sigg.switz

I switched over a 7800 rear derailluer on an old steel specialized allez. I fought to adjust the derailluer to no avail, when I noticed that the hanger on the bike is thinner than the other hanger. By unscrewing the derailluer 1 or 2 mm I was able to get perfect shifting.

My problem is this - Should I use a spacer, like a washer or do I have serious problems? Notice the picture, this is when the derailluer worked perfectly....

trekkie820

Did you try backing out the high limit screw?

sigg.switz

I did, as much as possible, still didn't work.

blamp28

Are the threads fully engaged? If so, buy a spacer or washer. Tighten it down and go with it.

trekkie820

Yeah, I would be okay with that. Make sure there are more than 1-2 threads engaged before you proceed.

sigg.switz

The threads are engaged, will any washer do the trick?

Grand Bois

No, it has to be one with the correct dimensions.

rickowensis

The deraileur should be completely tightened down without a spacer.

1) Examine cables and housing for kinks, rust, full engagement in cable stops and shift lever.
2) Loosen cable at deraileur.
3) Shift into small chainring w/ front der.
4) Shift onto smallest cog w/ rear der.
5) Loosen der. cable so it is slack.
6) Check movement of rear der. without interference from cable. Adjust hi-limit if necessary.
7) Lubricate cable/housing interface and slide cables through housing to ensure free movement
8) If movement is impeded in any way, replace cable and housing as a unit to ensure shifting precision.
9) Screw derailleur barrel adjuster in completely, then loosen two turns.
10) With shift lever positioned for smallest cog and housing run properly, insert cable into rear der. and tighten while holding cable taut. If new cable, stretch cable by pulling exposed cable at downtube to pre-stretch. Take out resulting slack and retighten at rder.
11) Shift front der to big ring and slowly and carefully shift thru gears to prevent possible overshifting from misadjusted limit screws.
12) When limit screws are properly set, adjust cable tension for snappy shifting.

General info:

Most shifting problems are caused by a lack of cable lubrication and or poor routing of the cables. This includes cables which are too short, tight curves and kinked, corroded cables and housing.

Derailleurs as well as all pivot points on a bike need to be lubricated occasionally to ensure optimum performance.

Derailleurs, but more often derailleur hangers can be bent by minor impacts which will lead to poor shifting. If a der. hanger has been bent, the only way to accurately realign it is with a derailleur alignment gauge at your LBS.

Derailleur cables which are excessively tight will prevent the derailleur from returning to it's low normal position at the smallest cog (SHIMANO). Dry cables and kinked or short housing can also cause this condition.

Check and clean your chain, cogs and jockey wheels. Relubricate with a bicycle specific lubricant such as Tri-Flow or ProGold. These lubricants are thin-bodied to penetrate the small spaces of the chain and will not gum up the chain if the excess is wiped off. Excessive grease buildup also causes poor shifting.

After going thru these steps, you should discover the root cause of your shifting malady and be able to remedy it quite easily.

REMEMBER: Analyze the problem, discover the cause and FIX THE PROBLEM, DON'T TREAT THE SYMPTOM.

Hope this helps. GOOD LUCK!!!

HillRider

Simple answer: Install a washer or spacer and tighten the bolt.

blamp28

What he said. Now ride your bike.