket head bolts with Loctite 242 threadlocker. They've been in and out several times with no hint of corrosion or seizing.

So, now, to lube: back with the BelRay, use some moly to really slick it up, what?

Bueno. Don't overdo. See Greg's photo above? IMHO this is about how it should look (before wiping up the excess) just before re-assembly of the wheel at every tire change. I use a plumber's flux brush to "paint" BTWBG (boat trailer wheel bearing grease) into the splines, but pick y'er own poison. Anything much more than this will be thrown out on the wheel.

[docc]

I've always greased the splines of the hub drive, but I don't see the friction disc in the pictures or any mention of it.

[Guest ratchethack]

Eh? Friction disk?

 

In Greg's first photo he shows the outside of the only disk other than the aforementioned forged steel plate with vanes (or webs). The "pie plate" fiber disk is not a "friction disk". It only serves to keep weather and road debris out.