I think I have a problem with my front derailleur.
My front derailleur won't shift from the small to the large gear when I am on one of the four largest gears on the rear. I had this problem since I bought the bike.
I recently installed a new Crankset, chain and front derailleur, but the shifting problem is still the same.
I adjusted the derailleurs with the help of GCN and Parktools videos.
What do I have to adjust tor change to solve that problem?
My shifters are Shimano 105
Rear derailleur is Shimano 105
Rotor Crankset
Front derailleur is Shimano GRX
Before the change, front derailleur and Crankset was 105 too.
by TarikRA
7 Comments
I wish this app had video call to better help you or voice chat but check the gap between the front derailleur and crank it has to be 2.5mm use an Ellen head wrench if that checks out check cable slack if that check out make sure your rear derailleur isn’t bottomed out like chain stretch if you went with the same size in crank set then your good but if you went bigger you might not have enough chain to go up on the crank
The derailleur looks really high off the chainrings. I suggest rewatching the park tool video or taking it to a bike shop/coop.
Also I remember doing a rotor swap for a buddy of mine and it needed spacers on each side of the cranks arms to help it align better with the derailleurs make sore no steps or parts weren’t used
First off, find the correct Shimano’s Dealer Manual at si.shimano.com. Read it and follow it.
Second, do you know the chain line for the Rotor crank? GRX FDs sit slightly more outboard than standard road FDs, but you’d think that would actually help in this case of getting the chain to shift to the big ring…
I guess ignore the stickers, the derailleur is too high. Move it down so when it is over the large front gear, it is only a bit over it. Try it, move as needed.
read the Shimano service manual for fd set up – this is most likely a cable tension issue. the new gen mechanical has that extra tension adjuster on the mech that is set in the trim position – the service manual explains it best imo.so check that out. you can still adjust tension with a barrel adjuster if you have one in the system but that screw lets you dial the tension to what Shimano has decided is ideal. it also looks like the free end of the cable isn’t routed fully under the hinge mechanism as per shimano.
also make sure the gap is set properly, 1-2mm with the mech position directly above the chainring teeth
It looks like your derailleur in the 2nd picture is twisted a bit outboard like it is not in line with the chain ring.