Sticky throttle

[Nobbylad]

OK - so the K8 and I are getting to know each other quite well over the last 2 weeks or so....

Anyways, noticed the last few days that the throttle grip had some lateral movement in it, not much but a few mm left to right. I was gonna post on here to ask about it but thought that it may have always been like that as I've been mainly concentrating on getting to know the handling etc since I bought it.

Tonight I get on to ride home from work and instantly the throttle feels very stiff. Not so stiff that it's sticking, but definitely takes more to wind it whereas before it was all too easy.

I also noticed the lateral movement had completely stopped and I wasn't able to move it side to side at all.

I get home and take a look at the grips and there's a small gap 2-3mm between the grip side of the bar end and the rubber grip itself. So, intrigued as I am, I undo the bar end and essentially there's a kind of plunger assembly inside the grip, presumably as you tighten the screw on the bar end, it compresses the rubber plunger and it grips inside the bar?

Anyway the plunger assembly has, what looks like beads of water on it and I refit the whole thing after taking it out. There is still a slight gap between the bar end and the rubber grip, almost as if the rubber seal at the end won't quite fit in the bar, but the lateral movement is back again and the throttle is v. smooth again.

I did twist the throttle to fully open and back again a few times whilst feeling around the throttle cable for any unusual kinks etc (advanced engineering skills I hear you say), but apart from that all I did was as above.

So, should the throttle be stiff, or v. loose and should there be any lateral movement?

If not, any ideas on what's wrong with it?

If so, any ideas why it might be getting tight?

Thanks in advance for any ideas :smt023

[Sid Squid]

I'd say your bar-end had been bumped and had moved up against the twistgrip. Yes, the twistgrip should move axially a millimetre or two, and your assumption on how the bar end fixes is correct. However the 'bar-end should be fitted against the end of the 'bar, if that makes the twistgrip stick then the rubber may not be correctly fitted on the throttle tube, or possibly the twistgrip housing, (where the cables enter the assembly), is incorrectly fitted on the 'bar, this is rather less likely as the housing has a positioning lug which fits in a corresponding hole in the 'bar, so it shouldn't be possible for it to be out of place. It's important that the throttle doesn't stick, you'll fail an MOT like that, (although your bike being a K8 means that won't be important for a while), but the consequences could be more immediate, not funny.

[Nobbylad]

Thanks for replying Sid....I did pull back the rubber on the twist grip and saw the positioning lugs, they are in place.

As well as the rubber plunger inside the bar, there is a rubber seal at the end of the bar, where the bar end fits against the bar. That doesn't seem to be seated properely in that it's not flush with the bar....it looks like it should site inside the bar and finish flush with the end, is that right?

[Baph]

In the past, I have accidentally done a bar end up too tight.

Works quite nice for cruise control though. ;) In other words, if the bar end is too close to the grip, you wont have left/right movement on the grip, and it'll be stiff. Otherwise, it should be free to move (and thus spring closed) and a little sidewas movement is usual.