Flywheel lightening

[guzzijack]

This is a slightly off camber question as it will not ultimately apply to a V11S.

 

We are currently in the 'parts collection' phase to build a roundfin based classic endurance racer. Amongst other items that have been disintered from beneath the workbench is a complete and new V11S flywheel, ring gear and driven plate which I had forgotten about. Comparing it with the LMV components I also have and looking at the appropriate Guzzitech webpage Flywheel Lightening there is hardly any difference between the lightened older unit and the standard V11S one - in fact the V11S components come out marginally lighter.

 

Bearing in mind that this motor is being put together for 6 hour plus endurance races - not short circuit sprints - any advice on whether or not to trim something from the V11S unit would be helpful, especially if you've done it yourself.

 

Cheers

 

Graham

[Pierre]

...

Bearing in mind that this motor is being put together for 6 hour plus endurance races - not short circuit sprints - any advice on whether or not to trim something from the V11S unit would be helpful, especially if you've done it yourself.

 

Cheers

 

Graham

 

Graham, I had the clutch lighened on my '97 sport i. Not sure how the '97 sport i clutch pacakge stock weight compares with V11 clutch.

 

The text in green is taken from correspondence with Bernd (he's quoting prices - which I've omitted) at Stein Dinse AU. I don't know what additional weight savings were realized by taking 1mm from the ring gear, but that was done as well. So the entire clutch package now weighs

 

 

1. Flywheel ultra light 1068 gramm

2. clutch pressure plate light

3. clutch plate surflex 1100sp. x2

4. clutch intermediate plate

5. clutch spring x 8

 

 

 

this set up should make your clutch 30% lighter, from 5600gr to 3900

gramm

 

 

now the ring gear, attached is a pic, so if you find someone with a milling

machine, he can take the oval holes between the mounting holes out. the

leftover of each mounting tongue should be ap.20mm.,but all holes must be

exactly the same !!! the original bolt holes are made to take a 6mm allan

head bolt, that needs to be changed to 8mm bolt holes (allan head), you'll

need 8 new bolts, 8mm x20, highest grade you can get.

from the rear of the ring gear, that part which faces the gearbox, you can

take away 1mm from the clutch plate part..hard to explain..its the inner

part of the ring gear, its now 6 mm thick, and it can be made to 5mm.

[guzzijack]

Graham, I had the clutch lighened on my '97 sport i. Not sure how the '97 sport i clutch pacakge stock weight compares with V11 clutch.

 

The text in green is taken from correspondence with Bernd (he's quoting prices - which I've omitted) at Stein Dinse AU. I don't know what additional weight savings were realized by taking 1mm from the ring gear, but that was done as well. So the entire clutch package now weighs

1. Flywheel ultra light 1068 gramm

2. clutch pressure plate light

3. clutch plate surflex 1100sp. x2

4. clutch intermediate plate

5. clutch spring x 8

this set up should make your clutch 30% lighter, from 5600gr to 3900

gramm

now the ring gear, attached is a pic, so if you find someone with a milling

machine, he can take the oval holes between the mounting holes out. the

leftover of each mounting tongue should be ap.20mm.,but all holes must be

exactly the same !!! the original bolt holes are made to take a 6mm allan

head bolt, that needs to be changed to 8mm bolt holes (allan head), you'll

need 8 new bolts, 8mm x20, highest grade you can get.

from the rear of the ring gear, that part which faces the gearbox, you can

take away 1mm from the clutch plate part..hard to explain..its the inner

part of the ring gear, its now 6 mm thick, and it can be made to 5mm.

 

Thanks for that Pierre,

 

I'll have to check the conversion from Kilo to lb to see how that compares but I see yours has 8 clutch springs compared to the later 10 spring clutches fitted to the Daytona RS, Centauro and V11Sport (not sure if it's the same clutch for the V11S as to the other two though). I suspect that yours would therefore be somewhat heavier than these later types though possibly not as heavy as the LM1000 one I also have which was the one lightened by Guzzitech.

 

Graham

[luhbo]

I'm thinking of swapping my V11 clutch with something like the old Eldo units. I can not see any advantages such a light clutch and flywheel gives me for my every day use of the V11. But I can see disadvantages like higher idle (just a personal quirk) or a very direct response of the whole drivetrain to any irregularities in the synchronisation or to mapping flaws. I find my older Guzzis to be operating smoother and I think a big part of this smootheness is induced by the heavy flywheels they have.

 

I remember to have once read that one of the biggest problems that Dr.John had with the Guzzi engineering in the beginning was caused by his insistence on a lighter flywheel for his early race engines. He needed the help of DeTomaso to get what he wanted.

 

If you're planning to use it for endurance races then take the clutch that lasts. If there are two good solutions, take the heavier one, or the one with the bigger momentum.

 

But I'm no racer, so it's just my

 

Hubert

[pete roper]

Two things here.

 

First to answer Graham's question.

 

While I believe that lightening the earlier flywheels is a great idea if you want a small amount of extra zip but a huge improvement in gearchanging by the time you get to one as light as the Sport1100/V11 unit it is my impression that it becomes a law of diminishing returns or at least that's the way it seems to us on our race bike. We had a really super-lightweight single plater in it until it wore the plate out and we have since gone back to the radically lightened unit pictured on the Guzzitech pages and to be honest Rob notices no difference.

 

If I was going to do anything I would slot the ring gear but probably leave the FW exactly as it is. YOMV.

 

On the second issue this is imply a heads-up to Luhbo on the heavier flywheel on a V11. I have NO experience of this mod, in a lot of ways I reckon it could be great fun BUT, here's always a but!

 

The V11 six speeder uses the same 'Stacked Washer' type of shock absorber spring as the later model Tonti's and earlier spineframes. When Guzzi went to this design the use of the stacked washers meant that the length of the splines on the face-cam section of the shaft was greatly reduced. If the six speeder is essentially the same as the later five speeds in this regard we in Oz have had several cases of these shorter splines getting beaten to bits in the high 70's low 80,000Km mark. I personally have not seen it but the problem was reported to me by Barry Jones of Italian Motorcycle Engineering in Melbourns and Barry is about as close to an unimpeachable source as you can get.

 

Taking into account the similarity of the designs and the spline depth and the fact that the only real difference is the size and effect of the flywheel I think that it is something worth taking into consideration before making the swap.

 

I am NOT, (before anyone jumps down my throat ) suggesting that it shouldn't be done, that it's a bad idea, that it will cause your bike to break or your underpants to burst into flame. All I'm doing is notifying people that on the newer, short spline boxes there have been some problems reported. OK.

 

Pete

[luhbo]

....All I'm doing is notifying people that on the newer, short spline boxes there have been some problems reported. OK.

 

Pete

 

Well, I have no idea how different the parts actually are. I just wish I could have installed an old clutch in my V11. I have a very early V7sport one laying around. That's a heavy piece! I thought maybe with some combination of new disks and the old metalparts it could work.

To be honest, I see no point to open my V11 just because of that idea. If I had it open, then probably.

 

Hubert

[Alex-Corsa]

Well, I have no idea how different the parts actually are. I just wish I could have installed an old clutch in my V11. I have a very early V7sport one laying around. That's a heavy piece! I thought maybe with some combination of new disks and the old metalparts it could work.

To be honest, I see no point to open my V11 just because of that idea. If I had it open, then probably.

 

Hubert

 

Speaking of clutch, I plan to have mine opened to change the clutch disks , any idea of what's the longer lasting ones?

Are these any better than the ''original' parts.?Seem to be in a nice price.