Gears not changing smoothly

brians947

Here is my issue. The rear Derailleur will change gear from the small gear to the large nice and smooth. Its going from the large to small its not. Gears wont change smoothly and sometimes jump to gears. It a shimano Sora derailleur. Im have thinking its a piece of sh-t- and to replace both the front and rear Derailleurs

cython

Have a look at this page. I have set up Sora derailleurs to shift perfectly adequately, so at a guess I would think you need to look at the adjustment, specifically the section titled "Checking the Rear Indexing Adjustment" in that guide.

If you are having difficulty shifting into smaller gears at the back, then maybe the cable tension is too tight, and you need to use the barrel adjuster to relieve this? If the tension were insufficient, then you would have problems shifting into lower, larger gears, so don't go too far with it. Definitely read the above link though.

furiousox

Handy video tutorial here from bikeradar showing how to adjust brakes and gears

http://bcove.me/ipt5aebn

Holyboy

Sora can work perfectly, I would recommend replacing the cable, inner and outer, it's probably got some corrosion or gunk in it, if it's shifting up gears fine the adjustment is probably OK but the cable may just be sticking a bit when the spring is trying to pull it back down!
If you're not sure about doing it, just bring it to your LBS, it shouldn't cost too much for a new cable.

ednwireland

how long you had the chain on there ?

brians947

Thats what i will do first replace the cable. Bike has been sitting in shed for few months so it may just have got stiff.

Holyboy

brians947 wrote: »

Thats what i will do first replace the cable. Bike has been sitting in shed for few months so it may just have got stiff.

A good decision, don't forget to lube it, no one in this country seems to do it but it helps things a lot!

coolbeans

There's not a thing wrong with a Sora derailleur.

funkyjebus

When did u last degrease and re-lube the drivetrain?

bmacg

If the problem is only with shifting on to the smallest (highest) gear, and the others change down smoothly, then it might be that your high gear limit screw needs to be slackened slightly. I had the same problem with my own bike, and had indexed and fine-tuned the gears several times, but it was still hesitating on the smallest gear. Let out the limit screw 1/2 turn or so and its fine now.
If, on the other hand, the problem also occurs when shifting down in other gears then I'd agree with the foregoing; its either the cable tension is too tight or the deraileur needs to be cleaned and lubed.

brians947

So took on board everybody's advice. Stripped down the gears and degreased them and lubed them. Purchased prelubed gear cables and replaced existing cables and gears running alot better now. Just need a slight tweak but changing much better and not skipping when changing to smaller gears.

Thanks to everybody for the help