Pete Roper saves the day - probably not for the last time !

[pete roper]

All the older Beemers have exactly the same sinusoidal vibrations, being equiped with only one joint in the drive shaft.

Guess what, they just ignore them. No lost mirrors, tortured splines or whatever horror is produced here.

 

So don't let the gurus spoil your day. If you find your shaft misaligned, correct it if you can. If you don't have the tools for it then ride on and ask your dealer next time you see him if he could have look after it.

 

Hubert

 

Yup, I'm full of shit. ignore me.

 

pete

[dhansen]

Yup, I'm full of shit. ignore me.

 

pete

Well done there Mr. Roper. The road to recovery begins with one admitting he has a problem.

[Guest ratchethack]

All the older Beemers have exactly the same sinusoidal vibrations, being equiped with only one joint in the drive shaft.

Guess what, they just ignore them. No lost mirrors, tortured splines or whatever horror is produced here.

 

So don't let the gurus spoil your day. If you find your shaft misaligned, correct it if you can. If you don't have the tools for it then ride on and ask your dealer next time you see him if he could have look after it.

 

Hubert

Hubert, the Bayerische Motoren Werkers are not unique in this. Before the "floating hub" design was introduced (the design we have on the V-11 Guzzi's), I b'lieve single joint driveshafts were used on shaft drive Guzzi's without any problem. To my knowledge (and here's where my understanding of Guzzi driveline joint design is far from adequate, let alone complete), these were not of the constant-velocity design. NOTE: I hereby declare my complete ignorance of the older designs, some of which evidently utilized a constant-velocity double cardan design, possibly others!

 

Now Pete's sure to cover this after his 3-day Oz weekend at the beach (sounds nice, Pete. It's been record cold here for a month with extended freezing temps, and my fruit trees are lookin' peekid...the entire state of Ca's fruit production is a horrendous disaster this year...must be that pesky anthro-glo-warmie crap! ), but the sinusoidal variations in angular velocity of a single U-joint are considerably less than those imparted by a mismatched pair in series. I haven't done a mathematical analysis, but I expect something far less than half. The beauty of a pair of U-joints in series with the floating hub is that they can be set to cancel each other's rotational variations perfectly and completely, giving the driveline a net constant angular velocity throughout the full range of motion of the rear suspension.

 

The important thing to note here is that when you get a pair of U-joints in series mis-aligned -- and depending on exactly how far out of line they are by number of splines, I believe that this amplifies the variations in angular velocity at the driven joint far beyond those imparted by either U-joint alone. If you get it far enough out of line, or even to a lesser degree slightly out of line, you've got a time-bomb on y'er drive train. You might think of the number of splines it's out of line as equivalent to the length of the fuse -- the more splines out o' line, the shorter the fuse.

 

Unless and/or until Pete or Greg or somebody who knows drivelines better than my admittedly armchair understanding sets me straight, that's my story, and I'm stickin' to it.

[luhbo]

...single joint driveshafts were used on all shaft drive Guzzi's without any problem. ...

 

No, the Tontis all had two joints quite tight connected to each other. That's why they needed an extra bearing in the swing arm. I actually know only of BMW having had the simple and cheap solution.

 

The interesting question is how bad a misaligned shaft treats the rest of the bike. Some have written they didn't notice anything at all.

 

On the other hand Gregg thinks he has a completely new ride now since Pete has reassembled his shaft.

 

Probably the truth lays somewhere in between, and the shit in Pete is at the same place where I carry mine.

 

Hubert

[pete roper]

The smallblocks only use a single trunnion at the front of the shaft, thing is they have an incredibly soft and forgiving rubber cush drive on the rear wheel, even so they are more prone to going tits than the big blocks. As for BMW using a single joint on their older models? Perhaps thats why their crappy gearboxes have to be re-bearinged every 60,000km or so. And yes, two out of alignment joints impose far greater forces than a single one, the further from correct they are the greater the problem.

 

Yes, I too have had customers who hadn't noticed that their driveshaft was out of alignment. Universally they HAVE noticed a vast improvement when the trunnions were aligned correctly and as I said, the earlier spineframes with the ten spline shafts are more than capable of snapping the end off their pinions if the splines are out a couple of teeth. Those sorts of loadings are going to give ALL the bearings in the entire driveline a real walloping, sap power and greatly increase the risk of catastrophic failure. If it isn't important why does evey other vehicle that uses a prop shaft have the trunnions aligned!?

 

Pete

[Miles Long]

Holy snappin duckshit....checked mine & the white lines are roughly 180* apart....& the bike's just had it's 20000k service.

Could it have been like this all it's life?

Could it have been done during the last service?

Has all my griping about Guzzi handling (it's the only one i've ever ridden) now been vindicated?

Moan groan.

Miles

[Murray]

Holy snappin duckshit....checked mine & the white lines are roughly 180* apart....& the bike's just had it's 20000k service.

