Contemplating modifying primary clutch

[larryd]

Dalton industries

https://daltonindustries.com/

I delt with Dalton Industries for all my ATV and snowmobile clutch needs for years...I always talked to a very knowledgeable person by the name of Dale...They always had the info, knowledge and parts need to make it happen for me...larryd

 

[ConorKnoxx]

My understanding of this, is that you can change rpm / to / speed ratio, up to the point the clutch is fully open/engaged. From that fully open point onward, only the engine rpm can effect speed. I have no idea at what speed / rpm it's fully engaged, but for the sake of argument, if it happened at 50mph cruise speed, no amount of clutch mod's will change your rpm/vs speed from that speed onward?

 

[SportsterDoc]

At steady cruise, 44 MPH is 4400 - 4500 RPM
I've seen 6700 RPM at 75 MPH and at 87 MPH..not consistent / linear RPMs vs speed.
8200 RPM at 108 MPH

On recent street bikes 5000 RPM is about 100 MPH

 

[lugnut1009]

It’s dependent on load as well. It’s a balancing act.

 

[SportsterDoc]

Yes, load is a factor in addition to RPMs.

https://www.youtube.com/watch?v=uCEvBGT8twM

I still do not see the need for a 82 HP motor to run 6,000 to 7,000 RPMs at highway cruising speed, when not accelerating.

The Rkyer certainly is responsive, but 33 MPG cruising is not a plus point.

 

[lugnut1009]

Yes, load is a factor in addition to RPMs.

https://www.youtube.com/watch?v=uCEvBGT8twM

I still do not see the need for a 82 HP motor to run 6,000 to 7,000 RPMs at highway cruising speed, when not accelerating.

The Rkyer certainly is responsive, but 33 MPG cruising is not a plus point.

Exactly. That’s why I think it would be as simple as replacing the spring in the secondary clutch with a softer spring. Primary is more or less tuned for the engine power band, secondary kind of sets the ‘gear ratio’ to the final drive. I know it’s not that simple, but that’s a simple explanation. Well at least until you get to full clutch shift. Hard to tell what we can do with cruising rpm without knowing what state the clutches are in at said speed. If primary is fully closed and secondary fully open, tuning won’t help at all. Maybe we just need taller tires? Ha