IdahoBrett
Well-Known Member
Rehabbing a 2001 R400. The Shimano Sora 3304 return spring retaining portion of FD is broken off. FD no worky. I've discovered that the rabbit hole is very deep when it comes to front derailleurs...
SOLD Front derailleur. Triple front (52/42/30), 8 speed
- Thread starter IdahoBrett
- Start date
Item sold.
Might have something here. Remind me to look.
IdahoBrett
Well-Known Member
Thanks! I may have found a substitute. Meant for a 9 speed. It’ll work, but it will have some chain rub during “cross chaining”. Might bother me or not. The “correct” one for proper chain ring tooth count and 8 speed is the goal. But not an absolute must have.
I doubt you will find one that was meant for 30/42/52 and 8 speed. I think your options are 9 speed Sora, Tiagra, 105, Ultegra, Dura Ace or 8 speed Claris. I really doubt the ring difference would be a factor. I'd be more concerned about the cable pull. I'm not sure if front cable pull changed between Sora 8 and Claris 8.
https://www.ebay.com/itm/1956336145...k06Xrnh7ZTd6UZg9hB24ey2A==|tkp:Bk9SR8Da_6fRYg
https://www.ebay.com/itm/1956336145...k06Xrnh7ZTd6UZg9hB24ey2A==|tkp:Bk9SR8Da_6fRYg
IdahoBrett
Well-Known Member
A short part to an explanation that I read:
Shimano in their infinite wisdom has decided that for 2009 all of the road triple front derailleur’s they make, both 9 & 10 speed will have at the least a minimum requirement of an 11 tooth difference between the large and middle ring, for example a 53-39-30 or a 50-39-30 works great , but when you try to use one of these new derailleur’s on a 52-42-30 set up or other chainring combinations with a 10 tooth difference the lower part of the cage on the front derailleur runs in to the middle chainring .
Link for the entire article:
Older 105's that work for 52/42/30
Shimano in their infinite wisdom has decided that for 2009 all of the road triple front derailleur’s they make, both 9 & 10 speed will have at the least a minimum requirement of an 11 tooth difference between the large and middle ring, for example a 53-39-30 or a 50-39-30 works great , but when you try to use one of these new derailleur’s on a 52-42-30 set up or other chainring combinations with a 10 tooth difference the lower part of the cage on the front derailleur runs in to the middle chainring .
Link for the entire article:
Older 105's that work for 52/42/30
IdahoBrett
Well-Known Member
Here is an answer to someone looking for a FD replacement:
It seems like an innocent question, but the situation can be maddening when a replacement FD is needed for any of the 30-42-52 cranks.
Front derailleurs have a spec that has been called by Shimano both "Min. difference between top and intermediate" and "Applicable top-mid tooth difference". It is the minimum difference in tooth count between the middle and large ring that the front derailleur can accommodate without the tail end of it bonking into the middle ring as it passes over, unless you make it much higher than you'd want to. For a long time, basically since the era of 9-speed front derailleurs that 4403 belongs to, Shimano changed to 30-39-50 for the road triples and the number for that spec is 11, whereas you need it to be 10. Being off by one forces the FD to be mounted much higher than optimal and it usually works poorly and can cause problems with derailment.
The good answers are any of the old Shimano 9-speed road triples where that spec is 10t, so FD-4403, 5503, 5504, 6503, and R443, in either the 34.9 clamp version if they came in one or in braze-on version plus an adapter. There have been a few repair type models that meet this compatibility too, such as Microshift R539 in braze-on configuration. That one appears to still be obtainable new, and I don't know if that can be said for any other compatible matches.
FD question and answers
And here is one that I think might work:
Older 105 ebay
It seems like an innocent question, but the situation can be maddening when a replacement FD is needed for any of the 30-42-52 cranks.
Front derailleurs have a spec that has been called by Shimano both "Min. difference between top and intermediate" and "Applicable top-mid tooth difference". It is the minimum difference in tooth count between the middle and large ring that the front derailleur can accommodate without the tail end of it bonking into the middle ring as it passes over, unless you make it much higher than you'd want to. For a long time, basically since the era of 9-speed front derailleurs that 4403 belongs to, Shimano changed to 30-39-50 for the road triples and the number for that spec is 11, whereas you need it to be 10. Being off by one forces the FD to be mounted much higher than optimal and it usually works poorly and can cause problems with derailment.
The good answers are any of the old Shimano 9-speed road triples where that spec is 10t, so FD-4403, 5503, 5504, 6503, and R443, in either the 34.9 clamp version if they came in one or in braze-on version plus an adapter. There have been a few repair type models that meet this compatibility too, such as Microshift R539 in braze-on configuration. That one appears to still be obtainable new, and I don't know if that can be said for any other compatible matches.
FD question and answers
And here is one that I think might work:
Older 105 ebay
I still find it hard to believe that a difference of one tooth count between two chainrings can cause a dramatic difference in a derailleur's ability to shift. I admit that I haven't tried the combination. I do have a NOS braze on Sora FD-2303 here, you would need a 31.8 clamp adapter. My guess is that the 105 FD you linked would work fine.
IdahoBrett
Well-Known Member
It could be that all the stuff I read was coming from the absolutist point of view that the FD gap once adjusted should be no more than 2 mm above the outer chain ring. I admit I can suffer from precision measurement disorder from time to time. But in my limited experience you are probably correct. It isn’t a gear driven device after all. It’s a chain. That over time will “stretch”/wear and tolerances are in tenths not thousandths…
Thanks for the offer on the Sora! If the 105 (5504) doesn’t work I’ll let you know.
IdahoBrett
Well-Known Member
The 105 from ebay works. Thanks for the opportunity to post.