No Modifications - what does it mean
 

I have read recently on another website about a DD bike having its crankshaft balanced.

From previous experience of this type of work it usually include one of the following
Grinding Metal away
Drilling or Milling away metal
Weldiing to add metal

Now with the DD rules concerning Crankshafts having remained unchanged in this area since the very first set of rule for the 2005 Season V1.01 up to the latest set of rules, they have always stated NO MODIFICATIONS TO THE CRANKSHAFT ARE ALLOWED.

Current rule reads
1.6.21 Crankshaft
No modifications are allowed (including polishing and lightening).

So how the hell do you get them balanced, even by normal methods which would be in breach of the rules its about £160 to balance a Ducati Crankshaft

I thought we were trying to keep the racing cheap especially class B and as such we don't need costs like this creeping in, after all if you can't split and rebuild your engine yourself the overall bill is going to add up to quite a bit more than I have paid for a spare engine

Don't know how you would police that! as the cranks are balanced from the factory to a certain degree, I've not done anything below the barrels on my bikes but if I did I would certainly balance the crank! it would be daft to go to the expense of a rebuild without.

And there in lies the problem
Policing it. A standard factory crank may or may not be distinguishable from a balanced or modified crank, I may have to investigate futher to see just how distinguishable they are

It would be hard to tell a balanced crank from a slightly lightened one without stripping the crank from the engine and removing the rods etc and then weighing to see how it compares to a crank that hasn't been modified in anyway after leaving the factory and allowaning a small tolerance

Now if its easy to tell a unmodified crank from a modified one be it balanced or lightened, possibly by just removing the front cylinder and rotating the crank, policing it becomes easy
eg.
Unmodified = legal
modified = illegal
which makes the rule as it exists suitable for the series

If this rule has to be modified to allow for grinding, drilling or welding then it becomes very unclear where balancing a crankshaft then becomes a performance advantage by removing a little extra.

To date DD bikes have proved fairly reliable with very few blow ups and little debris being left on the track for others to hit.
So if the rule can't be policed then it becomes meaningless and may as well be dropped which then leaves the way open to those that want to push the limits of crankshaft reliability vs weight.

Is it a gray area or is no Mods Clear enough
personally I don't see the need to modify the crankshaft on a DD bike as they do come with a certain degree of balancing from the factory and like the rule in its current state, as it should make the series easier to police.

I have owned bikes even back in the 80's such as my CB900F taken out to 1065, Carillo rods, Drysump, lightened, balanced and knife-edged crank so do know why its done and the benifits to be gained against the reliability factor.
But I certainly don't want to see DD heading down this route.

I couldn't even tell you what a crankshaft looked like, let alone the benefits of balancing or lightening it :confused:

Mine is balanced.... On the paint tins in the garage, Reminds me I really should start my prep...

Differences in crankshaft weight, which as Chaz says have been factory balanced are normal so not a discriminant.

And, lets put that somebody protests you because thinks you have your crank balanced: pays 250 to strip the engine, balancing would be undetectable unless a reputable qualified Ducati engineer ceritifies the modification, and you will be left with an engine in pieces which will cost 500 pounds to reassemble. It will be cheaper to pay the 150 fee..

Moreover, lets put the case somebody has to change one or two pistons in a 583, which currently are out of production, he/she will be forced to use non OEM pistons which again is against the rules.
Curently the only OEM pistons available from Ducati dealers come with barrels at ~600pounds/pair....cheap
Replacing the pistons with used standard will need re-balancing for a good result and increased engine reliability. However I am not technician and I don't pretend to be. I agree with Chaz though.

Why not limit the rules' policing within weight/bhp?

We are back to the subject of second hand bikes! I know for a fact that engines have been stripped by the likes of JHP/Louigi Moto & found to be illegal & the present owner had no idea! so you buy a bike in good faith what do you do? pay out a load of cash to have it checked! or trust the honesty of the seller?
There are quite a lot of bikes out there that have changed hands.

