Possible to lock the front deraileur?

[ckropp]

Hey everyone, I started a little project on my old cannondale f300 to make it into a 9 speed, using just the middle front chainring. I've noticed that the chain easily pops off and I was told to use an old front deraileur as a chain guide. can anyone tell me how I would lock out the front der. in the second chainring position? Thanks guys.

-Corey

[mtn_man2]

There are 2 screws on the top of the der. These are called limit screws and they do just that. They limit the range of movement of the front der. What you should do is hold the front der. cage where you want it and tighten both the screws down until they stop. You don't need to crank on them. Just snug them down. You should be set.

[ckropp]

hey thanks so much, appreciate it

[swift]

As an alternative, Rohloff makes a front chainguide that might be perfect for your application.

http://www.universalcycles.com/shopp...s.php?id=16800

Good luck!

[jaghouse]

There are 2 screws on the top of the der. These are called limit screws and they do just that. They limit the range of movement of the front der. What you should do is hold the front der. cage where you want it and tighten both the screws down until they stop. You don't need to crank on them. Just snug them down. You should be set.

Does this really work for keeping the middle chainring from coming off?? I have tried it on my bike and the front der. has to move a long ways out from the seat tube to secure the middle ring... beyond the range of adjustment for my der. I can totally see it working for using the granny. Jump stop would be the way to go on a F300 imo:

[shiggy]

Does this really work for keeping the middle chainring from coming off?? I have tried it on my bike and the front der. has to move a long ways out from the seat tube to secure the middle ring... beyond the range of adjustment for my der. I can totally see it working for using the granny. Jump stop would be the way to go on a F300 imo:

Checking the tightness of your chainring bolts regularly will keep the chainrings from coming off. A front derailleur or Jump Stop will make no difference.

[jaghouse]

Checking the tightness of your chainring bolts regularly will keep the chainrings from coming off. A front derailleur or Jump Stop will make no difference.

ahhh yes ... those darn bolts... I really should get some wrenches sometime.