Keychain woes?

[montymitch]

I recently built up a bike with a fresh drive-train comprised of Keychain, 28t Fang, and 9t Antigram. It wasn't as smooth as I expected when I first built it up, but these things usually need a little break in, so I didn't worry about it.
Yesterday I made a few adjustments and noticed that when the chain is tight, it is tight at the top and bottom of the sprocket, but not the middle. Am I wrong in thinking this is going to wear like mad, like when you use a stretched out chain on a new sprocket? It's a relatively expensive setup I have going and I kinda thought since it's all Odyssey gear I wouldn't have issues like this. Have you guys seen anything similar? Should I pursue warranty or just go ride?

UPDATE:
Problem solved. I swapped my 28t Fang for a 25t C512 and all is well. I prefer the taller gearing, but this runs much smoother and I was able to eliminate a half-link and move my wheel back a smidge which fixed the brake clearance problem I had.

[Bunky]

What kind of cranks do you have and do you have the proper spacer in between the cranks and the sprocket?

If the chain is tight when your cranks are in a certain place and only in that certain place, then that is a problem with the sprocket sitting off center on the cranks, and not a problem with the chain.  If the chain is tight you'll see that you'll feel the tightness in different areas as you move the cranks around. 

[montymitch]

No, everything is brand spanking new. Cranks are Thunderbolts with 1 ride on them. It's like the pitch is wrong between the chainwheel and the chain.

[Prodigal Son]

Its just the chain. Get a shadow next time.

[master]

How loose is the chain on the sprocket (mm of play)? I'm interested to see this.

[montymitch]

I'll try and get a pic this evening. Right now I'm supposed to be grading papers...

[GUMP_]

I had a similar issue when I was building my aod up. It was like the chain was trying to come off the sprocket

It ended up being the chain line wasn't quite right and once I used some more spacers and aligned everything up better the driveline hasn't made a noise since

[dude...]

yeah mine was rough as fuck when the chainline was out

[montymitch]

Here's a little video. My chain line is damn near perfect, and you can see the sprocket is already starting to show some wear.
https://youtu.be/vWMZgqhIdSw

[streetStreet]

Maybe you got a bad chain it's the first version.

[master]

Here's a little video. My chain line is damn near perfect, and you can see the sprocket is already starting to show some wear.
https://youtu.be/vWMZgqhIdSw

So that looks like at least 2-3mm of play... I'd email G and show him the video to get his input. Part of me says to ride it a bit to break it in if you haven't already.

[JFax]

Cold it really be the chain? Sounds like a slightly oval sprocket. Seems unlekely, but I would get a ruler or a compass out to check its roundness just to be sure.

[weedbix]

Keychain is going to be less tolerant of sprocky/driver misalignment. Have you worked out your chainline mathematically? Not always easy unless you know the distance from the driver teeth to dropout. I dunno what that dimension is on a Antigram but on a Ratchet it's 11.5mm so it _could_ be the same

[Louis]

Is this thread real?

Suggesting Shadow chains over Odyssey?
Chain line? what? How could that have anything to do with it? lol maybe im missing something.
Chain line mathematically?

Haha, anyway (after watching your vid) I've noticed this same phenomena before on my BMX with a Drop Buster chain (z510hx). I wouldn't worry too much about it... but thats just me.

If it was a more perfect fit I think we would get more adverse issues.

[G]

Is your chain very tight? The aim of a chain (or the threads on a bolt/nut) is to transfer the load from the sprocket to the chain (or the bolt to the nut). You can never expect the components to fit so perfectly that they all take an equal share of the load, so the last tooth will take most, and then the next one a bit less (or the first thread for a bolt/nut). Typically, it is just the first 3 teeth (or threads) that take 80% of the load or more, and the further you move from the load the less it is. So you would expect to always see something like you have there... having said that, it is obviously hard to tell from a video compared to having it in your own hands, but it does look like maybe that is a bit extreme for all brand new parts.

How does it ride? If it seems OK to ride, then please check that the chain tension isnt excessive and try riding it and see if it seems to improve or worsen.

I hope this makes sense and seems reasonable.


G.