Why do my road compact chainrings sometimes make chain noise?
Noise from chain contact with the shift ramps is heard sometimes on road compact rings such as the 50/34 and 52/36 sets. It happens when riding in the small chainring up front and the smallest 1 or 2 cogs in the back.
For the road compact, the 16 tooth jump is pretty big. On almost every bike that has a 50/34 the chain will rub the big ring when running on the small ring in front and the smallest couple cogs of the cassette. I’ve ridden lots of bikes, and they all do it to some extent. Admittedly, WickWerks chainrings cause a little more concern in that condition because the ramps tap the chain, making more chain noise, (and sometimes wanting to shift) rather than just rubbing it like most others.
Ramps are what makes the shifting good, and avoiding the small small condition is the trade-off. A good rule of thumb for all bikes, regardless of the chain ring size, is to avoid “cross chaining” — the large chainring, large cog condition, and the small chain ring small cog condition as well. It puts extra stress and therefore extra wear on the chain and the sprockets – both front and rear.
In general, use the smaller 3/4 of the cassette with the large front ring, and the larger 3/4 of the cassette with the small ring. It’s just a general guideline and there are plenty of exceptions, but it will certainly avoid the chain noise and the added wear and tear.
For more info, read the Cross Chaining” feature.