1x (Single Chain Ring) Bicycle Drivetrains: View this before conversion or buying

My daughter wanted to convert her 9-speed bicycle which has a triple in the front to a 1x (also called a 1 by or one chainring) for ease of use to get up big hills and coast down the other side. The triple was just a hassle and she never used all 27 speed combinations. If you want to know more about such a conversion, see the video in the upper right. In the process we learned a lot about 1x that also applies to some new 1x road bikes. Here are the pros and cons of a change to a single chainring and items you need to test out if you're contemplating a 1x. The front is a narrow wide 1x chainring 38T and notice how the wide tooth fits the wide part of the chain link and the small tooth fits the narrow part of the link. This prevents the chain from falling off the chainring when the chain is angled toward the large cogs.

Pros:
1. Lighten bike by removing front derailleur
2. Easy to shift when you only have to think about the rear cassette

Cons:
1. Less gear choices
2. Extreme angles similar to cross chaining resulting in noise from the narrow wide chainring when in larger cogs. We can see that the chain at an extreme angle click onto the wide teeth of the narrow wide chainring as the culprit in creation of the noise.
a. Let's look at the chain line. We can see when we check with a chain line gauge, the front chainring lines up between cogs #3/4 out of the 9 rear cogs. This results in an extreme angle for the chain when in the larger cogs.
b. If you're in the larger cogs, pedaling backward will cause the chain to jump down to a smaller cog. I, myself, to not pedal a bicycle backward. Bicycle derailleurs are not built for that. But some, for some reason, cyclist do this.
c. This may indicate more wear of components as well as on the derailleur but I have no concrete data on that yet.

To change that, we tried another crank in which the chainring sits inboard of the crank spider as opposed to outboard on the crank. The chain line now is between cogs #4/5 with less noise in the larger cogs and the chain does not come off when pedaling backward. Later, we replaced the rear cassette with an 11/40 T to allow a greater range in shifting choices. If you want to spend the money, you could convert your shifter, derailleur, chain and cassette to a 11 speed (correct spacers may be needed to fit the 11 speed cassette on the hub) to increase the shifting choices.

The importance of a 1x setup for a road bike is debatable. But for the casual cyclist, it could make the ride easier and hill climbing a breeze. Then again, so can an E bike. There's also less maintenance and repair with a one 1x upgrade.

[mysticscavenger]

Do you think a narrowide chain ring will worn out a chain faster?

[DennisNowland]

Very good. You can't beat mechanics. There is a lot to be said for a triple. Thanks for sharing.

[dan]

As a frame builder (retired) particularly for larger males, I offset the rear chain stays by 7-8 mm to the drive side. Allowes symmetrical lacing of the rear wheel and provides much improved chain line. Stronger more reliable rear wheel for heavy riders (100 + kg) and better shifting and chain life. The purpose of a bicycle is to carry and be powered by people over distance with more efficiency. The engineering of modern bicycles does not take that purpose seriously. Most bicycles are pretend clones of racing bikes either dirt or road.

[paule]

Thank you Tony, very informative with good clear filming angles. I have never been able to understand why cross-chaining has never been regarded (by those that market/sell) as an issue for 1x systems.

[pablomarquez]

I love my 1x. I installed them on 2 of my road bikes. I got a 11spd 11-32 with a 46t wolftooth ring. I love the simplicity and little extra weight savings also makes the bike look cleaner.

[AlexHasAnAxe]

First of, thank you for your service
Second, thank you for the informative video

[samspade]

Another option besides buying a new crank arm is to create your own spacers to move the crankring to the backside of the crank arms. In my case, four stainless steel washers from my local ACE hardware, a dremel and a little time is all it took.

[aaa]

This a good example of people following trends with no real good reasoning. 1x became a thing because of the need to lessen the chance of throwing a chain in serious and competitive mountain biking. Then through marketing and internet reasoning everybody needs to have a 1x setup. Tubeless tires fall within this same new components is fun, but not always necessary.

[knife]

usually pedaling backwards its mostly a gravel or mountain bike thing since you need to ratchet the cranks to get your pedals over rocks or big roots

[jamieahern]

Thanks so much. Very informative and helpful. I'm not a novice but I'm far from a pro, so the way you explained things was great.
Keep up the good work.

[nagylevi]

My Rockhopper had this issue, from the factory. On the smallest rear cog it was loud and annoying by default. I got extremely lucky, in that I changed my bottom bracket about a year after buying it and, purely by accident, the new BB I had chosen had a wider axle and that fixed the issue.

[Nosirrah]

Ive been riding for a while now and i want to switch to a narrow wide. I locked my front derailleur already and i havent had any problems with gear range. I got issues with chain jumping even when it was all stock. This video helps alot thanks

[Boopop]

My Larry Vs Harry Bullitt cargo bike is 1x, but then it also has hub gears so so far as the chainline is concerned, it may as well be single speed 😁 Interesting video, I liked the switching of the crankset to get a better setup :)

[potsy]

I bought the same sprocket (32T version ) there a good value @$8. They even included the hex bolts as a bonus. To convert a Specialized rockhopper to a 1x8. Mine would only bolt to the inside of the spider in the same position as the stock 2nd (middle) ring. I didn't use any washers or anything to alter the chains line. My chain looks straight on the 3rd gear cog and has no problem shifting through the other gears. The bike wasn't fussy about reverse peddling either. I rolled the crank back washing the bike and doing chain maintenance and it rolled along no problem. It didn't jump off of the cassette or do anything weird. I think if the change made using the highest couple gears act dodgy I could still live with it. I do most of my riding in 3rd gear anyway.

[alexmalone]

Tanks Tony from Bucharest România 🇺🇸!I used 1x12 transmission

[weaselpopper]

If you use the same triple crank converting to a single just use the middle 32-34 chain ring and leave it on the underside-same middle position of the crank. I`ve done it on three bikes now works and looks just fine.

[sagehiker]

Calculating your chain line ahead of time can help selecting a matching square taper bottom bracket. I lucked out on my first conversion. My first also changed my derailleur to long cage and wider range cassette for climbing hills with a big body rider.

[garygech]

Great video. I find the benefit of a one-by, acceleration on trail. I recently purchased a used Santa Cruz Stigmata and the one by works by making the bike psychologically fast, but you lose power options, and you lose some teeth on big pitch climbing. My advice is simple, take the bike and convert it to a reciprocal of your relationships. All in all, the goal is to have safe and wonderful relationships that motivate you to enjoy the sport together. If you are fixing your daughter's bike, you are teaching her independence.

[adonikam]

EXCELLENT EXCELLENT EXCELLENT VIDEO!! GLAD I FOUND YOUR CHANNEL, I SUBSCRIBED!!

[ianpearson]

i run a 1 x 10 system 42 at the back and 34 at the front.Now yes its great for uphill but on the flats and down i dont have enough high gears.Also cross chainging is a problem.I am considering going to a 2 x 10 system and front derailleur.