Push Bike Gears

[Paris2]

I have been using my dads old road bike to travel to work for the past week and have been having trouble with the gears.

When trying to select a gear for the rear derailer it doesnt feel like the cable is being engaged. So the shifter is moving freely without actually doing anything (make sense?)

But...occasionally it will engage and change the gears. This only happens when I want to change down to lower gears (larger sprockets), when changing the other way it will engage the cable straight away, but rather than changing up one gear it will skip the chain all the way to the smallest sprocket.

Any ideas anyone? Im sure it must be something to do with the cable, but would this stop the shifter engaging it at all?
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Current Ride: Daytona 600

[ninja_butler]

What make & model? The cable probably needs a slight adjustment, I haven't done it for ages though so I can't remember how to explain it. You'll find some guides on the internet though - try Sheldon Brown.
Remember to take the pressure off when you change gears; keep pedaling but don't stand up or you'll just crunch the gears.

[Ste]

https://bikemagic.com/gear/how-to/maintenance/rear-mech-set-up.html

[stonesie]

The cable only pulls one way so the linkages in the derailer have a spring to push it back. It sounds to me like it needs a bit of TLC, probably rusted up and just needs freeing off and the cable lubeing.

[Paris2]

Its a Carrera Road Pro (Halfords jobbie), but its a fair few years old now.

I have adjusted the cable and derailleur position no end, but to the same result. It was sat for months and did gather a fair layer of rust before I used it though

Could it be the mechanism inside the derailleur itself? Can they come apart for cleaning and maintenance?
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Current Ride: Daytona 600

[D O G]

It sounds as if the cable isn't moving freely.

When you want to move down sprockets you are relying on the power of the spring in the rear mech to pull the the mech down, with the chain, and the cable through the lines.

The whole thing can come apart, although I bet it is the cable gummed up in its cable outer, which is a fairly easy fix once it is apart.

If you want any help, despite my derisions of the charity event, I'd be happy to come and assist, I'm only in Soton.

[D O G]

Oh, and they can be a bit fiddly to setup, there is a sweet vid on youtube which I found about 3 months ago. After 6 years I can now correctly adjust my rear mech.

[Paris2]

Cheers for the offer DOG.

Charity event derisions aside, thanks for the offer. Ill see how it all goes when I take it apart on my day off.

Its liveable as it is, just a pain having to rely on a small number of gears. And the bike deciding when you can change.
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Current Ride: Daytona 600

[Drew]

[D O G]

[Paris2]

I can get it onto most of the sprockets yes. But the shifter only catches the cable occasionally, but when it does the cable pulls the derailleur up the sizes fine.
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Current Ride: Daytona 600

[AndyB1989]

older shimano ez fire shifters ?
probably two screws holding the cover on the shifter at the front take them off and have a look inside


there is a ratchet and pawl mechanism which gets quite heavily greased from the factory and over time this grease looses is lubricating propertys so find the pawl and wiggle it back and forth and give it a good lubricate with a silicone based lube something like tf2 or gt85


from the symptoms you describe im pretty sure this will be the problem

[Walloper]

It sounds like the de-railer/s is/are needing some lube.
WD40 to clean and washout any old lube then skoot the fookers with a bike lube.
Look for one with teflon.
It's probably stretched the mechanism now with you hauling on the shifter so may need a cable tweak too.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[AndyB1989]

[Walloper]