liveforphysics said:
Here are the first pictures of how my new project looks at the moment.
LFP, just from the few pictures you have posted, mechanically speaking, your front derailleur is positioned several millimeters higher than factory specified above your largest chainring,
I appreciate the advise, and I will play with shifting it down. That front Dura-ace triple is not designed for my size frame tubing, I had to enlarge the clamp bore and run a longer bolt, it was designed to be sitting back towards the frame by about 1.8mm closer IIRC. It sits where it does because I found best shifting performance to the granny cog happened when the step in the derailuer was engaging the middle sprockets recess just a bit so it could reliably kick it down a whisker. When pedaling, it never has any contact with the chain anywhere (if it's not currently mid-shift at that moment), the chain doesn't drop off anymore (unless I'm hitting big drops, which sometimes flings the chain off), and it shifts smoother and faster than any bike I've ever ridden before this. You can see the marks on the frame where I had it a few mm lower, and raised it to help it drop into the granny faster by bumping that step in the cage. and the cable housing loop run on your rear derailleur is longer than necessary. Both of these will decrease shifting performance. Extra length in your housing just slows shifting, but a poorly positioned front derailleur may throw the chain altogether. If it is misaligned laterally as well, you will invariably be unable to fully utilize the intended gear ranges of your rear cassette realtive to the front chainring you use without chain rub on the front derailleur cage. This will also add some degree of parastic drag on your drivetrain as a result. Additionally, the trim funtionality of your STI shifters will also be compromised.
I of course first adjusted the positioning screws and stops, and only then found the lower cage was bent a bit so it caused excessive side friction with the plastic pulley, I bent this until the pedal/chain assembly would spin as freely as possible backwards, whcih I assume is the point of least drag The deburring of the chain and chainrings will essentially yeild no net gain unless the mechanical aspects of the bicycle are addressed first.
Your octalink - era crankset (Ultegra FC6503) should be utilizing a 118.5 mm spindle. any other width, which are available for double road and triple mountain widths, also vary in length. There is consequently also a "gen 1" octalink splined style BB and a "gen 2" style splined bb which are not compatible. Proper chain line begins with proper BB and BB width.
To the best of my knowledge, that's the correct bottom bracket for the bike. I know sizing them is a PITA, so I took it to the LBS and paid out the ass for them to find out what BB my bike should have and ordered it at about 2x online prices, then borrowed the tap from a bike mechanic friend, removed the old one, compared it with the new one (visually identical to the best of my ability to find a mechanical difference), then installed it after cleaning the slightly rusted threads with the tap.
Rear derailluers are not adjusted by "making tiny bends" to adjust chain angle. There are high and low speed limit screws, low speed gear adjustment screws. These set screws are what defines the travel of the rear derailleur across the rear cassette, and the gap between the top floating pulley when riding along your lowest speed gear.
I used the high-low screws exclusively at first, but due to my derailluer being bent (it's been smashed on rocks and logs HARD many times) it required some small bends in addition to the normal screw adjustments to make it shift as smoothly as I desired.
If you are bending the derailleur hanger to adjust the chain line, I suggest you investigate the use of a PARK DAG 2 tool or other similar alignment guage. This guage will quickly determine if your rear hanger is bent.
Thank you for the tip on the tool! I didn't know a tool for it existed, I used dental floss and a yard stick, same trick I use to line up chainlines when making frames or mounting motors etc.
I am sure Chalo would explain all of this if I don't.....