curious , for techies [Archive]

pritch

29th December 2018, 20:05

No, it's a Ducati issue, same as those ridiculous clutches that sound like they are falling apart whenever they are disengaged.

Ducati recommended a belt change every year even if you didn't run the bike IIRC. There was waffle about "set".

Anyhoo the recent models have done away with all that. Still, if I had an older one I'd be careful, if a belt lets go it's expensive.

And yeah those clutches! My 1954 AJS probably had a better clutch. Imagine what the magazines would say if a Jap manufacturer offered a dry clutch.

But I did like my Ducati: https://www.kiwibiker.co.nz/forums/album.php?albumid=3878&attachmentid=228690

OddDuck

29th December 2018, 20:26

My guess: small pulleys compared to the ones on most cars. The belts have to go around a tight radius so there's lots of flexing, hence shorter belt life.

tanken2

30th December 2018, 07:32

My guess: small pulleys compared to the ones on most cars. The belts have to go around a tight radius so there's lots of flexing, hence shorter belt life.

i can relate to this.

Grumph

30th December 2018, 07:44

To a certain extent it's torque load distribution. A single with belt driven cam has very distinct torque load peaks as each cam lobe opens a valve.
A car engine - usually at least four cylinders - has a lot of torque peaks as multiple loads hit and release. This does at least distribute the wear around a belt.
Combine the Ducati's high point loadings with what are rather small pulleys and you get short belt life....

sidecar bob

30th December 2018, 07:59

AllanB

30th December 2018, 08:17

Belt servicing is either 24 or 30,000 kms on newer model Ducatis or 5 years. The same as valve clearance checks on a Japanese bike.

Smaller pulleys than cars, so tighter radius and I think critically a much narrower belt than what is used in a car engine.

They are all wet clutches now and have been for some years - I suspect only to meet noise regulations. I think the 1000cc race version of the new V4 comes with a dry clutch.

Grumph

30th December 2018, 10:20

So in brief, compounding stupid design.

I wouldn't disagree now. But when Ducati brought it in, on the first 500 Pantah, it was head and shoulders better than anything else they could have used.
The bevel twins were a cost nightmare - both to assemble and run. Italian camchain of the period had to be duplex to stand the pace - see Laverda twins.
The belt worked - and was affordable.

But as revs rose and DOHC heads came in, the limits were reached. It's hard to see what else they could have used at the time. The market had rejected the expensive bevel twins and a gear drive of some other kind would have been just as expensive. Yes, it's feasible now, CNC manufacture and the general willingness to pay for high tech at the top end of the market have allowed things like the new V4 Panigale.

AllanB

30th December 2018, 13:03

Mmmmm gear drive with clear windows in the covers to see them whizzing around.

sidecar bob

30th December 2018, 15:04

Mmmmm gear drive with clear windows in the covers to see them whizzing around.

Like watching Julian Clarry stand up comedy. Gay & predictable, but kind of fun to watch.

pete376403

30th December 2018, 16:29

I wouldn't disagree now. But when Ducati brought it in, on the first 500 Pantah, it was head and shoulders better than anything else they could have used.
The bevel twins were a cost nightmare - both to assemble and run. Italian camchain of the period had to be duplex to stand the pace - see Laverda twins.
The belt worked - and was affordable.

But as revs rose and DOHC heads came in, the limits were reached. It's hard to see what else they could have used at the time. The market had rejected the expensive bevel twins and a gear drive of some other kind would have been just as expensive. Yes, it's feasible now, CNC manufacture and the general willingness to pay for high tech at the top end of the market have allowed things like the new V4 Panigale.
did the "market reject bevel drive" or did Ducati (up against the financial wall as usual) have to introduce a cheaper system to survive?

husaberg

30th December 2018, 17:40

did the "market reject bevel drive" or did Ducati (up against the financial wall as usual) have to introduce a cheaper system to survive?
Second same as why they went to plain bearings.

sidecar bob

30th December 2018, 17:48

Second same as why they went to plain bearings.

