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Discussion Starter #1
I just picked up a 2000 ST4 about a month ago. I've been riding bikes for almost 18 years now, but this is my first Duc. It has 22,000 miles on it and it came with a stack of maintenance and repair receipts. I mean this guy did everything, he even put a new clutch in it at 17,000 miles already! But here's the thing, there's no mention anywhere of new timing belts. I can tell somebody's had the covers off at one point because the bolts that hold it on are a little chewed up, but I don't know if that was for new belts or what.

Here's my question: The book says to change them at 12,000 miles. I called the Ducati stealership and they said they do them between 6,000 and 10,000 miles. I work in the automotive industry, and yes I know there's a huge difference between a car and a bike, but most cars reccommend timing belts at 100,000 miles or more. I had an old VW Jetta back when I was a kid and it went 15+ years and over 150,000 miles before the original timing belt broke on me one day while I was driving. My point is, do these bikes REALLY need timing belts after only 12,000 miles? I'm not trying to "cheap out" here and look for an excuse not to do it, but for those of you who have changed yours, what kind of wear are you seeing on them? Are the teeth breaking off or the egdes fraying at all? Is the back of the belts getting glazed over? Are you seeing any cracking in the belts? I have the mechanical know-how to do them myself, problem is I don't have a garage and/or the time to do it. The stealership wants $200 labor plus the cost of the belts and I'm sorry but there is no way on God's green earth I'm paying that.

So what's the verdict? How far are the rest of you pushing your belts before you replace them, and what kind of wear are you seeing on them when you do? Thanks, and keep the shiny side up!
 

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2 years or 12,000 miles, whichever comes first is the general rule. It's cheap insurance against costly engine repairs, so why push it?
 

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Crunchy, do it yourself and save the dough:D

A guy up here on one of the Canadian sites just paid.......$1500 for a regular service on his ST4s, gave me the creeps and almost barfed up my dinner when I read that.
 

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If they are still the original belts it's probably just a matter of time before they let go. Most folks on the forums would recommend that they be changed. The expense of the belts has to be weighed against the expense of rebuilding or replacing the motor if they fail. I put 20,000 on a set on my ST3 and probably will not do so again. I couldn't see any physical damage but compared to the new belts they felt very stiff and inflexible. I think the heat they are subjected to plays a big role. Since the belts on our Ducs go around very small pulleys, smaller than is usual for cars, they may not have the same lifespan as automotive belts.

Changing the belts on my ST3 is not a difficult job and would only be slightly more difficult on an ST4. Much of the work is getting all the bodywork, battery and other stuff out of the way and then putting it all back. Could the PO have simply acquired them and done the work himself?

Did the dealer indicate the number of labor hours in their quote? 2 or 3 hours of labor would probably be considered normal if no other work is done. The belts will run about $130 or so for the pair.

Bill W.
 

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This is the price to play with a Duc. Either pay it or do it yourself. You will find a majority of people on these boards do it themselves and thus lies the passion for most.

The reasons for lower mileage have been brought up many times and they usually are arguable:

More heat and friction; due belts being closer to the engine, more enclosed, and motorcycles run at higer RPM's. than a auto.
 

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Mr Leakered
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Crunchy,

I looked at the timing belt off my old Dodge Stratus after 110,000mi. It looked identical to the ones I pulled off my ST4 last year after 12k. Pristine. The teeth and edges looked great. The problem with Ducs are the tight radii and high RPM those belts see. The Kevlar fibers break down over time and then it is a ticking time bomb. ST4 belts supposedly cross-ref with some SEAT timing belt that gets a 100k interval.

Edit, I agree with Ducsbill, they did feel more stiff than the new ones.

They are pricey, but easy enough to change.

BTW, I'm about 500mi out (3wks) from a valve adjust and everything that goes along with it. I have a post on the desmonorthwest board about a possible get together.

Have a good one.
 

