Rear Derailleur High Low Limit screws : which way to turn ? and indexing tension

H Hi High

 smallest

 hardest

 gear (furthest from wheel)

L Lo Low 

biggest

easiest

 gear (nearest the wheel)

H screw (furthest from wheel)

clockwise : moves the derailleur IN towards the wheel

anti clockwise : moves the derailleur OUT

L screw (nearest wheel)

clockwise : moves the derailleur OUT

anti clockwise : moves the derailleur IN

H - clock - in

H - anti - out

L clock - out

L - anti - in

INDEXING (use Barrel Adjustor)

CLOCKWISE = LESS tension / loosen / smaller - harder 

ANTI = MORE tension / tighten / bigger -easier

Clock - down - less - loose

Anti - up - more - tight

Clock-down-harder

 Anti-up-easier

Clock-loose

Anti-tight

2 possible tries :

try 1 : 

go to problem gear.

if not going up, tighten/anti while turning wheel. When it goes up, stop.

now check going down is ok. if not, need to loosen/clockwise the barrel.

try 2 :

go to smallest / hardest gear.

turn wheel and tighten (ANTI) the barrel.

when it goes up, stop.

now try going down.

keep trying until happy.

Barrel adjuster adds more/less tension to the CABLE HOUSING.

rear derailleur CABLE HOUSING TENSION is the index adjuster.

get right on 2 cogs = right for all

INDEXING is to adjust between 2 cogs.

since each cog is same distance, in theory ...

get right between 2 cogs = should work for all

barrel adjuster on shifter

you can use this to adjust while cycling.

Purpose of post :
To explain the limiter screws on a bike derailleur and which way to turn them.

main problem in explaining : big-small etc.

Big gear to me is the largest easiest rear gear, but to cycle industry it's the smallest rear gear.

Makes explaining up-down big-small difficult. 

Written by : naive cyclist
Expertise : 2/10