Shimano chains. HG 900, HG 901 etc.

velo.2010

How does an asymmetric chain (HG 901) differ to a directional chain (HG 900). I assumed all chain were similar in that you kept the Shimano logos facing out away from the bike.

Does it being 'super narrow' affect the running performance of the drivetrain in any great manner?

I ask because I replaced the 5800 chain ( I assume HG 600) on my bike with a Dura Ace HG 901. On the small ring the chain runs fine but its rough on the big ring. The chain was fitted like every other chain with the logos facing out.

CramCycle

Could it be your chainring, the old chain was worn so it didn't pick up the issue?

velo.2010

No, because I've primarily been using the small ring for the past while. The old chain was replaced because it was creaking and worn but was still smoother on the big ring than this current chain.

CramCycle

The old one would be smoother if the chainring is worn as it wore with it, if thats the issue. In answer to your first question, no, it should not affect the performance negatively.

can you put up a pic of the teeth, as that is the most likely issue, did you clean the cassette and chainrings?

velo.2010

Well, I now understand Shimano's chain nomenclature!

HG 600, HG 700, HG 900 are the basic 11 speed chains as released.

Hg 601, HG 701, HG 901 are updates e-Bike compatible chains presumably stronger to cope with the increased torque.

HG 601Q, HG 701Q, HG 901Q are chains that come with quicklinks instead of pins.

HG 901-11Q is the code for Shimano's Dura Ace asymmetric chain. I think that's what I have on the bike.

Maybe I got a dud chain, maybe the asymmetric design isn't really backward compatible with the prevous generation of 11 speed chainsets, I don't know. Safest bet is to go back to a 105 chain as on my other bike. No problems after changing that one. And I only got that Dura Ace chain as there were no 105 chains in stock in CSS.

doozerie

I don't know the difference between asymmetrical and directional for chains, as the two words seem to be used interchangeably it's quite possible that they are basically referring to the same thing.

The only reason I have a slight doubt about that is because for one model of chain I've installed (can't remember whether it was Shimano or Campag) the instructions were very specific about whether the joining pin was installed at the front/leading edge of the end outer links, or the back/trailing edge of them - I guess that's for the strength of the join, but basically it means the recommendation is to install the chain in a particular "direction" and perhaps that's what defines a directional chain.

I gather that some quick links are directional too.

As for the cause of a chain feeling rough on the big chainring, just guessing here but one possibility is that the chainline on the bike is "off" and that is being amplified on the outer ring. Another factor is that on the big ring the rear derailleur is under greater tension so some things that might be affected by that are: the upper jockey wheel may be pulled closer to the cassette and maybe too close (in which case adjusting the "b screw" might fix it); maybe an issue with the return spring in the jockey wheel cage; maybe the chain is too short (though if that's the case it should be okay in higher gears); maybe worn jockey wheels.