[manolis]

Hello.

It seems that at high gear (overdrive) and medium / light loads (say like going in the highway with constant 100Km/h) the SECVT of Suzuki Burgman overloads heavily its V-belt:

and operates at a poor efficiency.


Please take a look at

http://www.pattakon.com/pattakonPatBox.htm

at the PatEff CVT (at right):

and let me know your objections.

Thanks
Manolis Pattakos

 

[Kot]

Additional electro motor, additional plastic gears?

Not sure that it is really good idea. First of all, you will have to pay twice for replacing plastic gears. Next, how much watts additional motor will require? Sure, you've saw 40A fuse for CVT, not sure that all of these current is consumed by CVT controlling unit. Also, I'm afraid about synchronizing issues between both motors.

 

[ErikDK]

Since the E-CVT mechanism is the AN650's weakest point, adding a second unit would be a bad idea.

Why not use hydraulics instead, maybe oil pressure from the engine, You don't care about the position, only the force.
Like the modern clutch slave cylinders on cars, which are concentric to the gearbox' input shaft.

The engine's torque can be roughly calculated if you know rpm and injection quantity per revolution, and your controller could calculate minimum clamping force based on that.
Like cruise control, it could try to release clamping force up to the allowed amount of slip.

The way I ride, a mechanical lock-up in top gear would be advantageous.

 

[Chérie]

I love it when somewhere who not even complete his profile try to show all kind of deficiency with competitor product that have a solid company behind it, with resource of all kind, money, many many engineer in many field, R&D facility, testing facility and 13 year already of production.

Nothing easier on planet to do this, especially without R&D and testing proof and practical real world use and experience to back up claim.

It very curious that other company in industry with so many year of experience and R&D not intelligent enough to arrive to this same product.

Make me wonder why ?

Put no faith in such people under such situation.

 

[manolis]

I love it when somewhere who not even complete his profile try to show all kind of deficiency with competitor product that have a solid company behind it, with resource of all kind, money, many many engineer in many field, R&D facility, testing facility and 13 year already of production.
Nothing easier on planet to do this, especially without R&D and testing proof and practical real world use and experience to back up claim.
It very curious that other company in industry with so many year of experience and R&D not intelligent enough to arrive to this same product.
Make me wonder why ?
Put no faith in such people under such situation.

You have already my full name.


In the http://www.pattakon.com/pattakonContact.htm (open to everybody) you can find my e-mail, tel, fax, post address etc.
In the http://www.pattakon.com/ you can find several projects and prototypes of pattakon, some of the patents granted so far, etc.

Do you need more details about me ("profile") in order to comment on a "strictly technical" thread like this one?


Is the over clamping of the CVT V-belt of your Suzuki Burgman 650 in the range described?

If so, doesn't it increase the friction?

Doesn't it increase the consumption?

Doesn't it decrease the "life" of your expensive V-belt?

Doesn't it decrease the power that finds the way to the rear tire and to the road?

Why to pay for an expensive exhaust that increases your engine power by 10%, while you can do the same by improving the efficiency of your SECVT?


If you are not "technically oriented", let me put it more simply by an example:

Your are capable of carrying 30Kp of weight, through the stairs, from the first to the last floor of a tall building, from the morning to the night without a break. At the end of the day you count the total weight lifted to the last floor and get paid for it.
If instead of carrying 30Kp per time, you carry only 5Kp per time (you continue to lift your own weight), it is like spending resources inefficiently.
Operating the SECVT at a 500% "over clamping" is in a similar way inefficient. Isn't it?


By the way, "it costs nothing to be polite".

Thanks
Manolis Pattakos

 

[NormanB]

Manolis

First of all, welcome to the forum and thank you for the links to your interesting website.

You clearly are a learned chap, but many members may wonder what the aim of your thought provoking posts is? What do you expect forum members to do?

It would help if you completed your user profile and perhaps tell us more about yourself, as it is customary and polite to do, by posting in the 'Who are you,where are you from section'.

