mikepwagner

I am pretty happy with my RD-6700, but it's not perfectly adjusted. Sometimes down-shifting in the highest gears is a little iffy (when the chain is on the largest sprocket in front and the 2nd or 3rd smallest sprockets in the rear.

I find the instruction manual/sheet a little confusing.

https://media.canyon.com/download/man...RD_6700_EN.pdf

I can't quite follow the flowchart for step 5 "SIS Adjustment" - aside from the fact that I appear to need three hands (one for the shift lever, one for the crank, and one to adjust the outer cable adjustment barrel).

Can someone explain this procedure in their own words, or explain a different procedure?

Thanks

Kimmo

Just shift the chain to the second-smallest cog (ensuring you're only one click from the end of the shifter's travel), and pull the derailleur to tighten the cable. Then adjust the barrel adjuster to position the jockey wheels directly below the cog while maintaining tension on the derailleur. Shift up to the middle of the cassette and check the barrel adjustment again after pulling on the derailleur again.

Now, any shifting sluggishness is down to excess cable friction. If it's really sketchy, it could be down to poorly-prepared or damaged cable housings. If you have STIs, sometimes the cable starts to fray inside the shifter.

You can shift the chain to the biggest cog, then without pedalling shift to slacken the cable while pulling on it to feel for friction or mushiness.

nhluhr

There are 3 (possibly 4) things that can cause your issue.

1) adjustment - make sure the cable tension gives you the best compromise of shifting quality all the way up and down - check this by shifting one cog at a time while pedaling (i like to simulate light pedaling load by either accelerating or by dragging the brake as I turn the crank with my left hand and shift/brake with the right hand). Turn the adjuster barrel one or two notches at a time then repeat the pedaling/shifting check until you're satisfied the adjustment is correct.

2) limit screws - not a likely cause... this should only affect the biggest or smallest cogs and doesn't sound like what you're describing.

3) derailleur hanger alignment - if the derailleur hanger is misaligned you may see it shift poorly through a portion of the range. Check this with a hanger alignment gauge. Be careful about re-aligning a bent hanger. Small adjustments are probably okay but if it's way out of alignment, bending it may cause bigger problems and replacing the hanger is a better bet.

4) friction - Normal derailleurs have the least amount of spring tension when in the smallest cogs, so they can be very susceptible to cable/linkage friction.

If this is a brand new install (new cables, new housings, new shifter, new derailleur), I would first verify that all your cable runs are radiused correctly (extra housing adds friction, but too-short housing causes abrupt bends which can be worse), make sure all your cable housing ends are properly smooth (even high-end cable housing cutters often don't leave a perfect cut - pros will often use a bench grinder to flatten it, then a sharpened spoke to 'ream' the hole a bit and eliminate friction where the cable enters the housing).

Many bikes have various options for downtube cable routing - I like to choose the option that provides the largest bend radius for the bar-to-frame housing and typically will have my crossover occur along the downtube. If you have a BH frame, for example, they have a crossover cable guide at the BB but that increases the sharpness of bends and shouldn't be used.

If this is not a new installation, you probably could use a little cleaning/lubing of the cables and derailleur linkages.

Hendo252 

There are good videos on this at YouTube and Vimeo -- search and watch a few.

Some are awful, but some are very good, too!

-TH

mikepwagner

Just to follow up. I tried again, and the mechanic cleaned the chain and found that the derailleur hanger was slightly bent. He used a Park Tool derailleur hanger alignment gauge to straighten it. Then he adjusted the derailleur and it appeared to work fine (I haven't ridden it yet).

I may have to buy that tool.

$20, and out the door.