Springs in rear derailleurs: do these loose their strength?

betty swollocks

large member
Springs in rear derailleurs: do these lose their strength?

Tweaking the gears on my recumbent is proving problematic.
I know how to do this, but tension the cable enough to move chain up the sprockets easily and it moves down sluggishly. If tension is eased for it to move down easily, the chain chatters on the way up.
I can get the chain to move slickly up or down, but not both.
Played around with the B screw too, to no avail.
8 year old Shimano XT and equally old SRAM 'Rocket' twist grip shifters

Ideas please, or new derailleur?
 

cyberknight

As long as I breathe, I attack.
Not sure tbh .

Have you checked the cable is running smoothly ?I have had gear shifting being sluggish due to the cables needing a lube .
 

RecordAceFromNew

Swinging Member
Location
West London
Not that it proves anything, but one of my rear mechs is nearly 30 years old and it still works perfectly.

If the gear cable/housing is 8 years old, it is likely to be rusty and if so renewing is best. It is not (or rather does not need to be) expensive.
 

RecordAceFromNew

Swinging Member
Location
West London
In that case I would:
1) shift the gear normally so that the chain is on the largest rear sprocket
2) without spinning the rear wheel or freewheel, ratchet the shift lever to the opposite extreme (highest gear)
3) the cable should now be free to move against the housing(s) with very little friction - if not there must be a kink/friction somewhere that needs to be identified.
4) lubricate the various pivots of the rear mech.
 

dave r

Dunking Diddy Dave Pedalling Pensioner
If its not a sticky cable check for wear on the pivot points on the rear mech, if the mech is worn it will tend to change one way or the other way but wont change both ways. Is there a cable guide the cable runs through? If so check the cable runs free through the guide.
 

battered

Über Member
Not the springs but the whole thing gets gummed up and stops working. The usual symptom is that when you go down the cassette (gears with few teeth to gears with lots) everyth8ing is fine but going the other way is problematic. You end up stopping the chattering by going too far then shifting back. 9 times out of 10 this is dirt in cables or pivots or mechs. Give it all a good clean, clean and grease the cables, oil the mechs and Bob will almost certainly be your uncle.:tongue:
 

swee'pea99

Legendary Member
Not sure how recuments route cables, but I solved these symptoms on a regular bike with oil where the cable went round the bottom bracket. Is there anywhere on its run where the cable isn't running through the housing, but rubbing on the frame?
 
OP
betty swollocks

betty swollocks

large member
thanks everyone.
Everything is clean and/or new.
Took bike out yesterday. Lots of tweaking, but still far from perfect.
Had a dream last night and will now check the gear hanger alignment!
 
OP
betty swollocks

betty swollocks

large member
Bought an Ultegra, as only have a 11-28 and a 22 tooth difference on the front, whacked it on, adjusted it all up and all works perfectly, click click click up and down all gears. Sorted!
Can only conclude that the old XT was tired.
 
I had this problem with a campag Xenon rear mech. It was new in December and gubbed by March. I think salt from the winter just corroded something and it was beyond repair. A new mech sounds likely.
 

swee'pea99

Legendary Member
That's appalling! I've been spoiled, I guess, by only ever having used components pinched off (good) old bikes I've bought off ebay, but my bikes go out in all weathers, year round, and I've never had a moment's problem with any of it. I'm talking 20 years+, Shimano 600 or 105, with thousands of miles on the clock.
 
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