Front deraileur question
#1
Hey let's ride.
Thread Starter
Join Date: Apr 2006
Location: Allen, TX
Posts: 2,002
Bikes: Torelli road bike, Tsunami tandem
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
Front deraileur question
I just replaced my old 53 and 42 T chainrings with a smaller more compact set 48 and 38 T.
Will I need a new front deraileur or should my old one work?
I'm having trouble adjusting it but I'm pretty clueless and how to properly adjust it.
It's a late 90's Shimano Ultegra groupo.
Thanks
Will I need a new front deraileur or should my old one work?
I'm having trouble adjusting it but I'm pretty clueless and how to properly adjust it.
It's a late 90's Shimano Ultegra groupo.
Thanks
#2
Senior Member
Join Date: May 2003
Location: Mountain Brook. AL
Posts: 4,002
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 303 Post(s)
Likes: 0
Liked 136 Times
in
104 Posts
Fr der are pretty forgiving of moderate changes in CW size such as you
have done, the main change needed will be a lowering of the FD about
2cm +/- on the seat tube. Clampons move easily, but brazeons have
a more limited range of up down movement.
www.parktool.com and clik on the REPAIR button for a stylized pix of
a bike. Mouse over the bike to the FD area and clik will take you
to the FD adjustment section for pretty complete info on howto. You may
need to shorten the chain depending on how well the RD wraps it up.
have done, the main change needed will be a lowering of the FD about
2cm +/- on the seat tube. Clampons move easily, but brazeons have
a more limited range of up down movement.
www.parktool.com and clik on the REPAIR button for a stylized pix of
a bike. Mouse over the bike to the FD area and clik will take you
to the FD adjustment section for pretty complete info on howto. You may
need to shorten the chain depending on how well the RD wraps it up.
#3
Senior Member
Join Date: Apr 2006
Location: Clinton Hill, Brooklyn
Posts: 508
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Is it a clamp on FD? If it is, unclamp it and move it down the seattube to accommodate the new diameter of your large chain ring. You will probably only need to do this 2mm or so, but it might make a difference since your smaller chainring is also smaller. Then retension the cable so it is taut. Adjust the H/L screws if necessary (but, this will probably not be necessary). If you do need to tweak, very slight turns are all you will need. Check shifting with your bike on a stand if possible. Report back.
#4
Hey let's ride.
Thread Starter
Join Date: Apr 2006
Location: Allen, TX
Posts: 2,002
Bikes: Torelli road bike, Tsunami tandem
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
I dropped it down about 1cm but now I realize its still too high. Looks like it should be only 2mm above the big chainring.
Thanks
Thanks
#5
Senior Member
Join Date: Apr 2006
Location: Clinton Hill, Brooklyn
Posts: 508
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Originally Posted by sch
the main change needed will be a lowering of the FD about
2cm +/- on the seat tube.
2cm +/- on the seat tube.
#6
Senior Member
Join Date: Apr 2006
Location: Clinton Hill, Brooklyn
Posts: 508
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Originally Posted by pathdoc
Looks like it should be only 2mm above the big chainring.
Thanks
Thanks
#7
Senior Member
Join Date: May 2003
Location: Mountain Brook. AL
Posts: 4,002
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 303 Post(s)
Likes: 0
Liked 136 Times
in
104 Posts
My arithmetic engine failed, 2cm would be the diametral difference
between the 53 and 48t CW, so half that more or less would be
the proper radial difference and the amount to lower the FD, but
the right amount is determined by its relationship to the CW.
between the 53 and 48t CW, so half that more or less would be
the proper radial difference and the amount to lower the FD, but
the right amount is determined by its relationship to the CW.
#8
Hey let's ride.
Thread Starter
Join Date: Apr 2006
Location: Allen, TX
Posts: 2,002
Bikes: Torelli road bike, Tsunami tandem
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
Got it working. Deraileur was way too high and cable wasn't routed properly underneath the bottom bracket. Its all good now. Thanks