Desmo, bevel drive, dry clutch & roller bearing bottom end.
All ridiculous fancies that every 200 HP plus modern superbike manages to get by reliably without.
I'd rather shit on my hands & clap than own a Ducati.

george formby

30th December 2018, 18:18

I'd rather shit on my hands & clap than own a Ducati.

Don't mince your words, man. Tell us how you really feel.:confused:

:laugh: I'm gonna use that if you don't mind.

jellywrestler

30th December 2018, 18:29

Grumph

30th December 2018, 18:29

Desmo, bevel drive, dry clutch & roller bearing bottom end.
All ridiculous fancies that every 200 HP plus modern superbike manages to get by reliably without.
I'd rather shit on my hands & clap than own a Ducati.

Roller bottom end ? C'mon, you know you love your old GSX racebike, LOL.

I've had the dry clutch argument with a guy in Oz who was "improving" Laverda triple clutches by ventilating the drums to "let more oil in"...
I pointed out that all the modern clutches are so well ventilated that as soon as they're spinning, they're effectively dry....
So yes, it was an improvement but for exactly the opposite reason he thought.

sidecar bob

30th December 2018, 18:32

Roller bottom end ? C'mon, you know you love your old GSX racebike, LOL.

Yep, I sure do.
Someone asked me what the difference between one of them (roller bottom end GSX) & a later oil cooled plain bearing one for racing.
I thought for a bit & said, one is like bouncing a ball & the other is like bouncing a rock.

Grumph

30th December 2018, 18:34

Yep, I sure do.
Someone asked me what the difference between one of them (roller bottom end GSX) & a later oil cooled one for racing.
I thought for a bit & said, one is like bouncing a ball & the other is like bouncing a rock.

Ha - I'd have said, money. To get a GSX to go like a GSXR takes a large pile of it.

sidecar bob

30th December 2018, 18:36

Ha - I'd have said, money. To get a GSX to go like a GSXR takes a large pile of it.

Or you could just bolt a later one in your XR69 & get banned from racing at the Island Classic.

husaberg

30th December 2018, 19:41

Desmo, bevel drive, dry clutch & roller bearing bottom end.
All ridiculous fancies that every 200 HP plus modern superbike manages to get by reliably without.
I'd rather shit on my hands & clap than own a Ducati.

Prior to When they went to the Mille engine something like 2 in 10 crankshafts were within tolerance. the big ends shagged out real quick on the 900's
Even with the plain big end mille they had to use expensive annular contact bearings. (like a Norton superblend i believe)
The roller bearing needed the interference fit which in tur stressed the crankcases which in tuned engines leaded to cracking.
Which became a perennial problem with the 851-916 series
The cranks still flopped around which is why they had two outrigger bearings
The Supermono was the first Duke with all plain bearing and never gave problems and could ultilise much smaller crankcases.
The advantage other than friction reduction s the dry cluch doent put heat into the engine oil.

The Honda racing GP fours five and sixs had all roller bearings as did the Benellis and likely the MV;s as well

AllanB

30th December 2018, 20:40

The advantage other than friction reduction s the dry cluch doent put heat into the engine oil.

Or little bits of clutch as it wears.

Voltaire

30th December 2018, 20:45

Or little bits of clutch as it wears.

What? clutch and gearbox running in engine oil...that's a crappy clappy idea.:innocent:

husaberg

30th December 2018, 21:20

Or little bits of clutch as it wears.
True that

What? clutch and gearbox running in engine oil...that's a crappy clappy idea.:innocent:
Car makers tend to agree

AllanB

30th December 2018, 22:32

What? clutch and gearbox running in engine oil...that's a crappy clappy idea.:innocent:

It is really. But it's cheap to produce that way.

Could it be Harley got something right?

jellywrestler

30th December 2018, 23:02

Could it be Harley got something right? all bikes started that way, they just never evolved like the others...

husaberg

31st December 2018, 12:11

all bikes started that way, they just never evolved like the others...
And all those dry clutched Mgp bukes?

