Faulty CCT pics if you have them...

[Kev L]

This is what I was rattling on about, Beamish was the dude -
https://vtr1000.org/phpBB3/viewtopic.ph ... 68#p154768

[Bleh]

This is what I was rattling on about, Beamish was the dude -
https://vtr1000.org/phpBB3/viewtopic.ph ... 68#p154768

Interesting read, thanks Kev.

I'm not trying to re-invent the wheel here but more 'suggest' plausible failure modes and methods of improvement which may include elements of product redesign.

We already know it's the spring that's at fault, but the question is why? That's partly what I'm looking to address. Demonstrate some analysis and all that jazz.

As any Mech Eng should be able to explain better than I (I'm studying automotive eng, same principles but engines rather than lathes etc), there will come a point in a components life where it will pass a certain threshold and can be suggested that after such point, that component will have an infinite life and should theoretically never fail. A gudgeon pin is a good example of this. But we know that the spring is hopeless in the CCT's and it will never reach a state of infinite life!

Why don't Honda use better material? Because Honda don't make them, they pay someone else to and the failure rate for such design must be within tolerance in the factory on the day. Using a material with a more adequate modulus of torsion would mean more money and more money means less profit or higher purchase prices for the consumer... neither of which Honda would like, one for their own bank accounts and another for reputation!
Use the same material but more of it, i.e. greater diameter, and something else has to give, such as the space it takes up so there's a whole product redesign there just for a thicker spring, and with that, the spring rate changes so you will then need to decide the new length and number of turns required for desired effect.

The simple answer - MANUALS, but in an ideal world, we'd have a component that didn't suffer problems that could lead catastrophic failure. My initial plan was to simply suggest a version of MCCT's that were inclusive of a 'torque indicator' to help maintain the ideal torque setting on the cam chain, but when I looked at what else is required for this assignment (which isn't worth as many marks as another), then, I have been led down the path I'm currently on!

Hi Bleh, Good to see you back again sorry you had to let your VTR go.

I was only thinking about you recently, I was wondering if you remember who supplied your VTR rear undertray

Chris.

Have been on a few times just looking at threads without logging on but yeah, absolutely gutted the Storm has gone. It's another story for another time and the guy well and truly ripped me off - already spent a couple of hundred sorting out his cowboy tricks on the car I took, but ultimately, no fault but my own!

The undertray was an ebay job pal and sprayed with colour match paint.

Sorry I missed this question previously, was taken away by the image (ooooh shiny ), glad to see you're thinking of me though

[sirch345]

Hi Bleh, Good to see you back again sorry you had to let your VTR go.

I was only thinking about you recently, I was wondering if you remember who supplied your VTR rear undertray

Chris.

Have been on a few times just looking at threads without logging on but yeah, absolutely gutted the Storm has gone. It's another story for another time and the guy well and truly ripped me off - already spent a couple of hundred sorting out his cowboy tricks on the car I took, but ultimately, no fault but my own!

The undertray was an ebay job pal and sprayed with colour match paint.

Sorry I missed this question previously, was taken away by the image (ooooh shiny ), glad to see you're thinking of me though

No problem Bleh, hardly surprising when you have so much on the go, plus Xmas around the corner. A shame about being ripped off, it's not nice when that happens.

I've seen a guy on ebay who is supplying under trays, so I may give him a try. I liked yours as it was made from fiberglass.

Thanks Sirch, all the images so far are fantastic.

I'm doing a brief study on the CCT's for an MEng paper which is why I would like images of the broken bits. They will all go towards my analysis section and justifying any areas redesigned.

If you wish to supply me your actual name (via pm), I can accurately reference the images should you wish me to do so?!

You're more than welcome to use my photo's (of the broken CCT spring as below) in your MEng paper if they're any help, there's no need to reference my name to them, but rest assured those photo's are definitely mine.

[bazza696]

I have seen a few ccts both dead and alive, and there are few parameters to consider. We observed that there has been a lot of different finishes on the exterior of the main body and the inner machined surfaces, so you have to consider that they have come from different suppliers, therefore the same with the spring.