Could it have been like this all it's life?

Could it have been done during the last service?

Has all my griping about Guzzi handling (it's the only one i've ever ridden) now been vindicated?

Moan groan.

Miles

 

Providing they are 180 degrees out it shouldn't be a drama the problem really occour when the pivioting axis of the uni joints don't line up with each other and start woring against each other. Dunno about the V11's but witht he 1100 sports all three grease nipples on the shaft could be lubed without having to endlessly rotate the shaft to get them. Something like front two on top and the rear on the bottom. The 1100 sports owners manual had a fairly extensive spiel about lining up the crossoes of the uni jionts I'd be surprised if the V11 wasn't the same.

[Guest ratchethack]

Holy snappin duckshit....checked mine & the white lines are roughly 180* apart...

Miles, like Murray said, if the marks were exactly 180 degrees out of line, you were in fact aligned perfectly. The maximum out of line it can get is +/- 90 degrees.

 

As mentioned previously, the angular velocity of the driven side of each joint relative to the drive side varies on a sine wave output. The amplitude of the sine wave depends on the axial angle between the drive and driven shafts represented by the movement of the swingarm. The peaks and troughs of that sine wave can be aligned perfectly (perfectly out of phase, that is ) with those of the driven U-joint when the joints are used in series, exactly cancelling each other, resulting in a constant velocity output at the bevel drive regardless of swingarm angle (within the range limits of the joints).

 

When the sine waves of the two joints are mis-aligned (or out of phase) by 90 degrees however, the amplitudes of the (+) and (-) sine waves at the driven end of the driven joint are doubled rather than cancelled, and this is as badly mis-aligned as they can get -- It's far worse than having a single U-joint in the driveline with a sine-wave variance in angular velocity output that cannot be compensated! So for a pair of U-joints in series, somewhere between 0 degrees and +/- 90, or between +/- 90 and 180 mis-alignment will be less of a problem than +/- 90, depending on how far from the ideal settings of either 0 or 180 degrees they're set in the splines.

 

Ack. That's the best I can do. Where's Pete?

Has all my griping about Guzzi handling (it's the only one i've ever ridden) now been vindicated?

Moan groan.

Miles

Hmmmmmmm..... Griping about Guzzi handling, are we?? From your post, the driveline ain't in question here, but I'm compelled out of sheer duty to stand up for the honor of the marque and ask the obvious!

 

The first question is, "Have you set up the suspension according to the basic recommendations of the Pro's?"

 

If y'er answer is "No", you've got mighty slim justification to moan & groan!

 

If y'er answer is "Yes", the next question is, "Wot's y'er idea of basic suspension setup?"

 

Speakin' o' Pete R., are you within reasonable riding distance of "Bunged-end"? Much better you get advice straight from the horse's mouth (so to speak). . . .

 

NOTE: Hey Pete -- notice I referred to the "business end" of the horse? -- Thought you'd appreciate it.

[Miles Long]

Thank you Murray& Ratchethack, I feel much better now.

I don't want to digress into a "suspension setup" thread but I've explored every avenue down that road with limited success. I've found the biggest improvement with good tyres....& also tyre pressures.

Other bikes I own or have access to are Norton Commando & Dominator, Jota, Hinlkley speed triple & thruxton,Suzuki V strom & BSA Rocket 3...& whilst I love my Guzzi, it's handling with compared to this lot can only be described as ..."unique"....or...."er, um, it's all about the engine mate..!!!"

Thanks again for the info

Miles

[pete roper]

Ratch? With the trunnions, surely the sinusoidal wave would be greatest at 45 degrees misaligned? Although having the yokes lined up *correctly* would seemingly keep things better ballanced (? Maybe not.) the crosses of the trunnions at 90 degrees would still be working together to elliminate the loadings. I could be wrong, I'm not an engineer and thinking about such things makes my brain hurt

 

With both the 20 tooth splines used on the V11 and the 10 tooth ones on the five speed spineframes youd expect that having the shaft misaligned by 180 degrees exactly would be possible. I tend to think with the earlier, 10 spline shafts, which have separate yoke-pairs at either end clamped to the various splined bits that if one or other of these is turned through 180 degrees in relation to it's fore and aft orientation then it can be impossible to get proper alignment of the trunions as it is only two of the four yokes that are machined in such a way as to enable correct planar alignment. On the V11's the driveshaft yokes are actually part of the shaft from memory so this sort of mis-alignment isn't possible and so I'd assume that a 10 spline misalignment would cause a 180 degree difference from the painted lines which would be harmless.

 

The only way to be absolutely sure would be to pull the shaft off, not a big job, and eyeball it closely. As I said, this is all entirely hypothetical as I'm not next to a V11 to experiment.

