The Genius of Narrow Wide Chainrings - Why they work!

The 'narrow-wide' chainring is a drive gear for a bicycle that features an alternating tooth profile. This is to say, one tooth is wide, and the next is narrow just like a bicycle chain. Today we'll watch slow motion footage demonstrating why these gears are so effective at keeping your chain on.

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[carlholman]

I used to work with a pro shimano mechanic. He says narrow wide chainrings have been around in large machinery for ages. This made it hard for bike companies to patent this as it already existed, and everyone could start making them.

Id have to dig into this more, but makes sense!

[qwasdr]

This is so interesting.
Also made me aware of the fact that I have been riding with the clutch OFF all the time, lol.

[garrettgriffin]

Was about to go panic check my bike to make sure the chain is lined up on the right teeth 😂 glad this system is dummy proof. Interesting video as always

[manolmanolov]

Beautiful story, but you are saying a small portion of it. Narrow-wide are ONLY available if we don't have gears up front, which means we have to have wider range on back. Which means we need very small and very big cogs on the back and potentially more of them, which means more lateral twist on the chain. Which leads to the real revolution: The big cog on the back - why the chain is not dropping that often from the 52 tooth cog, given we have insane lateral twist? That deserves a larger attention IMHO. (keep in mind, the rear cannot be narrow-wide :) )

[Knitterfest]

I have a narrow wide chainring on my makeshift 1x11 Gravelbike. Although my chainline is messed up (needs to be a few mm more towards the inside) the chain never slips off the lowest gear.

[buzzlom]

Congrats on 1 million subs, Seth! Well and truly deserve them.

[Sundayfilmz]

i work on my bike all the time and i really like learning new things about working on my bike. thank you seth again for another great and informational video.

[EvanLownds]

Great video Seth, and I can confirm this from experience! I did a 1x conversion on my 2008 Trek last summer, and I took the frame in to a bike shop to have them pull the cranks as I didn't have the right tool. When I told the mechanic what I was doing he said without a clutch derailleur I'd be dropping the chain constantly and it wouldn't be worth the effort. Of course he kindly tried to sell me one, which I equally kindly refused. I purchased a cheap narrow-wide chainring from Amazon (something like $11) and after nearly 100 miles of trails and riding, I have only dropped the chain one single time, and that was when stick got sucked into my drivetrain and knocked it off. Otherwise, smooth sailing! The NW chainring really does hold the chain in place incredibly well.

[jimanastasio]

I once upgraded an old Stumpjumper from a 3x to a 1x drivetrain. Chain drop was chronic. The clutch didn't help, chain guides did nothing (some seemed to make the problem worse) but a cheap narrow wide chainring (same brand Seth was showing) cured the problem. To me, the narrow-wide based 1x and the dropper post are pretty important. One advantage of the 1x is that rear suspension design is no longer compromised by the need to locate a front derailer opening up new possibilities in suspension design. Every full squish I've had developed cracks in the rear suspension, and I believe that in every case it was due to compromises related to accommodating the derailer. It was hard for me to give up that front derailer. What convinced me to ditch it was the need for a better dropper lever. The left-hand shifter had to go at that point, no two ways about it. No regrets, I love the 1x.

[MarcoSantosMAMS]

I, m using narrow-wide chainrings by years, but never paid attention to all these details! Amazing!

[festerofest]

I don't even have an MTB but I love this channel because of the quality of content and presentation. And I always learn cool stuff and this is another example. I'd heard of narrow/wide chainrings but had no idea what that meant and what a great explanation I received!

[zubayrbhyat]

I think this is one of the coolest videos I've watched on bicycles. Having run narrow-wide chainrings for the last few years I get why I've barely had a chain come off. Awesome!

[storm]

I have the exact same experience. My cheap Decathlon E-MTB came with a stamped steel chain-ring that was still a narrow-wide and welded to the crank so not easily replaceable. I always had problems with the chain coming off, like several times every mile. I solved it with a front-derailleur-like chain-guide initially, but it always kept that unnerving sound of the chain wanting to come off every few hundred meters or so. Last summer I finally upgraded to a (still cheap) new set of cranks so I could change to a machined narrow-wide ring and I can finally run it without a chain-guide now. My chain hasn't come off at all for 6 months straight. I use a Shimano Alivio rear derailleur, so no clutch as well. Congrats on te 1 mil btw, very well deserved and way overdue!

[ayyggss]

That stamped steel chain ring has ramps that are designed to not hold onto the chain, allowing shifts . We used to run single speed from chain rings with taller teeth . Worked well enough at the time

[valeriesorrells]

Keep these videos coming! This is great information for those who are in the process of upgrading their older rides.

[alex_smallet]

The way Seth presents the information is mesmerizing. Even though I knew all these details, it feels satisfying to watch. I wish school teachers were like this.

[iKnowHowBucky]

Something so simple and I would have had no idea without it explained this way. Little bits of learning over time adds up!

[Sabitar]

And here I am still rocking 3 chain rings at the front in my old mountain bike 🙁

[xjuanx]

By far the most informative video on MTB tech out there. Need more "explained" series type vids from you Seth. Pinkbike needs to take note on the simplicity on how your videos details how MTB tech works from a real world perspective. I appreciate the more advanced posts PB has, but the simplicity in this video takes me back to my WLIW/PBS days (for the New Yorkers out there) when I was a kid. Love it.

[ATHIP]

I learned so much in this video! I've been wrenching on my bike for years and never realized the front chainring was narrow wide, and that the chain could only go one way. The chain must naturally fall into the right slots since I've never had trouble installing the chain. Thanks!