Fine tuning Ultegra Di2

cojones

Hi,

I'm new to Di2, since it came down in price and I'm struggling to fine tune my Ultegra Di2 and have scoured the internet and forums but cannot find any guidance for my specific situation.

I've managed to index the RD according to Shimano tech docs and it's shifting fine across the range apart from the bottom three gears, where it hesitates shifting up to the next sprocket. The tech docs say to run through the gears and fine tune if needed, but my question is do I need to fine tune/adjust at the sprockets that are having trouble or to return to sprocket 5 and run through the indexing again?

I'm not sure exactly how the electronics work and whether it memorises the shifts at each position or whether a fine tune in low gear ranges will affect shifts in high gear ranges.

Any advice greatly appreciated.

Cheers, Coj

skellator3

if its not indexing properly in only a couple of the higher gears, check to see if you have a slight twist in your gear hanger, i normaly find thats what causes this to happen. you can straighten them, or if you not sure try your LBS.
or replace the hanger

cojones

Thanks. I'm struggling to find a LBS with Di2 experience. Adjustment is so simple in theory that I'm only going to take it in to be looked at if I get VFM that I can't get through DIY.

Sorry for all the acronyms!

dawebbo

You can tune the indexing in any gear, but the middle ones on the big ring is when the chain line is most straight and hence alignment should be exactly in the middle.

Might be worth letting the limit screws out and redoing those, otherwise hanger alignment is worth checking.

cojones

Great...thanks.