Wildguzzi.com

General Category => General Discussion => Topic started by: willowstreetguzziguy on July 08, 2016, 08:11:26 PM

Title: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: willowstreetguzziguy on July 08, 2016, 08:11:26 PM
There seems to be a fair amount of dislike on here for the CARC shaft drive on the larger bikes. I myself find no fault with it on my 1200 Sport but I know it does add a decent amount of weight. With Harley having success, I think, with their belt drive, is it maybe time for Moto Guzzi to possibly think about replacing the CARC on the larger bikes with a belt? How would you feel about that change?
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: twowings on July 08, 2016, 08:15:40 PM
I'll take an enclosed shaft in an oil bath over a belt exposed to UV rays, dirt, grease, gasoline, and vandals most every time...just my two centavos... :popcorn:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Chuck in Indiana on July 08, 2016, 08:19:53 PM
It would take a clean slate redesign. Doesn't make sense to me. .
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: fotoguzzi on July 08, 2016, 08:21:52 PM
the layout of the Guzzi v twin doesn't lend itself to that kind of drive, it's perfect for a driveshaft out the back of the tranny, you'd have to turn the power 90* to adapt a belt.

the Buell I had with belt was superior to chains and rivaled the DS set up.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: beetle on July 08, 2016, 08:43:08 PM
No.




Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Daniel Kalal on July 08, 2016, 09:15:54 PM
...be a fair amount of dislike on here for the CARC shaft drive...

I don't follow your premise.  Most of what I've seen on this forum is that the CARC is quite rugged and has the tremendous advantage of making it possible to remove a rear wheel in one minute.  You've really seen a fair amount of dislike on wildguzzi.com?  Count me in the "like" camp.

The only real criticism (and it counts for a great deal) would seem to be from the coin-counters that rule Guzzi (they're probably not Guzzi employees, but that matters not one bit).
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: ITSec on July 08, 2016, 09:17:55 PM
No dislike of CARC here - in fact, an active dislike of (in increasing order of unpleasantness):


To my mind, any bike over 750cc should preferably come with a low-maintenance drive, single-swingarm shaft being the most desirable.

The possible discontinuation of CARC significantly lowers the likelihood of me purchasing a new Moto Guzzi in future; in fact, in many designs I'd prefer a chain to a dual-sided swingarm shaft, and definitely to a belt. This comes with some experience; I've sold motorcycles with belts as well as those with chains and shafts and have extensive ride time on them all.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: pete roper on July 09, 2016, 12:15:22 AM
Well at least at the moment its immaterial as the CARC or indeed any sort of reactive rear drive has been discontinued. The idea that the unit is particularly heavy is also a red herring. It certainly weighs no more than the unsprung weight tied up in a late model Tonti or Spineframe swingarm and final drive but has the advantage of both having reaction control so it can work properly and a rising rate suspension system.

As others have pointed out the longitudinal crank in the current motor requires the drive to be turned through 90* to make the back wheel go round. This can either be done at the rear wheel or at the gearbox. While doing it at the gearbox will allow less unsprung weight you will still get the mechanical losses of the 90* change of direction and then will add further losses from the belt or chain rear drive.

I really like the CARC design. Sure it's built down to a price a bit but generally it is grotesquely over engineered and strong as an ox! I've had very very few problems with them over the years and the two commonest failures are the big crownwheel support bearing chopping out due to water intrusion and a few cases of the pinion nut loosening for want of Loctite!

I have no real problem with modern chains, they are robust and very long lived if you maintain them properly and that is hardly a chore. I have no experience of belts but they seem to work in the applications they are used in. At the end of the day though a decent reactive system like the CARC is, IMHO, the best compromise for cleanliness, ease of maintainence and performance for a machine like a Guzzi.

So, you ask, why didn't they continue with the system? Well the Cali's are stupid heavy and have a swingarm about a kilometre long so torque reaction isn't much of an issue and it's a cruiser so it's not expected to handle. With the V9's? The people who these are aimed at don't know or care how stuff works as long as it *Looks* right to them. The bike could handle like a feral shopping trolley with a wonky wheel but they wouldn't care as long as it looked 'Cool' and had a USB port to charge their phone.

