HazeT

I've a new ultegra 6700 cassette, on a new ultegra 6700 chain and a new 105 5700 RD but the stars didn't align very well, I installed the cassette using the appropriate spacers (1mm +1.85mm) but what I see is that on the 2nd smalles ring one of the teeth keep pushing the chain up and dropping it back to it's place, of course that makes noise and will wear the chain/cassete tooth sooner.
Is this a problem with the cassette? should I try to straighten that pin?

LesterOfPuppets

There might be a bent tooth or a tooth with a snag on it. I'd look for a stiff link in the chain first, though.

If you spot the link, I'd take it out and get a KMC Missing Link to rejoin the chain.

Secret Squirrel

Derailleur hanger alignment problem?

AnkleWork

What pin?

Friendly suggestion: next time photograph the top of the cassette with the pin in question, in focus.

FastJake

I suspect your high-limit screw is too tight.

HazeT

Easier said then done. this one was just to try to highlight where the tooth is touching the chain. in the picture it's in the smallest sprocket but you can see that the 2nd smallest one is picking up the chain, and dropping it. if I look at the sprocket alone, I see that the tooth is more outward than the others, but I'm not sure if that is a feature to help shifting.

HazeT

it shifts fine to the smallest one, it's this one tooth that keeps picking up the chain on every rotation, do you think it can be the limit screw? I will take a look when I get home

LesterOfPuppets

Ohhh, so it's while chain is on small cog and that is an actual pic of the situation!!!

Which chainring is the chain on up front?

HazeT

Big chain ring. 50-12 configuration. I've a 50/34 compact on a new 12-30 cassette, got new chain and new derailleur (medium cage) since my previous one could only do 12-27.
At first I thought it was spacers problem, so I took off the cassette and I looked at that sprocket specifically and I can see that the one tooth in the picture comes more outward than all the others. I just don't have enough info to know if that's to help shifting (a feature) or a defect
I tried to straighten it up by pressing that tooth against the concrete, it didn't do a thing so I could not possibly see how could I could have bent it, in case it's bent, so I'm assuming it either a feature or a manufacturing defect.

RoadGuy

Impossible to tell what the problem from the photo and the text.

And I find it hard to believe that chain and cassette are new. They are filthy. The only part with more dirt/grease on it is the derailleur.

fietsbob

put a new cassette on and see if it fixes it, if it does not, you can put the old one back On..

Look to some other solution, process of elimination. Might be the Chain..

You will wear down the chain & cassette eventually , then you already own a new spare .

HazeT

Should I post pictures of the receipts too? by new I don't mean I installed on that very same day, what I mean is that I bought and installed them recently... ~200 miles ago? which is a week or two of riding so I count them as new.
The point of saying that they are new is not for people to evaluate how shiny they are, it is to emphasize that this is not a worn chain or new chain with worn cassette.

andr0id

Can you take it apart again?
I'm looking at the 12t from my 11-28 spare cassette.

There is one tooth with a shark fin shape opposite 2 teeth on the other side that have the side carved out.
Laid flat on the desk, none of them are out of line to the outside.
The shark tooth one leans a tiny bit to the inside.
I can slip my fingernail under the shark tooth and the half width teeth, but the rest are flat against the desk.

I think you should take it apart, wipe it down and make sure no crud got between any of the spacers or cogs while it was being put together.

HazeT

I already did the clean/reassembly. but good to know that there shouldn't be any tooth sticking out. I will escalate the problems to the pliers and mallet that I've at home

Secret Squirrel

Cogs are heat treated and brittle. They tend to break before bending

CliffordK

If you identified a single tooth that seems to be a problem, I'd probably whack off 1/32" or so with a file. Or maybe bend it, but that may be difficult to do without harming anything else.

If it seems to be several teeth throughout the cassette, perhaps an adjustment problem.

High limit screw if only on the smallest sprocket.
Cable tension if on other sprockets too.

LesterOfPuppets

I think I'd try an 1/8 turn CCW of the H limit screw, see if that helps.

If the cable is really taut when in the small cog, maybe relax the tension with the barrel adjuster a bit.

Another possible fix is screwing in the B-tension screw a bit.

FastJake

Yes. The high limit screw adjustment is pretty wide. It will often shift to the smallest cog fine even if adjusted "wrong." There is little danger of anything bad happening if you back it off, so give it a try.

RoadGuy

The condition of the parts are clues to what is wrong. Obviously you don't spend much time cleaning your equipment (judging from the filthy condition). That can be part of the problem. How clean the parts are will affect how and how far the moving parts move. The crud may be preventing the rear derailleur from moving enough outwards to keep the teeth of the 2nd cog from contacting the chain.

Did you didn't adjust the limits and the cable tension when you installed the new cassette and chain did you? Again, a sloppy bike usually points to a sloppy mechanic. I'm guessing that you simply threw the new parts on and went riding, without checking the adjustments.

In 200? miles you could have picked up a rock or dropped the bike and bent the rear derailleur or the derailleur hanger. These are problems that would not have been caused by your installation of the new chain and cassette. The point is, that the parts are no-longer new, and problems that you see now, may not be related to the parts that you installed 200? miles ago.

habilis

If you suspect that one tooth is responsible for snagging the chain, mark that tooth with a dab of white paint and see if that's the one that always lifts the chain. If you suspect a particular chain link, mark that link with paint. If you KNOW it's one tooth, look for an abnormality in that tooth and take action on that tooth. That entails risk of permanent damage, as others have noted, so first be sure you don't have a damaged or stiff chain link.

If the chain is lifted by seemingly random teeth, it's probably not the cog or cassette.

Even though everything is relatively new, re-lubricate the chain. Your road conditions may have gummed it up, and a dry or dirty chain is prone to snagging. If the chain still snags, and it lifts on random teeth, check for a stiff link. Is there a pin that protrudes farther on one side than another? You can correct that with a chain tool and working the link by hand.

Have you eyeballed the derailleur and hanger from the rear and made certain neither is bent? The derailleur must be parallel to the plane of the wheel.

AnkleWork

You might as well -- it'll get you just as close to a solution as what you are doing.

FastJake

Oh good grief. Give the guy a break. Taking another look, those parts actually look pretty clean. They look about as dirty as they'd be after ONE long ride. Maybe you keep your bikes showroom clean by not riding them

If you used a little common sense you could've figured out that the OP was talking about parts that were "installed new" and not still on the stand, never ridden.

LesterOfPuppets

My cassettes/freewheels are almost NEVER that clean!

Not gonna clean bike after every single ride.

HazeT

humm, very useful info, thanks for preventing me from ruining a cassette.

Homebrew01

Looks pretty clean to me. You are OCD or a troll.