Change to 11-30

DMHR2018

Hi,
I have a bike equipped with Ultegra r8070 di2. Currently a 52/36 chainset and 11/28 cassette but I would like to change to 11/30 on the back. I know the derailler can accommodate this but will I need to increase the length of the chain??
Thanks
DMHR

ugo.santalucia

no...

unless you plan to use the 52 x 30 combination... which you shouldn't use anyway

philbar72

you'll be fine, 8000 series runs 11-30 by default and the chain Big/big is a no no. check your b screw is set correctly.

DMHR2018

Thanks!

lesfirth

Just make sure that your chain is long enough to prevent a disaster if you do accidentally use big / big .

DMHR2018

Hi again - have made this change now and have 2 things:

First, any tips on tuning the rear di2 derailleur? I have followed the tuning instructions but find it very difficult to judge whether the derailleur is properly in line with the relevant cogs - whatever micro-adjustments I make in adjustment mode they all pretty much look the same to my eyes:

I've tuned it based on hearing so that the chain runs without rubbing and shifts into all gears however the shifting is not as good as it was previously and there is an unfamiliar sound when riding that cannot be heard when on the stand. Hard to describe the sound as its not a rubbing noise but more like an exaggerated normal chain noise which sounds like it is not doing the system any good. I also played with the limit and b screws, but in the same way find it very difficult to judge the changes this makes to alignment by eye.

The chain will go into big / big - but you have to coax it in, would be unlikely to go in under tension while riding without something nasty happening. I'd never use this gear anyway so planning to leave it...(?)

Thanks!