Pete
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: sib on July 09, 2016, 07:26:18 AM
...With the V9's? The people who these are aimed at don't know or care how stuff works as long as it *Looks* right to them. The bike could handle like a feral shopping trolley with a wonky wheel but they wouldn't care as long as it looked 'Cool' and had a USB port to charge their phone.

Pete
That's rather uncharitable, Pete.  Personally, I don't want or need a reactive rear end on my V7II Stone, because I don't care to push the bike to the point where the advantages of having one would compensate for the extra weight and complexity it comes with.  You ride your way, I'll ride my way, and we'll make our own evaluations.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Bulldog9 on July 09, 2016, 11:46:11 AM
CARC forever...... The CARC system should be further developed not dropped. Its why I own a Guzzi.....
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: RayB on July 09, 2016, 12:51:33 PM
I'll take an enclosed shaft in an oil bath over a belt exposed to UV rays, dirt, grease, gasoline, and vandals most every time...just my two centavos... :popcorn:

That would be great :1:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: sib on July 09, 2016, 02:26:03 PM
As long as we're telling Moto Guzzi how to design their products, I would like to have a shaft drive with a genuine constant velocity joint instead of a U-joint.  The latter, as I recently learned, does not have a constant output velocity when the input velocity is constant.  Instead, the output rotation rate has an superimposed sine component whose amplitude depends on the angle between the input and output shafts.  This apparently is the primary reason why such drives need cush rubbers, to absorb the rotation rate variations.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 09, 2016, 03:05:08 PM
The work/production to get it to work may offset the advantages to run a belt.  Replacing a belt is no picnic either.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: ITSec on July 09, 2016, 05:35:07 PM
As long as we're telling Moto Guzzi how to design their products, I would like to have a shaft drive with a genuine constant velocity joint instead of a U-joint.  The latter, as I recently learned, does not have a constant output velocity when the input velocity is constant.  Instead, the output rotation rate has an superimposed sine component whose amplitude depends on the angle between the input and output shafts.  This apparently is the primary reason why such drives need cush rubbers, to absorb the rotation rate variations.

So the CARC either doesn't produce such harmonics, or is missing the cush rubbers? And why do chain and belt drive bikes so often have cush rubbers? There's something in your explanation I'm just not understanding.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: WitchCityGuzzi on July 09, 2016, 05:39:28 PM
I really like the CARC on our Stelvio and Griso. I'm not interested in a rubber band powering my motorcyle. I find it unlikely, the belt would work that well offroad either. Seems like it's life span in the muck would be pretty short.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 09, 2016, 05:48:18 PM
As long as we're telling Moto Guzzi how to design their products, I would like to have a shaft drive with a genuine constant velocity joint instead of a U-joint.  The latter, as I recently learned, does not have a constant output velocity when the input velocity is constant.  Instead, the output rotation rate has an superimposed sine component whose amplitude depends on the angle between the input and output shafts.  This apparently is the primary reason why such drives need cush rubbers, to absorb the rotation rate variations.

That's true for a single U-joint.  That's why vehicles use two joints, either together like Guzzi, or separated with a shaft between them, like older rear wheel drive cars.  The intermediate shaft does have a non-constant rotational speed when the U-joint is not at 180 degrees, but when the joints are oriented properly, the output shaft does indeed turn with constant speed, because the second joint's non-uniformity cancels that of the first joint.  It all does have to be designed carefully for that to work.

Wikipedia's article "Constant-velocity joint" explains it, and has some nice animations to demonstrate it.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: pete roper on July 09, 2016, 05:53:13 PM
So the CARC either doesn't produce such harmonics, or is missing the cush rubbers? And why do chain and belt drive bikes so often have cush rubbers? There's something in your explanation I'm just not understanding.

Not quite.

By using paired Hookes couplings the varying output from each one cancels the other out pretty much meaning the forces imposed are greatly diminished. The further apart they are the more effective this is. It's the reason why the newer driveshafts have a coupling at each end and last so much better than the earlier UJ's used on loops and earlier Tontis.

And Doug, I hate to tell you but your Stelvio and Griso both have 'Rubber' drives. :D the shaft is a two part assembly with some sort of bonded, synthetic, high hysteresis rubber in between the two to act as a Cush drive. It seems to work well as I've only heard of UJ failures, never a failure of the Cush.

