Adjusting rear Derailleur - Setting limits

Screws L, H and B are set during the initial installation of the derailleur on the bike and since we do not deal with them again. Their only function is to define the limits of movement of the derailleur. No related how changing speeds. In the event of deterioration of the derailleur, do the following.

Screw «H» (High): As the screws more left (inward) moves the derailleur.

Screw «L» (Low):
 As the screws more right (outwards) moves the derailleur.

 

Starting from "H" put long drive ahead and the smallest rear sprocket. If the cable is too tight, loosen the tension a little screwing the barrel (red arrow, the right turn a few turns). Begin to rotate the pedals, a gear change inwards (cog to the left) and change again outward (resetting the smallest). If the change is normal, minimum screw (1/4 turn) the screw "H" and do it again the above gear changes. The whole process (change inside out, screwing one quarter turn), repeated until the change to the smallest sprocket (outward) becoming slowly or with difficulty. At this point unscrew (quarter turn) the "H" to restore the proper functioning point . Furthermore, if the «H» screwed too, then when pedaling in the smallest cog the chain will rub in the next gear and possibly frolicking as they try to move to the left (inward). Therefore, if you encounter these symptoms we know from the outset that the 'H' wants unscrewing.

 We have now finished setting the lower limit. The derailleur moves as needed to descend on the small gear and never mind again the 'H'.

Continuing the screw «L» put the middle front disc (small if we have two drives) and the second largest rear sprocket (what is the largest right).
CAUTION, do not start the changes within - outside as if the «L» is unscrewed, the derailleur will pass the cartridge and throw the chain in the spokes. Screw the «L» a few turns, the pedals rotate and change a speed inward (one gear to the left). If the change is normal, minimum screw (1/4 turn) the screw «L», we return to the original sprocket and repeat the change inwards (towards the larger sprockets).


The entire process (switch inwards screwing 1/4 turn), is repeated until the change to the large gear (inwards) or presents a difficulty or not done at all or have caper and rattling when the chain located on the larger sprocket. At this point unscrew (quarter turn) the «L» to restore the proper functioning point. Generally if the «L» unscrewed too, then the derailleur will spend the last gear of the cassette and chain us flying through the spokes. That's why in many bikes (mostly children) put a plastic tablet after the cartridge to prevent the neglect of the owner and maladjustment.






We have now finished with the setting of the upper limit, never mind again the screw «L». The derailleur moves enough to bumped in large gear without throwing the chain in the spokes.
Note: The value «H», «L» is likely to reverse in old bikes. May deem the «H» to regulate the upper limit (inner gear) and «L» the lower limit (the gear out). The procedure is the same just make sure it works with the correct screw.


Set the distance from the sprockets.

Screw 'B': As the screws removed both the upper wheel of the gear cassette.

 

In the rare event that requires adjustment screw "B" put medium or small tray in front and larger rear sprocket. Unscrew the "B" until the upper wheel derailleur too close the cassette and started to rub the large gear. Then we start to screw the "B" until the upper wheel removed just enough to avoid contact with the sprocket and the chain moves smoothly.

Generally we want the derailleur to be close to the gear but not so close as to the chain jamming or rubbing parts together.

 

 Having thus set the limits movement of the derailleur and the distance from the toner, move to what we call "speed setting ".