Damage on new cassette

[Balooba]

I fitted a new Shimano Deore 10 speed 11-42 with a new KMC chain on my hard tail. I had the bike at my LBS for set-up. The cassette and chain has about 300km on it.

 

Why does it look like this (attached)   Click on picture to open it up all the way.

[Allrounder]

Any mud riding?

 

Chain lubbed? 

[Kalahari Vegmot]

It got hit? You shift really poor?

[ALLMTB]

When the chain is running on the 42 cog, how far the the top pulley wheel from the cog?

The B-tension screw might have been adjusted incorrectly which would place the the top pulley wheel to close to the 42 cog which will cause grinding.

[Skinnyone]

That is normal, and came from the factory like that - I am referring to the "half tooth" that you may be querying...compare it to a new cassette and see what you think...

 

The half teeth are there to help the chain shifting up as they make it easier for the chain to engage the next tooth along. Watch how the chain shifts whilst pedaling slowly to see how this works...

[Balooba]

Any mud riding?

 

Chain lubbed? 

 

Nope, too dry in Pretoria.

[Balooba]

It got hit? You shift really poor?

 

Shift really poor????

 

Please explain what you mean??

[Balooba]

When the chain is running on the 42 cog, how far the the top pulley wheel from the cog?

The B-tension screw might have been adjusted incorrectly which would place the the top pulley wheel to close to the 42 cog which will cause grinding.

 

I have a suspicion that it is my b-screw that is the cause of the problem.

[Skinnyone]

I have a suspicion that it is my b-screw that is the cause of the problem.

If it was this then you would have an audible grinding whilst riding...

[dirtypot]

That's completely normal - it's the part of the cassette that allows the chain to shift off to a lower cog.  Nothing to worry about.

[s14phoenix]

If it was this then you would have an audible grinding whilst riding...

 

I think he means the setting on the B screw has made the derailleur too low and the derailleur is catching the gear during up or down shifts - Have seen that happen so its possible.

 

However it is usually quite audible when that happens

[Kalahari Vegmot]

Shift really poor????

 

Please explain what you mean??

To shift under extreme load.

 

Skinnyone and dirtypot has thw right answer though

[arendoog]

I never use a granny gear ! ,but the soles of my shoes look similar 

[droo]

To shift under extreme load.

 

Makes my nuts tighten when I hear it happening. Often experienced riders too.

 

Good for business though...

[Balooba]

To shift under extreme load.

 

Skinnyone and dirtypot has thw right answer though

 

Thanks.

[Balooba]

Thanks guys. Will have longer b-screw inserted and try and shift when not on the power.