Pete
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: twowings on July 09, 2016, 05:53:31 PM
As far as I'm concerned, my 2008 Norge IS the pinnacle of form AND function...stick on all the bells and whistles you desire, my motorcycling 'needs' are already met! :thumbs:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: oldbike54 on July 09, 2016, 05:58:56 PM
As far as I'm concerned, my 2008 Norge IS the pinnacle of form AND function...stick on all the bells and whistles you desire, my motorcycling 'needs' are already met! :thumbs:

 I felt the same way about my 1970 TR6R Triumph back in 1971  :shocked: :rolleyes: :laugh:

 Dusty
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: sbaker on July 09, 2016, 06:23:25 PM
Carc heavy ???? Every time I think I would increase my gas mileage if I didn't have a Carc that weighted so much, I step on the scale... Case closed.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Daniel Kalal on July 09, 2016, 07:18:08 PM
...The latter, as I recently learned, does not have a constant output velocity...

With two u-joints in series (as used with all the big blocks: CARC, Spine, Tonti and Loop), if the input shaft is exactly parallel to the output shaft the result will be perfectly constant rotation at the wheel.  The CARC is best at doing this--you need a 4-bar linkage system (which means a floating rear drive) to work best, else your best bet as a designer is to try to be close to parallel within the normal shock stroke.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: twowings on July 09, 2016, 08:20:02 PM
To paraphrase Lee Iacocca, "If you can find a better bike, buy it!"
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: sib on July 10, 2016, 06:58:54 AM
With two u-joints in series (as used with all the big blocks: CARC, Spine, Tonti and Loop), if the input shaft is exactly parallel to the output shaft the result will be perfectly constant rotation at the wheel....
But, that's also true of the 1 U-joint system.  The difference is that with 2 U-joints, it is possible for the input and output shafts to be DISPLACED but still parallel.  Now, we need an expert to tell us whether, with a 2 U-joint system, it is possible for the input and output shafts to turn at constant velocity when they are NOT parallel.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: pete roper on July 10, 2016, 07:17:53 AM
(Groan.)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Daniel Kalal on July 10, 2016, 07:25:01 AM
But, that's also true of the 1 U-joint system
No; it's not.

possible for the input and output shafts to turn at constant velocity when they are NOT parallel
No; it's not.

This is pretty basic.  The calculation of u-joint characteristics is a topic for a freshman engineering class.  You'll find the Wikipedia entry for "Universal Joint" gives the needed equations.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Nic in Western NYS on July 10, 2016, 07:39:57 AM
Guzzi did real well with CARC.  Substantial, lasts 150k+ miles, solid engineering.  Few failures.  What's the problem with it other than weight?  And shaving ounces isn't what Guzzi's been about. 
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: leafman60 on July 10, 2016, 07:55:24 AM
I've owned and ridden both H-D's and BMW's with belt drives and I like them better than any other drive system. They are simple, light weight, efficient, reliable, permissive of ratio changes and low maintenance.

However, I do not expect it on a longitudinal crank bike like the Guzzi. Since the power output of from the engine is longitudinal to the bike, adapting to a belt drive would still require a 90-degree change of direction in the power train that would bleed off some of the inherent efficiency of the belt drive.

Maybe a special-designed transmission with a side output would work.

As far as the belt itself, though, they are great.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 10, 2016, 08:06:29 AM
No; it's not.

Actually it is.  The double Cardan joint, like in most Guzzi rear drives, is a CV joint.  In any double Cardan joint system, when the input and output shafts are parallel, or if their angles are the same, the input and output shafts runs with smooth rotation (CV).  The double Cardan joint in many Guzzis is a CV joint.

Again, the Wikipedia article "constant-velocity joint" explains it well.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Daniel Kalal on July 10, 2016, 08:15:16 AM
...are parallel, or if their angles are the same...

Exactly.  If the angles are the same then they are parallel and the output is constant*.  That's the special case where  two u-joints in series behave as a CV joint.  Real CV joints are more clever than that.

* and if not parallel, then the output is not constant, which was my earlier comment.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 10, 2016, 08:52:29 AM
Exactly.  If the angles are the same then they are parallel and the output is constant*.  That's the special case where  two u-joints in series behave as a CV joint.  Real CV joints are more clever than that.

* and if not parallel, then the output is not constant, which was my earlier comment.

