Thanks Mike I'll try that.
On the stand I notice that when the plate displaces the chain enough to get
it off the small ring, the chain is actually past the outer ring. With the
40 tooth that doesn't happen. Be interesting to see what changing the angle
does.
Bob
"Mike Jacoubowsky" <[email hidden]> wrote in message
news:[email hidden]...
Quoted message said:I swapped out 54/44 chainrings for 50/38. Followed Shimano specs when I
lowered the shifter. After making the change the chain would repeatedly
roll off the outer ring (i.e. going from small to large ring). When I
increase the size of the middle ring to 40 problem goes away which
indicates
Quoted message said:I have the shifter adjusted OK.
Anyone know if a 12 tooth change is too much or is a shifter that can
handle
Quoted message said:a 54 tooth ring too large for a 50 tooth ring?
Also wondering if filing down one tooth on either or both rings might help
the problem. Thought before I file I'd check to see if anyone had
thoughts
Quoted message said:on subject
Don't file the teeth; that's not going to help anything. My guess is that
the angle of the derailleur is off a bit. In general, when you're in the
large front/small rear combo, the derailleur's outer cage plate should be
just slightly pointed out at the back (away from the chain & wheel). Not
much, just slightly. You might have it parallel or even inboard a bit,
requiring that the limit screw be moved out further than it ought to be in
able to get it to shift up.
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
