Adjustment FD-RX810-F (Shimano GRX 11-speed front derailleur)

Hi everybody,

I have an issue with my front derailleur. The way it was adjusted, I could not ride on the large plateau without rubbing to the plate. I tried to finely tune the L and H screws in order to not be touching it anymore. But this way, it is rubbing while on my small plateau and larger cassette. I tried back and forth, but it seems I am not able to put it the right way. 

For your information, I have ridden the bike only once since it has been shipped by Canyon. Hence, I expect the cable tension to be correct. Indeed, I followed the instructions from the dealer's manual from Shimano but I do not manage to make it work, by touching only the "A" and "B" screws (<=> L and H screws).

Did anyone ever encountered this issue? Do you have any tips to make it work. For your information, I am a newbie in bike mechanics, so any tip might be useful.

Many thanks,
Alex

Soooo.. Sorry for the late reply, I could not make it yesterday.

So I followed, again, the instruction from the manual linked in my first message.

1. I am asked to put the chain on the largest chain ring and the the largest sprocket (i.e, extreme right in front, extreme left at the back) For some reason, I cannot put the chainring on the largest sprocket at the back, but only 2 below otherwise I will broke the rear derailleur. I guess this is wrong already but... I still try with it. 
2. Adjusting the top position of the chain guide, I cannot have that few space at the left on my picture, there is quite a huge gap and turning the screw they say only make it going to the right (in the A direction), it looks like I am at the maximum in the B direction .. Whatever
3.    For the low position, everything to the left, as asked
   
4. Now, adjusting the position, with the screw they mention. Same problem as before, even at the maximum in the B direction (I know I reached the maximum because turning it has litterally no effect anymore) the chain is rubbing against the "skid" see picture below. And in this position, well no need to be a genius to know that this is not right, but I cannot go back to the largest chainring (at the front) as you can maybe see on the picture below, the derailleur is not enough to the right in order to push my chain to the largest chainring.
    
   So either I am a complete dummy, or the explanationa re fucked up, or something else is wrong. But now I am really pissed at it. 

I understand the frustration, and I am sure many people on this forum do as well!

The biggest problem here is not being able to shift into the largest cog in the rear.  You should be able to shift into that cog without damaging the rear derailleur.  If you cannot change into big ring on the front and the big ring on the back without damaging the rear derailleur, then your chain is too short.  And if you cannot shift into big/big or small/big, you cannot accurately adjust the GRX front derailleur.

Both the high and low limit adjustments require you being in that big cog.  Doing it from a few cogs below the big gear will not work.  You would only be guessing at the correct position and it will not shift properly.  Guessing at the high and low limit positions also will risk you dropping the chain and potentially causing damage to your frame.


You need to contact Canyon or a local bike shop and ask them about not being able to shift into those gears.  Until you get that first problem sorted, you will not be able to continue.  

Good luck!

StuartH165 wrote:Doing this job myself yesterday my top trim adjustment has never been working and I found that I actually need to adjust the trim screw to about half way, then reset the cable under the attachment screen (when not under tension, so in small ring), this them allowed me to line up the 2 lines in your picture via the adjustment screen. The cable tension was not correct from factory.

CasualGravel wrote:Those two lines should line up if the derailleur is in the Top Trim position.  Your front derailleur has four positions:  Top, Top-Trim, Low, Low-Trim.  To get to the Top Trim Position, shift into the big ring.  While in the big ring, just barely press the shifter like you are shifting into the small ring, just until it clicks.  That is the Top Trim Position, and the lines should be lined up there.  If not, your cable tension is off and it will not shift correctly. 

If you really do not want to handle this through a bike shop,  then make sure you read the manual and follow each step to the absolute letter.  Do not skip anything and verify that all steps are done exactly as it says in the manual.  It is very straightforward.

https://si.shimano.com/pdfs/dm/DM-GAFD001-00-ENG.pdf

Unless you started loosening and moving the derailleur around, it's probably an issue of cable tension.  But now that you've started messing with the high and low limit screws, you should just start over.  Verify that the derailleur is in the proper place according to the manual, adjust the cable tension, and then go for the high and low limits.

As an aside, your bike should still shift into the big cog in the back with the clutch (shadow option) on.  If it does not shift when that is on, then it is still a problem. 

KrKAlex wrote:Thank you a lot, I managed and it was indeed a tension problem. So now it's better. Only for the low adjustment I am not sure about the L-trim. To make it simple, I will speak in "click". We start from the Top position, 1 click on the small cog and we are on T-trim, 1 more and we are on Low and 1 more again and we are on the L-trim, right?
So here, if this was right, I have 0.5 mm between the skid and the chain and it's done.