SIS shift lever is loose

[[email protected]]

I just got a new bike and know very little about maintenance. I rode
it for about half an hour on a mag-trainer and it worked very well.
Today, while riding, after about five minutes, the front derailleur
shift lever just started loosening and causing downshifting. I can't
figure out how or why the lever is loose, it has a plastic nut that I
can finger-tighten, but am afraid to put too much torque on it for fear
of breaking it. I can pull the cable with my finger and cause the
lever to loosen and downshift. The levers are mounted to the downtube
and are shimano SIS the model is SL-SY20A

Thanks for your help

 

[Qui si parla Campagnolo]

[email protected] wrote:
> I just got a new bike and know very little about maintenance. I rode
> it for about half an hour on a mag-trainer and it worked very well.
> Today, while riding, after about five minutes, the front derailleur
> shift lever just started loosening and causing downshifting. I can't
> figure out how or why the lever is loose, it has a plastic nut that I
> can finger-tighten, but am afraid to put too much torque on it for fear
> of breaking it. I can pull the cable with my finger and cause the
> lever to loosen and downshift. The levers are mounted to the downtube
> and are shimano SIS the model is SL-SY20A
>
> Thanks for your help

a screw driver and tighten the bolt in the center of the shiftter a
wee bit.