Narrow Wide as a middle chainring - issues

I'm guessing it won't shift properly.

Narrow-wide rings aren't designed to let go of the chain and won't have any shift ramps and bobbins on the back.

Middle chainrings have ramps and pins fitted to help move the chain from the chainring to the outer and inner. A narrow/wide will not have this assistance and being as they are designed to hold the chain on, it may cause issues.

It won’t shift - teeth are designed to hold chain in place plus lack of shift pins and profiled teeth. Look at a regular ring.

I presume you're shifting with a front mech (rather than stopping and moving the chain by hand when you get to a hill on a tour)?

I'd have thought that there's a 50:50 chance that when you change into that ring, the chain will be out of sync (so a narrow link hits a wide tooth). At best a disconcerting clunk as it rectifies itself. At worse jammed in place.

Also a N/W chainring won't have any ramps to help smooth shifts (as the point is to keep the chain on that ring), so I can see it struggling to make shifts with scraping noises for a few revolutions...

They're designed to NOT let go of the chain. Shifting will be less than optimal...

I have an unused 104bcd 9 speed middle chainring (probably 32t, need to check) you can have for postage. Alternatively, I will soon (next week) have an entire new 3x9 set of 104bcd chainrings surplus to requirements that I'll be looking to move on.

Edit: yes, 32t 104bcd black Shimano 9 speed middle ring.

Hi all,

thanks for that, better by another ring for the bike I am not sure what I am building up for 🙂

Panda

If you want to run a double chainring setup, you can either use regular chainrings that are designed for shifting, or you can use a single Narrow-Wide chainring and remove the front derailleur altogether.

As well as not being able to easily shift off, there is only a 50% chance of the chain landing on the correct narrow/wide profile chainring teeth.

(edit - what Toby said)

Agree with all of the above - it won’t work!

but, given you’re not sure what the build is for, why not take the opportunity to simplify and ditch the front mech, shifter and the extra two rings altogether and just use the NW ring - no need to get hold of a suitable middle, just use what you’ve got 👍

Yep. What Toby wrote. 50/50 it won’t sync.

the chain will be out of sync (so a narrow link hits a wide tooth).

Am I missing something here? Is there a specific narrow-wide chain folks are using?

No, you just set the chain on when you first fit it.  It's a single chain ring so just stays in place.

Am I missing something here? Is there a specific narrow-wide chain folks are using?

this is what we’re talking about here. A chainring that - given we’re not bothered about shifting between chainrings - is desinged to be a perfect fit on the chain