An interesting discussion and one I that I've enjoyed reading (even if I am in anorak mode for a while).

A question:

If someone has a big end failure and NEEDS to rebuild and finds the crank is scored:

Does this then mean that for DD racing (using our rules) it means a replacement crank straight away???

Also -
My basic impression of 'balancing' is that it matches components (or, yes - alters them) to reduce vibration and hence increase reliability....

But perhaps someone might like to explain further

Cheers - Frank

Then go through EVERY DD bike and make sure NOTHING on any of them is modified beyond your interpretation of the rules Kev. Thats the only fair thing to do...or adopt a common sense approach and accept that balancing does NOT involve modification or polishing or lightening, and neither does it give any performance advantage whatsoever.

Nog, how was your crank balanced?
If it involved removing material in any way then the rules say it's not allowed.
Factory tolerances? Was the item found to be outside these tolerances to start with? If not then your arguement for reliability falls down, it's good enough as it is and doesn't NEED balancing.

For what it's worth, (assuming material has been removed in order to balance it) I don't see what you've done is giving any noticable performance advantage, so personally wouldn't have a problem with it.
BUT... it's subjective to opinion isn't it? So what must be done is simply follow the rule book and not have an entrant try arguing that his/her opinion is of higher importance than the written rules we've all subscribed to.

Ok, that seems fair enough.....


...but now you rather shoot down your own argument. If it makes it smoother/more reliable then is that not giving you an advantage over someone who does not balance their crank?

too much sense in this post....


if its just had parts mixed and matched, but not modified and standard parts from standard ebngines, surely thats fine isnt it? only if its actually been changed to bring in to whatever tolarance and has it therefore been modified. Thats how I read and interprit the rules, seems simple?!?!

I'm obviosly missing something here

The rules clearly state that the Crankshft can not be modified and also state it must remain as originally produced by Ducati,

It does not say as designed by Ducati

If your Crankshaft has not been modified during the balancing procedure it is within the rules, if it has been machined (modified) to balance it then it is in breach of the rules.

I have no problem with people doing anything within the rules and don't care how much they pay to have it done providing they then don't bitch about the cost of racing.
But with the rules as they are which includes phrases such as No modification or must remain as originally produced by Ducati, there is only so much that can be done and that in itself helps stop costs spiralling out of control to the sort of levels seen in SoT racing.

Having a crankshaft machined to balance it is Modifying it to improve its performance, otherwise why would anybody bother or is what the Ducati Factory put out just cr4p

I agree balancing alone gives no real noticeable power or acceleration increase so why bother spending the money, breaking the rules and having it done. Over the years many have abided by these rules so why would we need to change them now

The point is the rules on crankshafts say No Modifications, yet you have your own interpretaion of the wording taking it to mean altering the balance of the crankshaft to meet a better spec than that delivered by Ducati.

Now if the rule included wording like that it would be taken by some as anything goes.
Finding suitable wording to allow a crankshaft to be balanced to a tighter factory toleance should't be to hard, but then it comes back to how to distinguish the difference between a crankshaft as supplied by the factory, one modified to balance it to meet a tighter factory tolerance and one that has been modified to give improved engine performance, without having to resort to full engine strips and crank removal for weighing something I would rather not see.

I started this post to gather views on what may well be a gray area as covered by the 3rd post on page 1.

and as this years rule book was ammended to try and clarify some issues and cut out gray areas this maybe one issue that slipped through the net.
I have said before if a rule can not be policed it has no value so either needs ammending or throwing out.

Now if a technical inspector could not tell if a crankshaft has been balanced by looking at it then the rule as it stands has little value.

This wasn't meant as a personal attack its just that your post stating that you had got your Crank balanced showed it was a subject that needs debating and a conclusion arrived at and I tend to gather as much information as possible to arrive at my own conclusions.
The thing is all evidence could point to leaving the rules as they are and altering a crankshaft to balance it be classed as a modification and deemed to be breaking the rules.
On the other hand it could point to the fact that unless someone states there crank is balanced by means of modifying it a technical inspector would never be able to tell (as weighing would only show a lightened crank) then the rule may have to be ammended.

My view is that if by looking at a crank you can tell it has been altered/modified even if only for balancing reasons then the current rules are good enough for policing the series, but if you cant tell by looking then ammend the rule.

Just have a random dyno check at 1 or 2 rounds next year. If anyone has an unlawful amount of power we can worry about how they got it then.

Just a note one of the most powerful 583 engines seen was a lump bought off ebay with no history at all, it was checked and put in the bike. The dyno centre said it was the most worn loosest engine they had seen with the most piston slap ever when cold :(, it went on to produce the most power they have ever seen from a 583 and more than one or two 620's, it wouldn't last half a season they said.....2 years later it was still going :)

So don't waste time/money with new components buy an old shitter and enjoy the power ;)

Thats pretty much the same story of my old 583, 52 BHP and it sounds like a bag of ****.

worked for me (well it worked, i didn't!) - just balancing the carbs and plastic welding a crack in the airbox gave me an extra 2 bhp :eek:

my bike had been stood outside for 7 years before i (or rather my kind local dealer) got their hands on it.