How do I adjust RD 5800 derailer correctly

[Neddysmith]

OK guys i need a little help for those a little technically minded.

So i am not a complete tard when it comes to things mechanical but i am new to the world or derailers and bike stuff.

So i have a new, well first, roadie and when riding on the weekend i noticed it wasnt shifting to lower 2 gears. so instead of running an 11sp i was effectively down to 9sp.

I have googled this a bit and looked at quite a few of the youtube vids around which i have found quite useful, HOWEVER, when giving this a crack tonight i was still unable to solve the problem.

First i started by checking the alignment and to my eye looked and straight, so i noticed one of the adjustment screws was screwed a quite a bit out, so decided to adjust everything right the way back in, this actually restricted the movement of the dereailer and wouldnt select the smallest 2 gears, but also still wouldnt goto the largest 2, i tried tighening the cable as the guy i bought the bike off said that all cables were replaced an make have stretched slightly so could need adjustment, this didnt help either.

So i adjusted the high screw back out and was able to select the smaller 2 gears again but still not the higher 2.

Anyone have any suggestions on what to try?

I am thinking about taking it to a bike shop and just paying them to do it but also watching them and hopefully get them to show me as they fix it so at least i learn something in the process.

Cheers for any help.

[Tim]

Anyone have any suggestions on what to try?

RTFM.

http://si.shimano.com/pdfs/dm/DM-RD0003-09-ENG.pdf

[Duck!]

Before anything else, disconnect the cable from the derailleur. Hold the end of the cable and pull a bit of tension on it. Shift through the gears and feel for excessive friction, especially on the release shift; you should not need to tug particularly hard to pull the cable through the housings as it's released from the shifter. If it feels draggy, pull the cable back & forward through each section of housing to see if any are particularly rough & draggy, and roll the shifter hood forward from the bar to uncover the cable feeder hole in the outer side of the shifter body. Poke the cable out of the feeder hole and inspect for broken strands. Gear cables will ALWAYS break about 15mm from the head, as that's the section that fatigues from getting wrapped & unwrapped around the shifter barrel. Replace the cable if there is any sign of fraying, and any offending bits of outer casing if there are any excessively draggy sections.

The "adjustment" screws are more properly referred to as the limit screws, and as the name suggests, set the limits of the derailleur's travel. Winding them both in will bring available range of travel in towards the centre of the cassette. They are not meant to sit flush with the derailleur body, in particular the High one; it has a fair amount of adjustment available when set properly so that in the event of cable breakage it can be wound in to set the derailleur in a more knee-friendly gear to get you home.

Start by setting the high (outer) limit. While turning the cranks, wind the screw out until the chain drops to the smallest sprocket, and carefully keep winding it out just until the chain stops rattling against the side of the next gear. When viewed from behind the centre of the top jockey wheel teeth should align with the outer face of the smallest sprocket.

Again while turning the crank, push the derailleur by hand up to the big sprockets - be very careful as you get to the big one, because if the limit is too far out you'll shove the derailleur and chain into the spokes! Use the Low limit screw - winding in to bring the derailleur toward the centre of the casette, out to bring it toward the spokes - to align the centre of the jockey wheel teeth with the centre of the sprocket teeth. Once set, let the derailleur back to high gear for connecting the cable.

Wind the barrel adjuster on the derailleur until the top of the inner part just sits proud of the plastic knob, then feed the cable through. Note the indicator arrow printed next to the anchor bolt, which tells you which side of the bolt to pass the cable. Ensure the shifter is fully released, pull a little bit of tension on the cable and snug down the anchor bolt, firmly but not to the extent of crushing the cable. Run through the gears. If it's hesitant shifting to the next bigger sprocket, wind the adjuster out slightly until it shifts up. If the chain shifts and then makes noise on the side of the next gear, or hesitates to drop to a smaller sprocket, wind the adjuster in a bit to reduce cable tension.

[Neddysmith]

Anyone have any suggestions on what to try?

RTFM.

http://si.shimano.com/pdfs/dm/DM-RD0003-09-ENG.pdf

Amazing......

Was not aware this was available.

Anyways, cheers guys, awesome write up Duck!, i did manage to get things adjusted so far, and appears to be working although the real test will the first test ride, which as its raining now wont happen till at least tomorrow...

[uad782]

Hi Everyone,

I am looking for a bit more advice please. I am building my first bike with road components. I have installed the RD 5800 (105) rear derailleur. When I shift the chain towards the large cogs it will not go to the largest cog. It stops about 4 cogs short. Reading the above posts I think I need a lot of tension with this derailleur. I used a set of pliers to pull the cable tight when the derailleur was in the smallest cog.

So, should I use the barrel adjuster on the derailleur to adjust the derailleur to shift to the largest cog? If I do this is it going to make it tricky to get the indexing correct? I thought the barrel adjusted was mostly for indexing not making large shifts to the whole derailleur.

Any advice appreciated (duck??). I have RTFM and it doesn't help.

Thanks

[Duck!]

What shifter are you using? To be that far out sounds like you're using an incompatible shifter.

[uad782]

ST 5800 (105) shifters

[Duck!]

Hmm..... Make sure the shifter is in the 11th gear (fully released) position, and that the cable is properly seated inside the shifter before you connect the cable to the derailleur. The 11-sp. rear derailleurs don't need any more cable tension than any others. It's the related front derailleurs that need a truckload of tension.

[uad782]

Thanks Duck,

that was my first mistake but I fixed that one. I will try again.

[tez001]

Make sure the cable at the rear derailleur is routed correctly too.
If you're not getting enough tension on it, my method is to push the derailleur in slightly while holding the cable tight and doing up the bolt (yes you need three hands )

If using this method, don't screw the barrel adjuster all the way in, so you can slacken off the cable if needed.

[uad782]

Thanks everyone,

I think I have sorted it. The cable end ferrule was possibly not all the way in at the shifter. It is tricky to get it in correctly but I think I have.