An Important Thing To Know About Narrow-Wide Chainrings

from Rookie’s keyboard

Hello, friends

Today, I will shed some light on narrow-wide chainrings as they are becoming increasingly popular and many rookies wonder whether they can be combined with a variety of chains.

Narrow-wide chainrings are thin because they’re built for multi-speed bikes with cassettes/freewheels. Therefore, by default, you have to use a chain that matches the number of cogs at the back. 

But technically, if you’re running a single-speed drivetrain, you might also use a single-speed chain. But that combination is just illogical.

Why? Narrow-wide chainrings (NWCs) are built to provide extra chain retention when running a 1x drivetrain. Meanwhile, SS chains are overbuilt for extra strength as they face greater torque due to the lack of gearing. There is zero practicality to mixing the two even if it’s possible.

NW Rings and Chain Retention

Narrow-wide chainrings have teeth of different widths – one is narrow, and the next is wide.

This engineering is there to match the varying width of a chain.

A chain has an inner width framed by the inner plates and an outer width formed by the outer plates.

The wide set of teeth goes between the outer plates whereas the narrow ones go between the inner plates. 

As a consequence, the chain remains“glued” to the chainring and is a lot less likely to fall off even if there isn’t a FD or a tensioner.

The wide teeth on a narrow-wide chainring cannot be wider than the outer width of a 12-speed chain as most models are engineered for 9,10,11 and 12-speed chains.

Therefore, the wide teeth cannot exceed the outer width of a 12-speed chain which is the narrowest on the list.

Don’t forget that as the gears increase, the outer width of a chain gets smaller too. Otherwise, the chain won’t fit between the cassette cogs.

SS Chains

A 12-speed chain has a 5.3mm outer width and a 2.18mm inner width. 

А single-speed chain has a 1/8″ (3.3mm) inner width and about 9mm outer width.

Single-speed chainrings are therefore too thick for cassettes. The chain will just get stuck.

That said, narrow-wide chainrings are slim and thus compatible with a single-speed chain.

But as I’ve already said the benefits of matching the two are dubious. The only pro of this combo is the re-use of available parts. 

If you’re looking for a new chainring to use with a single-speed bike, purchase a dedicated SS model because it’s thicker and will last much longer than a narrow-wide one.

I also have to mention that a similar combination (SS+NWC) has two additional downsides:

  • A poor connection between the chainring and the chain due to the width discrepancy.
  • Faster wear of the cassette cogs.

Until next time,

– Rookie






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