No longer a virgin.

[sirch345]

Oh yes yes, I beieve you right, it was from Roger, as he doe's not like the manual cct's

I believe Roger doesn't mind them in a race engine that is used on the track, but not so happy with manuals for a road bike.

Chris.

[VTRDark]

No Carl nothing to do with the colour of the dot's or earlier or later models....

I understand now, I misunderstood what you said. And yes that is a very good point about the the shelf life which sort of makes a service interval irrelevant. They wont be doing any miles but all that time they are still under tension.

(:-})

[sirch345]

I understand now, I misunderstood what you said. And yes that is a very good point about the the shelf life which sort of makes a service interval irrelevant. They wont be doing any miles but all that time they are still under tension.

(:-})

And most likely under twice the amount of tension compared to once they're fitted

Well done Carl, that's spot on

Chris.

[rollingthunderx2]

Why do people keep referring to lack of oil making the tensioner fail?
Theres plenty of oil coming off the chain, and its not wear on the internals which causes failure but the spring tang breaking.

[sirch345]

Probably because the rear CCT due to it's location and the angle it sits at means it's full of oil, unlike the front one,

Chris.

[BigVeeGrin]

Probably because the rear CCT due to it's location and the angle it sits at means it's full of oil, unlike the front one,

Chris.

Yep, I reckon. My front spring was corroded to a hair's width, and nothing like any oil had been near it.

[VTRDark]

+1

Exactly, and your not the only one that has had corroded springs, so with thin springs and added corrosion it don't leave much chance.

(:-})

[rollingthunderx2]

So people have actually seen with their own eyes corroded springs..I'll ACF50 mine.
Were there any other internal parts corroded?
If not...why not?

[Wicky]

I'll ACF50 mine.

If you're going to all the trouble to take it apart to spray some oil on your CCTs why not instead fit manuals or rejig a stopper mod.

[rollingthunderx2]

The corrosion is probably from condensation too.
Does the spring always break in the same place, at the bend which locates the spring in the slot in the end of the screw?
Or does rust make them break somewhere else?
Or is it just a spring breaking in the same place every time, but sometimes its a little rusty?

In which case it does'nt matter whether its rusty or not, its going to break anyway, whether you oil it /acf50 it or not...as I said, the spring gets weakened by the heat, and is'nt cooled by the oil(on the front CCT)
The only difference I can see in oiling the front CCT is it will be oiled when it breaks...

Someone on here sells replacement springs?
Anyone know who?

And for anyone wondering whether to modify their CCT's..Just do it. Before its too late, like me, who put it off.....

[AMCQ46]

its called fretting corrosion where the spring vibrates against itself or the housing in very small amplitude motion , even without moisture the fine iron oxide particles generated are harder than steel, so they accelerate the wear, and the fretting effect also reduces the fatigue life of the spring.

so it becomes a self propagating cycle. only running lubricated would stop / slow it down

[BigVeeGrin]

its called fretting corrosion where the spring vibrates against itself or the housing in very small amplitude motion , even without moisture the fine iron oxide particles generated are harder than steel, so they accelerate the wear, and the fretting effect also reduces the fatigue life of the spring.

so it becomes a self propagating cycle. only running lubricated would stop / slow it down

wow. Must remember not to fret if I want my life spring unfatigued

[rollingthunderx2]

its called fretting corrosion where the spring vibrates against itself or the housing in very small amplitude motion , even without moisture the fine iron oxide particles generated are harder than steel, so they accelerate the wear, and the fretting effect also reduces the fatigue life of the spring.

so it becomes a self propagating cycle. only running lubricated would stop / slow it down

Fretting:
That is complete baldrocks.

There was no sign of "fretting", nor can I see any way that could occur to an extent to cause failure.
The failure point is well away from any contact, and would in fact be impossible to occur.
The failure is due to cyclic stress fatigue from the forces on the spring tang causing failure at the bend.

Corrosion:
That is an argument for rusting, not breakage.
There was no rust at all on my broken spring, and to suggest that oiling it will prevent failure is misleading.

[AMCQ46]

[quote="rollingthunderx2Fretting:
That is complete baldrocks. .[/quote]

you could be right as mine havent failed yet, so I havnt seen the failure mode or modes. Your analasys suggest that the spring is just too highly stressed to have the required fatigue life, but there must be other factors that add to this to make the front pot failure rate higher than the rear?

as for fretting of baldrocks, complete or partial, I would suggest lycra undershorts when running

[rollingthunderx2]

The most stressed part of the spring, is where it has been bent to engage with the slotted end of the adjuster.
That is where they break. That is where clock mainsprings fail, its been that way since victorian times.
Saying fretting is the cause is guessing.

I have looked into chafing also, as you suggest, butt could only come up with this...I could think of something to stop the chafing, a light oil rubbed on may help, however, watching this did cause some Fretting...

http://withleather.uproxx.com/2012/07/m ... cing-video