Belt tension

Started by ungeheuer, January 20, 2011, 01:20:05 AM

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ungeheuer

G'Day Ducatters  8)

My vertical timing belt is noticably less tight (cold) then my horizontal timing belt (cold). 

Normal or adjustment required?

Thanks in advance.
Ducati 1100S Monster Ducati 1260S Multistrada + Moto Guzzi Griso 1200SE


Previously: Ducati1200SMultistradaDucatiMonster696DucatiSD900MotoMorini31/2

Ddan

Some people adjust the vertical belt a little looser to account for the supposed higher head temps on that cylinder.  I don't know how noticeable the difference should be. Maybe check with your shop
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SDkid

Quote from: ungeheuer on January 20, 2011, 01:20:05 AM
G'Day Ducatters  8)

My vertical timing belt is noticably less tight (cold) then my horizontal timing belt (cold). 

Normal or adjustment required?

Thanks in advance.

my .02, they should be equal.  Trying to account for any temp difference might be tough.  If you haven't already, check out the quick overview at:
http://www.ca-cycleworks.com/videos/
He slides a 5mm hex between the pulley and the belt, and makes it so a 6mm won't fit.  On both belts.

ducpainter

Quote from: SDkid on January 22, 2011, 08:30:28 PM
my .02, they should be equal.  Trying to account for any temp difference might be tough.  If you haven't already, check out the quick overview at:
http://www.ca-cycleworks.com/videos/
He slides a 5mm hex between the pulley and the belt, and makes it so a 6mm won't fit.  On both belts.
I agree they should be equal, but you can't use the hex key method on the DS motors.
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
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ungeheuer

Thanks for the advice fellas  [thumbsup]

Raises a couple of questions....  5mm?... Seems like a lot...

Quote from: humorless dp on January 22, 2011, 08:35:48 PM.... you can't use the hex key method on the DS motors.
If its not a totally stupid question..... Why cant you?
Ducati 1100S Monster Ducati 1260S Multistrada + Moto Guzzi Griso 1200SE


Previously: Ducati1200SMultistradaDucatiMonster696DucatiSD900MotoMorini31/2

ducpainter

Quote from: ungeheuer on January 23, 2011, 03:27:18 AM
Thanks for the advice fellas  [thumbsup]

Raises a couple of questions....  5mm?... Seems like a lot...
If its not a totally stupid question..... Why cant you?
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.

The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



DucNaked

#7
Quote from: humorless dp on January 23, 2011, 05:35:43 AM
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.

The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.


What he said. You were paying attention in class.

5mm is way to loose on our engine do not use this spec.
"If your bike is quiter than mine your a pussy, if it's louder you're an asshole." Monster 1100S

ducpainter

Quote from: DucNaked on January 23, 2011, 08:52:26 AM
What he said. You were paying attention in class.

5mm is way to loose on our engine do not use this speck.
I was not...

I was sleeping. :P
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



SDkid

Quote from: humorless dp on January 23, 2011, 05:35:43 AM
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.

The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.


where could one (hopefully) borrow a sonic/optical tuner from?  That is my preferred method once I get to that job.  Also, you mentioned all the motors that the 5mm method wouldn't work on, when would it work?

ducpainter

Quote from: SDkid on January 23, 2011, 01:56:02 PM
where could one (hopefully) borrow a sonic/optical tuner from?  That is my preferred method once I get to that job.  Also, you mentioned all the motors that the 5mm method wouldn't work on, when would it work?
The commercial tools are pricey. I don't think a pro would lend one out.

You can use a guitar tuner that gives you the frequency. There are also downloadable programs you could use with a laptop. Do a search here on the forum. The problem is you can vary the results by how hard you 'pluck' the belt. That is where the twist check comes in and that involves some feel/experience. Like a chain, a bit loose is safer than too tight. Too loose and all bets are off. If you do a belt tension and all of a sudden your tensioner pulley or idler pulley bearings start screaming at you they're probably too tight. The original Ducati spec was too tight and those bearings were failing left and right.

The 5mm method works on all 2V belt motors except the ones I mentioned.

Those would be 400, 500, 600, 620, 650, 695, 750, 800, 900.
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



jwoconnor

Quote from: humorless dp on January 22, 2011, 08:35:48 PM
I agree they should be equal, but you can't use the hex key method on the DS motors.

I still use it as do others, 4mm allen.
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ducpainter

Quote from: jwoconnor on January 23, 2011, 09:44:10 PM
I still use it as do others, 4mm allen.
Not sure how much drag is on the 4mm hex, but I bet if you tested your work with a meter you'd find them pretty loose according to spec.

It's your bike. Do it how you want. [thumbsup]
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."



DucNaked

#13
Quote from: humorless dp on January 22, 2011, 08:35:48 PM
I agree they should be equal, but you can't use the hex key method on the DS motors.

The way I understood Ducvets demonstration on the dualsparks is that they are NOT equal. I had my hands on those belts after he sonically set the tension and vertical had less tension. On that cylinder a 2mm allen may have fit between the belt and pulley. The horizontal one I don't think a 1/2 mm would have fit.
"If your bike is quiter than mine your a pussy, if it's louder you're an asshole." Monster 1100S

ducpainter

Quote from: DucNaked on January 24, 2011, 04:34:19 AM
The way I understood Ducvets demonstration on the dualsparks is that they are NOT equal. I had my hands on those belts after he sonically set the tension and vertical had less tension. On that cylinder a 2mm allen may have fit between the belt and pulley. The horizontal one I don't think a 1/2 mm would have fit.

By equal I meant when adjusting you use either the same frequency or the same allen key to measure as opposed to intentionally leaving the vertical looser to account for increased expansion.

The actual tension is what it is.
"Once you accept that a child on the autistic spectrum experiences the world in
 a completely different way than you, you will be open to understand how that
 perspective
    is even more amazing than yours."
    To realize the value of nine  months:
    Ask a mother who gave birth to a stillborn.
"Don't piss off old people The older we get, the less 'Life in Prison' is a deterrent."