Yet you can buy a standard 583cc engine from a breakers for £250 stick new belts on it, give it a oil and filter change Put it in a chassis and then stick it on the podium.

So why spend so much money on all these engine rebuilds, new pistons etc.
I've see engine bills from £900 to £1350 for rebuilds without any crankshaft balancing and if you really think the balancing is going to improve your results, I doubt it.
Where as a bit of lightening for quicker acceleration (still the same bhp and weight, bit like fitting a lightweight flywheel) may help with the results as that would be cheating and I along with others would rather not have cheating going on in DD.

Now if the easy way to police it is to ban Cranksharft modifications of any sort then I'm all for it and thats how the rules have been for the last 4 seasons.
Currently modifying the crankshaft in any way is breaking the rules, is that rule not Clear enough.

Saying it is better for the bike to have the crank balanced isn't much different from saying its better for the bike to run Ohlins forks, Mag wheels or Diablo Corsas and just ignore the rules so long as it meets the BHP and weight limits.
Or is it the risk of getting caught out that determines what rules people follow and which they choose to ignore.

Here is a bit from the Sigma Performance website, they are on about the 944cc Monster but I bet the same applies to the 600

" it would be nice to rebalance the crankshaft to make sure the engine is smooth…….experience has taught us however that the 900 twin is quite resilient in terms of crankshaft balance (an alternative explanation is that its not very sophisticated engine as standard and a mere 75gram change in piston weight isn't going to make a big difference!!)."

I agree with you about getting motors from a breaker that is what I would do, not to many 620/6speed around though & later 583's are getting harder to find.

..as if I have not looked for one...No chance. Let me know if you find one please.

because the front piston is grooved and I cannot find a replacement. A dealer
has a HC pistons but no OEM which are unavailable even in Bologna unless you buy the barrel.

I am not looking for increased performance, just peace of mind that my engine will not blow up. There is no point in giving out obviously not pertinent comment on forks and tyres.

Thanks

The only way you can get round it is to have a large selection of pistons and rods available and to balance the whole reciprocating mass (ie crank, piston and rods) by substituting different standard OEM parts.

So once again, if you have the money and/or can go to the specialists you can get a better(?) motor than taking pot luck on what the factory puts together.

Although, from a purely hypothetical stance for a racebike I wouldn't see the point in balancing a crankshaft without lightening it as well, and then you may as well go the whole hog and use a lighter flywheel and flow the heads too...:devil:

Who's website was it? I've checked mine for typos! :lol:

Alesandro,

I have confirmed this afternoon that the pistons are available from the factory, please contact Ducati Coventry and they will sort you out.

Ultimately the rules have been the same on balancing (that it is not allowed) since the start of the series and from memory we have only had one motor blow up (Ali's fire in year 1). To a certain extent balancing, expecially on the Class B engines is not worth the expense as they do not rev that high anyway and are somewhat overengineered for 52bhp.

Chris

What markings are on your piston, I have 2 used ones that are still very useable, Yours for now't if they are the correct ones.
Glyn

No Chis,
pistons for 583 are not available anywhere unless you buy the barrels and cost in excess of 350 pounds a piece. Baines has suggested to arrange production of 80mm pistons for 583 for DD which can be doen for appox. 70 pounds/piece but they won't be OEM...

Thanks a lot Glyn,
What do you mean by markings? I know that the brand is MP but if you have 2 of the same brand available it won't matter. My front piston is grooved unfortunately...

Matt & I have spoken, well argued:rolleyes: about this, what is the factory tolerence on wheight, is it "A" - x and + X if so, then that could solve the argument and the rules could be changed to allow balancing (only) of the crank, but not polishing or knife edging but stay with in the wheight tolerences of the factory original specification.


Chris:burn:

They have an A or B stamped on the top of the piston usually That is matched to an a or b on the Barrels.
Will check what I have and let you know
Glyn

Picked up a 8500 mile late 583cc Monster engine in October off Ebay for less than £300, then picked up a similar engine on New Years day for less and the guy had older 583 engines sat on his garage floor,
I'll dig the contact details out

The 1998 Monster engine in Dallas's 583 cost me £250 and without any carb work, cam timing or a like, just belts and oil/filter he was able to run at the front with Harriet at Cadwell.