 

Pete

[Guest ratchethack]

Ratch? With the trunnions, surely the sinusoidal wave would be greatest at 45 degrees misaligned? Although having the yokes lined up *correctly* would seemingly keep things better ballanced (? Maybe not.) the crosses of the trunnions at 90 degrees would still be working together to elliminate the loadings. I could be wrong, I'm not an engineer and thinking about such things makes my brain hurt

Pete, I'm no engineer either, however I have a pretty fair ability to conceptualize in 3D.

 

Think of the U-joint alignment problem this way: Picture the entire V-11 driveshaft out on a bench with the splines at the mid-section of the shaft engaged and alignment marks in sync. The "inner" yokes (those attached to the shaft itself) are in the same plane. Now pull it apart and re-assemble it by aligning the splines with the marks at 180 degrees -- or 10 splines out of alignment. The relative positions of each of the drive and driven yokes and their crosses appear identical in each case, the only difference being the location of the alignment marks. The "inner" yokes on the shaft are again in the same plane.

 

In either case there's no functional difference, and the phase alignment resulting in maximum worst-case scenario conditions occurs when the alignment marks are set at +/- 90 degrees -- or +/- 5 splines off the marks.

 

If it doesn't make sense with mental imagery, its probably my description , but I reckon it would with the shaft on the bench!!

[rossoandy]

aaaagh!!!

[wildbill]

>

This all makes my head hurt. I leave to the pros everything but fluids and a few minor bits. I just love to ride the fukkin' things.

[Gregg]

I don't know whether this is circumstantial evidence or not, but I took the back wheel off my V11 (which started this string originally) to measure up for a piece of rubber to protect my gearbox breather from water spray as recemmended as an enhancement by Pete. I noticed an oddity in my back wheel hole when repacking it with grease to re-fit. One of the bearings had split around its circumference ! The break looks fairly old as the surfaces had discoloured - I am now wondering if this damage is due to riding for 3 years with the shaft out of position. I had felt no resisitance in the wheel before taking it off and the inner bearing still turned on its race quite freely - scary stuff !

Some things have not been having a nice time in my rear end -(so to speak).

 

Thanks again Pete for noticing the original problem & inspiring me to do more work and checking on my bike - I may well have been riding into oblivion on my next ride ! I will try to post some photos of the bearing failure tonight when I get home.

[Guest ratchethack]

I don't know whether this is circumstantial edidence or not, but I took the back wheel off my V11 (which started this string originally) to measure up for a piece of rubber to protect my gearbox breather from water spray as recemmended as an enhancement by Pete. I noticed an oddity in my back wheel hole when repacking it with grease to re-fit. One of the bearings had split around its circumference ! The break looks fairly old as the surfaces had discoloured - I am now wondering if this damage is due to riding for 3 years with the shaft out of position. I had felt no resisitance in the wheel before taking it off and the inner bearing still turned on its race quite freely - scary stuff !

Some things have not been having a nice time in my rear end -(so to speak).

 

Thanks again Pete for noticing the original problem & inspiring me to do more work and checking on my bike - I may well have been riding into oblivion on my next ride ! I will try to post some photos of the bearing failure tonight when I get home.

Gregg, I b'lieve y'er referring to the small needle bearings in the outboard side of the bevel box? (see link to Pete & Colin's masterful strip & illustrated inspection here):

 

http://www.v11lemans.com/forums/index.php?...ost&p=21056

 

These bearings are notorious for trouble when not cleaned and lubed properly with some regularity. The area tends to collect water somehow, as we found in the case of my Pal's '04 LM (which is seldom ridden in particularly wet conditions, BTW), as confirmed by the rust accumulation visible in Pete's photo's. Note photo and Pete's comments about the convenient "water entry" hole in the inner race. It's not a high speed application for a needle bearing, since its function is only to handle the relatively slight reciprocating motion between the spindle (axle) and the housing of the bevel drive as it moves with the swingarm, being one "corner" of the floating hub parallelogram, the ends of the torque rod and the swingarm pivot being the other 3 "corners". Since this relatively small bearing is not supporting a rotating load and is very low speed, stresses on it are relatively low. One poster not too far back was looking into replacing it with a bushing, which I reckon might be satisfactory as long as it's kept lubed. The failure of this bearing would have nothing to do with driveshaft spline alignment. I'd get it replaced and keep it serviced. If memory serves, from at least one post I read on it, it ain't all that easy to match in terms of a generic number (?) YMMV. Thankfully, it pops right out from the outside with no fuss. I find that when packed with boat trailer wheel bearing grease, which is formulated to resist water intrusion, mine has maintained serviceable condition for 31K miles without any evidence of water yet.

 

As far as a piece of rubber to protect the gearbox breather, I came up with something awhile back that may be an idea:

 

http://www.v11lemans.com/forums/index.php?...ost&p=69420

 

It's worked exceptionally well since I installed it.