Clutch engagement during fast start

[Shelterwoods]

When trying to launch hard, like a drag race start, my R1250RS will engage like a light switch, feeling as though I've dumped the clutch.  I could launch like this with any of my Japanese bikes, (CX500, VF1100F, VFR800, ZX9R, GL1800) and get a smooth engagement every time. The BMW feels like there is a servo acting on the clutch. Normal starts are easy and sure, and once started I almost exclusively shift without the clutch with no problem. It feels as though the switch that indicates to the shifting system that the clutch lever is being pulled for shifting instead of just moving the shift lever without the clutch, is engaging the clutch. As I write this though, I'm reminded that the quick shift system doesn't work if the clutch lever is pulled, so perhaps as I've described, as I release the clutch, the switch indicating clutch use is engaging the clutch, regardless of my use. Perhaps I can change this behavior by adjusting the engagement point at the clutch lever with the knob on the lever. Your thoughts? 

[gary45]

Slipper clutch

 

[DakarTimm]

I don't believe this is the work of the slipper clutch . As I undewrstand it the "slipper clutch " only comes into play if the selectred gear is spinning faster than the engines rpm . It only slips when down shifting. This keeps the engine from overreving and damaging the valve train . 

As to the original post . What functions of engine control are activated ? There are a plethora of options "Dynamic " ride control for example

[DakarTimm]

A second point . You have a hydraulic clutch do you not ? Is there a reservoir on the handle bar do you not ? If indeed you do . Then the only function of the adjustment wheeel is to bring the levere closer to the handlebar for smaller fingers .

[dirtrider]

6 hours ago, Shelterwoods said:

When trying to launch hard, like a drag race start, my R1250RS will engage like a light switch, feeling as though I've dumped the clutch.  I could launch like this with any of my Japanese bikes, (CX500, VF1100F, VFR800, ZX9R, GL1800) and get a smooth engagement every time. The BMW feels like there is a servo acting on the clutch. Normal starts are easy and sure, and once started I almost exclusively shift without the clutch with no problem. It feels as though the switch that indicates to the shifting system that the clutch lever is being pulled for shifting instead of just moving the shift lever without the clutch, is engaging the clutch. As I write this though, I'm reminded that the quick shift system doesn't work if the clutch lever is pulled, so perhaps as I've described, as I release the clutch, the switch indicating clutch use is engaging the clutch, regardless of my use. Perhaps I can change this behavior by adjusting the engagement point at the clutch lever with the knob on the lever. Your thoughts? 

Afternoon  Shelterwoods

 

It doesn't sound like the quick shift as that really only acts on the engine power side not the clutch engagement side. 

 

It could possibly be the traction control sensing impending wheel spin therefore cutting some engine power  (that could allow clutch engagement slippage to instantly lock up due to handling less engine power).

 

You might try turning off the traction control then re-trying your hard launch as a quick test (but do be careful if you are doing this as you could get some front wheel lift or rear wheel slippage)

[gary45]

https://www.k1600forum.com/threads/what-is-a-slipper-clutch.154417/post-1977161

 

Article explaining slipper clutch, the 3 ramps that allow it to slip also increase pressure during acceleration to stop slipping

[Shelterwoods]

Thanks for the thoughts and information.

 

Regarding the traction control, I've tried setting the system to Dynamic Pro, and setting traction control to the lowest setting, to no avail. 

[Quasimoto]

Turn the TC off and then try it (same switch as your suspension settings). Mind, this will default back ON every time you turn the engine off and back on again...