The PB bike that Luke rode to a podium at Mallory had a bog stock engine, again not even a Dynojet kit and I doubt if the engine had been apart since it had left the factory in 1995.

As Paynep (humouros post Paul) well knows spending your money on track time can reap better rewards than spending it on the bike
ask yourself could another rider get your bike around the track quicker than you, if the answer is Yes, work on the riding not the bike

The problem isn't with balancing as I believe there is little to be gained for the cost involved, its the modification.
As there are two types of Crankshaft
1, unmodified
2, modified
the second group can include lightened, knife-edged, stroked and balanced, so for policing reasons Unmodified is the way to go

Chris it would not be easy to police, as I have already mentioned doing it on weight would require the crank to be fully stripped from the bike and then weighed on accurate scales and compare to a verified factory figure with a +/- tolerance.

and as the RC don't have to stump up any protest money (see extract from rule 2.1.1 below) is it worth the risk/cost of having a bike that is thought not to comply with the rules

2.1.1 Compliance Control
are placed in a parc-fermé for a period of at least 30 minutes.

Any motorcycle can be checked for compliance with these rules, and any other technical requirement, if requested by a representative of the DSC Race Committee.

The DSC Race Committee may require a rider or team to provide such parts or samples as they deem necessary without the need to resort to the ACU protest procedure.


At no point do you have to ask your engine builder to balance the crankshaft and they can't make you do it, the rules clearly say No Modifications, its the same rule for everybody.

I think Skids is referring to my post on Ducatisti, in my 09 prep thread, where I stated that my crank was ready to pick up after balancing. The crank and all associated parts are made with certain tolerances. When you hand the entire mass over for balancing ( crank, rods, pistons, gudgeon pins, circlips ) all thats done is to make sure that WITHIN THE FACTORY TOLERANCES the crank is not running out of balance. What I have had done is nothing to do with performance enhancement, just to try to ensure the engine doesnt fly apart. NOTHING has been lightened outside tolerances, NOTHING has been polished, its just been PUT TOGETHER PROPERLY, no more no less. Its a bog std 583 crank, with bog std 583 rods, and bog std 583 pistons, and bog std 583 gudgeon pins, and bog std everything. I have several engines and have mixed and matched parts.....so balancing is then an absolute necessity imho. NOT lightening or polishing, BALANCING. Its NOT been modified in any way shape or form, nor even has it been lightened to get to minimum factory weight, just put together to run evenly, bearing in mind it was an engine that I had bought that had been sat in a wet shed for a year, it all HAD to come apart as all the bearings needed renewing. No modifications could go so far as meaning using std gaskets instead of 3 bond for instance, or not shimming the crank to take into account the lack of gaskets today. the rules also state :
Wheels including diameter and rim width must remain as originally produced by Ducati since 1992 for the 600/620 bikes.
Front wheel 17” X 3.5”, Rear Wheel 17” X 4.5
but we all know 748/916 wheels are used......I think some common sense needs to prevail here.

According to the rules it's illegal then;)

There you go Matt, I think I win;) :D


Chris:burn:

But that is cheating then, you would be well within your rights to protest those that run 916 type wheels and your protest would be upheld.

Or are you saying its OK to cheat because others have done it?

Not at all Tim, cheating should not be allowed. My understanding of the rules is that no mods are allowed to the crank, and as far as I can see balancing a crank is merely good practice, not cheating in anyway, as I have already said, it is absolutely bog standard in everyway, with no performance enhancement inferred or gained from just putting the thing together properly. I handed them a crank, 3 sets of rods and pistons and gudgeon pins, circlips piston rings etc and told them to balance the thing.

i am so glad we dont do this any more.
have a nice day everybody, as we do now :) :) :)

sorry if you think i am taking the pi55 but this is something i realy dont miss :smug:

just goes to show you have to be careful what you say as blueprinting means putting the engine together properly as not many factory engines are put together to within close tolerance.
What nogaro has done is the right thing for the engine as in putting it together properly which some people call blueprinting.

im going to butt out now as my 6pworth is just spent.

