curious , for techies

[jellywrestler]

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.

can't deny them their wins especially the 78 iomtt though

what about a harley then Steve?

[Grumph]

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]

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]

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]

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]

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]

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]

Or little bits of clutch as it wears.

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

[husaberg]

Or little bits of clutch as it wears.

True that

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

Car makers tend to agree

[AllanB]

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

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


Could it be Harley got something right?

[jellywrestler]

Could it be Harley got something right?

all bikes started that way, they just never evolved like the others...

[husaberg]

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?

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]

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]

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]

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.