feel a bit daft for asking but I see them talked about all over the place, how do they differ from normal rings and can you run them on a 2×10 set up
thanks

They have alternating narrow and wider tooth profiles to match the narrow and wide links in your chain. Helps it stay on without a device.

No go for 2×10. 1x only.

Designed for 1 x setups. They have alternating teeth profile to stop chain jumping off. You can use them 2 x but it’s a waste and will not work well.

Tis clever simple stuff.

Glad you asked because I never knew!!

When you have a multi cog setup, (ie 2x or 3x) you need the chain to be able to “fall off” the cogs as that’s how the system changed gear ratio. As such, the profile of the teeth is a compromise between staying on (and transmitting the chain loads) and yet being capable of being pulled off (pfnarrr pfnarrr) by the front derailleur!

Once you’ve gone 1x, then you can modify the profile of the teeth on the single cog to be optimum to transmit the chain loads and stay retained to that single cog. Hence, the teeth on a single ring 1x setup are taller/deeper and the latest trend is to make them alternate narrow / wide in thickness to better match the chain (which has narrow and wide links) This means the chain is much more secure and less like to be shaken / bounced off the cog. One reported downside is that the lack of “free space” in the narrow wide system means that when riding in heavy mud the system is more sensitive to being clogged up, but i’ve not found that to make a big difference personally 😉

A silly question probably, so I won’t start a new thread about it.
Even though I get the concept of NW, or WN as it started, I am however a little perplexed as to how it retains the the chain better that a dedicated 1 X ring?
A 1 X ring has full hight pointy teeth to aid non derailment, so is NW really appreciably different, or just a new way to sell us the latest kit?

A genuine question BTW.

Cheers.

The teeth fill the gap in the between the chain links. It’s not marketing BS.

Sui- they will not work with 2x. The chain needs to on the correct teeth, ie wide tooth in the outer plates narrow tooth in the inner plates. If your mech could shift the chain it would only have a 50/50 chance of being on the right teeth.

And given that the N/W rings are designed to stop the chain derailing I don’t think the mech would pull it off the ring to well.

is NW really appreciably different

Yes. Very much so.

For most people, you can just run a narrow-wide front chainring with no chain device and it’s very reliable.
In the Enduro World Series, most riders are using NW + top guide when a year or so ago they’d all have been on proper wrap-around chain devices. In fact even a few DHers are doing this.

Essentially you can ‘downgrade’ whatever chain retention system you had been using and therefore save a bit of weight.