rollingsound514

Hi guys, my LBS told me this is just normal "gear meshing" noise and feel, but there's a noticeable difference in the smoothness of the drivetrain when I'm in the little ring up front and biggest cog in the rear. There's a noise, nothing brutal but definitely there, and the pedal stroke isn't as smooth. The noise goes away and everything feels smoother going to the next biggest cog (2nd gear if you will). The front derailleur is not rubbing so that's not it. Is this just something I should be expecting on an 11 speed? I'm used to 10 speed set ups.

Bike is a brand new CAAD12 with a 105 groupset, I replaced the wheels with some Ksyrium SLs but popped the "stock" cassette on those wheels without a spacer (Mavics work with 10 speed with a spacer or with 11 speed without as per my understanding):

Crank

Cannondale Si, BB30a, FSA rings, 52/36

Rear Derailleur

Shimano 105 5800



Front Derailleur

Shimano 105 5800 braze-on



Rear Cogs

Shimano 105 5800, 11-28, 11-speed

Abu Mahendra

Not enough tension on the chain alias chain too long?

TimothyH

Derailleur pulley rubbing on the big sprocket.

Check the B screw.

-Tim-

alcjphil

This may well be the case. When you are in this gear, get off the bike and look to see how close the upper pulley is to the cassette cog. If it is too close, the B screw adjustment can correct this

TimothyH

Thanks for filling in my brief post.

I just ran into this on a cassette with a big 36 tooth sprocket. The drivetrain will produce a low rumble which can be felt through the pedals when it rubs.

If the pulley is close to the sprocket then the B screw has to be screwed in, rotated clockwise.


-Tim-

rollingsound514

There's no noise coming from the back and there seems to be sufficient clearance between the cog and pulley. I've isolated the noise to the front of the drivetrain, it's not rubbing on the front derailleur but at one point of the pedal stroke theres' definitely a noise up front. I think this one's going to be a live with it kinda situation

2manybikes

How new is new? How many miles on the chain and cassette?

2manybikes

Also, I find the FSA rings not as smooth as Shimano. I have also run across a huge smoothness improvement when up grading to a Ultegra, or D-A chain, from an unknown chain. Both easily noticeable on my 105 ten speed bike.

rollingsound514

Brand spanking new, less than 100kms on it

shelbyfv

You may as well check the rear derailleur inner limit screw. Just pull on the cable and see if the derailleur can move inward a little. If it's jammed up tight, loosen the screw, maybe 1/8 turn. It can be really hard to tell where noises originate, so try all the easy stuff.

OshkoshBiker

I had a similar problem and I have found the 5800 front derailleur on my 11spd particularly difficult to set up. I am running a compact FSA chain ring with a Gossamer crank. The 11spd set up seems to require more attention/time than most. After following the dealer's manual to the letter, all of my noise went away and it is still trouble free one year later needing no adjustment.

Here is the link to download the dealer's manual for your FD5800: https://si.shimano.com/pdfs/dm/DM-FD0002-05-ENG.pdf

Good Luck,

OshkoshBiker

GuyWood

A good tip I worked out, and have heard elsewhere since, when setting up a 5800 front mech is to set the position and limit screws and then trap a 6mm allen key through the mech and tighten down the cable bolt with the allen bolt trapped in position. You then release the allen key and the mech is more or less spot-on.