Also for a racing Vincent what clutch would you recomend a Vee Two Ducati conversion? or a norton AMC dry with diaphragm?
<img src="https://s-media-cache-ak0.pinimg.com/originals/60/16/f9/6016f9a2b3e4b21cad2e17ce65e28807.jpg" height="250px"/><img src="http://images.motorcycle-usa.com/photogallerys/15-repsol-honda-6.jpg" height="250px"/><img src="http://images.motorcycle-usa.com/photogallerys/15-yamaha-m1-8.jpg" height="250px"/><img src="http://photo.gp/wp/wp-content/uploads/2015/10/Aprilia-dry-clutch.jpg" height="250px"/>

It is really. But it's cheap to produce that way.

Could it be Harley got something right?

i dont agree it needs seals at the back of clutch plus a two piece hub i would say its dearer to produce not to mention the noise emissions cost for every Db it makes they have to quieten down the exhaust

WALRUS

31st December 2018, 12:31

My guess: small pulleys compared to the ones on most cars. The belts have to go around a tight radius so there's lots of flexing, hence shorter belt life.

Also consider how high these motors rev (compared to most "big twins").

It's just a part of the game that is Duc' ownership. If I wanted something boring and easy, I'd have bought a Honda. I like working on stuff and while the tension and replacement schedule for belts puts a lot of people off (and the mechanical/financial ruin if you balls it up) it's actually SO easy to do yourself. I've tensioned and replaced belts on Desmoquattro engines, Testastrettas, and a Testastretta Evo1 with no troubles whatsoever.

Same with the whole dry clutch thing. Some people love it, more people loathe it.. I can't get enough, personally.

sidecar bob

31st December 2018, 13:18

Also consider how high these motors rev (compared to most "big twins").

It's just a part of the game that is Duc' ownership. If I wanted something boring and easy, I'd have bought a Honda. I like working on stuff.

And that sums it up.
If you worked on stuff for a job, by the weekend, all you would want was a reliable low maintenance bike that didn't even have a chain to worry about.
Doesn't it bother that they are a bit of a pile of shit though? Good quality stuff doesn't need constant expensive fettling.

Cadbury

31st December 2018, 13:33

husaberg

31st December 2018, 13:38

While I'd love to join in on a Ducati slagging match just for S&G, I would offer that the belt drive on a Honda ST1100 has a 144,000km replacement interval. The superior Honda design uses single large idler sprockets for the cams, driving the DOHC through a gear drive system. :bleh:

The design is i guess also non interference if the belt breaks i doubt the piston and valves will ever meet let alone fall in love and want to be joined together for ever then escape the confines of the cylinder head and cylinders.

Voltaire

31st December 2018, 13:54

And that sums it up.
If you worked on stuff for a job, by the weekend, all you would want was a reliable low maintenance bike that didn't even have a chain to worry about.
Doesn't it bother that they are a bit of a pile of shit though? Good quality stuff doesn't need constant expensive fettling.

That explains why I have two dukes then, along with other assorted high maintenance vehicles :msn-wink:

sidecar bob

31st December 2018, 13:56

While I'd love to join in on a Ducati slagging match just for S&G, I would offer that the belt drive on a Honda ST1100 has a 144,000km replacement interval. The superior Honda design uses single large idler sprockets for the cams, driving the DOHC through a gear drive system. :bleh:

I'm not slagging them, if anything I have posted is incorrect then I'd be happy for someone to correct me.:niceone:

husaberg

31st December 2018, 14:21

I'm not slagging them, if anything I have posted is incorrect then I'd be happy for someone to correct me.:niceone:

I know you are stiring but People buy Ducatis as they are riders bikes they stir the soul people also appreciate their idiosyncrasies or they are that smitten like a hot girlfrind they simply over look them.
Same reason people spend silly money on 1950's tech harleys and Endfeilds.
Ducati keeps to their own heritage and followed a simple formula often at the cost of being competitive ie 90 degree v and Desmo dry clutch.
They couldn't compete on mass market so they made their own niche just as Guzzi and Harley did.
Of all the millions Hondas made how many have a genuine cult following? Hawk/Bros RC30/NC30/35 CR500 Cb400F SOHC 750 CBX1000 MB/H100 CB1100R and Fireblade
Modern Triumph soon learned the same hence the twins and threes.
As Yamaha learned in the early 80's when they tried to take Honda on head to head you cant beat Honda at their own game you have to do something different.

george formby

31st December 2018, 14:26

Ducati Rider, you can tell by the eyes.

