CCT information

[Red3446]

Looking around forums and FB groups, I can see that a lot of people had breakage problems of the CCT, me too.
By my side I don't know my bike history before I bought it and looking to official technical documents, no CCT breakage is mentioned, only noise.

So, what I'd like to ask to people who had this breakage problem is: have you increased internal CCT's spring preload to prevent noise before the breakage occurred?

[Wicky]

Replace auto CCTs ASAP with manual tensioners before problems occur

The auto tensioner's spring either works - or it doesn't. There's no grey area in between.

Kreiger, APE, Bazza and Ade Whitmarsh's CCT's > http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=22720

CCT broken spring. > http://www.vtr1000.org/phpBB3/viewtopic.php?f=9&t=28666

[mike.kir]

It is quite common to find VTR engine with bent valves on some auction websites. If money is the issue you can always make your own manual tensioner using stainless bolt and some basic tools. I went this way and it works.

[Red3446]

My breakage was different: the breakage occurrs at the spring hook.....

Concerning the manual CCT, some questions:

How to be sure about the right chain tension?
As the manual CCT's push rod is made by a "common" stainless steel bolt, is it sure that it cannot become bent during usage?

[Wicky]

My breakage was different: the breakage occurrs at the spring hook.....

Concerning the manual CCT, some questions:

How to be sure about the right chain tension?
As the manual CCT's push rod is made by a "common" stainless steel bolt, is it sure that it cannot become bent during usage?

How to be sure about the right chain tension?

Either by hand by tightening up the manual tensioner bolt 'finger tight', then slackening it off by a specified quarter turn or so - or directly measuring the deflection of the cam chain imparted by the manual tensioner bolt . See in the Workshop knowledgbase instructions for installing Manual CCTs. If its too tight there will be an audible 'screech' and if too loose it will rattle. The sweet spot is between these two extremes.

As the manual CCT's push rod is made by a "common" stainless steel bolt, is it sure that it cannot become bent during usage?

Never heard of a bent manual tensioner - there's not enough force from the cam chain that could bend it. The only problem generally reported after manual tensioners have been fitted is for oil to leak up past the thread in the bolt due to non-application of thread lock/ silicone during installation. And at worst the tensioner bolt unwinding out due to vibration (again due to lack of thread lock)

[mike.kir]

I've measured the slack directly as described in Workshop section. Everything is described there in great detail. As for the bolt I've used normal hex SS bolt and rounded its head. M8 size that I've used is really difficult to bend. Adding a drip of sealant on the tread and two security nuts with nylon protected it from leaking oil and unwinding.

[sirch345]

In my experience, when a CCT spring is starting to lose it's tension (making a noise as you say) they are on their way out, unless something has made the CCT worm stick and it rights itself after a couple of ride outs or so.
I can't see the point of re-tensioning the spring if it's showing signs of a failure by being weak in the first place,

Chris.

[lumpyv]

mine went at about 10 k miles whilst at tickover at the test center . now at about 22k miles , never been adjusted and still going strong

[tony.mon]

In my experience, when a CCT spring is starting to lose it's tension (making a noise as you say) they are on their way out, unless something has made the CCT worm stick and it rights itself after a couple of ride outs or so.
I can't see the point of re-tensioning the spring if it's showing signs of a failure by being weak in the first place,

Chris.

Agree. Overtensioning the spring will do two things:
1. advance to onset of failure, and
2. force the tensioner blade against the chain mro than the designers intended,
The result will be increased wear on the blade, and loss of horsepower.

A few years back the was a company (??woodcraft??something like that... it's on here somewhere)- who were supplying replacement springs made of SS, but a SS spring won't hold its temper the way a high carbon steel one does.

Don't wait until it gets a bit rattly until you change to manuals, stopper mods or regularly replaced std ones, you'll get caught out- I did, 18 months after fitting new std ones.
The failure, when it happens, is quite often catastrophic, not progressive.
You don't often get a warning; they just go.

[OldFart]

Good Evening Tony.. Are you still offering a fitting service for the CCTs ?