We have seen that on some of the springs there is a blueing on the outside of the spring and not on the inside, so we have concluded that there has been localised heat treatment, rather than complete heat treatment this could account for the way the spring has sheared.

From our observations the majority have failed as shown in sirch's picture and only few have failed as in wicky's.

A few have been corroded and failed, but because of the spring being rusty has caused it to jam in the body and saved the cct.

The best option would be Suzuki option of having it sprung with a ratchet mechanism to stop it retracting after spring failure.

[Bleh]

Thanks for the input Bazza. Wouldn't happen to have any images of any of the failed CCT's you've looked at by any chance?

This could ultimately become an extensive study but not enough time or enough resources (CCT's good and bad).
I've seen various designs today on my image viewing adventures and quite a few appear to have a fail safe built into the design. At least these manufacturers (or designers at least) acknowledge that there is an area of concern... 'le spring'!

The absolute ultimate ideology would be to get rid of CCT's altogether, I'm sure we'll all agree on that one. Honda VFR 400 system comes to mind (has the SP got the same?).

Liking this thread though, some lovely feedbacks coming.

[sirch345]

Thanks for the input Bazza. Wouldn't happen to have any images of any of the failed CCT's you've looked at by any chance?

This could ultimately become an extensive study but not enough time or enough resources (CCT's good and bad).
I've seen various designs today on my image viewing adventures and quite a few appear to have a fail safe built into the design. At least these manufacturers (or designers at least) acknowledge that there is an area of concern... 'le spring'!

The absolute ultimate ideology would be to get rid of CCT's altogether, I'm sure we'll all agree on that one. Honda VFR 400 system comes to mind (has the SP got the same?).

Liking this thread though, some lovely feedbacks coming.

I'm finding this thread very interesting too, good to see what you have been doing with your drawings Bleh
Yes the SP1/2 has gear driven cams.

I have seen a few ccts both dead and alive, and there are few parameters to consider. We observed that there has been a lot of different finishes on the exterior of the main body and the inner machined surfaces, so you have to consider that they have come from different suppliers, therefore the same with the spring.

We have seen that on some of the springs there is a blueing on the outside of the spring and not on the inside, so we have concluded that there has been localised heat treatment, rather than complete heat treatment this could account for the way the spring has sheared.

From our observations the majority have failed as shown in sirch's picture and only few have failed as in wicky's.

A few have been corroded and failed, but because of the spring being rusty has caused it to jam in the body and saved the cct.

The best option would be Suzuki option of having it sprung with a ratchet mechanism to stop it retracting after spring failure.

It's interesting to hear your finds too Bazza I'm going to disagree though with the ratchet idea, unless one could be built with enough movement in it to allow for the different tensions required, as happens with the standard Honda CCT.
When I was putting time (too much I hasten to add ) into R&D of coming up with the Stopper Mod, I found that both the front and rear standard CCT's do self adjust as the rev's rise and fall. So for a ratchet designed CCT to work on a Firestorm/Superhawk as the OEM does, it would need to accommodate that,

Chris.

[KermitLeFrog]

It's interesting to hear your finds too Bazza I'm going to disagree though with the ratchet idea, unless one could be built with enough movement in it to allow for the different tensions required, as happens with the standard Honda CCT.
When I was putting time (too much I hasten to add ) into R&D of coming up with the Stopper Mod, I found that both the front and rear standard CCT's do self adjust as the rev's rise and fall. So for a ratchet designed CCT to work on a Firestorm/Superhawk as the OEM does, it would need to accommodate that,

Chris.

Now that's very interested as well. I can't think of any obvious reason for this. Do they slacken at higher speeds or tighten?

[fabiostar]

This problem of CCTs is a long standing problem not for all the jap factories but Honda. history shows us that infact Honda are sh1t at making them, Early V4s, cb750/900s, VTRs, smaller VT and VT400/500s. it just seems to be a long ongoing problem for honda that they never really cured .or will admit to!!!

[bazza696]

Thanks for the input Bazza. Wouldn't happen to have any images of any of the failed CCT's you've looked at by any chance?

