Belt tension S2R 800 definitive?

[Bigxr]

Hi,
Regarding the belt tension on my Monster (S2R800) I am a little confused. :worried:
I am going to change the belts soon, they are sat on the bench poised for installation, but I have conflicting advice on the correct tension.
Specifically, I have no less than FOUR separate bits of advice for the same thing.
1) 160hz/145hz (Downloaded Ducati S2R 800 manual).
2) 110hz/110hz (forum gossip)
3) 5mm go / 6mm no go Horizontal cylinder, 6mm go /7mm no go vertical cylinder (you tube ducati service)
4) 5mm go / 6mm no go for both cylinders (you tube Ducati service)
Now. The forum gossip has mentioned that the original 145hz/160hz resulted in siezed tension rollers hence recommendations for setting both to 110hz.
The Old method (allen keys) seems to have been used for years, and one method differentiates between the Horizontal (cooler) and hotter vertical cylinder. Which is right?
Do I download a tuner program or app and trust that it's accurate enough?

Can anyone shed some light on the situation and confirm the definitive method???????????

:confused:

[Flip]

Just to add to your dilemma- for the last eleven or so years of owning my old 900 I've used a spring balance to set the the belt tension as per the factory manual.

Haynes manuals quote a similar way of setting them along with the 'twist' test.

[Bigxr]

Thanks Flip, it obviously works for you, but I've yet to come across a spring tension specification for the S2R, I guess the guage would also have to be accurately placed to be consistent. Would the 900 spec be different from mine?
As for the twist method, I'm more than a little cautious about that as my mate did the Optic 2000 rally on a rotax engined CCM. He set the belt tension using the rotax's method of the twist, (45 degrees I think) and had a tensioner collapse in the middle of the Tunisian desert. Took them all day to find him, by which time he was well out of water and a getting little concerned! He's not a bad engineer, its just that I think some methods can leave too much room for interpretation.
I'm more confused now! :-{

[dunlop0_1]

5mm H & 6mm V allen key method works a treat. :mand:

[gary tompkins]

Just to add to your dilemma- for the last eleven or so years of owning my old 900 I've used a spring balance to set the the belt tension as per the factory manual.

Haynes manuals quote a similar way of setting them along with the 'twist' test.

Same here for over 12 years of monster ownership on 3 different bikes

[Zimbo]

I've always used the 5mm and 6mm allen keys on all my air-cooled Ducatis - 600, 750, 800 and 900cc engines.

[zhango]

The forum gossip 2) is the nearest - the Ducati Manual is wrong and here is the wording of a Service Bulletin to correct it. I've got a M1000 and have put two sets of belts on using the 45 deg twist method - it's done about 30k miles ok. The tension is not that critical although can be too tight or too loose. The 160Hz in the manual would be too tight and give the bearings a problem.

Sonic Belt Tension - Ducati update
The following service bulletin has been issued by Ducati North America. Note that the specs are now the same for all models 2V and 4V. There are a few omissions from the list - 748 and ST4s, but I would think that's just an oversight.

All previous and new model Ducatis requiring belt tensioning now will be standardized to the below specifications.

IMPORTANT: When checking and adjusting timing belt tension at the recommended scheduled maintenance intervals, if tension reading is less than 70 Hz (minimum allowed value on all Ducati motorcycles), reset belt tension as follows:

Refer to the appropriate shop manuals for cam timing procedure and belt tension setup, then reset to the below tensions for service.

Model
Belt tension spec for new belts upon replacement
Belt tension adjustment settings for used belts when inspected value is determined to be 70 Hz or less

All models:
Streetfighter, 1198, 1098, 1098R 999, 998, 996, 916, 848, 749, M1100, MS4, MS4R, MS4RS, ST4, SC, ST3, ST2, SS1000 HYM 1100, MTS 1100,MTS 1000, MS2R 1000, M696, MS2R 800, M620, M400, M695, SS800, MTS 620

New Belts:
110 Hz +/- 5, Horizontal and Vertical *

Used Belts:
90-100 Hz +/- 5, Horizontal and Vertical *

* Please note, these values may be inaccurate on previous Ducati Technical Data posters and service manuals. Data listed above should be considered the new standard and supersedes all previous bulletins and documentation. Please print and post this bulletin to be displayed with the most current Ducati service poster.

