Vibration in grips at 3k-5k RPM...any way to correct?

[VtwinStorm]

7 hours ago, Lucky Phil said:

Well that's because it's got 2 balance shafts. A flat plane in line 4 is not an inherently smooth engine, not by a long shot. I've got a physical problem with my right hand outer palm and little finger from many touring klms on a couple of K100 BMW's back in the day. No Guzzi will ever be as smooth as a Ducati V twin because of the crank orientation. 

Ciao 

I know that, silly. I have been in the game nearly 30 years myself. I was just describing how smooth the Triumph Four and Ducati Twins are versus the Guzzi Twins.

Just my experience. I also understand Triumph Triples are amazing and very, very smooth...haven't ridden one in 20 years, but I remember it very fondly. Might go find a Thunderbird Sport 900 to add to my collection in 2022 because they are so great.

I've loved all kind of engines: parallel twins, v-twins, triples, inline fours, v fours, one-lungers, Guzzi V-Twins, BMW Boxers, but I have never gotten on a Benelli Sei or Honda CBX Six...or a two stroke.

Variety is the spice of life! I just don't want numb hands while I ride my V11 Sport.

[Chris Wilson]

19 hours ago, Lucky Phil said:

 No Guzzi will ever be as smooth as a Ducati V twin because of the crank orientation. 

Ciao 

Why would crank orientation make a difference to smoothness?

Secondaries adding up along a lateral horizontal plane with no mass to counteract?

Thanks.

[gstallons]

Just for kicks , look at the oriveshaft to see if it is indexed correctly

[Chris Wilson]

22 minutes ago, gstallons said:

Just for kicks , look at the oriveshaft to see if it is indexed correctly

But the drive shift will always be orientated laterally regardless of engine design  so you think maybe is manufactured error?

[gstallons]

I mean where the driveshaft is splined to each half

[docc]

14 minutes ago, gstallons said:

I mean where the driveshaft is splined to each half

[Lucky Phil]

1 hour ago, Chris Wilson said:

Why would crank orientation make a difference to smoothness?

Secondaries adding up along a lateral horizontal plane with no mass to counteract?

Thanks.

Because what is felt is about more than just the quantifiable amount of secondary forces but also the direction of those forces. A Guzzi V twin secondaries act laterally and the Ducati fore and aft. The chassis and suspension does a much better job of absorbing the fore and aft secondary imbalance than it does laterally. I've owned a lot of different Ducati's over the years in many different configurations and none buzzed the bar/s as badly as a V11 sport. On a Ducati handlebar vibration simple isn't an issue. So Guzzi changed their balance factor to 52% at one point I heard from the std 50% to compensate and try and reduce the vibes.. An Aermacchi single requires a very different balance factor than an equivalent upright single due simply to it's lay down cylinder and the resultant direction of the secondaries and the chassis ability to dampen them.

Ciao   

[Chris Wilson]

I agree, and I remember a Dharma I had that was uncannily smooth. 

Perhaps adding a sidecar might smooth things out!

Chris.

[VtwinStorm]

43 minutes ago, Lucky Phil said:

Because what is felt is about more than just the quantifiable amount of secondary forces but also the direction of those forces. A Guzzi V twin secondaries act laterally and the Ducati fore and aft. The chassis and suspension does a much better job of absorbing the fore and aft secondary imbalance than it does laterally. I've owned a lot of different Ducati's over the years in many different configurations and none buzzed the bar/s as badly as a V11 sport. On a Ducati handlebar vibration simple isn't an issue. So Guzzi changed their balance factor to 52% at one point I heard from the std 50% to compensate and try and reduce the vibes.. An Aermacchi single requires a very different balance factor than an equivalent upright single due simply to it's lay down cylinder and the resultant direction of the secondaries and the chassis ability to dampen them.

Ciao   

A damned fine answer, Lucky Phil. Thank you!

[p6x]

14 hours ago, VtwinStorm said:

I've loved all kind of engines: parallel twins, v-twins, triples, inline fours, v fours, one-lungers, Guzzi V-Twins, BMW Boxers, but I have never gotten on a Benelli Sei or Honda CBX Six...or a two stroke.