There's one more special case, and that's when the two angles are the same, but not opposite as when the shafts are parallel.  For example, each shaft is angled 10 degrees, for a total of a 20 degree angle.  The joint is CV in that case too.  It's the case in a double Cardan joint, as I said above, and is why Guzzi uses a double Cardan joint in its swing arms.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: redrider90 on July 11, 2016, 11:19:07 AM
Actually it is.  The double Cardan joint, like in most Guzzi rear drives, is a CV joint.  In any double Cardan joint system, when the input and output shafts are parallel, or if their angles are the same, the input and output shafts runs with smooth rotation (CV).  The double Cardan joint in many Guzzis is a CV joint.

Again, the Wikipedia article "constant-velocity joint" explains it well.


Well what is my split drive shaft with a carrier bearing on my 4X4 called?
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: RogerGuzzi on July 11, 2016, 11:23:28 AM
Aside from engineering considerations, a Guzzi with a belt drive wouldn't be a Guzzi.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: bad Chad on July 11, 2016, 12:41:59 PM
Yes is would.  Guzzi has made tons of chain drive bikes, so going to a belt seems like a none issue.  But for my two cents, I love the CARC.  It works great, and in my OP looks cool!
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 11, 2016, 01:05:11 PM

Well what is my split drive shaft with a carrier bearing on my 4X4 called?

That's as good a name as any.   :grin:  My motor home has three drive shafts and four U-joints, all aligned for constant velocity.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 11, 2016, 01:58:29 PM
An updated 500 single.  Fuel injected, turbo charged belt drive bike would work.  :thumb: :thumb: :thumb:  The Carbineri would love it for their enforcement work.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: rboe on July 11, 2016, 02:30:57 PM
They could call it the "Centipede"......  :boozing:

500 single would be the bomb. Wonder if it would sell though.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 11, 2016, 02:50:51 PM
How's about a 650 single.  Counter-balanced crank.  Make it an updated horizontal single w/suspension and other parts.  Dual purpose set-up with tubeless tires.  :thumb:  Would they sell?  Yeah.....more so than a baby Stelvio.  Roll cage the engine.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Kiwi_Roy on July 11, 2016, 02:57:18 PM
How's about a 650 single.  Counter-balanced crank.  Make it an updated horizontal single w/suspension and other parts.  Dual purpose set-up with tubeless tires.  :thumb:  Would they sell?  Yeah.....more so than a baby Stelvio.  Roll cage the engine.
We don't need no stinkin counter balance crank, give me a big (650) horizontal single like an old bacon slicer.
I want it to vibrate, Belt drive, kickstart, now were talkin.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: leafman60 on July 11, 2016, 03:17:15 PM
(http://i1213.photobucket.com/albums/cc462/leafman60/Nuovo%20Falcone%20II/040.jpg) (http://s1213.photobucket.com/user/leafman60/media/Nuovo%20Falcone%20II/040.jpg.html)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 11, 2016, 03:23:44 PM
We don't need no stinkin counter balance crank, give me a big (650) horizontal single like an old bacon slicer.
I want it to vibrate, Belt drive, kickstart, now were talkin.

 :grin: :grin: :grin:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 11, 2016, 04:17:16 PM
(http://i1213.photobucket.com/albums/cc462/leafman60/Nuovo%20Falcone%20II/040.jpg) (http://s1213.photobucket.com/user/leafman60/media/Nuovo%20Falcone%20II/040.jpg.html)

Update the whole bike.  Bump up the metallury.  Fuel inject it.  Removable horizontal crash bar around the cylinder.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: pete roper on July 11, 2016, 04:35:01 PM
And watch it sink without trace :rolleyes:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: oldbike54 on July 11, 2016, 04:38:14 PM
And watch it sink without trace :rolleyes:

  :1: And then show up 10 years later on E bay advertised as "rare" , or "collectible"  :rolleyes:

  Dusty
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 11, 2016, 05:45:49 PM
 :grin: :grin: :grin:  Only conjecture here.  Obviously the company is going with other engine configurations.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: keener on July 11, 2016, 09:17:57 PM
My Griso is my first Shaft Drive bike  / CARC  and i fricken love it ...why change , why even question a change ?
I guess really good design and reliability are passe now ...i dont get it...
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Bulldog9 on July 12, 2016, 12:31:00 AM
Only if they want to guarantee people like me will never buy another. I've exclusively ridden shafties since 1984.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: kirb on July 12, 2016, 07:41:00 AM
As others have pointed out the longitudinal crank in the current motor requires the drive to be turned through 90* to make the back wheel go round. This can either be done at the rear wheel or at the gearbox. While doing it at the gearbox will allow less unsprung weight you will still get the mechanical losses of the 90* change of direction and then will add further losses from the belt or chain rear drive.
...