This could ultimately become an extensive study but not enough time or enough resources (CCT's good and bad).
I've seen various designs today on my image viewing adventures and quite a few appear to have a fail safe built into the design. At least these manufacturers (or designers at least) acknowledge that there is an area of concern... 'le spring'!

The absolute ultimate ideology would be to get rid of CCT's altogether, I'm sure we'll all agree on that one. Honda VFR 400 system comes to mind (has the SP got the same?).

Liking this thread though, some lovely feedbacks coming.

I'm finding this thread very interesting too, good to see what you have been doing with your drawings Bleh
Yes the SP1/2 has gear driven cams.

I have seen a few ccts both dead and alive, and there are few parameters to consider. We observed that there has been a lot of different finishes on the exterior of the main body and the inner machined surfaces, so you have to consider that they have come from different suppliers, therefore the same with the spring.

We have seen that on some of the springs there is a blueing on the outside of the spring and not on the inside, so we have concluded that there has been localised heat treatment, rather than complete heat treatment this could account for the way the spring has sheared.

From our observations the majority have failed as shown in sirch's picture and only few have failed as in wicky's.

A few have been corroded and failed, but because of the spring being rusty has caused it to jam in the body and saved the cct.

The best option would be Suzuki option of having it sprung with a ratchet mechanism to stop it retracting after spring failure.

It's interesting to hear your finds too Bazza I'm going to disagree though with the ratchet idea, unless one could be built with enough movement in it to allow for the different tensions required, as happens with the standard Honda CCT.
When I was putting time (too much I hasten to add ) into R&D of coming up with the Stopper Mod, I found that both the front and rear standard CCT's do self adjust as the rev's rise and fall. So for a ratchet designed CCT to work on a Firestorm/Superhawk as the OEM does, it would need to accommodate that,

Chris.

you could fit a softer end cap or a dampened end cap that would allow for some flex.

I also know that at some point Suzuki had a cct that had an oil feed, so it was hydraulic. This would solve some of these problems you mention. There are some obvious disadvantages of being hydraulic, getting gummed up and chances of leakage.

[mattycoops43]

Can I bring a bit of (hopefully) clarity here.

I run a storm with manuals, I don't claim to be a storm expert, but I work in a garage with a business partner, and we build bikes together, now my partner has 30yrs service in honda workshops. I have tried arguing with him in the past, and to be frank he always ends up being right, it's bloody annoying.

We looked at this. Honda use the same CCT in quite a few bikes, including the cbr600 all through the 90s, that bike was NEVER known for cct failure. We do not think this is an issue with the tensioner.

The rear's on the storm are not prone to going. they sit at a totally different angle from the front one, and get more oil feed.

Any auto tensioner run dry will fail. We are pretty convinced the layout of the engine means the front one runs dry, causing failure. If you crack one of the mounting bolts on a rear cct on a storm, oil pisses out, so they are running flooded with oil. Front does not.

I don't know about the other honda's mentioned as failing above, VTs etc, but I would be very surprised if it was not the same problem.

You want to run an auto without issues? I reckon try running an oil feed up to it, I just don't think it's worth the hassle, manuals are so easy.

[bazza696]

I agree with you and one of the things that I notice is that the spring rusts.

I believe there are two reasons for this, more of us only use the storm as a luxury item and only ride during the summer, so the bike is left over the winter where condensation can build up in the engine and get trapped in the cct.
and as you mention, the cct doesn't see much oil during normal operation.

My observations have never seen a set of rusty ccts, only one from the pair.

But I do believe that because one doesn't see much oil and sits around in a garage for half the year this causes the problem with the cct, that is why some guys on here that use the bike all year can run OEM autos for so long without failure.

[sirch345]

It's interesting to hear your finds too Bazza I'm going to disagree though with the ratchet idea, unless one could be built with enough movement in it to allow for the different tensions required, as happens with the standard Honda CCT.
When I was putting time (too much I hasten to add ) into R&D of coming up with the Stopper Mod, I found that both the front and rear standard CCT's do self adjust as the rev's rise and fall. So for a ratchet designed CCT to work on a Firestorm/Superhawk as the OEM does, it would need to accommodate that,

Chris.

