meakinsl

Hi,

Had a Giant defy from few years back with Ultra groups and was perfect, would shift and not click in any front and rear cog combo even when crossing the chain which know shouldn't do but sometime it happens or is convenient for a few moments.

Treated myself to a Giant defy advanced pro 1 in an end of year sale last year, believe it has R8000 version of ultra on it and won't let me cross chain at all, makes horrible noise when speaking with LBS they said due to that groups being designed for di2 which won't let you change into the crossed gear combos. Thing is the bike doesn't have di2 so is a bit annoying and my last bike with ultegra seems better. Is what the LBS saying correct ? Whatever is done will it alway make horrible noise if cross chain ?

Other thing (not very good at the mechanical side) is that bike doesn't seem to want to change into lowest gear and slips out, is that just a case of turning the barrel adjuster anti clockwise ? I have read that the R8000 barrel adjusters have a plastic tooth that doesn't engage even on first uses - anyone else had experience of that and is there a replacement for it ?

Many thanks,

Lawrence

Ferrouscious 

Don't cross chain.

ARider2

Cross chaining will cause noise and is mentioned in the Shimano documentation for the FD-R8000 (DM-RAFD001-05-ENG.pdf). Shimano recommends shifting to a different gear if noise is a problem...

cxwrench

OP which cross chaining are you talking about? Big/big or small/small? Sml/sml is just dumb and shouldn't be used. It will cause noise on most bikes and is prevented from being used (11, 12, & 13 cogs in the small ring if you have a 50) on new Di2. Every drivetrain made today is designed to allow big/big. Use it whenever you need it, but obviously don't spend all day there as it will accelerate wear.
If your rear derailleur shifts well in the other gears it's obviously not cable tension, but the low limit screw. Check it with the bike in a workstand or someone holding the rear wheel off the ground while you pedal it and gently push on the rear derailleur linkage to see if it will move that far. If not, slightly loosen the L limit.
The diagram in the post above mine shows that Shimano doesn't recommend riding small/small or even the 12 or 13 when in the small ring.

Iride01 

I have the Di2 version of your Ultegra. (R8050). And when in the big big there is much more rub and noise than with the Shimano 105 5800 on my other bike in the big big.

As for your other thing, If lowest gear is the small front and big rear, then reach down and pull on the bare rear shifter cable while riding or turning the cranks. If that doesn't let it go into that gear and keep it there, then I'd suspect the low limit on the rear DR. Otherwise you need to adjust the barrel adjuster some either on the rear DR or inline if you have one. Or maybe reset the cable in the DR's holdfast if the barrel adjusters don't have the range.

Though some fear the cross chaining, there isn't much wrong with cross chaining if you only do it to top a hill or for other brief times. There is something to the Small Small combo on Di2 because of chain slack more so than cross chaining issues. Don't know if that applies to R8000 as it does with R8050.

On the Di2 version you are locked out of the two smallest rear sprockets when in the small front. Unless you know how to trick it into thinking you have a configuration that it's okay for.

meakinsl

Cool thanks for all the great info, the link to the manual was useful and also pulled down the rear one as well, sounds like have to have a little play with the low limit screw, could be the moment to justify a workstand ! Many thanks, great forum and will use again.

deacon mark

My mechanical 6800 is quiet in all gears both chainrings. Never misses a shift and I love it and it makes di2 not a thing I need. Yet.

rovis

I had my chain recently replaced by LBS and supposedly tested for shifting and noise. Of course, after first rides, found noise in both big/small chain rings from friction in the FD. Small adjustments in L/H screws at FD fixed the problem No noise in any combination of gears. There's more to FD setup, so I looked into Shimano's manual and other sources, but for me it came down to only adjust these two screws.
Ultegra 6800.