You forgot the Kawasaki KZ1300 in your 6 cylinders roster.

The two strokes, you have missed out on something, that I can assure you.... Of course, the legendary Kawasaki triple, Mach III, H2, S1, S2, S3, S4. And later, the Yamaha RDLC and Suzuki 2 strokes four cylinders....

I have not looked for one here in the USA, but if you could get your hands on an Aprilia 250 RS, you would have a hard time leaving it alone!

[Lucky Phil]

14 minutes ago, p6x said:

You forgot the Kawasaki KZ1300 in your 6 cylinders roster.

The two strokes, you have missed out on something, that I can assure you.... Of course, the legendary Kawasaki triple, Mach III, H2, S1, S2, S3, S4. And later, the Yamaha RDLC and Suzuki 2 strokes four cylinders....

I have not looked for one here in the USA, but if you could get your hands on an Aprilia 250 RS, you would have a hard time leaving it alone!

Inline 6's have perfect primary, secondary and rocking couple balance. The smoothest configuration along with the V12.

Ciao

[po18guy]

2 hours ago, Chris Wilson said:

Why would crank orientation make a difference to smoothness?

Secondaries adding up along a lateral horizontal plane with no mass to counteract?

Thanks.

Rev the engine in neutral and see what the entire bike does. In slow motion, one bar goes up and the other goes down. In that same plane, secondary imbalance wants to shake the bar ends up and down, except at 2X the engine RPM. 

This video regards the primary/secondary imbalance of twins - parallel twins in this case, but the principles of primary and secondary imbalance are explained. He is preparing a V-twin balance video, but we'll have to wait on that one.

 

[VtwinStorm]

1 hour ago, p6x said:

You forgot the Kawasaki KZ1300 in your 6 cylinders roster.

The two strokes, you have missed out on something, that I can assure you.... Of course, the legendary Kawasaki triple, Mach III, H2, S1, S2, S3, S4. And later, the Yamaha RDLC and Suzuki 2 strokes four cylinders....

I have not looked for one here in the USA, but if you could get your hands on an Aprilia 250 RS, you would have a hard time leaving it alone!

A KZ1300 weights as much as a house. My Daytona 1200 is almost 550lbs. fully fueled up (6 gallon tank), and rest assured, she's a full figured woman.

Other than straddling one of those at a standstill, I don't know how I would handle it.

An Aprilia RS250 would be great...but damn, they are rare here in the States.

Next bikes on my bucket list to own are a Norton 750 Commando and a Triumph 900 Thunderbird Sport.

After that, perhaps a 916/996/998?

Too many great machines...

[Chris Wilson]

4 hours ago, po18guy said:

Rev the engine in neutral and see what the entire bike does. In slow motion, one bar goes up and the other goes down. In that same plane, secondary imbalance wants to shake the bar ends up and down, except at 2X the engine RPM. 

This video regards the primary/secondary imbalance of twins - parallel twins in this case, but the principles of primary and secondary imbalance are explained. He is preparing a V-twin balance video, but we'll have to wait on that one.

 

Thanks, I have looked at the theory on Vee twin secondaries being 1.44 the counterweight each revolution instead of 2  and indeed mentioned the lateral issue a few posts back but what gets me in all this theory is that it's alawys modelled around the central shaft supplying a constant rotation and not the reciprocating motion of the pistons and thus flawed when considering primaries being in balance.

Thus I think that it's a lot more complicated than just lateral secondaries.

Worthy of another thread perhaps?

Chris.

[po18guy]

Indeed. Even if engineering does not solve a problem, it can explain it.

EDIT: There are aftermarket bar-end makers that make extra heavy weights. This can go a good ways toward slowing the problem. Shorter bars reduce the leverage the vibration has on your hands, and even though solidly mounted, the clipon models of V11 'may' have a certain advantage here. Or may not. I know that my high barred Ballabio is not offensive as to bar vibes - but everyone's experience varies in this regard. I have bar-end mirrors installed, so they essentially replace the weights that were OEN.

This is one company which makes heavy, stainless Guzzi weights that might be considered. $102 US/pair, but comfort is as comfort does, eh?

http://www.hvmp.com/category-s/50.htm