Rapid fire(?) right hand shifter problem

[Tim Hall]

The Boy's bike has 8 speed transmission with flat bar mounted sghifters. Part number ST-EF50R.  The bigger paddle, for shifting to a bigger sprocket, is loose and has to be pulled into position to do its job, IYSWIM.  It's as if there should be a return spring.  A bit of webbery suggests the main fault with these is the grease drying out, but I don't think it's that. I've had that on another bike and it felt different.  This will shift once the lever is in the right place. The dried out grease one I had just waggled around doing bugger all.  Is there a spring that's busted? Youtube wasn't much help and I'm scared of pingfuckits escaping if I just dive in.

[Torslanda]

Not common but I have come across the paddle getting bent up. It shifts but the lever rubs on the body of the shifter. Try gently bending it down and away.

Readily available, cheap and simple to fit. They're generally not worth trying to repair if the shifter's gone buggrup . . .

[Vince]

I have a set in the garage. I check return spring function in the morning if that's any help.

[Torslanda]

You haven't fitted BMX type grips have you?

The hand guard will foul the lever too . . .

[Tim Hall]

I have a set in the garage. I check return spring function in the morning if that's any help.

Vince, that would be great, thanks.

Tors, no, standard grips, nothing fouling anything.  They used to work properly and have recently gone floppy.  He does rest his thumb against the lever while riding. Whether this has contributed to the problem or  not I don't know.

[Brucey]

FWIW most of these units can have the cover removed without PFI trauma.  You may then see what is going on.

However what they don't like is having the cover removed (or the single screw on the underside -if fitted- backed out) and then the shifter used; this can encourage the nut that holds the workings together to back out and then the shifter will disassemble itself...

cheers

[drossall]

Worth trying spraying with WD-40, surely? Open up the outer case a little so that you can use the tube that comes with the can.

[Vince]

I've had a play and there is definitely a return spring that works on all gears.

[Tim Hall]

Minor, non traumatic, non ping fuckit loss, surgery reveals the end of the return spring has broken off.  It's a smaller version of a canti/V brake spring.  I'll have a go at bending a new tab, just because I can (or not).

[Tim Hall]

Despite extensive use of asking my Dad, using Youtube to learn about hardening, tempering & quenching, blagging a small blow torch and misc pliers, I b0rked it.  The end of the spring fell off during adjustment.

New shifter or new spring it is then.  Bum.