Shimano 105 shifter problem

huntswheelers wrote:

Common issue...on 105/Ultegra/DA to be honest the design of the shifter with a 90 degree turn of the cable in the shifter & tight wind of the cable promotes cable strands to break around 6-10 mm from the barrel end..... I see it all the time in the workshop and for those who put a decent amount of riding in I advise annual change of cables ...when you look at the cost of a cable verses the cost of a shifter if the barrel end can't be retrieved... Swap the cable out fella in the first instance....

Thank you for the amplification of the issue.  I've replaced two cables to date on 2 year old bikes that have been ridden ~10km each. Both cables frayed at the same place, approximately where you stated. Shimano Optislick cables are pretty cheap ($6 US if bought in bulk packaging) and replacement is easy.

Replacement is easy if you can get the old one out !
Just cost me 23 quid for the lbs to fix it and it took them over 20 mins with know how and whatever tools they had fashioned with experience.
I was pretty lucky they did it there and then, the first one I went to told me to come back in 3 to 4 weeks.

jaylockwood1978 wrote:

Thank you, I've ordered some more cables so going to give it a go. Never done it before but figured the worse that can happen is I have to take it somehwere for them to replace the cables! Currently geeking up watching videos and reading g the steps another poster gave me. Fingers crossed. 

You got this! Lots of good videos and instructions available, and you don't need any special tools (#1 phillips screw driver, needle nose pliers, and a 4mm hex wrench) .  Be sure to watch a few videos on adjusting a front Shimano derailleur. It's not hard, just trial and error.

It's super easy to get to (and change if necessary) without removing the bar tape, shift lever, etc. I literally just replaced the rear derailleur cable yesterday on my wife's bike.

1. Pull the rubber hood forward as far as you can to expose the black plastic piece that's covering the shifting mechanism (bottom side of the shifter near the handle bar).

2. Unscrew the single black screw that holds the cover in place (#1 phillips screw - very small)

3. You will see the cable end wrapped around the circular mechanism from the inside of the lever. Shift the cable back and forth to see if the cable is frayed near the end (look from the other side of the lever also). I find that it tends to fray about 1-2cm from the metal end grommet.

4. If damaged, loosen the cable screw at the front derailleur so it is completely free. NOTE: You may need to use a flash light (torch) to see if there is damage inside of the shifter.  NOTE: One single broken cable strand will cause it to bind. This can be hard to see in poor lighting.

5. At the shifter, use a needle nose pliers to get some cable slack and release the cable end from its securing mount, then pull the cable out of the bike from the lever. This make take a little force, but not too much as the cable should come out freely.

6. On the other side of the shifter (outside), you will see a clear/white plastic cover. Pull this out by hand but do not remove it from the lever.  It's held in place by a small retaining piece.

7. You will need to feed the new cable from the inside (relative to the handle bars) of the shift lever through the lever body, then bend and install inside the hole that was covered by the clear/white plastic cover. NOTE: There is a tiny black rubber hole that you need to fit the cable into facing towards the back of the bike, just behind where the clear/white plastic cover was (see the top of page 30 of the linked PDF).

8. Feed the cable all the way down towards the front derailleur, leaving just enough slack to secure the new cable end in its retaining holder (towards the inside of the handle bar. NOTE: If your bike uses internally routed cables, there should be an internal cable guide that will drop the cable end near the bottom bracket.  You will likely need to do a little fishing to get the cable out of the hole at the bottom bracket (which may be covered by a plastic cover that needs to be removed depending on the bike).

9. From here, you will reroute the cable to the front derailleur and secure using the cable screw.  The routing is specific for the 105 R7000, but getting the cable tension correct for proper shifting takes a little finesse.  Lots of YouTube videos on this.

Link to Shimano's official instructions: https://si.shimano.com/api/publish/storage/pdf/en/dm/RACBR01/DM-RACBR01-...

Shifter cable installation starts on page 30.

Hope this helps!

To you and Nigel,

If you can change a chain (break the link and measure and install a new chain), you can replace a shift cable. There are absolutely no special tools needed to replace a cable (short of a cable cutter, but a good snip will work in a pinch). Have confidence in yourself and don't hesitate to watch a few YouTube videos. I find the ones from GCN and ParkTool are the best.  Watch more than one so you can see how to do it from various angles/techniques.

You've got this!

In that picture, your hood looks like it's not sitting flush and is too far forward (hence the gap between the hood and the shifter body).

ChasP wrote:

Can't see any pictures but first thing check the hood is correctly positioned and not interfering then check the cable hasn't started to fray inside the shifter. 

This is likely the cause. I just replaced a damage cable in a right 105 R7000 shifter yesterday. While troubleshooting (and indexing after replacing the cable), the rubber hood was blocking the metal lever from returning correctly (I had the hood pulled back over the top). The initial symptom was poor shifting and binding of the shift lever. Removing the hood and the plastic guard that sits under the lever, revealed the cable was beginning to fray, which was binding the entire mechanism.