shifting issues

rubertoe

I changed my chain yesterday and now I am having all sorts of problems shifting.

The previous chain was basically knackered! and it needed changing so I did. Now when in the small cog of the cassette and shifting up it wont sit in the 2nd cog and is jumping all over the place up to 3rd cog and when the chain is sitting in the third cog and i shift down it jumps straight to the small cog!

It shifts fine when i am off the bike and turning the pedals but as soon as I put any pressure on the pedals in the lower gears its jumping and slipping all over the place.

Any ideas, i have tried all the usual adjustments and am having no joy.

I am thinking it might be a knackered cassette, but am hoping not as it seems alright when in gears 4-8.

I'm running 2300 (shimano).

please help/any ideas?

g00se

Hi,

It sounds like you let the chain wear too far and it took the cassette with it. Check the chainwheels for wear too.

rubertoe

any idea how i do this? (check the cassette)

And what you mean by chainwheels?

g00se

Hi,

A chainwheel is identical to a chainring - in my world or typos :roll:

A worn cassette sprocket will have teeth that look narrower and maybe a little shark-finned. As the chain has 'stretched', the extra play in it widens out the valleys of the sprockets and chainrings.

Some pics:

http://cyclinginfo.co.uk/blog/1221/bike ... placement/

http://www.londoncyclist.co.uk/maintena ... in-london/

http://www.bikediy.co.uk/maintenance/wo ... te-207.htm

Sleeping_menace

Ok, forgive if this point is too obvious for words, but it's happened to several people. Just make sure the chain you actually got is the right size (as in number of speeds) for the drivetrain you're running. The lower the gear count, the wider the chain ends up being, and I've seen more than one person who'd simply bought the wrong chain and had the extra width causing the chain to catch on the adjacent cogs out back - causing the problems you describe.
Do, as the other contribs suggested, check for very worn teeth on the rear cassette. Make sure they're not narrow, shark finned, or otherwise look funky..

If those definitely aren't the issue, then have a look at your rear mech alignment. There are various ways to do it, but I always set the shifter until I'm into the 3rd from smallest cog position, then trim the rear mech until the chain is riding perfectly centrered on that cog. That tends to result in pretty flawless shifting right across the range of gears.
Let us know how you get on.

mustol

You certainly need to check that you have fitted a Shimano compatible 8 speed chain. Assuming you have and the chain was really knackered, it's likely the cassette has gone too. A new cassette for 2300 is approx £20 plus you'll need a lockring tool to remove the old one. I had the same problem, but unfortunately had left it too long, so the middle chainring (which gets most use over my local hills) had to be replaced as well. I'll certainly be checking for chain wear on a more regular basis in future!

rubertoe

The cassette is knackered!

I have a shimano compatible 8 speed chain! i may be stupid but not that stupid.

a new cassette will be ordered today (luckily i already have the tools for cassette removal from a wheel upgrade).

Oh well, more money up the swanny and the new bike will have to wait.

g00se

if it's any conciliation - my beater needed a new chain, cassette and chainring as I had left it too long. Luckily it was stolen before I had forked out for the new bits....!