340084

sidecar bob

31st December 2018, 14:47

I know you are stiring but People buy Ducatis as they are riders bikes they stir the sole.

I know a bloke with an old bevel & it definitely stirs the sole, I've seen him kicking it over in the beating sun outside a crowded biker pub for ages.
He called my R100rs Purple Rain, I call his Ducati Purple Face.

husaberg

31st December 2018, 15:27

I know a bloke with an old bevel & it definitely stirs the sole, I've seen him kicking it over in the beating sun outside a crowded biker pub for ages.
He called my R100rs Purple Rain, I call his Ducati Purple Face.

Out of interest just how wet is that cltch in the beemer:laugh:
Bikes that stir the sole might explain the dirty old oiler you have hanging up in your house as well.

sidecar bob

31st December 2018, 15:33

Out of interest just how wet is that cltch in the beemer:laugh:
Bikes that stir the sole might explain the dirty old oiler you have hanging up in your house as well.
There's a difference between motorcycle dry clutch & automotive clutch.
Hey, that "dirty old oiler" is the cleanest bike I have.

Voltaire

31st December 2018, 15:34

That’s where your going wrong, your getting your soles and souls mixed up, ah soles :msn-wink:, reminds me of the crap in float bowels thread:laugh:

husaberg

31st December 2018, 16:03

There's a difference between motorcycle dry clutch & automotive clutch.
Hey, that "dirty old oiler" is the cleanest bike I have.

The automotive dry clutch and the motor bike hey are just as dry as each other.
Even now some higher performance cars are going multiplate now ie slowly following bike practice
The dirty old oiler likely is full of Grease to stop the leaks.
<img src="https://www.newshub.co.nz/dam/form-uploaded-images/simon-bridges-countdown-checkout-with-leek-1120-jono-and-ben.jpg" width="440px"/>

ps here is a Triumph Trident Clutch notice the springs and plate how automotive of them.
http://www.rcycle.com/DW_Trident_158__Medium_.JPG

sidecar bob

31st December 2018, 16:28

Well whatever your take on it. Non motorcyclists don't look at me like my bike is fucked when I pull my clutch in at an intersection.

OddDuck

31st December 2018, 17:28

Well, it sure sounds like a drier drum full of bolts when it's idling in neutral. Clutch pulled in, in gear, it's usually OK. The plates skimming usually keeps the tangs engaged so that way things don't tumble and make a racket.

Just for the record Bob, I agree, the dry clutch might have had good reasons to exist before but its a PITA now.

pritch

31st December 2018, 17:45

If I wanted something boring and easy, I'd have bought a Honda.

Having owned both Honda and Ducati, I became aware that Honda offer more and demand less. Even Ducati admit that. I usually agree with your posts, but anybody who finds a bike boring needs to look somewhere other than the bike to identify the problem.

jellywrestler

31st December 2018, 18:36

Well, it sure sounds like a drier drum full of bolts when it's idling in neutral. .

you mean two skeletons having a fuck on a tin roof, using a tin can for a condom....

husaberg

31st December 2018, 19:11

Well whatever your take on it. Non motorcyclists don't look at me like my bike is fucked when I pull my clutch in at an intersection.

Non motorcycists also think Harleys are fast

WALRUS

31st December 2018, 19:35

Having owned both Honda and Ducati, I became aware that Honda offer more and demand less. Even Ducati admit that. I usually agree with your posts, but anybody who finds a bike boring needs to look somewhere other than the bike to identify the problem.

Fair call, I was being facetious :P