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"RECOMMENDED" 12K miles or 2yrs. I interpret that as better-do-it-now-for-less-or-pay-a-lot-more-later.
6K to 10K miles, your dealer is trying to rape you.
Kinda like the 6 month dentist visit.

I don't trust the dealers. I take my bike to a local shop with over 15 yrs of Duc experience and runs a pro duc racing team.
 

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Mr Leakered
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If you do some searching around here, you will find some pics and stories of shredded belts after about 13k. There are many variables to this, did the bike sit too long, was it run at redline at a ton track days, or was it the belt design?

Duc has gone through many design revisions to these belts and have only upped the recommened interval to 15k with the obligatory check at mid-life.

Have a good one.

That's weird. This was supposed to be a reply to Crunchy's post below (#9).
 

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Discussion Starter #9 (Edited)
I appreciate all the responses. I guess I'm just having a hard time understanding why such an important part of the engine would be so seemingly fragile. I had the timing belt replaced on a Chrysler I had a few years ago (and again, yes I know there's a difference between a car and a bike) at about 110,000 miles, and if you were to clean the dirt off the old one and set it next to the brand new one you wouldn't be able to tell them apart.

I'm going to go ahead and do them I guess, I just wanted to get other people's opinion (who, unlike the stealership, have nothing to gain monitarily by telling me to change the oil every night and replace the belts every other Saturday) on the actual neccessity as opposed to "overkill maintenance." I have a couple of Harley buddies who change their oil every 500 miles and swear by it, but to me that's just a waste of oil.
 

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I have wondered why they don't use chains? Would the noise be that much greater? I doubt that you could hear it going down the road.
 

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Discussion Starter #11
I have wondered why they don't use chains? Would the noise be that much greater? I doubt that you could hear it going down the road.
That would be sweet. I know that you can order timing gear sets for smallblock Chevys and Fords that are intentionally extra-noisy. :)
 

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Mr Leakered
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I appreciate that one of our cars came with a timing chain. After the Duc experience, I may attempt to try changing the belt on our other car.

The problem with a chain is rotating mass. Also, for the Duc, that would create an interesting oil bath arrangement. Funking with chains each valve service would be less fun, IMHO. I'd thoroughly appreciate a self-contained belt tensioner arrangement though. How slick would that be??

I'd personnally like to see the return of the bevel drive, but I believe there were issues with gear lash on those, though.

Maybe pushrods. :D
 

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Mr Leakered
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That would be sweet. I know that you can order timing gear sets for smallblock Chevys and Fords that are intentionally extra-noisy. :)
The timing gears are sweet, but the chain was only 3in long with the cam down in the valley. :p
 

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I have wondered why they don't use chains? Would the noise be that much greater? I doubt that you could hear it going down the road
I think I can answer that. They use belts because of tradition.

When Taglioni designed the origional pantah engine he chose belts. I suspect the reason was for simplicity over the bevel drive system, and weight saving over the v4 Appolo engine he designed for the Americans.

Evidence can be seen in the the desmo valves that we are continually servicing. The original reason for their design was because of the unreliability of valve springs for racing in the 1950s. Valve springs improved to the point where desmo valves became unnecessary very quickly but Ducati continues to produce them because they are ducati.
 

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Chilehead
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New Ducatis are 15k miles, no time limit, which for me works out to be every three years, each (I have 6 bikes, three of which are Ducatis).

Belts are cheap, and easy to change, what's the big deal?

Tom
 

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New Ducatis are 15k miles, no time limit, which for me works out to be every three years, each (I have 6 bikes, three of which are Ducatis).
Hmm whats the difference between new and slightly older Ducati's??
Different belt manufacture??
 

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Discussion Starter #20
Nice Guzzi by the way! My first bike was a 1974 Moto Guzzi 850T. It was given to me when I was 15 years old by a friend of my dads after it had been sitting in pieces under a tarp in his back yard for almost 10 years. It was about 80% complete and we restored it together on a budget of "beg borrow and steal." I had to sell it when I was about 26 because times were hard. I wish I had it back. :(
 
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