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Hello,

I believe I read somewhere on this forum that duc singles don't like low revs. I searched and cannot find that thread. I recall there being as suggestion that low rev riding, or 'babying' these bikes is actually detrimental to the big end.

Is this true, or did I misunderstand? Would this be true of the widecase singles? Or just narrowcase?

Any wisdom on this topic is much appreciated!

Kind regards,

David
68 Monza

Hi David . The roadgoing singles are a direct decendant of the 1950's race bikes that were designed and built for endurance races. The oil flow and stress on major engine components is optimised at revs above 3000. They do not survive well if plodded about. I keep my 250 above 4000 if possible and rarely use 4th and 5th gears in town. Revs over 8ooo ( mine will easily pass 9000) are best restricted for a long life big end.The motors porting will usually restrict the max revs unless modified.

Like he said.

Ride it like you stole it!
Cheers,
George

Thank you Gentlemen! This is exactly what I was looking for. I wish I had a tachometer!

Kind regards,

David

Hi David. I reckon I've read the same comment as yourself, but I also remember reading that fitting a high output pump means you don't need to keep the revs high (although you may be happy to anyway....). Nigel Lacey sells them (made to his specification), but he has no stock at present. https://laceyducati.com/ducati-parts/ti ... p-291.html

Aye Hiya9612,

With a standard oil pump in good condition, or one of Nigel's upgrades fitted, it's nothing to do with the engine requiring high revs to pump oil through the big-end, but the hammering/peening effect on the big-end bearing rollers from lugging the engine in too high a gear. Lugging the engine in too high a gear, especially with a 450, also results in potential damage to both the 4th and 5th gears, causing the gear teeth to break up.

Rev them out, or well into the upper half of the engines rev range, before selecting the next higher gear and use a good quality oil, changed between 1,000 and 1,500 miles.

As for David's

I wish I had a tachometer!

Just do it by ear and the vibe!

Good health, Bill

themoudie wrote:Aye Hiya9612,

With a standard oil pump in good condition, or one of Nigel's upgrades fitted, it's nothing to do with the engine requiring high revs to pump oil through the big-end, but the hammering/peening effect on the big-end bearing rollers from lugging the engine in too high a gear.

Hey Bill
Good information.
Goes to show the value of being a member of this forum!
Thanks
Phil

Aye Phil, a pleasure!

Good health, Bill

There's another factor that puts excessive load on the big end bearing - large throttle opening.
A recipe for short life of the bearing is consistent: high gear, low revs, wide open throttle.

A plain bearing engine with similar dimensioned big end copes better than with a roller big end.
A compromise for constant low revs with rollers, is to ditch the cage and install more rollers in the added space.
That's what some Vincent engines had, also my 1960 Panther 600cc single.
I'm not suggesting that as a course of action for our Ducati singles.
Just alter the riding style recipe.