Front Derailleur Issues! 100k this weekend, please help!
I am struggling to get the Ultegra front derailleur to play nicely with a new Tiagra crank (it is a braze on FYI). When the derailleur is positioned so it only passes a couple mm above the largest chain ring, as it should, that it cannot move properly as it catches the middle chain ring. Then positioned so that it does not catch the middle chain ring the derailleur is very high, I can stick my index finger between the large chain ring and the bottom of the derailleur; even when slightly cross chained it loudly complains. This seems odd as I think the 50-39-30 sizing of the crank is typical of shimano triples and should therefore be fine to work with a triple derailleur.
I thought one solution would be to use a different derailleur, perhaps a Shimano CX-70 (praised as versatile here Trouble with STI Triples | Off The Beaten Path
) that is meant for a double and would therefore not have the extra body of the triple derailleur and not catch the middle chain ring? Does anyone have experience with this or have another recommendation? There seem to be mixed opinions about if a double FD will work for a triple. Another problem is that when the derailleur is mounted flush to the braze on tab the arc is not correct (the arc is the correct shape but when mounted the rear is too low and front too high) and therefore I have had to put a little metal shim below the bolt to bring the rear of the derailleur up. Makes me wish I had a clamp style but I donít think there is any going back now (carbon frame FYI)?
I am running a 3x10 Ultegra setup and recently started having issues with the chain skipping under load (it is about 8 years old). Not sure exactly how to describe it but the pedals would give underfoot a bit, it would feel choppy and sometimes the rear gear would change Ė especially when climbing, it was not acceptable to ride paceline with etc bc of this.
The cassette is relatively new and because the front crank had pretty severe shark teeth and chipping I replaced the crank and chain (cables and housings also replaced recently) thinking this would help the issue. It seems to have helped that particular issue and the rear is shifting beautifully. In an effort to save some dough I put a new Tiagra crank on the front; Shimano FC-4500 Tiagra Crankset Hollowtech II (Robot Check
). Should I have any compatibility issues with this, it should be for a 10 speed no?