Now that's very interested as well. I can't think of any obvious reason for this. Do they slacken at higher speeds or tighten?

From my findings the standard OEM front CCT slackens off approx 1/4 of a full turn as the rev's rise at approx 3,000rpms, then as the rev's come back down it re-tightens. The rear CCT however tightens up as the rev's increase, and slackens off again as they decrease.

This problem of CCTs is a long standing problem not for all the jap factories but Honda. history shows us that infact Honda are sh1t at making them, Early V4s, cb750/900s, VTRs, smaller VT and VT400/500s. it just seems to be a long ongoing problem for honda that they never really cured .or will admit to!!!

I think you'll find most, if not all of the of the big four Japanese motorcycle manufacturers have had their share of CCT's failing over the years, it's not just Honda. No you're right they wouldn't admit to it. A petition was got up by the Superhawk forum years ago when the Superhawk/Firestorm was relatively new to the biking scene, it was probably only a few years old by then. IIRC some of the members from this forum also supported it, but it was dismissed by Honda.

Can I bring a bit of (hopefully) clarity here.

I run a storm with manuals, I don't claim to be a storm expert, but I work in a garage with a business partner, and we build bikes together, now my partner has 30yrs service in honda workshops. I have tried arguing with him in the past, and to be frank he always ends up being right, it's bloody annoying.

We looked at this. Honda use the same CCT in quite a few bikes, including the cbr600 all through the 90s, that bike was NEVER known for cct failure. We do not think this is an issue with the tensioner.

The rear's on the storm are not prone to going. they sit at a totally different angle from the front one, and get more oil feed.

An inline four puts less strain on a CCT due to the configuration of a four cylinder, also if one does fail there's more chance of getting away without damaging valves. This is due to one cylinders valves being open and another being closed which equals out the pressure applied to the cam chain. As the Firestorm has two CCT's one for each cylinder, there can be no counter balance between the two cylinders, that's why there is more chance of valves getting bent compared to a multi-cylinder engine. I agree, the position of the front CCT has to have something to do with it, with it's lack of oil compared to the front one, although some rear CCT's have failed even though they are running in oil.

you could fit a softer end cap or a dampened end cap that would allow for some flex.

I'm not sure if that would work due to the nature of how the front and rear standard OEM CCT's operate (as I've described above) but you may know more on that idea than I do,


Chris.

[NZSpokes]

Early CBR600s and Hornet 600s are known for CCT failure.

[Bleh]

Well that was a busy few days...

Good to see plenty of posts providing food or thought... Some of the observations I have already witnessed, such as oil pouring from the rear CCT when loosening the bolt off at the back, and others I hadn't considered until just now like Sirch's observation where the two CCT's behave in an opposite manner, i.e. when accelerating, the front slackens off and the rear tightens up - also makes sense when you think about it as the crank rotates the same way always. With this in mind, the rear CCT presses against the rear of the cam chain and the front CCT presses against the front of the cam chain, but under load, it will always be the same side of the cam chain that is under tension due to the direction of crank rotation.

That leads on to a new branch of questions such as 'What's the tolerance for the allowable movement within the tensioner?'.

What else would be interesting to know is if anyone has set up a rig, such as a vice, where a CCT has been placed between the jaws, and then clamped tight with a torque wrench until some movement is witnessed in the CCT for an 'approximate' linear spring rate? I have 2 problems with trying to do this.... No vice and no torque wrench!

Also, I'm having a mare trying to get the actual torsional modulus for the spring used. Without knowing the exact material, it's a real pig trying to work out. And trying to establish all the forces from combustion transferred to relevant components, including frictional forces, bladdah bladdah bladdah, to eventually establish the 'ideal' spring rate is a whole lot of another type of work and not really time worthy for the type of assignment I'm currently doing.

I do have some spring formulas which I wanted to eventually incorporate and will eventually share, but they are more for the ideal linear function rather than it's torsional function - and it's this torsional function that may be a) the necessity and, b) the actual downfall of the CCT.

Does anyone have experience of a linear springed CCT that have either failed or work so much better than these?

[bigtwinthing]

you buggers have too much free time