DarKris

I知 planning on converting my gravel bike that has 2x9 gearing with 1x11. The crankset I知 running is a Shimano Metrea and I bought the single 42t chainring to swap the 46/32t rings out. I guess since this is a more urban crankset the 42t is not a narrow wide chainring.

Since I will be using a clutch derailleur, is it still a big deal if I don稚 run a narrow wide chainring?

tomtomtom123

I've never used a 1x11, but a long time ago when I had a 1x8 with Sram IGH dual drive, which makes it a 3x8 internal gear, when I changed the worn out chainring with another "normal" chainring, the chain would keep falling off the largest cog onto the 2nd largest cog, or the chain would fall off the inside of the chainring because of the extreme chain angle. I assume the new chainring had the teeth slightly further outward. I switched to a narrow-wide chainring and the chain stopped dropping and the noise at the largest and smallest cogs was reduced. I think if I had the chainring a couple of millimeters further inward, I could have solved the chain drop, but I didn't want to swap the square tapered BB because I had no experience doing it at the time.

Even so, Dahon folding bikes use "normal" chainrings for 1x8, but they add a clamp to the seatpost with a tab that extends a few millimeters above the chainring to prevent the chain from rising over the teeth and falling off.

So your "normal" chainring may or may not get chain drops at the largest or smallest cogs. I think it depends on where your chainring chainline ends up in relation to the centerline of the cassette. But 11 speed cassette is wider than an 8 speed cassette so the chain angles will be more extreme.

Although, Why do you want to change from 2x9 to 1x11? Won't you get a smaller gear range with farther gearing spacing? You haven't said what cassette you have or will change to, but assuming that you currently have 11-32T 9 speed cassette with 46/32 double chainrings, that's 418% gear range. If you changed to 1x11 with 11-42T cassette then you're getting 382% gear range with bigger jumps between gears.

I have 2x10 with 12-34T cassette and 44/24T double chainrings on a 20" wheel. It gives me 519%.
I have a front chainline of 44mm which means that the outer chainring is around 47.8-48mm from the center of the frame, with a 130mm hub and 10 speed cassette, and the 44T outer chainring doesn't drop the chain at all even on the big cog, so I assume your "normal" chainring could work if you are careful with the chainline. But the chain is very noisy on the 2 largest cogs when on the outer chainring, because of the chain angle.

So, a narrow wide chainring would be better, but you could go ahead and try your normal chainring that you bought if you don't plan to return it or sell it, and if you encounter trouble, then you could always go and buy a narrow wide chainring to replace it.

dsbrantjr

There are numerous chain keepers available if chain drop is a problem for you.

DarKris

I wanted to switch because I realized that in my everyday riding that I didn稚 use the full range of gearing and that for the most part I stayed in the center of my cassette. The other reason was so I could upgrade from Shimano Sora and the Giant Conduct brake system to GRX full hydro levers.

My current cassette is a 12-36 (up from an 11-34) and for the 1x setup I will be running a Tanpan on an SLX M7000 derailleur so I can run an 11-46 cassette. I figured since my 9 speed range in the back is already so high, I can go to a 46t 11 speed cassette and the gear changes after the first two large sprockets will be similar to my current 9 speed setup.

Reynolds 531 

Not worth the frustration.

trust me.

By the time you do every trick in the book, and buy every crutch from ebay, you will have spent way more money, time and patience than just putting on a narrow wide to ride to the city limits without your chain falling off three times.


I have good luck with these
https://www.ebay.com/itm/J-L-Narrow-...yWGn_NTQeCjWRg

DarKris

See my crankset has a 96 BCD and there aren稚 many chainrings available for a 40-42t at that BCD from what I found

Reynolds 531 

96mm shimano "rectangle"

I see what you mean. 38 is easy to find, but there are 42 and 44

https://www.ebay.com/itm/Fouriers-Bi...P7s0ldPct0umeA

HillRider

That's right, and the least expansive is to use the current front derailleur centered over the chainring with the limit screws. Disconnect and remove the shift cable and discard the left shifter.

Moe Zhoost

When I first set up my 1x11, I used a generic 39t inner chain ring with a road rear derailleur (non-clutch). I rode over 1,000 miles on varied surfaces (none too rough, but many unpaved dirt roads and paths) before I dropped a chain. I decided at that point that I wanted to go with a larger ring anyhow, so I opted to install a WolfTooth narrow-wide. I think I would have been ok without it, though.

With your clutch RD I think you will be fine without the N-R ring. Size your chain length as short as reasonable to minimise the potential for going slack. You can always opt for additional measures if you start dropping your chain. Also, you may want to carry a Rehook tool:

DarKris

So I realize something after reading some of the replies. I intended on putting the current 2x9 drivetrain on my other bike to use as a training bike. As a result I would also need to swap the Metrea crankset back to that frame since it痴 the only crankset that reasonably works on it.

I also realized that even though running a 42t with an 11-46 would still be close to my current range of 46/32t with 12-36, I think it would be overall better to spec for a range that I know I will at least use my smallest cassette and still be able to spin. Currently I don稚 see myself realistically using a 46-12 combo the way I知 currently riding.

With that said I have opted to get a new crankset entirely, that being the GRX RX600 40t crankset. I値l run the narrow wide chainring and it should work out better that痴 trying to run a non-narrow wide single ring.

Darth Lefty 

I believe the Metrea crank's bash guard acts as a keeper. Not so?

Metrea was so beautiful but just didn't catch on, it's a shame.

tomtomtom123

Interesting tool, but if I need to move the chain by hand, I just use a free paper napkin that was leftover from eating that would have been thrown away anyway, which I stuff in my jacket pocket when I finish eating, or the dozen squares of toilet paper that I usually carry with my air pump. I also have some disposable gloves that are with my air pump in case things get very dirty. Although the Rehook tool might save you a couple of seconds and make your hands immediately cleaner, it still has an oily and dirty head, which has to be cleaned later, and could still transfer the oil somewhere else, wherever you choose to store the tool.

DarKris

It does but mine has the bash guard for the 46t ring. I would still need something to stop it from falling on the inside of the chainring.

Since I知 going to keep the Metrea for a different bike now it痴 a moot point.

Moe Zhoost

Yeah, when I first saw this tool I wondered why not just use my hands like you do. Curiosity got the best of me, so I made my own out version of 1/4 sheet aluminum. I have to say that it works more efficiently and quickly than the hand method and because the head engages only one link, there really is not much muck on the tool. I'm not sure that I would fork out the $ for a manufactured one though.

stardognine

I feel totally uncivilized now, not having one. 😁😉