eabaggot

I am wanting to get a new bike (a Trek something-or-other road/hybrid) and am thinking of getting one that only has the rear derailleur. Anyone got any experiences/opinions to offer? I'm intrigued because of (a) the simplicity and (b) almost all my chain/gear problems and noises have historically been on the front. I am a little concerned about the lateral stress from shifting across the the sprockets over time.
FWIW, I do all my riding on decent roads and my routes climb a *lot* of long, steep hills (+700' over a 1.5 miles)

Eric F 

A single-chainring setup (commonly referred to as "1x") continues to grow in popularity. With MTBs, 1x is the current standard. Less frequently, people are finding it works for them on a road bike, as well. As long as the gear range from highest to lowest provides what you need for the terrain you ride, 1x can be a very good choice.

With the 1x chainring set to be in line with the middle of the cassette, you might get a little bit more chain angle at the extreme ends, but this hasn't show itself to be problematic with modern drivetrains.

I recently switched my gravel bike drivetrain from 2x to 1x, and I like it a lot. I lost a couple of gears on the top end that I never really used, but otherwise I have pretty much the same range of usable gear ratios that I had with 2x

Steve B.

You can get the same range of gearing, for the lows and highs, but you lose in between gears that can be useful on flat rides or in a headwind. I love my 1x systems on my mt. bikes, but would not want it on my road bikes unless all I rode was constant up and down hills.

Jughed

I absolutely love the 1x on my CX bike.

I think I run an 11x44 in the rear with a 42? Up front. It climbs very well.

Im not real sensitive to fine gear adjustments, I have a pretty big range of cadence comfort 80-95 and I’m fine. Some folks don’t like that lack of fine tuning.

Top pedaling speed is 30+\-

Mtracer

In general a 1X setup is not going to get you the range of gearing you will get with a 2X setup. Even ignoring the larger jumps in gears. The climb you describe is almost 9% which is pretty steep for mere mortals to do for 1.5 miles at a stretch.

Apparently you have a bike now and ride these routes. What gearing do you have on that, and how well is that working for you? If you're riding roads, but doing a lot of steep climbing, a gravel bike might be the best idea. They are like a road bike but they come with lower gearing. Some even in 1X setups.

Trek has the Checkpoint ALR 5 Driftless which is a 1X with a 40T upfront and 11-24 rear. So in the lowest gear you would have a 40/42 = 0.95 ratio. This is low-ish, but not really low. On the upper end you would have 40/11 = 3.6:1. I happen to have a Trek Checkpoint in a 2X setup with a 48/31T up front and 11-34 in back. This gets me 31/34 = 0.91 in the lowest gearing and 4.4:1 in the highest. So, more gear range overall.

While I know you mentioned having issues with a front derailleur, my own experience is once setup, the front just works. Now, some people have, I believe, overly optimistic ideas of running all gears and never having chain rub up front when cross chaining. While sometimes possible, it's unrealistic in many if not most cases.

Simply put, I'd find the bike that is right for what you need and if it is a 1X great. But if it turns out a 2X gets you the gearing you really need, keep in mind that many, many people get along just fine with 2X and even 3X setups.

Camilo

I think you've nailed it. Although I don't agree that you can get the same range of gears. A 1X just can't match both the high and low of a 2X. It will match or could even exceed either one or the other (usually low gear) but will lack 1-2 gears at the other end (usually high gear). But a 2X can be easily made to match any 1X at the low end while keeping 1 or 2 higher gears.

If one rides a gravel bike or hybrid more like a mountain bike, the 1X will probably be perfect because simplicity is important, and a high gear is not. If the rides are more road-ish, the 2X - even with the small chain ring and cassette set up for approximately the same low gear as a 1X - will have smaller jumps between the gears in back and will gain 1 or 2 higher gears, just because the large chain ring can be larger and the small ring smaller than the 1X chain wheel.

A 1X is probably close enough for many riders, if not most, because most riders don't care if they can keep pedaling at 30+mph as long as they can get up the hills.

