strawbs

I'm sorry that my first post is one asking for help. I have looked but can't find a similar post. I have an issue with my rear derailleur on a Felt F75 with Shimano 105.

The problem is I can shift from largest down to smallest and back up again in sequence ok. However if I go into the middle of the cassette (11-28) when shifting up and down one cog at a time (starting in the opposite direction to the original shifts) nothing happens the derailleur hardly moves.

This does work however when you get into the top large cogs which makes me wonder if it is a tension thing?

The bike got soaked at weekend so I decided to clean the cable as shifting was that smooth on the ride. I didn't remove the cable just unclamped it to get rid of tension and squirted it with Muc-Off Bike Spray.

I would appreciate it if anyone has any pointers. Thanks!

Airburst

That sounds like it might be a cable issue, how old are the cables and cable housings?

strawbs

Thanks for taking a look Airburst. They are about 3-4 months old. I've put a few thousand kilometres on it. It was a very wet ride at the weekend and I did squirt into the cable housings on the frame, could that have pushed muck in? If so do you know how I can reverse it?

mrt2you

the lube might have swelled up the cable housing liner.

Altbark

First of all, don't lube cables. It doesn't need to be done. Use them until they wear out and then buy a new set.

Troubleshooting 101 - did the bike shift well during the ride? Yes or no. If the answer is yes then the next question is what did you do after the ride to change the situation? You unclamped it and then sprayed something into the housing. OK. Are all the housings properly sitting in their stops? Is the cable sitting in its bottom bracket guide? Did you do a derailleur setup in accordance with Shimano's tech instructions? Is it working now? No. Is there some binding between the cable and one or more of its housings?

Working on drivetrain stuff does not involve rocket science but does demand a certain attention to detail. Good luck. Al

cny-bikeman

From what I read Muc Off is meant for the frame and other external parts, not for lubrication or internal parts. In addition you may have sprayed contamination INTO the housing. You need to properly clean things out. If the housing stop on your down tube has a split you can use that to get access to the area of the cable that is covered by housing to clean and lube it. Shift to the largest cog in back, and then without turning the cranks shift the lever all the way back to the small cog position. The shift cable will then be slack. Pull the housing away from the down tube stop (see pic below - not at the down tube but same idea) and you will then be able to do the same with other sections enough to expose the cable, wipe it off, spray a light lube into the housing, and get things cleaned/lubed. If you see any corrosion replace the cable. When done, put all of the housing back in place and shift through the gears a few times to check things out.

strawbs

Some great pointers to try out this evening thank you. I did a quick roller session earlier, pushing the shifter inwards (up the cassette) was a lot stiffer than usual. Thanks again, I'll report back.

Al1943

Try shooting lots of WD40 into the shifters. Friction builds often builds up in STI shifters due to hardening of the original factory grease and also from dirty water spray from riding in wet conditions.

Both Shimano and Campagnolo recommend greasing cables when installed. I doubt that additional lubrication will hurt them. Dirty water spray can certainly add to friction inside the housing, especially the short housing found at the rear derailleur. Shift to the smallest cog and see if you can release the short housing and slide it forward on the cable, exposing it so that it can be lubed. It may be necessary to release the cable from the rear derailleur. If this is done be sure to re-attach the cable exactly as it was before releasing it. If lubing helps shifting performance consider it a temporary fix and plan to replace the cables and housings soon.

caloso

I would bet on gunk in the cable housing. Put it on the stand and click the shifter as if to shift it to the smallest cog. If the derailleur doesn't move and you see slack in the cable along the chainstay, you have some blockage in the short loop.

strawbs

Thanks for all of your help with this one. I tried freeing up all cables where possible and dowsing the shifter with wd40 to free it up. Unfortunately nothing has worked. Taken it to LBS and they are looking at it now. They suspect that it is friction up in the handle bar cables. I need the bar retaping anyway so not to worry as long as it is fixed. Thanks again.