5

I feel bad asking this question because I've been doing bicycle maintenance for over 20 years and this seems like a noob question. I was unable to find a Shimano manual to answer this question. I just bought a Norco Threshold CX bike with Shimano Ultegra SL-RS685 brake/shift levers. I want to adjust the cable length for the front derailleur to fine-tune the derailleur position. The cable is routed inside the frame and there is no barrel adjuster to be found anywhere. I looked under the brake hood and did not see anything that appeared to be involved in adjusting the cable length.

Obviously I could adjust the cable length at the derailleur, by loosening the bolt, moving the cable a tiny bit, and tightening the bolt again. But it seems difficult to do fine adjustment that way.

In case you're wondering why I'm adjusting the derailleur on a brand new bike: The front derailleur wasn't shifting properly because the rear fender (installed by bike store) interfered with it. Before I figured that out, I thought the cable length needed adjusting, and I couldn't figure out how to do it. Techically I can leave the cable alone for now, but eventually it will need adjusting and I would like to know how to do that.

  • It seems to me to be inexcusable for a derailleur bike to lack adjusters on the shift cables. – Daniel R Hicks Mar 12 '15 at 12:05
  • Double-check for cable adjusters. Daniel's right - it's hard to believe they forgot something basic like that. Maybe they're hidden out of sight somewhere, maybe they don't look like cable adjusters... – Mike Baranczak Mar 12 '15 at 15:45
  • I will take another close look tonight. If it's not there, I'll get one installed by the LBS. They said I get 1 year of free labor for anything I want done, so if they don't want to give me a free adjuster, I'm just paying $10-$15 and they will install it for free. – Nik Mar 12 '15 at 20:50
  • Talked to bike store guy, he says Norco doesn't put adjusters on this bike. I'm having one installed now. – Nik Mar 13 '15 at 18:20
  • It can be done without a barrel adjuster with a "third" hand-tool. – Carel Aug 3 at 21:06
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If there's no barrel adjuster, then you'll need one installed. Ask LBS to do that or do it yourself:

  1. Get an inline barrel adjuster and two 4mm ferrules. These are pretty cheap.
  2. Get tools to cut cable housing.
  3. Make sure there is enough shifting cable left to accomodate extra 3-4 centimeters added by adjuster. If it's too short, get a new cable.
  4. Detach cable from derailleur.
  5. Find a straight section on cable housing that doesn't rub anything and mark it.
  6. If your frame runs cable bare and not through inner liner, attach a long string to cable end before pulling it out. This will help to route cable back.
  7. Cut housing in marked location, install ferrules on both ends. If ferrules have long tongues, cut them down too.
  8. Adjust the adjuster to shortest position, install it in the cut.
  9. Route cable back using the string. Now you can tweak cable tension for front derailleur.

The result should look something like that. As a side note, 5800/6800 derailleurs have more complicated installation procedure than older models, make sure to download dealer's manual and read carefuly for instructions.

  • Thank you for the answer and the excellent picture. LBS will install it for me since they already have a list of issues that need to be fixed. I'll print out that manual and keep it around in case I need to adjust things in the future. – Nik Mar 12 '15 at 20:54
4

You still may want an inline adjuster, but if you don't have one, here's the procedure I use (I don't have one):

  1. Disconnect cable from front derailleur
  2. Shift to small ring, large cog
  3. Adjust the lower limit screw to put 1mm of clearance between chain and inner cage.
  4. Turn the lower limit screw clockwise 1/2 turn (pushes cage further outboard)
  5. Pull cable tight with pliers and reattach.
  6. Turn the lower limit screw counter-clockwise 1/2 turn (undo adjustment from step 4).

Steps 4 and 6 allow you to add a bit of tension to the cable.

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