Ducati Monster Forum

Do lightened cranks increase engine breaking like lightened flywheels do? 

Others more qualified should chip in.

My experience is comparing the heavy crank 900, "medium" crank 1100DS  and light crank 1100 Evo motors. It may be more than just the crank getting the Jenny Craig treatment, but associated rotating parts like the flywheel, primary gears, timing gears, alternator, etc.
I would think so as a side effect which you may or may not like. The benefit of course is quicker acceleration. It's very noticeable on the 1100 Evo motor which also has a lighter flywheel. The 1100 Evo will spin up or down, very quickly. Some tune the effect by playing with flywheel weight or mitigate the influence on corner entry using slipper clutches.
What are you working on?

Lightweight crankshafts (or lightened ones) do mimic or add-to the characteristics of a lighter flywheel.

I thought that might be the case.


I've started lightening internals, beginning with a lighter stator from a sbk and a machined stock flywheel.  I have to say, I don't like the engine-braking-like phenomena (or is it actually just engine braking?) at all; it's so dramatic that once I'm off the throttle, the bike basically slows as if I'm on the rear break (but no accompanying brake light to let traffic behind me know that I'm slowing).  The machining was done by a known tuner to a weight that a lot of people seem to like, but I'm almost certainly going back to stock, and if lightening the crank is going to result in the same experience, I'll pass on that, too.  

You can go the lightweight route if you want vivid acceleration but get a slipper clutch to roll thru corners without stopping on the corner entry because of excessive engine braking. For a track bike I hate engine braking, but I have found it useful on the street and modulate it old school style by manipulating the clutch in some corners. It's all personal preference. A heavy crank/flywheel is smooth and satisfying on a highway, but a light crank is awesome exiting corners in the canyons (or track). Depends on the bikes purpose.

I've got a slipper, and I've been basically pulling the clutch in every time I'm off the throttle to avoid the sudden deceleration.  Acceleration is great, but the "on/off" feel is too much.  It's weird, because I had a Nichol's aluminum flywheel on another bike, and it wasn't this severe.

If your slipper is adjustable you can tune it to really "let go" on corner entries.
What bike is it again?

S2R800, so while it is technically a slipper, I don't think it's all that tunable. 

I honestly have no experience with 800's. Maybe a wet slipper from another model can fit. I'm guessing the internals on an 800 are pretty light compared to say the 900 and 1000DS bikes, so you would feel that machined flywheel.