2V belt tension question (!!)

[scott_araujo]

Said already, but yes, they will loosen up after a few miles.  I check mine every few hundred miles until they settle in.

Since I'm sure plenty of people never check them after install at the dealer I'm guessing you can run them fairly loose with not ill effects.  Haven't heard any stories here of a belt jumping a tooth after replacement.  Still, you'd think Ducati would  say to take a look at the tension after a few hundred miles.

Scott

[bigiain]

Still, you'd think Ducati would  say to take a look at the tension after a few hundred miles.

What, and screw with their "half the service costs" advertising campaign? 

big

[brad black]

yeah.

here's the bill for your 20,000km service and you HAVE to bring it back in 1,000km for us to retension the belts. 

at your cost.

what's that you say, another lost customer?

ime, most ducati owners are too governed by cost and the expectation of being ripped off to even contemplate something like this as worthwhile.  they won't be listening as you tell them, they'll just hear another reason why they have to give us money, even if we do say it's good for their bike.

and, after all, no one else does it.  and they must be right.  it's on the internet.

[ellingly]

yeah.

here's the bill for your 20,000km service and you HAVE to bring it back in 1,000km for us to retension the belts. 

at your cost.

what's that you say, another lost customer?

ime, most ducati owners are too governed by cost and the expectation of being ripped off to even contemplate something like this as worthwhile.  they won't be listening as you tell them, they'll just hear another reason why they have to give us money, even if we do say it's good for their bike.

and, after all, no one else does it.  and they must be right.  it's on the internet.

If they sneakily managed to chuck 30 minutes of extra labour onto the original price to the 20k service and said "bring it in in about 1500 km / 1000 miles, and we'll do a free retesnion of the timing belts just to make extra sure they're all happy" then I would be more forgiving. Perhaps even more forgiving if they just ensured their inflated labour rates covered the cost of doing it anyway .

It is also an excuse to get someone in and go "hey, look, we got that new model, perhaps you'd like to purchase said new motorcycle from us".

Put it another way: if I highly trusted the mechanics, being asked to bring it back in? No worries. I've done it before with my cars. In the case of where I had a timing belt done on a car (which is also italian and has non-self adjusting tensioners), the mechanic said bring it it, it'll take an hour, go sit up in the lunch room and have a beer. Not bad, not bad at all.

Brad: on the trust thing... I have reasons not to trust some mechanics. I should have made a trip to Melbourne and get you to do the 20k service. Go hit the spurs for two days, then come back and get you to retension? . Guess I'd want to do it midweek, cause as far as I understand the spurs have a few too many cops on them during the weekends these days.

I'm happy to pay good money for good quality service, but it just seems that's very, very hard to get.

[scott_araujo]

All of this is just one more reason to learn to do your own routine maintenance.  Belt replacement and valve adjustment can be a little daunting but setting tension isn't hard, esp on a 2V.  Checking tension is even easier.  Just my 2 cents.

Scott

[nomadwarmachine]

Does anybody have a frequency spec for the horizontal and vertical belt tension frequency at TDC on a 2000 M900?

Also, I have a Mac and am looking for a good program to provide the frequency measurement. Do I use Audacity? Do I need a microphone? 

Thanks!

[AndrewNS]

I've never tried the audio method (and I'm certainly not an expert at anything Ducati), but it seems to me that if you are going to do it this way that it would be important to rotate the crank between measurements to make sure the valve gear is in the same state each time. Is this correct? Just lining up the crank marks for TDC would release the closer spring forces on the horizontal cylinder, but they would still be there on the vertical cylinder, and that would have to give a different frequency reading, wouldn't it?

Also, I read somewhere that it was recommended to use 4/5 mm go/no go allen key test with the 1000DS engines. That would make the belts just slightly tighter than you'd get with the standard 5mm test. I did it this way the last time I adjusted my belts and nothing has broken yet, but I'm curious as to whether I'm out to lunch or not. Anyone know what  those frequencies would test to using the audio method?

   

[Howie]

Do what everyone else has been doing for years, 5 mm allen key.

[woodyracing]

I've never tried the audio method (and I'm certainly not an expert at anything Ducati), but it seems to me that if you are going to do it this way that it would be important to rotate the crank between measurements to make sure the valve gear is in the same state each time. Is this correct? Just lining up the crank marks for TDC would release the closer spring forces on the horizontal cylinder, but they would still be there on the vertical cylinder, and that would have to give a different frequency reading, wouldn't it?

Also, I read somewhere that it was recommended to use 4/5 mm go/no go allen key test with the 1000DS engines. That would make the belts just slightly tighter than you'd get with the standard 5mm test. I did it this way the last time I adjusted my belts and nothing has broken yet, but I'm curious as to whether I'm out to lunch or not. Anyone know what  those frequencies would test to using the audio method?

   

your supposed to lock the cams and crankshaft in place using the Ducati tools and on most bikes you loosen the 3 bolts on each cam gear to allow movement without changing cam timing so that when you tension the belts it tensions the belt all the way around

ALSO 130+Hz is NOT the Ducati spec for belt tension!  That spec was intended for degreeing the cams instead of clarifying it in the manuals Ducati sends out a service bulletin to the dealers (often) reminding us that all bikes are to be set at 110Hz for new belts and 90-100Hz for used belts. 

[Langanobob]

your supposed to lock the cams and crankshaft in place using the Ducati tools and on most bikes you loosen the 3 bolts on each cam gear to allow movement without changing cam timing...

Could be that my creative visualization technique is off this morning but it seems to me that loosening the three bolts and allowing relative movement between the cams and the cam gears is gonna change your cam timing. 

Edit:  OK, I think I see now, after adjusting the belt tension with loose bolts, you have to go back and reset the cam timing.

[EEL]

Personally, for all the non DS motors I've tensioned, I've always used 5mm on the horizontal and 5.5 mm on the vertical. I havent had any issues for the 35k miles I've had on my monsters. I probably should go back and retension them after 1k but I'm too lazy and never get to it.

That being said, when I do take them off, the tension seems to be Ok..

If you tension them too tight you'll have bearing failures on the rollers.

[nomadwarmachine]

How tight should the Allen key fit between the belt and roller? Should I not be able to get the next size in there?

[scott_araujo]

There should be some resistance.  I like to be able to slide it through from one side to the other without significant force.  You certainly shouldn't be grunting, holding your breath, or wrestling the key with two hands.  Getting the next 1mm+ size through should be very difficult comparatively but it's not impossible.

And remember, a little too loose is better than a little too tight.

Scott

[BK_856er]

How tight should the Allen key fit between the belt and roller? Should I not be able to get the next size in there?

I struggled with the same question.  Take a look at the belt change video Chris K. made for a good perspective on it.

I should update this old thread with a link to the more recent thread where the current recommended belt frequencies were confirmed....

GOOD STUFF -->  http://ducatimonsterforum.org/index.php?topic=18964.0

BK

[woodyracing]

Could be that my creative visualization technique is off this morning but it seems to me that loosening the three bolts and allowing relative movement between the cams and the cam gears is gonna change your cam timing. 

think about it a second.  Cams locked in place, crankshaft locked in place.  Those locks don't come off until the belts are installed and tensioned.  You have a tensioned belt and where exactly are the camshafts and crankshaft?
in the EXACT same position in perfect time (as perfect as you can get without degreeing the cams at least)