Newer dura ace shifters with older front derailleur
09-15-21, 11:09 AM
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Newer dura ace shifters with older front derailleur
Newer dura ace shifters with older front derailleur.
Hi all,
I am adding newer bits (dura ace 7700) to an older frame (Panasonic ar6000). The frame was purpose built around the Dura Ace AX groupset in the early eighties. Mostly smooth sailing on the swapping of relevant parts, but running into an issue with the front derailleur.
I have the DA 7700 fd (double) but the angle of the Braze on attachment point on the frame makes it so the far tip of the cage just hits the teeth on the big chainring. I have an angled shim on order, but because I can't source anything local, it'll take X weeks to get it in the mail. In the meantime, I put the DA AX FD back on the bike. Angle with the Braze on is improved, but I just cannot get shifting to work. It appears the cage has sufficient travel (manually moving it over the big chainring to the small chainring), but if I set cable tension tight enough to keep it over the big chainring, the shifters won't downshift to pop it back over the small chainring. If I set tension loose enough appropriate to be over the small chainring, the upshift doesn't seem to travel far enough to pull the cage all the way over the big chainring.
Am I doing something wrong with tension (limit screws are fine... manually pushing the cage it will travel sufficiently)? Are the bits not compatible? For instance does the DA 7700 shifter pull less than what the DA AX front derailleur requires to travel sufficient distance?? That's my hypothesis, but would love to be wrong :-)
Using bits, each quite old, and decades apart from one another is probably the culprit here, but all advice would be very welcomed!!!
Hi all,
I am adding newer bits (dura ace 7700) to an older frame (Panasonic ar6000). The frame was purpose built around the Dura Ace AX groupset in the early eighties. Mostly smooth sailing on the swapping of relevant parts, but running into an issue with the front derailleur.
I have the DA 7700 fd (double) but the angle of the Braze on attachment point on the frame makes it so the far tip of the cage just hits the teeth on the big chainring. I have an angled shim on order, but because I can't source anything local, it'll take X weeks to get it in the mail. In the meantime, I put the DA AX FD back on the bike. Angle with the Braze on is improved, but I just cannot get shifting to work. It appears the cage has sufficient travel (manually moving it over the big chainring to the small chainring), but if I set cable tension tight enough to keep it over the big chainring, the shifters won't downshift to pop it back over the small chainring. If I set tension loose enough appropriate to be over the small chainring, the upshift doesn't seem to travel far enough to pull the cage all the way over the big chainring.
Am I doing something wrong with tension (limit screws are fine... manually pushing the cage it will travel sufficiently)? Are the bits not compatible? For instance does the DA 7700 shifter pull less than what the DA AX front derailleur requires to travel sufficient distance?? That's my hypothesis, but would love to be wrong :-)
Using bits, each quite old, and decades apart from one another is probably the culprit here, but all advice would be very welcomed!!!
09-15-21, 12:30 PM
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aka: Dr. Cannondale
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Your suspicions are correct: the friction FD doesn’t want to play nice with the indexing shifter.
I’ve had great success GENTLY bending the FD braze-on mount using a long handled crescent wrench. Doesn’t take much at the braze-on to correct the angle of the FD.
Think teeny bits.
I’ve had great success GENTLY bending the FD braze-on mount using a long handled crescent wrench. Doesn’t take much at the braze-on to correct the angle of the FD.
Think teeny bits.
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09-15-21, 02:30 PM
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Your suspicions are correct: the friction FD doesn’t want to play nice with the indexing shifter.
I’ve had great success GENTLY bending the FD braze-on mount using a long handled crescent wrench. Doesn’t take much at the braze-on to correct the angle of the FD.
Think teeny bits.
I’ve had great success GENTLY bending the FD braze-on mount using a long handled crescent wrench. Doesn’t take much at the braze-on to correct the angle of the FD.
Think teeny bits.
THank you!! This was my suspicion. For bending the FD Braze on mount, mind sharing more specifics on procedure?? Sound alike something I don't wanna mess up!
09-15-21, 07:23 PM
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Can’t really be more specific than ‘use crescent wrench, gently bend braze-on’
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09-16-21, 03:33 AM
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Using 6700 series shifters with a 7sp DA FD currently, but ran it with 7700 in the past. If I remember correctly the cage is wider than the 7700 FD cage. I ended up swinging the back just a bit wide if I remember correctly.
My main issue is that it occasionally dumps the chain off the inside downshifting unless things are perfect. My solution was to put a Deda Dog Fang on the seat tube and all has been well since.
My main issue is that it occasionally dumps the chain off the inside downshifting unless things are perfect. My solution was to put a Deda Dog Fang on the seat tube and all has been well since.