It would be useful to explain also, what your aim is by questioning forum members about the relative merits of your designs and the inefficiencies of the SECVT as fitted to the Burgman 650. Remember, we just own and ride these bikes and we have no influence on product development. The forum is not an arm or agent of Suzuki.

Have you had any dialogue with Suzuki or any other motorcycle manufacturer? This would be, perhaps, of much more interest to forum members, many of whom would either have little interest in the technical details of your learned articles or question their relevance directly to them right now as an owner/ rider.

Do you ride a Burgman or any other motorcycle?

This is the sort of angle that this forum is interested in, this forum is a community of common interest 'like minded' people. Of course, there is no compulsion to comply with these polite and reasonable requests, but then again we are under no compulsion to host your 'technical promotion'.

I would therefore suggest and request that you give us some more information, so that we can better understand your aim and motivation in context.

 

[hatman]

Although I am a technical numpty I did find Manolis' detailed analysis and explanation pretty convincing and the significant efficiency losses caused by the over-clamping phenomenon would certainly help explain the pretty horrendous fuel-usage figures when compared with a chain-driven motorcycle of similar size and engine capacity. As regards Cherie's scepticism concerning Suzuki's inability to identify such an apparent design flaw, the explanation is most likely that they are already fully aware of the points raised by Manolis but, as in all manufacturing decisions, the pursuit of perfection is invariably compromised by the need to minimise manufacturing costs so 'near enough' is often regarded as 'good enough'.

 

[bikerdoc]

although i am a technical numpty i did find manolis' detailed analysis and explanation pretty convincing and the significant efficiency losses caused by the over-clamping phenomenon would certainly help explain the pretty horrendous fuel-usage figures when compared with a chain-driven motorcycle of similar size and engine capacity. As regards cherie's scepticism concerning suzuki's inability to identify such an apparent design flaw, the explanation is most likely that they are already fully aware of the points raised by manolis but, as in all manufacturing decisions, the pursuit of perfection is invariably compromised by the need to minimise manufacturing costs so 'near enough' is often regarded as 'good enough'.

+1

:d

 

[ErikDK]

I like technical discussions for their own sake.

Idea: a mechanism using the torque of the output shaft to clamp the driven pulley.

The more torque, the more clamping force applied. Easily done by driving the output shaft through a thread or ramps with balls in between. Something along the lines of a limited-slip differential.
A 7 or 8 step DCT shifting as fast as in VW cars and not as slow as Honda's NC700 would be better.

 

[Just Me]

I see absolutely no advantage to the pat box cvt. over clamping in the Patbox CVT would be greater then the SECVT. Look at the factors causing the over clamping and the Patbox increases the cause approximately by two. Nice diagrams, etc and all but a glaring oversight. Reminds me of the man who showed up in my shop one day who had the answer for a perpetual powered engine he claimed to have invented. Never did get it to run and it is my fault because I refused to get involved.

 

[manolis]

I see absolutely no advantage to the pat box cvt. over clamping in the Patbox CVT would be greater then the SECVT. Look at the factors causing the over clamping and the Patbox increases the cause approximately by two. Nice diagrams, etc and all but a glaring oversight. Reminds me of the man who showed up in my shop one day who had the answer for a perpetual powered engine he claimed to have invented. Never did get it to run and it is my fault because I refused to get involved.

Hello JustMe.

Here we talk for the PatEff CVT in comparison to the SECVT.

For the PatBox CVT go to

http://burgmanusa.com/forums/15-bur...cvt-continuously-variable-transmission-4.html

and see the firgures.

Thanks
Manolis Pattakos

 

[manolis]

Hello NormanB and thanks.

If it helps, I am an engineer.
Pattakon is a team of Greek engineers (brothers and sisters).

