Front Derailleur

[Jdratcliffe]

dear all need some help i had a scare this morning on the way in went across traffic to filter from a hill went to change up chainrings as previous road is a steep hill but chain dropped instead luckily got it to the side put chain back on. turns out now i cant change chainrings up unless the rear cassette is on on of the highest three or four gears.

ideas as to why and how to correct it, id rather not have to take it to the LBS.

 

[NorvernRob]

I'd reset the FD up from scratch and see if that sorts it. If it's over shifting and dropping the chain the limit screw must be allowing it to travel too far, you wouldn't notice this if the cable tension is also a little bit slack as the derailleur would come back in slightly after shifting. In that moment of over-shifting when you've got the lever pressed is when the chain can drop.

This is the best video I found for explaining it really clearly:

http://roadcyclinguk.com/how-to/maintenance/video-how-to-adjust-a-front-derailleur.html

 

[Cycleops]

Sounds like your f/d has gone out of adjustment thus causing the problem. Start from scratch as NorvernRob says. Also check the clamp hasn't come loose, unlikely but worth doing.

 

[Jdratcliffe]

thanks guys need some fettelering time