cam belt

[hardo]

dear all

tried the search function but did not get the answer.

how often do you guys change the cam belts on your paso?

my manuel says every 20.000 km. in my case, this would mean every 15 years ..... strange, but the local ducati dealer told me every five years.

on my new monster, it is 24.000 km or every second year (!). clearly, not driving still leads to an aging of the cam belt.

another guess: to be on the safe side, would you change it every second year even though I am only doing around 1.500 km in two years? (did not do this in the past, changed it after 6 years of use).

how do you deal with that topic?

thanks for your opinion!

hardo

[Derek]

Every 12,000 miles (20,000km) or 2 years, whichever comes first.

[Mc tool]

Ah the old cam belt hysteria. A cam belt on a car lasts ( typically ) 100,000 km's, I would suggest that the loading on a duke engine is no more than a car and possibly a lot less .Yes I know that if the belt breaks it will pretty much total the engine , but the same could be said for con rods( Im not suggesting that you should expect 100,000k's from a set of belts ,but Id be happy at 30,000 if they pass inspection and are not to old age wise ). What is wrong with a routine inspection of the belts , looking for obvious damage ( dont lever them on/off with any thing other than your fingers ) , frayed edges , look for the join, and check the working surfaces ( teath ). Check them against a new belt and notice the new belt will have a rough working surface and a worn belt will be polished smooth. Keep them properly tensioned ( dont just guess ) There are a few different ways of doing this simply , without expencive tools . Bear in mind that rubber will deterioate over time, so if your not doing high miles you should get at least 5 years out of a properly installed belt .On my SS motor , which has been mothballed I backed off the tensioners, and if it turns out that I dont use the motor for more than 5-6 years Ill probly fit new belts . At the end of the day these parts aint cheap , especially if you have to pay someone to change them. If you buy a bike and cant be sure about the belts ( especially if its a non runner or if the seller seems like more of a bike user than a bike lover) ... change em. While your at it check the condition of the pulley's and seals behind them, the idler bearings and make sure the retaining nuts are tight , and dont run a road bike without the belt covers.

[paso750]

I don`t know if car belts are a good comparison. They are much stronger, the radiuses of the belt pulleys is much bigger and the accelleration and decelleration is not what it is on a bike.
Still I do agree the belts won`t immedeately snap after 2 years. It`s definetely necessary to check them for any hairline cracks and if you`re in doubt or unsure stick to the original service recommendation.

G.

[Derek]

Every 12,000 miles (20,000km) or 2 years, whichever comes first.

Here I am replying to my own posts now!
Having said the above, a schedule which I've stuck to with my ST4s since buying it at 2 years old with 1,000 miles on it (it now has over 40,000), the previous owner of the 907 changed the belts at 12,000 miles and 24,000 miles, ignoring the 2 year rule. In the 18 years since it was first registered it has only ever had the belts changed twice.
It is now over 2 years since they were last done but I will be changing them soon, although they would probably last another 6 or 7 years I'm not going to take that chance.

[Mc tool]

I don`t know if car belts are a good comparison. They are much stronger, the radiuses of the belt pulleys is much bigger and the accelleration and decelleration is not what it is on a bike.
G.

Yeah its a hard one. On a car the belt is running at crank speed ( for want of a better term ) where as on the paso its 1/2 that as the belt drive shaft is already at 1/2 crank speed , and the crank pulley on a car is about the same size , but the cam pulleys are bigger , so thats one pulley thats bigger , but then the paso belts are a lot shorter which means they are being used at a faster rate ( if you think of belt speed in feet per second ) but then there are no valve springs to oppose , just the inertia loadings for the the valve gear to overcome, but cars have that as well as the springs . Im pretty sure that on a spring valve motor the load on the cam belts is at its highest at idle ( I have had 2 damaged cam belts break one caused by a head of a broken bolt and the second by a stone that got in the hole in the belt cover made by the 1st breakage and they both broke while idling at an intersection after the car had been driven at road speed for some distance ..... maybe coinsidence ), but anyhow , this is all just food for thought ... if you can be bothered

[hardo]

thank you for your input + all the best, hardo