Long ago I had a Yamaha XT250 and drove it for a few times before to remove its cylinder and cylinder head that were used for the harmonic engine prototype at http://www.pattakon.com/pattakonPPE.htm#harmonic An old project of pattakon.
It is a single-cylinder (75mm bore, 80mm stroke, 353cc) four-stroke with pure sinusoidal (harmonic) motion of the piston. It is perfectly balanced; as perfectly as the Wankel rotary engine. The balancing of the single cylinder prototype is so perfect that it can stand free on the ground operating from idling to top revs (9,000 rpm, 24 m/sec mean piston speed) without any tendency to leave its place.

I don’t own, nor drive a Burgman.

I was involved with the V-belt CVT’s by chance.

A guy who sells and repairs motorcycles and big scooters here in Athens / Greece, and who is involved in racing things, met me in the machine shop of a common friend and started explaining (actually complaining for) the problems of the CVT’s and of the aftermarket variators.
“This is fast but burns a lot of fuel, this is better but quite unreliable, this is fuel efficient but too slow, . . .”
He liked SECVT of Suzuki Burgman, but not its reliability issues.
As a practical mechanic, he was wondering why nobody yet achieved to make a really
good CVT, good from every point of view.
Theoretically a good CVT is superior than a good manual gearbox, but in practice (and excluding the “easy of use”) the CVT proves worse.


You write:
“It would be useful to explain also, what your aim is by questioning forum members about the relative merits of your designs and the inefficiencies of the SECVT as fitted to the Burgman 650. Remember, we just own and ride these bikes and we have no influence on product development. The forum is not an arm or agent of Suzuki.”

Don’t underestimate the technical background of your forum members.
There are individuals (engineers, physics, mechanics, people who like to think) with great technical, scientific and practical background.
Those I am looking for.
Their “justified” objections may save a lot of time and money for me.

You write:
“Have you had any dialogue with Suzuki or any other motorcycle manufacturer? This would be, perhaps, of much more interest to forum members, many of whom would either have little interest in the technical details of your learned articles or question their relevance directly to them right now as an owner/ rider.”

Try, as an individual, to have a dialogue with the head of an R&D of an engine maker, and you will see how things work.
The people there obey to the strict policy of the company, and simply avoid responding. Some times politely, some other times rudely.
Read the first paragraph at http://www.pattakon.com/pattakonPatMar.htm to understand what I mean.

With the PatEff presented in some big forums like this one, there is a chance the heads of Suzuki’s R&D (hopefully mr. Shinobu Tsutsumikoshi, the inventor of the SECVT of Suzuki) to see it and communicate.

On the other hand, the forum members have nothing to lose.
On the contrary they can start thinking / understanding the way their scooters operate as well as their limitations.
I think you should ask for threads like this one.

If the SECVT (the best CVT in its class) can be substantially better (a substantial reduction of the friction inside it, makes it better and greener and faster etc), isn’t worthy the trial?

I asked if somebody sees where my mistake is.
Because if the “state-of-the-art” CVT for lightweight vehicles (yours Suzuki SECVT) does operate with 500% over clamping at light / light-medium load and high gear (i.e. wherein most of the time it operates during a long trip on the highway) something is quite wrong and must be corrected.

If Suzuki does know already it and has the intellectual property for it, you should ask (as a big and respectable forum) the next version of the Suzuki Burgman to have the spring control because it saves a lot of fuel, of belt replacements, of power.

If, on the other head, Suzuki’s engineers never thought about this problems, it is time to start thinking about it.

Thank you
Manolis Pattakos

 

[sirkitrider-2]

Well, If it ain't broke ..........

Sirkitrider

 

[NormanB]

Thanks Manolis

I think your post helps to put your 'agenda' in context for the members.

By the way, I do not underestimate the forum members here in any way, many are accomplished mechanics and professional engineers.

 

[manolis]

Thanks Manolis

I think your post helps to put your 'agenda' in context for the members.

By the way, I do not underestimate the forum members here in any way, many are accomplished mechanics and professional engineers.

Thank you NormanB.

I would expect more "reaction" by your forum.

Somebody comes and claims that as it is now your SECVT, at a usual trip on the highway at normal speeds (partial load / overdrive) it burns 10% more fuel than it should, it wears the expensive V-belt several times faster than it should, it passes to the rear tire 10% less power than it should, and so on.


