Slipping Suntour Sprint Shifters

[Gary Jacobson]

I've made bar end shifters using an old pair of Suntour Sprint shift levers and a Shimano bar end
assembly. This is a standard set up that some people who like simple bar ends use.

I am getting the dreaded "auto shift" both front and rear. I've lubed the BB cable guide, but
unfortunately there is no way to use a plastic sleeve over the deraillure cable to decrease friction
on the rear as there is just a single guide/eyelet. I'm not so sure that is the problem, as other
bar ends I've used (old Suntour Barcons) have not been trouble.

I wonder if I might be missing a shim that would go between the Suntour Sprint lever (containing a
sealed assembly) and the standard washer that is placed next to the square keyed index washer which
fits over the boss.

Anyone know how the Sprint is attached to a shifter boss? If I'm missing a shim, what thickness?

Could there be other sources causing this trouble besides cable friction under the BB and what I
have described?

Thanks so much.

Gary Jacobson Rosendale, NY

 

[A Muzi]

"Gary Jacobson" <[email protected]> wrote in message
news:[email protected]...
> I've made bar end shifters using an old pair of Suntour Sprint shift
levers
> and a Shimano bar end assembly. This is a standard set up that some people who like simple bar
> ends use.
>
> I am getting the dreaded "auto shift" both front and rear. I've lubed the
BB
> cable guide, but unfortunately there is no way to use a plastic sleeve
over
> the deraillure cable to decrease friction on the rear as there is just a single guide/eyelet. I'm
> not so sure that is the problem, as other bar
ends
> I've used (old Suntour Barcons) have not been trouble.
>
> I wonder if I might be missing a shim that would go between the Suntour Sprint lever (containing a
> sealed assembly) and the standard washer that
is
> placed next to the square keyed index washer which fits over the boss.
>
> Anyone know how the Sprint is attached to a shifter boss? If I'm missing a shim, what thickness?
>
> Could there be other sources causing this trouble besides cable friction under the BB and what I
> have described?

Counterintuitively, coating all the internal washers of a classic friction lever with a drop of oil
lets them shift smoothly and avoid slipping. There should be a square-hole flat washer on the boss,
then a round 2mm tall washer under the lever, just as in the classsic Campagnolo model from which
the Sprint is copied. You do know that the wire-bale screw can be tightened while riding, right?

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971