Rear derailleur cassette teeth worn down?

[TheOnlyRick]

Hi - New to the forum.

I recently had my rear derailleur cassette replaced. It keeps on jumping when in the middle range of gears. (It doesn't go to a different gear, but it does 'stutter' within the gear.)

I'm thinking I need to change the tension (the black plastic twiddly knob).

Could it be one stiff link in the chain?

Also, when I look close up at the chainset, the ends of the teeth on the cogs aren't identical. It looks they are worn.

Should they be? It's the same thing here: http://media.photobucket.com/image/rear chainset/jon_mithe/rear_chainset_flash.jpg

Off to work now, so can't post pictures or more detail. But if useful, will do this evening.

Cheers,

Richard

 

[P.H]

Did you change your chain at the same time as the cassette?
If not what you describe is a worn chain not meshing with a new cassete.
The short term solution is simple, buy a new chain.
The long term solution, is to frequently measure the chain length and replace before it wears the cassette. There's a choice of ways to do this.
I can't open your photo (from work) but the odd size teeth you describe are there to aid shifting.

 

[Mr Pig]

You might need new chain rings at the front too. Just thought I'd cheer you up ;0)

 

[Kidge004]

Check your chain for wear as most guidlines say change your chain at the same time as cassete!!

As for the stiff link, that could be a possibility so try and see!!

Other than that there isnt really anything you can do, possibly look at the cable tension!

 

[Mr Pig]

If you change the chain before it gets past about 1% worn you get away with it. I've had four chains on this transmission with no problems at all.

 

[02GF74]

Hi - New to the forum.

I recently had my rear derailleur cassette replaced. It keeps on jumping when in the middle range of gears. (It doesn't go to a different gear, but it does 'stutter' within the gear.)

what are you talking about? did you replace the cassetter: the set or 8 or 9 round rings with pointy bits or the derailleru: two plastic wheeles in a mechnism though which the chain goes throuigh (hmmm, hard to escrtibe).

The picture shows that cassette as quite dirty so it soes not appear to be that, or is it?

Depending on make/model of cassette, e.g.shimano ones have specially shaped teeth - look like they are damaged or worn - supposed to help with shifting the chain.


Fitting a new cassette with old chain would tend to jump in the larger gears, not just the middle ones.

If it was the derailleur that was replaced, you need to adjsut the endstops and also the cable tension so that the shifters (that you operate with the fleshy bits on the end of your hands) will put the chin in the correct place.

Kinda hard to tell what the problem is without accurate data, i.e. what is a "rear derailleur cassette " ?????

 

[TheOnlyRick]

Apologies

Hello, I am a bad and forgetful person.

I completely forgot I ever joined this group until just now when I was having a clearout of my emails, so here I am, replying a mere 7 months after my first post....

In answer to various questions, it was simply that the chain was worn. I put a new chain on (well, a shop did) and it was plain sailing. (But it really did look like the teeth on the cassete were worn down.)

I know we're meant to replace chain and cassette at the same time, but that gets expensive! I guess I need to get better at judging when to replace the chain before it gets too worn. Perhaps I should invest in a ruler and refer to this page: http://www.bicyclinglife.com/HowTo/ChangeAChain.htm

Cheers,

Richard

PS: Two top tips I will share for town commuters (particularly in London)
1 - The back of a clean black cab can be used as a mirror to see what's behind you.
2 - If going alongside traffic, but you're in an empty lane (and so there's a risk of a car cutting you up as they change into your lane), you can see if the car is planning to change lanes by the direction the front wheels are pointing. If they're pointing into 'your' lane, it means the car is getting ready to change...

 

[Cubist]

Theonly rick

Some of the teeth on some sprockets on the rear cassette are different shapes as standard. It's done to aid smooth shifting.

See you in another 7 months

 

[TheOnlyRick]

:-)

See you in 7!