I have no real problem with modern chains, they are robust and very long lived if you maintain them properly and that is hardly a chore. I have no experience of belts but they seem to work in the applications they are used in. At the end of the day though a decent reactive system like the CARC is, IMHO, the best compromise for cleanliness, ease of maintainence and performance for a machine like a Guzzi.
...

Pete

HD and Buell have had belts for a long time. I owned a Buell for 11 years and the belt looked like new. The only belt failures I have heard of are Uly owners who managed to get a rock between the pulley and belt. Belts are a PITA to change on most of those bikes. Most of the big cruiser guys don't worry about the belt until 30k miles or later. Ducati has also adopted a belt on the XDiavel.

Chains are fairly efficient and can transfer some major horsepower. I suspect more efficient than a 90deg bevel drive. Motus has been doing this exact thing to save on weight: http://www.motusmotorcycles.com/

 
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: leafman60 on July 12, 2016, 08:33:24 AM
Big singles are not big sellers nowadays.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Cool Runnings on July 12, 2016, 08:49:12 AM

Well what is my split drive shaft with a carrier bearing on my 4X4 called?

Muffler bearing.  :popcorn:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: bad Chad on July 12, 2016, 10:30:38 AM
And watch it sink without trace :rolleyes:

Absolutely.   After the first 30 were sold to hundreds clamoring for such a bike, they wouldn't sell another!
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 12, 2016, 01:17:37 PM
and.......like that would stop Moto Guzzi.   :shocked:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: mjptexas on July 12, 2016, 02:23:40 PM
....The bike could handle like a feral shopping trolley with a wonky wheel... ..

My dear man, you certainly do know how to turn a phrase. :thumb:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: bad Chad on July 12, 2016, 05:04:10 PM
and.......like that would stop Moto Guzzi.   :shocked:

Yes, it would, in this decade.   Since Piaggio took over, for better or worse, things have changed.  The v7 series has been a hit.  The 1400s a work in progress, but certainly not a flop.  There have been no sales flops introduced that I can think of since Piaggo took over.  This an't your uncles Moto Guzzi!
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 12, 2016, 06:22:49 PM
Their dealer support still sucks.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: N97972 on July 12, 2016, 10:23:11 PM
Update the whole bike.  Bump up the metallury.  Fuel inject it.  Removable horizontal crash bar around the cylinder.

Now that would be a bike that would replace a few in my garage! light and simple to work on, perhaps so good you wouldn't have to work on it.

Petes
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Bulldog9 on July 12, 2016, 11:13:11 PM
As long as we're telling Moto Guzzi how to design their products, I would like to have a shaft drive with a genuine constant velocity joint instead of a U-joint.  The latter, as I recently learned, does not have a constant output velocity when the input velocity is constant.  Instead, the output rotation rate has an superimposed sine component whose amplitude depends on the angle between the input and output shafts.  This apparently is the primary reason why such drives need cush rubbers, to absorb the rotation rate variations.

What? Any joint design/universal/constant velocity will have some level of vibration, and FWIW, a 'u joint' is a constant velocity joint.  :popcorn:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Dogwalker on July 13, 2016, 03:57:43 AM
Update the whole bike.  Bump up the metallury.  Fuel inject it.  Removable horizontal crash bar around the cylinder.
(http://www.motociclismo.it/galleries/image/the-bike-field-foto-di-moto-special-e-altro-la-gente-i-test-ride-latmosfera/236334/F)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Rough Edge racing on July 13, 2016, 05:22:19 AM

 The Guzzi already has a right angle drive...it's the ring and pinion at the rear wheel. So in theory the right angle could be at the tranny and belt or chain then used to drive the rear wheel with same number of gears...
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Dogwalker on July 13, 2016, 05:28:08 AM
The Guzzi already has a right angle drive...it's the ring and pinion at the rear wheel. So in theory the right angle could be at the tranny and belt or chain then used to drive the rear wheel with same number of gears...
That way the power dispersion of the chain, or of the belt, must be added to that of the bevel gear.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: sib on July 13, 2016, 07:44:35 AM
What? Any joint design/universal/constant velocity will have some level of vibration, and FWIW, a 'u joint' is a constant velocity joint.  :popcorn:
Sorry, a U joint is a constant velocity joint only when the input and output shafts are perfectly aligned.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 13, 2016, 08:07:29 AM
Sorry, a U joint is a constant velocity joint only when the input and output shafts are perfectly aligned.

