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Discussion Starter #1
I read a few topics on timing belt recommendations. Some people say 12K miles 2 years, while my original manual (1995 M900) says 30K km (about 18K miles). In the automotive world belt recommendations are pretty conservative, so I'd imagine 30 K km is pretty conservative as well. After all the bike is never started in sub zero temps like cars are. Has anyone experienced belt failure before 18K miles on the street (racing and extensive rack use is a different deal IMHO).


TIA
 

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The earleyer type belt (white print) you'd better change on time ,when you have the red print belts you could gamble
But do you know what happens when the belt breaks
i think it will cost you a bit more dan 40$ for new belts
 

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Discussion Starter #3
I defintely have the red belts, I leave mine open so they are subject to less heat. They have about 8K miles 2 years on them,. I don't think it is a big gamble to run them at least 1 more year. The are still pretty snug even with 8K miles on them and I don't ride that hard either.
 

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mnztr said:
I read a few topics on timing belt recommendations. Some people say 12K miles 2 years, while my original manual (1995 M900) says 30K km (about 18K miles). In the automotive world belt recommendations are pretty conservative, so I'd imagine 30 K km is pretty conservative as well. After all the bike is never started in sub zero temps like cars are. Has anyone experienced belt failure before 18K miles on the street (racing and extensive rack use is a different deal IMHO).


TIA
mnztr said:
I defintely have the red belts, I leave mine open so they are subject to less heat. They have about 8K miles 2 years on them,. I don't think it is a big gamble to run them at least 1 more year. The are still pretty snug even with 8K miles on them and I don't ride that hard either.
Conditions for your bike aren't really the same as automotive applications. Lose a belt on the duc and it's a catastrophic event. While yes, I agree, you've got some room to wiggle beyond 12k 2years and there aren't THAT many examples of failed belts, they do exist.

A quick search comes up with 2 very useful threads that you should read through:

http://www.ducatimonster.org/smf/index.php/topic,46485.0.html

http://www.ducatimonster.org/smf/index.php/topic,48161.0.html

will your belts break with the intended extended use? I doubt it, but it's definitely a risk that you take
 

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mnztr said:
I defintely have the red belts, I leave mine open so they are subject to less heat. They have about 8K miles 2 years on them,. I don't think it is a big gamble to run them at least 1 more year. The are still pretty snug even with 8K miles on them and I don't ride that hard either.
The only comment I would share is that hey are cheep and easy to replace, why not just replace them vs wonder?
 

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Discussion Starter #6
Desmopilot said:
The only comment I would share is that hey are cheep and easy to replace, why not just replace them vs wonder?
Well, after reading some of the threads, there is little peace of mind to be had by replacing early. There is one case of a belt breaking at 1000 miles!!! Also, someone pointed out, many things will fail early in their lifecycle due to a manufacturing defect or installation error. Ducati says 18K miles for my belts, and I think, due to the very critical nature of the item, they would use a very conservative figure to minimize the risk of lawsuits etc. There is little evidence of timing belts faliing and I'd bet a fair amount of $$ that there are many Ducs out there that receive very little maintainence. Heck PhilB did 24K miles on a regular basis so going 18K is pretty conservative.
 

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In his service manuals for our bikes, LT Snyde, says our duc's belts deteriorate more quickly than those in cars...mainly because of their proximity to engine heat. That's why he likes to vent his belt covers for a little more leeway in the lifetime of the belts.

I'm following his advice and will change my belts as he recommends. Cheap insurance is always good :)
 

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Discussion Starter #8
Who is LT Synde? I run my belts uncovered, since I did this, they don't even need re-tensioning!!! (about 10 K km/25 months on the current set. I can also inspect them very easily. Frankly, I would not retension the belts more then once, if they are stretching, that is not a good sign.
 

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Discussion Starter #10
I agree with him that they will not last as long as car belts (5 years 60K miles) but my Mazda MX5 has its belt in an enclosed area at the front of the engine between the rad/AC condensor and hot engine, so it gets a lot of heat as well. What does he recommend for Tbelts?
 

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Its not just heat thats the issue I think. Our bikes' engines usually are happiest at higher rpms than those in cars, and are subject to greater wear than car belts. Correct me if I'm wrong anyone.

As for timing belt brands, I can't recall sorry. He sells some on on his site, so you might want to visit to see for yourself  :)



BryanS, thanks for completing LT Snyder's name...must have missed a key on that post ;)
 

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what about age?? i`m looking to buy a bike; 2001 m900, with only 11k kms on it....should i replace the belt directly, just because of the age of them???
 

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Two years or 12K miles, whichever comes first. In other words, if you don't know when they were last changed, change them.
 

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Discussion Starter #16
Jethro said:
Pulley diameter may be a factor as well?

Not too sure about all that, the drive pully on my Miata is pretty small, (driven pullieys are larger). Also as far as RPM, the Miata cruises at about 3.5-4K rpm with is only slightly lower then my M900. and has a redline of 7K rpm. Like I said, I have not heard any case of belts "timing out" and breaking. I've had my belts on for 2 years, and about 8K miles. I run them open. I have not even had to retension them yet. I would not retension the belts more then once. To be honest when I did my fist ever belt change on this bike, the old belts were so loose, I was stunned!!! I had been riding the *rap out of it with really loose belts and it STILL did not skip!!! So that has conviced me that perfect tension is not so critical although making them too tight will shorten their life, but as long as they stay pretty snug after initial install they are good to go.
 

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it seems you're pretty hard up on running the belts past the recommendations, so no biggie as it is your bike  [thumbsup] 

not to beat a dead horse and all that, but really, if you're trying to save money somewhere, belts would probably not be the best place to do it.

just a few more threads to read up on (only if you're interested):

these have some interesting pictures:
http://www.ducatimonster.org/smf/index.php/topic,43988.0.html
http://www.ducatimonster.org/smf/index.php/topic,43989.0.html
most notably pics like this:


http://www.ducatimonster.org/smf/index.php/topic,36115.0.html

and to a lesser extent:
http://www.ducatimonster.org/smf/index.php/topic,21302.0.html


and trust me, I'm seriously not trying to be an ass about this at all as I agree with you that the recommendations are probably pretty conservative and i understand your points. Just want to make sure all the information is out there
 

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mnztr said:
Not too sure about all that, the drive pully on my Miata is pretty small, (driven pullieys are larger).
I've done belts on 3 cars and they all had larger dia crank pulleys but  it looks like your Mazda has got 24 teeth on crank pulley with my M1000 having 20 teeth so agree not much difference. I think the 900 engine has 18 teeth.
Regarding speed, the Monster pulleys all run at half engine speed as opposed to the car crank pulley running at engine speed so that should be better for our belts.
I'm wondering if running the belts without covers can cause  abrasive damage from road grit?
Perhaps the improved Gates 'red letter' belts can safely run more miles but Ducati would sell less belts?

Interesting stuff there hiero but it looks like those pics are because the belt was fitted wrong. Aren't we talking about belt life when fitted right?
Having said that, I've just replaced my belts at 6500 miles because the bike was a left-over and had been standing still for a long time. I'm not risking it - just enjoying the discussion :)
 

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Well when I bought a fully rebuilt 944 I had this question about age. Since the engine was built at just 2 years ago but has not been started yet. I called the shop that did the engine (extremly respected BTW) and asked them if I should change the belts since it had been sitting so long. There short answer.... Nope belts will be fine change them at the milage point.

Now this thread has me wondering again.
 
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