[Bobster]

Hi,

I've just bought this bike with only 9000km on it. I love it but on initial take off the clutch seems to have a delayed reaction to the lever. That is, the clutch continues to let itself out even though the lever is not moving (but not fully released) This has resulted in a couple of embarrassing stalls!

Does anyone else have this problem with the Supersport, or is it just characteristic of a slipper clutch?

Any advice welcome.

 

[Bobster]

Hi Bott, thanks for replying however this 2017 series Supersport has a cable operated clutch. Sounds like my issue is NOT normal with a slipper clutch then?

 

[Bobster]

Thanks cs363.

Prompted by Bott's reply I went out and lubed the cable anyway. While I was there I observed the actuator rod and it moves exactly with the lever whether released fast or slow so unfortunately my problem is not there. Looks like it's internal :-(

Sounds like it's not a known issue. Apart from getting it looked at for weak / missing / damaged springs, do you think an oil change would help? Pretty sure it's a wet clutch.

 

[Bobster]

Thanks for your thoughts Bott. I’ve been trying different techniques to get around it but I’m convinced the clutch is still disengaging even though the lever is still. With enough revs I can always get away from a standstill but you can really feel it if you’re trying to move the bike slowly, like around a garage etc. You let it out just enough to crawl forwards and suddenly it lets a lot more out resulting in a jump forward and often a stall. Like the clutch is on delay. I’ve been riding for many years so I’ve got an idea how it should work. Chain free play is within the standard spec.

 

[Bobster]

Thanks to everyone who replied to this post.

Just to wrap it up, and for the benefit of other 2017+ Supersport owners, I found a forum dedicated just to this model "Supersport939" and put my issue to them.

Multiple owners assured me that it is very characteristic of this model before the oil warms up. I tried a gentler take off towards the end of my last ride and guess what? They were right. I had a progressive linear clutch! Prior to that, even though the bike was warm I wasn't taking the chance of stalling in traffic, so I was doing higher rpm starts with a fairly quick clutch release therefore masking the improvement as it warmed up.

Relieved to find this out and now totally happy with a great bike!

 

[Bobster]

Thanks cs363,

I don't know what sort of oil is in it as I've only just acquired it and I'm waiting for the service records to arrive (long story).

If you want to plough through a separate post just on the subject it's here: Grabby Clutch? It also introduces another factor - clutch oil pressure, but I'll let you work through that if you're interested.

Couple of other comments:

• Another user on the dedicated Supersport939 forum also reported good results with Penrite
• A much more mechanical mind than me suggested that the cold oil, being more viscous, was slower to be squeezed out between the clutch plates hence the delayed effect. As Mythbusters would say, sounds plausible!

 

[Bobster]

Thanks for advice cs363 and Turtle, and additional thanks for the Bulletin cs363. Interesting reading.

I agree with both of you, definitely going to try the easiest fix first. I've already come around to living with it but if Penrite makes it better it's another step forward!

 

[Bobster]

Thanks whitetip84. I’ll try that also!