1100ds belt tension

[SpikeC]

 The engine is from a Multistrada 1100DS, and it lives in my Bimota. In September of 2013 I installed a set of Exactfit belts that Cal Cycleworks supplies. When I did the instal I checked the tension they had and used the same for the new ones. A few days ago I rented a harmonic do-hicky from Ducati tool rental. The device was rather difficult to get reading with, but I was able to get a reading of 110 hz give or take a couple. They felt quite tight compared to what I had set them at.
Then I looked up the specs in the factory shop manual and they spec the 1100s motor at 140hz. The book says to tighten used belts to 140 if they are down to 70, so there seems to be a pretty broad range.
Now my bike has an aluminum fuel tank, so engine noise is transmitted pretty well to the rider. after tensioning the belts to 110 there is quite a bit more engine noise coming up.
I am wondering what the experience has been for others with this motor. This one has a wet clutch so there is less background noise to mask other engine noises!

[oldndumb]

I could not get that particular tool to work with any degree of consistency, especially on the vertical cylinder. I used the Gates belt app on my Android. I have better luck with that than the guitar tuners.

https://play.google.com/store/apps/details?id=com.gates.carbondrivecalculator

[jduke]

The manual is probably wrong, I would go with California Cycleworks 110 hz.
Check them about in about 600 miles.

[memper]

Is it wise to adjust belt tension after they are warm or cold?

[oldndumb]

The manual is probably wrong, I would go with California Cycleworks 110 hz.
Check them about in about 600 miles.

Wot he said. ^

[ducpainter]

Is it wise to adjust belt tension after they are warm or cold?

Belt tension is set cold.

Wot he said. ^

Ditto...if you set them at 140 you'll destroy tensioner or idler bearings.

[SpikeC]

Well, I set them cold, at 110hz, according to the Ducatitool tool, and double checked with the Gates, and it showed 60hz which I know wasn't right as the belts seem quite tight.
The factory does specify 140 for this engine only.
The thing that concerns me is the increase in mechanical noise that I'm hearing.

[ducpainter]

Well, I set them cold, at 110hz, according to the Ducatitool tool, and double checked with the Gates, and it showed 60hz which I know wasn't right as the belts seem quite tight.
The factory does specify 140 for this engine only.
The thing that concerns me is the increase in mechanical noise that I'm hearing.

The factory changed the spec. 140 is wrong.

It's the bearings complaining. Check the bearings.

You should check the belts hot just to see how tight they really get. It's amazing how much the tension increases. You might be able to back off on the tension when cold to quiet things down.

[DarkMonster620]

Since your belts are now "used", set them between 100Hz~110Hz +-5Hz . . .This is from my OEM manual, updated Jan15 . . .for 2V engines, no matter displacement.

I had a screen shot of it, but, it was on the damaged laptop, sorry bout not having a pic

[SpikeC]

 Thanks for all the feedback, guys! Since the book says to tighten them up when they get down to 70hz a little loose does not seem to be a problem! Too bad that the unit that desmotool rents does not register that low. I think I had to get the belts up to nearly 100 to get it to register at all.

[ducpainter]

Since your belts are now "used", set them between 100Hz~110Hz +-5Hz . . .This is from my OEM manual, updated Jan15 . . .for 2V engines, no matter displacement.

I had a screen shot of it, but, it was on the damaged laptop, sorry bout not having a pic

They must want to sell tensioner bearings if they're using the same spec on all 2V motors.

[oldndumb]

Thanks for all the feedback, guys! Since the book says to tighten them up when they get down to 70hz a little loose does not seem to be a problem! Too bad that the unit that desmotool rents does not register that low. I think I had to get the belts up to nearly 100 to get it to register at all.

No indication that this is the case in your instance, but getting a reading can be a function of the "twang" technique. In my case, I can go through a series of no/low readings to the point of frustration, only to then find the correct technique and get repeatable readings without knowing what I had done differently.

I can't help but feel that measuring the roller gap is better than checking the frequency, unless you are using the factory tool.

[DarkMonster620]

They must want to sell tensioner bearings if they're using the same spec on all 2V motors.

according to them these new values DIMINISH the wear on said components . . .

[ducpainter]

according to them these new values DIMINISH the wear on said components . . .

You know how they lie.

According to them the belts on my old 900 should be the same frequency?

No indication that this is the case in your instance, but getting a reading can be a function of the "twang" technique. In my case, I can go through a series of no/low readings to the point of frustration, only to then find the correct technique and get repeatable readings without knowing what I had done differently.

I can't help but feel that measuring the roller gap is better than checking the frequency, unless you are using the factory tool.

The tool they use on the assembly line is optical and has a built in twanger

[oldndumb]

.....
The tool they use on the assembly line is optical and has a built in twanger

Yep, a Friggin Magic Twanger, better known as an FMT to be precise.  The dealers use a similar, if not the same, set up.

Which is why I have always been suspicious of audio tuners, but admire the fact that our belts persevere.....most of the time.