And if it's a double U-joint with the input and output shafts parallel, or at the same angle, (10 degrees at each joint, 20 degrees total, for example) as I posted above.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Daniel Kalal on July 13, 2016, 09:26:18 AM
The topic is interesting, so I put this together (which reinforces what Jim has said, above).

Let's look at the output shaft rotation velocity, where the input rotation is always a constant value of 1.

(http://www.dankalal.net/wildgoose/ujointchart.jpg)

Using the example of 10 degrees, you can see that a shaft with a single u-joint (such as a small block) will speed up and slow down (by a factor of .015) twice with each rotation of the shaft.  That's vibration.

Now, if we add a second u-joint we can see what happens if that output angle is either -10 degrees or +10 degrees: the vibration goes away.  That is; there is no change in rotation velocity.  Even if the output angle does not match the input angle (+/-) you still have an advantage over just a single u-joint.  In this case, if you're off by 3 degrees out of the desired 10, the vibration will still be cut in half.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Rough Edge racing on July 13, 2016, 09:55:09 AM
  Anyone who builds hot rods or 4x4 vehicles knows what Jim is talking about...

  This short video might help....https://www.youtube.com/watch?v=gmV4qwLfOMY (https://www.youtube.com/watch?v=gmV4qwLfOMY)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Kiwi_Roy on July 13, 2016, 09:57:17 AM
So that's why we have the alignment paint mark on the splines for the VII Spot shaft.
Thanks for the explanation.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Penderic on July 13, 2016, 10:08:14 AM
(http://i1299.photobucket.com/albums/ag77/Penderic/Penderic002/Drive20shafts20fitted_zpsfgclmvdn.jpg)

Inboard brakes the next development? Move the weight of the brake hardware and if possible, the weight of the gear hub to a more central location? Might improve the suspension.

And add a PTO take-off for the lawn accessories!  :boozing:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: twhitaker on July 13, 2016, 10:16:35 AM
Quote
Inboard brakes the next development?

Audi did that 45 years ago.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Dogwalker on July 13, 2016, 10:27:25 AM
Audi did that 45 years ago.
Lancia, 79 years ago.
(https://lanciaapriliadiary.files.wordpress.com/2012/12/complete-rear-end-assembly.jpg?w=800)
(https://lanciaapriliadiary.files.wordpress.com/2012/12/rear-brakes-001.jpg)
(https://c2.staticflickr.com/8/7323/8880051319_2d1a2d5881_b.jpg)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 13, 2016, 11:29:22 AM
Inboard brakes the next development? Move the weight of the brake hardware and if possible, the weight of the gear hub to a more central location? Might improve the suspension.

The problem I have with that is if something like a U-joint breaks, you lose braking for that wheel.  I really like brake parts to be in very close proximity to the wheels.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Kev m on July 13, 2016, 12:29:47 PM
Ironically I skipped this thread when it was posted a few days ago because I felt the question was patently ridiculous (sorry Willow, nothing personal).

I mean, as addressed:

1. The CARC is dead.
2. Even if it wasn't, well, shaft drive seems to work just fine for Guzzi.

I've often professed my preference for either Shaft or Belt drive motorcycles, so maybe I shouldn't be quick to judge the concept.

But then I noticed when reading through this I got stuck on one point - the realization that with the CARC dead, should no replacement Single-Sided Swingarm (SSSA) surface in the near future, Guzzi will have abandoned the easily serviced rear wheel.

I mean, by all reports accessing the rear wheel on the Cali 1400 line is a "right front bottom" or something like that.

And though rear wheel access on the V7 (and presumably V9) line isn't any sort of nightmare, it IS un-necessarily complicated. I mean, I really shouldn't have to remove a muffler or a shock, NEVER MIND a REAR DRIVE UNIT in order to swap a friggin' tire.

