Why are my gears not working fully ?

[cougie uk]

So I got the summer bike out of hibernation for the good weather to come. Took it out for a spin and the gears work perfectly in the smaller sprockets but as the road rises and I want lower gears - I can't get the bottom 3 or 4 sprockets. It keeps pinging back from about half way through the block.

Was all good when I put it away. .
Maybe the cable has slipped or stretched ? That's my working theory.

Anything else out there for me to check ?

 

[T4tomo]

is it just dropping back int the sprocket changed from all the way up, or is is dropping from largest cog to somewhere back in the the middle? Former may be a misaligned mech hanger

is it 11 speed STI or 5 speed friction etc?

 

[geocycle]

Gear hanger bent is possbile? If not that then it could be the cable, the spring will be trying to move outward to the small cogs so your cable is too tight if it is not getting there, most likely snagged somewhere as it cannot tighten itself.

 

[cougie uk]

10 speed cassette SRAM force.

Just drops back from the sprocket I was in before. Weird cos it was fine when I last rode it and it's been tucked away safely.

 

[Cycleops]

Just release the cable and start from scratch. New cable might be an idea if it hasn't been changed in a while.

 

[Tigerbiten]

Sounds like the ratchet in the shifter may be gummed up beyond a certain point.
It's possible any grease in it has dried out and/or got contaminated.
Hence it works fine until it hits the gummed up section, at which point it won't hold.
Take the cable off the mech, pull tight by hand and work the shifter.
What do you feel when you work the shifter both ways ??

Luck ......

 

[cougie uk]

Just the cable tension. Reset it and it's ok now. Thanks everyone.