IMHO, it would have made more sense simply to continue the Thread you recently started on this -

Smart mouths on slow twitch never disappoint

After using many different brands of single rings, the offset is not enough to matter in practice. I’ve also found the they narrow wide design is not necessary either, provided the the chainring has a simple straight tooth design, with no pins or ramps. Additionally, the cheap single rings one can buy on ebay work as well as the expensive versions.

I'm simply trying to keep all the information in one place for others that might be following this.


You're primary concern should be to keep your chainline offset as small as possible, to minimize friction. I run a 56 front with a 12-13-14-15-16-17-18-19-21-23 cassette. From experience, I know I will usually be in the 13-14-15 when racing, so I want the least possible chain offset when in these gears. To do this, I've adjusted the chainring to sit slightly outboard by placing small washers between it and the arms of the Shimano crank.

Chainline is important. The SRAM ones you're probably talking about are designed to sit about 2m inward of where an outer ring would sit when mounted on the outer position of a SRAM 2x crank. This was for "1x conversions."

If definitely helps shifting and chainline efficiency.

But the story is more complex with newer cranks, as chainline is very much a combination of the specific crank in addition to chainring.

As for Wolftooth, it depends heavily on the specific Shimano crank. They have lots of different variants. If you mean 110bcd 4-arm, they state a chainline of 47.5mm, which is the same as "SRAM Wide," which, as the name suggests, is a bit wide if you're talking about a road TT bike, which is what I think you're talking about. And in fact may 1x chainlines are going wide, as they're largely intended for gravel bikes, and the trend is to push the chainline out further to get more clearance for frames that accomodate wide rear tires.

Sorry I had no clear answer there.

I've found the opposite. Narrow-wide is very important.

For reference, my (older) cranks are Shimano FC-7800, installed with as low of a "Q" factor as possible, and then the chainline adjusted to 46mm.

Yeah, 45-46mm is seemingly the ideal for classic road 1x, to put the neutral chain position near the middle of the cassette. For 1x TT - what I'm pretty sure Fishbum is doing - I think even 47-48 would be OK, as TTers tend to probably use the outer half of a cassette more than the inner half, and you can still get "good enough" shifting to your big cog.

Agreed. You'll notice my smallest cassette gear 12T, not 11 - my days of really big gears are behind me!!

The best performing rings I have are Fiberlyte’s carbon fiber rings, which have a simple straight tooth profile. The old TA rings work well, too. This said, narrow wide tooth designs won’t hurt, either. The key is to avoid shifting pins, ramps, and shaved tooth profiles, which create a lot of problems in a single ring application.

Interestingly, I’ve never used a double ring in a TT bike, the first one of which was back in the early 80s.

Fair. I apologize.

Correct I am using this for Lake placid. I had been running a 1X for other races that was a 50 tooth SRAM x sync. I had intended to go back to 2X but promptly damaged my front derailleur hanger so the hell with it I'm going to go up there and ride a 1X. I had recently taken off of 155 crank and went to the 160 mm Shimano 105. I realize the setup for up there will not be ideal but the hell with it so I'm probably going to have to ride either 46 or 48 chainring and something at least with a large bailout cassette in the back..

If nothing else it'll be different.

I still have this ram 155 cranks that I could put another one of their chain rings on but I'm rather enjoying the change in position even though it's my new it feels a little better with the different cranks.

In complete agreement that chainline is important. Put your bike in biggie smalls and turn the crank with your hands. The resistance is crazy. Of course this resistance gets smaller until reaching a minimum when the chain is straightlined. It's further complicated because any actual race is going through different gears, so unless its like IM Maryland you're just going for the least imperfect setup.

So yes, chainline is important, but I wouldn't buy a specific chainring when the problem can be obviated with $0.50 worth of washers.

As far as narrow-wide, I'm not sure I understand the question, but a narrow wide chainring fundamentally should have greater resistance when crosschained that an traditional straight tooth. The narrow-wide design facilitates more chain-chainring contact, so instead of missing contact every other tooth the plate to tooth contact is made on every link. Guessing here, but I'd think the efficiency loss crosschaining a narrow-wide v straight tooth is going to be a lot less than a dirty chain.

I think you both are really onto something here. I went to a "wide-narrow" chainring profile for fear of chain drops when I concerted to 1x, and it has worked well, but I'm also sure it has more friction. I just dug through my pile of old chainrings and found a real plain-Jane 53T one, which I'm going to try asap.

You will drop a chain sooner rather than later without a narrow wide chainring (assuming you don't have a chain guide). Unless you know you have 100% perfectly smooth roads, I wouldn't bother.

I understand the temptation though, as just feeling the spin with the hands when I'm setup 1x or 2x is fairly noticeable even in a good chainline.

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Benjamin Deal - Professional - Instagram - TriRig - Lodi Cyclery
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I don't know quite what you mean about feeling the spin, but I've heard from multiple credible sources there is no measurable drivetrain efficiency loss with narrow-wide.

https://velo.outsideonline.com/...-and-2x-drivetrains/
It's only an average of 3w across all gears, so really not bad. I'm as big a 1x proponent as anyone out there, but I can feel increased resistance spinning the cranks under no load. Which of course isn't really a real world scenario but I'd put good money on there being at least some delta in favor of standard chainrings.

Edit: and this test used a clutched RD for the 1x setup so that may account for some?

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That's all about 1x vs. 2x efficiency. I'm talking about narrow-wide vs. non narrow-wide. There is (afaik) no loss due to the tooth profile of narrow-wide.

But what is the difference in 1x vs 2x except for narrow wide? It's pretty much the only significant change you need to make between the two setups. I think it's safe to assume that nearly all the losses they found with the 1x can be attributed to the NW chainring.

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As the article states, the losses are mostly due to running non-optimal chainline when shifting to cogs on the extremes of the cassette - chain articulation losses. The article is averaging those all together.
Second in line would be chain tension from higher tension clutched RD (though this is changing with better clutches coming out).

I could be wrong, but I believe the CeramicSpeed guys and others were unable to find a loss with N-W.

Shifting pine, ramps, and sculpted tooth profiles. Double rings are made to derail the chain easily.

Another opinion - https://rappstar.com/...x-friction-profiles/

But look at the actual chart. If it was all chain line then the optimal chain line on the 1x setup would have been equal to optimal on the 2x. Even the little ring optimal line ended up being better (marginally) in their test.

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Benjamin Deal - Professional - Instagram - TriRig - Lodi Cyclery
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I guess I'm assuming those things either don't affect the friction or benefit the 2x. The NW seems to me the biggest difference maker friction wise.

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Benjamin Deal - Professional - Instagram - TriRig - Lodi Cyclery
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