If I am wrong, the "technically oriented" are kindly requested to explain where.
I know that you prefer to come with a prototype and comparative dyno and road and consumption tests, but for the moment there is only the theoretical analysis.

If, on the other hand, I am right, i.e. if the control over the spring of the CVT is so important / critical / vital as I claim it is, it would be good to hear that you agree with me and that Suzuki must do something to make things better.

Thanks
Manolis Pattakos

 

[hatman]

...Suzuki must do something to make things better.

Thanks
Manolis Pattakos

Whilst your theories may be absolutely right Manolis I, for one, am convinced that there is no way at all that Suzuki would consider, even for a moment, taking them up with a view to re-engineering the Burgman drivetrain. I think it would be fair to say that the maxi-scoot has proved to be something of a blind alley for the major motorcycle manufacturers, with worldwide sales figures being miniscule in comparison to those of traditional motorcycle designs and the wonder is that Suzuki, for example, continue to persevere with the concept at all, much less committing further expensive R & D resources to a re-design. A pity, but there it is.

 

[Roger32849]

Manolis: While I understand the theory of your engineering and have a high regard for innovation the best we as a collective can do is comment, pro or con on your ideas. As I have posted before, the scooter manufacturing world has their CVT the way they need it to be. Manufacturing a product, no matter what it is, remains only a medium to make money. It has (good enough) engineering to sell the product, but the product itself isn't about engineering at all.. It is about making money. Regardless of what we all want, we buy what is manufactured and available (for a price)

I wish you well in your effort to affect your ideas into production. If you have not approached the major motorcycle manufactures with your engineering ideas, I urge you to do so. The members on this forum are a global sampling of Suzuki Burgman owners that enjoy riding what is already engineered, and works well. It isn't perfect, but as stated in a previous post, "sometimes close is close enough" but there is always room for change and improvement. If your goal is to obtain feedback, please consider the assimilated BURGMANUSA riders dedicated and loyal to the Suzuki Burgman....and enjoy it just the way it is... It could be better but most of us like the simplicity of how it works.. When it breaks, it is easy to fix in an hour or so, and can be done with a few common tools and usually a replacement (single) drive belt. Speaking of the drive belt... It is the weak spot on any CVT but then, when you consider he cost, vs longevity, it does pretty darned good.

Just my point of view

 

[trainman]

Why do you think that Honda has gone to the DCT on several of their new bikes, they saw the future.

John

 

[TheReaper]

Why do you think that Honda has gone to the DCT on several of their new bikes, they saw the future.

John

John got it right , Honda did see the future and they are committed to a viable , cost effective , automatic transmission for 2 wheel and ATV vehicles . I am reasonable sure that the other manufacturers are too , if not they will go the way of the Dodo Bird . Just to prove my point about Honda's commitment to automatics , after failing with the DN-01 they came right back with the DCT at nearly half the list price .

Think about it for a minute , Harley with their trike and lots of other 3 wheelers , Honda with their automatics etc etc . Why now ? Demographics , nearly half the market has bad hips , bad knees and arthritis . Also historically companies spend much more in R&D in bad economic times that in good times . Why ? Because they have to , their survival depends on it .

On top of all of that , the coming of age of the micro processor is making things possible now that were only dreamt about a few years ago . We are in a sort of limbo right now , were saying goodbye to the industrial age and hello to the age of , well I really don't know what to call it ??? But it looks some thing like this . https://www.youtube.com/watch?v=1lKLJTI6aqk&list=FLFpmvfyHnFqTyigpxW839cg&index=4

See any employees ? This is just a tiny sliver of what the coming of age of the micro processor means . Actually it's already there , from this point on it's just a matter of putting the parts together .

TheReaper!

 

[ErikDK]

Honda needs to, if not openly, then by letting information seep out, let the owners play around with gearchange settings, within the bounds of safe operating for the gearbox an engine.
The way the current Honda DCT "forgets" to gear back up after kickdown is intolerable for me.