Timing belts on the ST4S every 2 yrs or ooo miles ?
 

Hello all , I’m a new member so know that A my typing is slow B my knowledge is limited !!

That said , I just bought my first Duke in 30 + - yrs and I’m asking do the belts need changing every 2 yrs or is the mileage since last changed most significant ?:) :up: :down: . The machine in question is a 51 plate ST4S with 52000 on the clock ...

Belts are very subjective...

We all know that they should be changed because a failed belt can cause catastrophic failure.

However...

Belts can fail before a two year time and/or mileage limit if they are badly adjusted or if you are unlucky enough to suck up some road debris.

The point is that looking after your belts frequently is better than sticking to a rigid time/mileage schedule. Sometimes you can let your belts stay for another year (or more!) if you regularly have the bike running to stop the belts spending too long in one position, and they are checked for wear/cracks/splits, as well as being adjusted properly.

Getting into the habit of checking your belts regularly means that you will spot any issues before they happen. There's also the bearings on the guides and adjusters to take into account too!

The belts are now quoted at 5 years or 15,000 miles for the newer Scrambler models, because materials have improved!

So, as a rule you *should* change them every 2 years or 10,000 miles but as you get comfortable with the bike you may want to adjust that yourself.

As for the type of belts, yes you can get them cheaper (Dayco or whatever) but there's very little price difference between these and OEM Ducati, and if you join the Club you will receive discounts at the dealer so this makes it even less of a difference.

I notice you said materials have improved for the newer models, is that not the same for my model ? Is it the materials that changed or the engine design ?

Belt materials have improved and will have been incorporated into all belts, so yes yours will be better (stronger, last longer, better construction, etc) than they would have been 20 years ago.

The design of the newer engines hasn't changed that much, but it will have been engineered (design and materials) for an extended life on the belts.

Ive been checking on eBay and there is a huge difference in prices , I’ve seen Dayco for as little as 25 quid and others for as much as 130 , is there really that much difference in quality? What experiences have people had of different belt specifically any problems with Dayco , or others ?

Ive just realised some have the bearings too , I don’t believe the bearings will need replacing but should I do it anyway . Bearing (no pun ) in mind its only been 1000 to 1500 since last belt change ? All advice appreciated ...

There's a thread here about Dayco vs Gates (Ducati OEM) belts...
https://www.ducatisportingclub.com/s...ad.php?t=83685

Another question if you please about the ST4 S , re the tensioner bearings , does anyone know the part no , are all 4 bearings the same or have different parts no’s ? Or where can I find out the no’s ??

Later bikes have larger diameter pullies to help with belt life, 749/999 on I beleive.