Which reminded me how ridiculously easy it was to quickly drop the rear wheel on a CARC. I mean, seriously:

1. Put it on the centerstand.
2. Unbolt/pivot the brake caliper out of the way (and that wasn't even really NECESSARY).
3. Pop off plastic hub-cap, then loosen the lug nuts.
4. Remove wheel!

Damn, I miss that.

I have to admit that I actually LIKE the looks of twin-shock bikes from a "classic lines" standpoint. But I could forgive a single shock rear suspension for that kind of ease of service!


Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 13, 2016, 02:05:36 PM
(http://www.motociclismo.it/galleries/image/the-bike-field-foto-di-moto-special-e-altro-la-gente-i-test-ride-latmosfera/236334/F)

Cool!  I bet that thing is easy to ride.  Leave in one gear and work the throttle for mountain roads.  Any more info?
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: kirby1923 on July 13, 2016, 02:20:39 PM
[IMG]Inboard brakes the next development? Move the weight of the brake hardware and if possible, the weight of the gear hub to a more central location? Might improve the suspension.

And add a PTO take-off for the lawn accessories!  :boozing:


And the E type Jaguar!
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Dogwalker on July 13, 2016, 04:28:25 PM
Cool!  I bet that thing is easy to ride.  Leave in one gear and work the throttle for mountain roads.  Any more info?
It's a caf� racer made by Gianni Gagliotti, ex official pilot with the Beta 250 enduro in the '70s and ex Paris-Dakar pilot with the Morini 500 in the '80s, starting from a Nuovo Falcone. The pictures had been taken at a rally organized by the magazine "Motociclismo".
(http://www.motociclismo.it/galleries/image/foto-di-moto-special-the-bike-field-in-bianco-e-nero/237544/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237204/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237206/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237207/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237208/F)
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: lucky phil on July 13, 2016, 04:44:40 PM
The topic is interesting, so I put this together (which reinforces what Jim has said, above).

Let's look at the output shaft rotation velocity, where the input rotation is always a constant value of 1.

(http://www.dankalal.net/wildgoose/ujointchart.jpg)

Using the example of 10 degrees, you can see that a shaft with a single u-joint (such as a small block) will speed up and slow down (by a factor of .015) twice with each rotation of the shaft.  That's vibration.

Now, if we add a second u-joint we can see what happens if that output angle is either -10 degrees or +10 degrees: the vibration goes away.  That is; there is no change in rotation velocity.  Even if the output angle does not match the input angle (+/-) you still have an advantage over just a single u-joint.  In this case, if you're off by 3 degrees out of the desired 10, the vibration will still be cut in half.

This might be easier to understand.
https://www.youtube.com/watch?v=gmV4qwLfOMY

Ciao
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 13, 2016, 04:56:15 PM

This might be easier to understand.
https://www.youtube.com/watch?v=gmV4qwLfOMY

Ciao

Rough Edge racing posted that link in reply #62.  You're right, it's a very good demonstration.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Rough Edge racing on July 14, 2016, 05:32:27 AM
  My experience with Guzzi U joints is on Tonti frames...The Guzzi U joint functions exactly the same as the two u joints on the shaft in the demonstration video...
 Older Jeeps and 4x4 trucks have a single u joint on the front driving axles and some of you have probably experience the "bind" occurring when making a tight turn on a hard surface with the front axle engaged. WW2 Jeeps had CV front axle joints just like a modern front drive car...They were replaced by a single U joint in the CJ civilian Jeeps, probably a cost factor...
 If you talk to enough Harley riders you will get stories of sudden belt failures ,many on low mileage belts. Some are from a small object getting between the belt and pulley...Some are likely from misalignment or other butchery, and some are just bad luck...
  When it comes to surviving abuse from racing or riding in hostile situations, a chain is King...
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: jcctx on July 14, 2016, 10:57:26 AM
Don't see it anymore but an enclosed oil bath chain set-up is very durable. Should be able to incorporate into single sided arm easily enough. Must be some reason I haven't thought of it is not used by someone???????
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Triple Jim on July 14, 2016, 11:07:04 AM
Fully enclosed chains had a small following in past decades.   There were even conversions kits to add the feature.  I think the complexity offset the advantages.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: jcctx on July 14, 2016, 11:16:49 AM
Fully enclosed chains had a small following in past decades.   There were even conversions kits to add the feature.  I think the complexity offset the advantages.
More complex than an open chain; but surely less than a shaft???
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 14, 2016, 02:17:49 PM
IIRC, the main reason is that it was ugly.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: ITSec on July 14, 2016, 03:14:49 PM
Fully enclosed chains had a small following in past decades.   There were even conversions kits to add the feature.  I think the complexity offset the advantages.

