[Iranian-Mechanic]

HI riders
I have had some problems with my gears these days.
When i start hammering or when i am riding in bumpy trails my chian comes of my cogs and sometimes off my chainwheels and with a loud sound of the chain sliding through the cogs or the chainwheels my leg goes free for a round.
I noticed that when i am using the cogs which i oftenly use (4,5,6) or the second chainwheel which i oftenly use too this problem occures.
I lokked at the cogs and chainwheels and noticed that their theeth are sharpened i mean the theeth of the cogs are turned to very sharp ( V )shape.
Now what should i do
1-Change chain
2-Chainge chain and cogs
3-Change chain cogs and chainwheels and crankarms.
I am waiting for your replies.
Tanx

 

[Stick]

Now what should i do
1-Change chain
2-Chainge chain and cogs
3-Change chain cogs and chainwheels and crankarms.
I am waiting for your replies.
Tanx

The short answer? Assuming everything is set-up right (chain is the proper length, derraileurs properly adjusted, chainline is okay, etc) start by just replacing the cogs and chain. If you still have issues with the chain skipping, then you may need new chainrings. There's no reason to replace the crank arms, unless it makes sense financially to do so. If you have inexpensive cranks, like Deore or LX, for example, it may be cheaper (and easier) to order a new pair of cranks w/ rings than it is to buy replacement rings.

 

[SwissBuster]

All of the below..

Now what should I do?

1. Post your questions in the appropriate forum (eg General or Drivetrain in this case).
2. Proof-read your posts before posting.
3. Replace your drivetrain - cogs, chain and chainwheels.

 

[Iranian-Mechanic]

My problem has been solved i bought a Shimano cshg308L 8sp cogset aShimano IG narrow chain and i found one of my friends who had a new shimano deore chainrings and crankarms i asked him if he sels only the second chain ring and he did.