Campag H screw Hell....!

[Michael Clark]

The H screw on my Campag Veloce rear mech doesn't adjust the cage when I turn it either clockwise or anti-clockwise. The cage is right up close to the cog (actually touching) but the H screw doesn't adjust. Any help would be greatly appreciated. Thanks, Mike

 

[RecordAceFromNew]

Strange, are you at the lowest (biggest rear sprocket) or highest (smallest sprocket) gear? Is the chain length correct? In normal operation the rear mech cage shouldn't be anywhere near enough to touch the smallest cog irrespective of H screw adjustment.

The H screw is there to stop the mech from getting too far outboard, and only when you are on the highest gear (smallest rear sprocket), but it is only in play IF the cable is not taut then, otherwise the cable is functioning as the stop no matter how much you loosen the screw. For rear mech adjustment including H screw this is as good a guide as any.

 

[Michael Clark]

Strange, are you at the lowest (biggest rear sprocket) or highest (smallest sprocket) gear? Is the chain length correct? In normal operation the rear mech cage shouldn't be anywhere near enough to touch the smallest cog irrespective of H screw adjustment.

The H screw is there to stop the mech from getting too far outboard, and only when you are on the highest gear (smallest rear sprocket), but it is only in play IF the cable is not taut then, otherwise the cable is functioning as the stop no matter how much you loosen the screw. For rear mech adjustment including H screw this is as good a guide as any.

Thanks for this, its appreciated. The H screw on Campag replaces the 'B' screw on other derailleurs I'm told. The rear mech cage shifts along smoothly under each cog right through the range but is always almost touching the cog it sits beneath. The only screw I can find that adjusts the cage is located at the top of the cage itself (rather than where the derailleur attaches to the frame as on my Cube bike)
I checked with a LBS to see if maybe the chain is too short and they thought that was unlikely. The chain doesn't seem too tight when on the outer chainring (54 teeth) but the rear derailleur does look like its being pulled towards the front of the bike too much! Maybe the chain is too short?

 

[RecordAceFromNew]

You are right regarding the screw. You can check if the chain length is correct by using this calculator.

 

[Michael Clark]

Brilliant, many thanks

 

[TAV]

It happened to mine the cage was catching the cassette the h screw had broke inside I had to get a new deralier.