Ducati.ms - The Ultimate Ducati Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
1,210 Posts
Discussion Starter #1
Just looking around for belts for the ST2 and was wondering if anyone has used this make?

John
 

·
Registered
Joined
·
121 Posts
I used a pair on my ST4s and thought they were fine...
until I was riding back from seeing one of the last flights of the Vulcan and met a sudden loss of power and a horrible rattle which I immediately knew was the sound of valves hitting piston.
I had installed the belts myself, and it was my first service task with a Ducati. I might have missed something - I don't know, but everything seemed to be in place and functioning. After completing the task I did have a pause for thought about whether I had the tension setting correct on the horizontal belt, but failed to open it up again to check, so the failure could be down to my initial oversight followed by laziness and my keenness to ride.
Upon inspection the belt had split longitudinally and frayed, at the same time stripping some teeth. I am considering sending the belt back to Dayco for their own analysis (when I get round to it), but on the positive side the vertical cylinder belt is fine!
Dayco belts are used on a number of high end cars, and seem to be well regarded. I probably would give them another try.
If you are going to try them, you might want to try a seller called 'Busters'.
These are what I bought.
Engine - Busters motorcycle Accessories
Good price when compared with Ducati - who let's face it are unlikely to make their own belts.
I know someone will be tempted to chime in with smart remarks such as 'you get what you pay for', and 'Cheapskate' etc., but please keep these to yourself. I have presented this as my own honest experience in order to help others make an informed decision.
I'd be more interested in finding positive experiences of these belts, tbh, and whether others have had belt failure on any brand including originals.
Seasons greetings to all!
 

·
Registered
Joined
·
1,210 Posts
Discussion Starter #4
Thanks for taking the time to write a detailed review, I must admit I'm scared of using another make other than genuine. But saying that, who makes the belts for them? I change the belts every 2 years irrespective of the milage, which is usually well below the 12000 miles! I've heard enough stories of genuine belts snapping or stripping teeth on car belts over the years. I guess it's alot to do with conditions etc...

John
 

·
Registered
Joined
·
284 Posts
Belt tension

Just for the sake of knowing:

I got a M750 once and it was running fine, so I rode it for a month or better, rode it hard.
When I finally started to check things out,I found one bolt fell out of the tension adjusting arm, leaving the vertical belt with zero tension. It didn't break or cause any problems and I can't say how long it was like that.

Point is :how crazy is it to be super concerned with exact tension?
Mark

Just looking around for belts for the ST2 and was wondering if anyone has used this make?

John
 

·
Old Wizard
Joined
·
3,006 Posts
Point is :how crazy is it to be super concerned with exact tension?
GatesFacts Technical Information Library

TENSIONING SYNCHRONOUS BELTS

http://ww2.gates.com/IF/facts/documents/Gf000278.pdf

Proper installation tension is essential in any belt drive for optimum performance and reliability. Ideal tension is the lowest amount that properly seats the belt in the sprockets during maximum loading at all points around the drive. Optimum tension leads to maximum belt life and lowest bearing loads for a given application of power transmission.

Laboratory testing has shown that synchronous belts, like V-belts, operate ideally at approximately a 5:1 tension ratio (tight side to slack side tensions). The correct installation tension for a belt depends on drive geometry and loading. Procedures for calculating these tensions are relatively straight-forward and found in most belt manufacturers’ drive design manuals.

While over-tensioning a belt can impose higher bearing loads and lead to reduced belt life, under-tensioning can be just as detrimental to the life of the drive. When the belt is too loose, and inherent “self tensioning” characteristic results in belt teeth climbing out of the sprocket grooves, leading to increased stresses on the teeth, accelerated tooth wear, and reduced belt life.

In most cases, the entrance to the driven sprocket on the slack side of the drive is where the belt begins to ride out, if under-tensioned. Severe under-tensioning can lead to belt ratcheting or jumping of teeth. At that point, significant shaft separation forces are instantly developed in the drive, resulting in damage to bearings, shafts, other drive components, and the belt. Using ideal tension helps prevent excessive belt wear without over-stressing bearings and other drive components.
 

·
Registered
Joined
·
1,210 Posts
Discussion Starter #8
One of the reasons I've invested in a tension tool!
 

·
Registered
Joined
·
1,210 Posts
Discussion Starter #9
Well finally got around to removing the belts today, and they are Dayco belts! I changed the belts 2 years ago and never really noticed the make. They were good shape apart from the rear was abit slack.

I'm pretty happy to fit another set.
 

·
Registered
Joined
·
121 Posts
Well finally got around to removing the belts today, and they are Dayco belts! I changed the belts 2 years ago and never really noticed the make. They were good shape apart from the rear was abit slack.

I'm pretty happy to fit another set.
Thanks for the feedback on the Dayco belts - I blame the failure of mine on my inexperience on the service task. I'll go with them again, and this time make sure that I double check tension settings on both cylinders.

I also completely understand the argument presented for correct tension provided on the Gates site. For me, it makes absolute sense to follow the logic, and not doing so becomes a version of 'Russian Roulette'. Belt Roulette???
 

·
Registered
Joined
·
138 Posts
Are these dayco belts your planing to use actually made for the ducati ? Or are they generic belts for the Renault engines.
It's not an issue with the ST4 as no car belts cross reference to it, if you get the correct size!
 

·
Registered
Joined
·
1,210 Posts
Discussion Starter #13
I can just about see the part number on the belts, so will reference them later. The fact they are in good condition after 2 years is the selling point for me.
 

·
Registered
Joined
·
121 Posts
Hi Broadie,
I bought the belts from here:
Engine - Busters motorcycle Accessories
I got there via the search tool on the site. Now I look more closely, I see that the belts are describes as incorporating Fibreglass - and not Kevlar - could this be a problem?
mw0dbb, can you confirm that this is the same belt that's been on your bike? Thanks
I'm having second thoughts about this option now...
 

·
Registered
Joined
·
138 Posts
I think originally on the 916 ducati thought they could pretty much use car belts!
I remember going to the bol d or in 97 and seeing 3 guys that turned up in brand new Vauxhall Vectras ( hire cars ) dressed in leathers. First of all I thought they were Dave Van Browns mates:grin2:.
It turned out they all started out on Ducatis in the UK that had belt fails.
But that was nearly 20 years ago and all belts have moved on, we hope.:smile2:
 

·
Registered
Joined
·
1,210 Posts
Discussion Starter #17
070 SP 180 looks like the part number
 

·
Registered
Joined
·
138 Posts
Thats some price saving.
I'm sure Dayco do ducati specific belts, to manufactures specification.

Give dayco a shout and ask for a part number and recommended place to order. Preferably a place that has to order it in, personality I wouldn't want old stock!
 

·
Premium Member
Joined
·
1,198 Posts
Geezzz, at $20 each belt, it sure is inexpensive.

Profit can't explain the huge price differential.

The belt may work but may cut into the safety margin in the factory belts.

No thanks,

Bob
 

·
Registered
Joined
·
138 Posts
070 SP 180 looks like the part number
Dayco site comes up as a motorcycle belt only with no cross reference to Renault:wink2:
Condition looks really good I will certainly be considering these when the time comes.
 
1 - 20 of 21 Posts
Top