Gear indexing issue

[screenman]

I need not say anything, as anthing I was going to say has already been said. But just incase, alignment.

 

[confusedcyclist]

Hi, It's really unlikely the cassette is the issue, unless you changed to an incompatible speed version. Another vote for get the tool, or let a bike shop sort it. The former will be cheaper and pay for itself in the long run. The latter will mean the bike is sorted no matter what the issue is, as they will troubleshoot for you. Once you've checked and addressed alignment, follow this guide step by step:

https://www.parktool.com/blog/repair-help/rear-derailleur-adjustment

Read it all, understand what your doing before you do it and you won't go wrong. I have been doing my own maintenance for years, but because I don't do it every day, I sometimes forget an important step. So be sure to read it carefully.

 

[Tim Hall]

If you can't get hold of an alignment tool you can still check whether the hanger is straight or not by fixing a second rear wheel into the hole in the hanger normally used by the mech and measuring the gap between the two tyres in several locations.

 

[screenman]

I can see that this might be true, but ...

Isn't the whole point of separate hangers to avoid that combination of circumstances arising?

They make it less likely, but on every bike I have tested fitting a new one it has still needed tweaking.

 

[gbb]

An unlikely reason but one that happened to me once...i'd done some work on the rear and could NOT index it, whatever i tried. Over and over it i went, just would not have it. At some stage i took the wheel out to have a look at something...put it back and it miraculously changed gears as sweet as a nut.

I can only assume i'd not had the wheel seated correctly the first time around.

 

[bpsmith]

Since I bought the tool, I have checked brand new bikes of mine, and mates, and 4 out of 5 have been reasonably out of alignment.

When adjusting, I tend to use the same point on the wheel (such as the valve area) to measure against just to remove the element of the wheel not being true.

 

[cyberknight]

Its always the simple jobs that cause the most grief, had to take the bike to the shop once as i couldnt get the brake cable through the hole in the shifter , after an hour i gave up !

 

[Crankarm]

The joys of a deraillieur transmission!

 

[Chris1983]

Hi guys

I don't have the tool yet but fitted a new hanger and all sorted.

But before I fitted I compared the two and couldn't see any bend in the old one. To the point that once I set it up with the new hanger I stripped it back down again and refitted the old hanger and the issue can back. So 100% the rear hanger.

New hanger back on. Indexing nicely again. Happy days.

I'll be ordering a hanger alignment tool and a new hanger for spares this evening.

Happy days and thanks for your help folks.

Cheers

Chris

 

[Ajax Bay]

@screenman - you may have read this article to which @Dogtrousers links:
"Replaceable Derailleur Hangers: Clever Design or Achilles Heel"

 

[bpsmith]

Interesting article. Personally, the fact that a steel hanger can “almost always” be straightened is a good enough reason for replaceable softer hangers. “Almost always” wouldn’t cut it for me.

 

[Ajax Bay]

“Almost always” wouldn’t cut it for me.

Has "cut it" for millions of riders of steel bikes since early in the last century.
Brake cables 'almost always' don't part.

 

[raleighnut]

Interesting article. Personally, the fact that a steel hanger can “almost always” be straightened is a good enough reason for replaceable softer hangers. “Almost always” wouldn’t cut it for me.

With a steel frame there are 2 cures for a damaged hanger, have a new dropout brazed on or grind off the gear hanger part and fit one of these,

 

[bpsmith]

Has "cut it" for millions of riders of steel bikes since early in the last century.
Brake cables 'almost always' don't part.

My luck would be the one time that it couldn’t be straightened.

 

[Pale Rider]

Indexed gears and ever more gears have presumably made alignment more critical.

I seem to recall some simple friction shifters had a trim control.