DaveSSS 

Compare the lowest gear ratio that you currently use now, to what's available in 1x. If it's not low enough, the chain ring size can be reduced, but then you lose top gear. I do a lot of climbing on grades up to 13% and use a gear ratio below 1/1. I'd need a 38 chain ring and a 10-44 cassette. That top gear is like my 46/12, so no 46/11 or 46/10. Then there's bigger jumps between sprockets too. you can't have your cake and eat it too.

eabaggot

Good idea. I never thought about this type of evaluation or had to look at this level of detail. Things always just worked. My current bike is 2x, so I will go out and start counting teeth.

PeteHski

Don't worry about that, it isn't a problem. Just make sure it has the range of gears you need. This is a really nice gear calculator to compare setups:-

Bicycle Gear Calculator

DangerousDanR

Just made a down payment on a Time Scylon Disc which will be fitted with an Ekar group set. Using the 9-42 cluster you get a good mix of wide ratio 5 speed at the low end and a close ratio 8 speed for the high gears.

I suppose that only Time will tell how it goes.

SpeedyBlueBiker

I've always wondered if the 1X was really an improvement or just a way for bicycle companies to get people to buy the "latest greatest bicycle style/fad" in order to increase sales. 25 years ago, almost all mtn bikes were running a triple up front. A lot of road bikes came out with triples as well. I have a 2002 LeMond Zurich with a triple and I love it. Great for riding very steep hills with a 52/42/30 up front and a non-stock 12-28 cassette in the back. My other road bikes are just standard double front derailleurs. I wonder how much torque is put on the chain when climbing with a 1X and you are in the lowest ring whether it is on a mountain or road bike? i.e. 40X42.

Eric F 

Ride what works for you. I started riding MTBs in 1990, and up until I stepped away from riding and racing in 2004, MTBs were always 3x. When I got back on the bike a few years ago, 1x with a giant, wide-range cassette seemed weird to me. Then, I bought a newer MTB with a 32x10-52 setup. I dig it. It's simple. In a way, it reminds me of semi-automatic sequential shifting that you find in many cars. What I found is that the low end is every bit as low as we had with compact 3x, and the little bit of range you give up on the top end is pretty inconsequential for most people. When you look at how the ratios of a 2x or 3x system overlap, there is a lot of redundancy. 1x eliminates the redundancy.

Additional lateral stress due to a slightly higher chain angle at the top and bottom of the cassette with a 1x system has not shown itself to be problematic. 1x has been popular long enough that it would be a frequent topic, if it was an issue.

Road bikes have changed the least. 2x is still the standard. However, running an 11s or 12s system has required the use of longer cage derailleurs than used to be the standard because of the extend range of modern cassettes.

GamblerGORD53

IF you want to go 1x with a pie plate dork disc on the back, go ahead. LOL.
They are mostly being used for MTB with a low 30s crank. Useless on any highway.
I run my SA 5w at 41 to 110 GI now. Absolute fun on centuries, heavy weight and all. LOL.

Eric F 

Useless? I suppose that depends on your needs. A 32T chainring and 10-52 cassette found on many modern MTBs can roll along at 25mph pretty comfortably. Faster than that means I'm probably going downhill, and I can just coast. However, I don't ride my MTB bike on pavement enough to worry about its road capabilities. I have other bikes that are better for road or mixed-surfaces rides. IMO, criticizing a MTB's gearing for its limitations on pavement is kind of silly. How's your 41GI low gear for getting up 15%+ singletrack climbs?

eabaggot

That's the gist of my concern, actually. The lateral angle the chain makes to get from the crank to the largest rear sprocket is just going to be a bit more severe than it would make from the interior front sprocket of a 2x or 3x. Being in lowest gear basically implies you are in a mechanically stressful situation that could create strain on the links, and a chain failure during a steep 20 minute climb could be unpleasant.
But actually, maybe I'm just over thinking this and am worrying over nothing. Still, I'm tending towards a 2x for my nest bike. Appreciate all the replies.

jaxgtr

My wife and I both have Trek FX 1x's , she has a 4 and I have the 5. They are great bikes for what they are used for. They came with 40 on the front and an 11-42 on the rear, but living where we do, the 11-42 is pointless, so she has a 14-28 cassette, and I run a 12-25 cassette. Lots of single tooth jumps that work perfect in out very flat windy area. Not had any issues with the chain line as generally use these for casual riding, mups, light gravel.