Sincerely,

Ducati North America
Service Department

[dunlop0_1]

American's :chuckle:

[Bigxr]

Thanks Zhango, I think a consensus is emerging...
As I don't have access to information regarding a spring guage, that method is out.
As I don't trust the twist method (a strong person will get 45 deg where a weak person wouldnt be able to move it) that method is out.
I haven't access to a decent sonic frequency counter, and the use of a mobile phone or a laptop with some downoaded program sounds too prone to improper use or inaccuracy with a big question over calibration, so that method is out.
Therefore I'll go with the allen key method and take Zambo's and others advice with the 5mm H and 6mm V measurement.

:idea: (has anyone ever measured the sonic frequency after setting with an allen key?) :idea:

[zhango]

Fair enough but if you look at the Service Bulletin it gives the same tension for H and V. The 5mm and 6mm Allen key method will give belts that are loose but also the Service Bulletin refers to adjusting used belts which give a frequency of 70Hz or less and that really is loose but the engine had been running like that until the service so are obviously ok. The assumption must be that if the frequency is 71Hz then don't adjust them?
The Allen key method cannot be called 'wrong' as many guys have used it for years - it just will not give the ideal tension.

[utopia]

How critical is the belt tension anyway....?
Ok, I accept that too tight could cause extra stress on the tensioner roller etc, and too loose may cause accelerated belt wear or even cause the belts to jump teeth, but surely there must be a pretty wide tolerance between these two extremes.
I can't see that belt tension would affect valve timing or engine performance to any significant extent.
So why all the complicated methods ?
Is it perhaps just that the use of a factory-specified gizmo leads to a more reliably consistent result, eliminating any variations that may otherwise occur between different mechanics when performing an adjustment that relies on a bit of interpretation or "feel" ?

Personally (and I've only done mine twice, so I'm no expert) I use the allen key method, but I also give the belts a twist, and generally tug them around until I've got a good feel for the tension from a number of different perspectives.
I also recheck them after a couple of hundred miles.

And .......why allen keys anyway ? Surely a short piece of round (rather than hexagonal) bar would be a more suitable gauge.....??

[Bigxr]

How critical is the belt tension anyway....?
Ok, I accept that too tight could cause extra stress on the tensioner roller etc, and too loose may cause accelerated belt wear or even cause the belts to jump teeth, but surely there must be a pretty wide tolerance between these two extremes.
I can't see that belt tension would affect valve timing or engine performance to any significant extent.
So why all the complicated methods ?
Is it perhaps just that the use of a factory-specified gizmo leads to a more reliably consistent result, eliminating any variations that may otherwise occur between different mechanics when performing an adjustment that relies on a bit of interpretation or "feel" ?

Personally (and I've only done mine twice, so I'm no expert) I use the allen key method, but I also give the belts a twist, and generally tug them around until I've got a good feel for the tension from a number of different perspectives.
I also recheck them after a couple of hundred miles.

And .......why allen keys anyway ? Surely a short piece of round (rather than hexagonal) bar would be a more suitable gauge.....??


Excellent point, I've been changing and tensioning industrial kevlar belts on printing machines for 20 odd years - without a written tension spec. other than "not too loose and not too tight" and anyway most car belts which on the face of it do more work, last donkeys years longer, and are tensioned with guesswork see the 60,000 mile interval with no time limit.
I had a Pantah for three years without changing the belts, and it was laid up in a shed for two years before I bought it and the previous owner hadn't changed them from new. As far as I know it could still be on the standard belts.. :rolleyes: hmmmmm my pantahhhh - drifts off into a trance.....what a bike....

Could this fear about Ducati's shredding belts if you dont change them every two years and tension them with a harmonic sonic screwdriver lithium crystal tricorder just paranoid mythology? :look:
I saw a photo of an old removed set 2 yrs old and a new set side by side, and apart from a little fading of the print the condition of the old belts looked fine to me. The caption said "the old belts looked like they were ready to be changed" -- Not to me they didn't!

I'll use an allen key as its a nice simple, mechanical well used method. (I don't have a 5mm and 6mm metal bar handy, or it'd do just as well)

[gary tompkins]

The setting tension on the rollers as quoted by Haynes is 10lb

I use a fishing spring balance that reads up to about 30lb to set mine.. or the twist method

[FRASER24]

I've always used the 5mm and 6mm allen keys on all my air-cooled Ducatis - 600, 750, 800 and 900cc engines.
+1
10 years and approx 70k miles of air cooled Ducatis, always used the method above and never had a problem.