Mostly in wonky dual-sport and off-road bikes with limited displacement, from what I recall. Bultaco, Jawa, some others. I don't recall any enclosed chains on bikes with substantial displacement (i.e., more than 500cc).
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: huub on July 14, 2016, 03:48:28 PM
Mostly in wonky dual-sport and off-road bikes with limited displacement, from what I recall. Bultaco, Jawa, some others. I don't recall any enclosed chains on bikes with substantial displacement (i.e., more than 500cc).

didn't you get the yamaha TR1?
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Lannis on July 14, 2016, 04:57:23 PM
Mostly in wonky dual-sport and off-road bikes with limited displacement, from what I recall. Bultaco, Jawa, some others. I don't recall any enclosed chains on bikes with substantial displacement (i.e., more than 500cc).

BSA A10 650cc twin models came with enclosed chains as an option.   Good for the chain, but fiddly when maintenance had to be done.   Most chain cases disappeared after two or three chain/sprocket replacements, I suspect.

Lannis
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: leafman60 on July 14, 2016, 06:19:26 PM
It's a caf� racer made by Gianni Gagliotti, ex official pilot with the Beta 250 enduro in the '70s and ex Paris-Dakar pilot with the Morini 500 in the '80s, starting from a Nuovo Falcone. The pictures had been taken at a rally organized by the magazine "Motociclismo".
(http://www.motociclismo.it/galleries/image/foto-di-moto-special-the-bike-field-in-bianco-e-nero/237544/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237204/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237206/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237207/F)
(http://www.motociclismo.it/galleries/image/the-bike-field-2016-mega-gallery-delle-special-dei-lettori-esposte-alla-prima-edizione/237208/F)

Very nice!
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: ITSec on July 14, 2016, 09:00:40 PM
didn't you get the yamaha TR1?

I had to go look that one up - in North America, it was sold (in a reduced displacement version) as the XV920R, a Virago/Seca derivative that was spectacularly unsuccessful. It was only on the books two years, and many were unsold when it was withdrawn. I don't recall having ever seen one on the street...
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Penderic on July 15, 2016, 12:45:23 AM
Driveline efficiency is important ....

(http://i1299.photobucket.com/albums/ag77/Penderic/Penderic002/push%20motorcycle_zpsds2aqh0e.jpg)
...sometimes!  :wink:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: kingoffleece on July 15, 2016, 01:16:47 AM
Harley had an enclosed chain on the then 1200 bikes in the early 80's if I recall correct.
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Lannis on July 15, 2016, 08:57:56 AM
Harley had an enclosed chain on the then 1200 bikes in the early 80's if I recall correct.

By gar, you're right, I'd forgotten about those.   My new '84 ElectraGlide (last shovelhead) had a belt, but some of the other bikes had an enclosed chain which made changing the rear tire a huge pain unless you drilled a hole or two in the case .... not many of them survived the second tire change!

Lannis
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: Tom on July 15, 2016, 01:21:01 PM
Driveline efficiency is important ....

(http://i1299.photobucket.com/albums/ag77/Penderic/Penderic002/push%20motorcycle_zpsds2aqh0e.jpg)
...sometimes!  :wink:

Somehow, I find this disturbing and enticing at the same time.  :shocked:
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: ITSec on July 15, 2016, 05:06:49 PM
Somehow, I find this disturbing and enticing at the same time.  :shocked:

Actually, looking at the fact they rider has white hair, it got me thinking of Dusty's recent adventures...
Title: Re: Should Moto Guzzi consider a belt in place of the CARC shaft?
Post by: oldbike54 on July 15, 2016, 05:55:16 PM
Actually, looking at the fact they rider has white hair, it got me thinking of Dusty's recent adventures...

 Nah , mine is prettier  :laugh:

 Dusty