No issues with the crank - but it sounds like Class B is the new Class A with a selection of engine parts available to create the best engine - nice work. ;)

Part of the challenge and enjoyment for me of DD was creating and building a bike that was within the rules, but took advantage of any available advantages that could be had by applying the rules. Sounds like you've done that with the crank, by using OEM parts that best match (without any machining) to run as efficiently as possible.

My point was about the wheels, if riders are cheating (knowingly or otherwise) by using illegal wheels then they should be protested, or better still, a quiet word should be had with them to point out that they are outside of the rules if they don't run a 583 or 620 OEM wheels. Then they avoid getting protested (and paying out £s) and also avoid getting black-balled by the rest of the paddock.

Maybe its time to plan and run an early "this is what you can do to a DD bike and this is what you can't" session.

Or maybe as part of a FAQ list in the DD section?

Tim

Get out of it, this is why you still read the DD section !!!! ;)

Anyway, its bloody freezing outside, we can't ride our bikes and the season is months away, what else can we do??? :eek:

And its a laugh.

ok... two questions..

how can you tell the difference in the wheels - is it obvious for numpties lke me?

second - I assume the wheel I got from you was kosher :D

I think its more of a 583 thing? But could be wrong. As the earlier wheels were a lot heavier than the later 620 Monster and Sport ones. I only ran 620 wheels on my 620 ( I don't know if the 916 type are any lighter than these anyway) - so the one I sold you is fine as its an original 620 wheel.

a month away tim just a month
and yes, i like to delve in here on occasions not to remind me of the politics and borrocks that i dont miss any more, but to enjoy the banter with the dd people still.
after all if it wasnt for dd then we wouldnt be doing what we do now in running in a great club which has televised racing all season :p

As far as I am concerned I have no truck with cheating. As far as I am aware I have neither broken nor infringed any rules, neither have I gone against the spirit of DesmoDue. To harp on about keeping costs down is just nonsensical when you permit the use of plenty of non standard parts. EVERYTHING in my engine is standard, and within factory tolerance, as it was last year and will be next year. What I have had done is good assembly practice, no more no less.

I know what you mean Alan, SoT rules were always quite easy to comply with but then again it was far more costl than DD.
What rules a series does have need to be clear, for that to happen we need to close out gray areas

As for blue printing there is the large factory way or the small team way.

Large factory, take 1000 of each component and find a pair that best meets the design spec and use them, no modification required

Small team way, take the pair of items that you have in your engine and modify one so that it matches the other.

Now if you go some where in between and start with several items and get them matched up as best as possible without modification then thats fine by DD rules but if modifications are carried out then rules are being broken.

What would be next porting/flowing heads so that both heads flow exactly the same, anybody got the factory figure for the CFM of a 620 cylinder head, I know the rules say no material can be added or removed but surely its just good practice and therefore I should be allowed to do it :p

A month? Is there a class for these? ;)

That's what I understand. It's like putting balancing weights to the wheels then :)

Very good analogy Alex, you are adding material there but it gives no performance advantage, just makes the wheel run correctly.

PMSL :lol: :lol:


Chris:burn:

Quite right re the last sentence

For example the same front wheel (501.2.069.1AB) is fitted to both MY03 620 and 750 Monsters.
So if I took a front wheel off a 750Monster from another year and used it, would it be illegal?

Mind you, my bike has a 900ss frame, Mhe900e forks, a 750ss rear wheel and an ST2 front wheel so I might as well be banned now and save on all the race entries...:lol:

Stick bit's of lead on the crank:eek:

count me in.. i can crash them just as well as a DD bike :D

Say no more He that should be obayed has spoken;).