04-09-2021, 03:46 AM
The first time I encountered an rpm-assist clutch was on the 2016 Triumph Street Twin, which they called "Torque Assist". It was noticeably lighter than the clutch on my T100 Bonnie. hmmm.
But they don't mention a slipper clutch. Looking at their entire range, some have "Torque Assist", some have a slipper clutch, but only the new 660 Trident triple has both.
Just curious, how does a Crampbuster on the left grip help? Isn't it just a throttle assist for the right side?
Thanks for the clarification PD, personally I never knew that there was any difference between "clutch assist" & "RPM assist", since all road test reports I read only mentioned of the 17% lever effort reduction due to the "slipper clutch".
The "RPM Assist" technology part was never ever mentioned; however, it did mention of the high rpm deceleration causing rear wheel hopping reduction due to the cam design inside the clutch basket. The 2-way cam design advantage also apply during acceleration for a lighter lever application.
I did not put 2 & 2 together - stupid me.
No, certainly not stupid, just confusing. The press has been somewhat confused by referring to it as a slipper clutch. Slipper clutches preceded the RPM-assist (or Torque-assist or something-assist), and when this function was added to bikes with a slipper clutch, it was just referred to as slipper clutch. (most motorcycle media are not so technical any more.
)
Interestingly, the Africa Twin has a slipper clutch and a "cam-assist", but it is not mentioned in their website. Way to go, Honda.
Thanks for the information.
Regards
Alain
But they don't mention a slipper clutch. Looking at their entire range, some have "Torque Assist", some have a slipper clutch, but only the new 660 Trident triple has both.
(04-08-2021, 02:21 PM)rich_imp Wrote: i have been using a cramp buster on my clutch grip with good results
Just curious, how does a Crampbuster on the left grip help? Isn't it just a throttle assist for the right side?
(04-09-2021, 02:20 AM)Alain Lee_imp Wrote:(04-07-2021, 05:03 PM)pekingduck_imp Wrote: Just wanted to clarify something first - slipper clutches and rpm-assist clutches are 2 separate functions. The slipper function does not affect clutch lever pressure.
There are bikes with only slipper clutches, while the feature you want - rpm-assist, is on the 2017 EX model, which also has a slipper function. You could have a clutch with just rpm-assist, but it is so easy to add the slipper function (or vice versa).
These 2 innovations are so mechanically and cost effective, they will likely become standard equipment on most bikes.
With rpm-assist, like the CB650R also has, ramps in the clutch help force the clutch plates together, something that only springs could do before. On the 2017 EX, only 3 springs are used, instead of 6 (although the 3 are heavier ones). I believe lever pressure was about 17% lighter
A longer lever will give lighter lever pull, but needs extra travel to engage/disengage. Same thing with a smaller clutch master cylinder bore. There is no real way to cheat physics, except with the rpm-assist in the clutch itself.
Adapting the 2017 EX parts has been tried, but the results were not completed in this thread:
http://cb1100forum.com/forum/showthread.php?tid=12071
I believe it would have worked properly with just the right spacer installed, but I wasn't there.
Thanks for the clarification PD, personally I never knew that there was any difference between "clutch assist" & "RPM assist", since all road test reports I read only mentioned of the 17% lever effort reduction due to the "slipper clutch".
The "RPM Assist" technology part was never ever mentioned; however, it did mention of the high rpm deceleration causing rear wheel hopping reduction due to the cam design inside the clutch basket. The 2-way cam design advantage also apply during acceleration for a lighter lever application.
I did not put 2 & 2 together - stupid me.
Thanks for the information.
Regards
Alain
Thanks for the clarification PD, personally I never knew that there was any difference between "clutch assist" & "RPM assist", since all road test reports I read only mentioned of the 17% lever effort reduction due to the "slipper clutch".
The "RPM Assist" technology part was never ever mentioned; however, it did mention of the high rpm deceleration causing rear wheel hopping reduction due to the cam design inside the clutch basket. The 2-way cam design advantage also apply during acceleration for a lighter lever application.
I did not put 2 & 2 together - stupid me.
No, certainly not stupid, just confusing. The press has been somewhat confused by referring to it as a slipper clutch. Slipper clutches preceded the RPM-assist (or Torque-assist or something-assist), and when this function was added to bikes with a slipper clutch, it was just referred to as slipper clutch. (most motorcycle media are not so technical any more.
)Interestingly, the Africa Twin has a slipper clutch and a "cam-assist", but it is not mentioned in their website. Way to go, Honda.

Thanks for the information.

Regards
Alain
