jyl

I have generally ignored the 1 x drivetrains from SRAM until now, when I'm reading news of a 1 x 11 road drivetrain.

Hmm. What are the advantages and disadvantages of 1 x drivetrains?

Today's mountain bikes have very small chainrings, they seem to be geared low, maybe a 1 x gearing makes sense. CX bikes are not ridden up very steep grades or at high speeds, a 1 x gearing seems very logical. Road bikes are supposed to tackle everything from steep grades to 40 mph, I don't understand why a 1 x gearing makes sense.

rms13

I do not and have never had a 1x bike but I have often heard that the best front derailleur is no front derailleur.. So that is one advantage as well as minimal weight savings. But I see lack gearing options as a problem. But I have often thought what a 46t chain ring and 11-32 cassette 1x11 would be like

gregf83 

I use a 1x10 cross setup for commuting. It works well for me and I like having no front derailleur. I've used it on group rides in the winter and it's fine for most of the rides although sustained speeds above 45kph are a challenge. I think it's 42 x 12/27.

KenshiBiker

I could see using a 1x drivetrain for commuting, and actually for quite a bit of my recreational riding. After all, until I got my new road bike last year, I did almost all my riding on a 1x1 (i.e., fixed gear). It's only now that I'm doing a lot more hill climbing that I would really feel the loss of a second chainring.

Kopsis

In CX racing, I love a 1xN setup because it's one less mechanical bit to break and one less shifter for my oxygen-starved brain to think about. For road I just don't see much benefit. I've done road rides on my 1x10 CX bike and the reduction in gear choices is definitely noticeable even in flat-as-a-pancake Florida. A 1x11 would be slightly better, but it still feels like a compromise with no up-side. I'll be using my CX bike as a travel road bike for three months this summer and I'm definitely going to put the double back on for that.

cyccommute 

Mountain bikes are supposed to tackle everything from steep grades to terrifying 40 mph downhills as well. 1x systems make sense if you are doing laps on a mountain bike race course and know every bit of terrain that you might run across on the course. Out in the real world, they are just as dumb as 1x systems for road bikes would be. You can choose (with either discipline) to have climbing gears or to have descending gears. You are kind of hosed if you need both.

cyccommute 

A front derailer on a bicycle isn't that complicated a mechanism nor is it that hard to keep working properly. Even the indexed ones for integrated shifters are easy to adjust and maintain. I'd rather have the ability to go a bit faster and climb a bit better than have the "simplicity" of a 1x system. A 46/11 spins out at 30 mph which, for me, would mean that I'm coasting most hills from just a few feet from the top all the way to the bottom. I'd be coasting before I hit the gate 1/4 of a mile from my office with a 46 and would keep doing so for about the next 3 miles.

dr_lha

I did all of my riding last year on a bike with a 46 big ring and 11 or 12 smallest ring at the back. I did centuries, metric centuries, many group rides on this configuration, with no issues. Yes, I spin out around 33 mph in this configuration going downhill, but is that really much of an issue? A compact crank (50x11) only gives up an extra 3mph.

I'm not advocating 1x11 FYI, as my bike is 46/34 up front, I'm just arguing that a 46 big ring isn't that much of a limitation.

Looigi

Also, because of rapidly varying terrain, it's rare on an mtb to go at a constant speed and cadence for a length of time like is often the case on road bikes. Because of this, wide gaps between adjacent gears is more acceptable because you'll be stuck in any gap for a much shorter duration and can get by without the optimal gear.

CliffordK

I've started getting a bit lazy shifting with the FD on my Cargo bike and Litespeed.
On the cargo bike because I didn't get around to building a FD mount, so I have to manually shift.
On the Litespeed because upshifts are slow.

And, both bikes got an 11x30 or 32 cassette/freewheel (8s on the cargo bike, 9s on the Litespeed).

Anyway, for 99% of my riding, (no loads or light loads), I think I'd be perfectly happy with the 54T front and 11x32 on the back. Steps are a bit greater than I'd like, but filling in with an 11s cassette, and it wouldn't be too bad.

Considering shift overlap.
Here is a quick gearing chart:
11-25 (9s) vs 11-34 (11s)
53/38 front.



What you see is that a 11-25 9s cassette with a 53/38 front chainrings gives almost the same gearing as a 11-34 11s cassette, and a single 53T chainring.

(34T range on the large chainring is almost directly above the 25T on the small chainring).

https://home.earthlink.net/~mike.sherman/shift.html

gsa103

If you don't do steep hills, 1x works fine. I did my last group ride entirely in 50t ring, since there was no long climbs.

FastJake

The only thing I use 1x gearing for is cyclocross racing. I don't need a wide range of gearing, just a low gear for steep climbs and a few more ratios for other stuff. Close spacing between gears is not needed or desired. And having just one chainring with a guard greatly improves reliability. I've done 1x8 the past couple years and I'm toying with the idea of going back to 1x7 for stronger rear wheels.

I mostly ride fixed gear on the road but my geared bikes have doubles or triples. Wider gearing range and/or tighter spacing between gears than with a 1x setup, even with a silly amount of rear cogs like 10 or 11.

Paul Barnard

Interesting topic. I am seriously considering buying a carbon fiber frame from Bikes Direct and building it into a 1X do it all bike. I live in NOLA where it is almost perfectly flat. I already have a new spare 9X cassette, 9X shifter, 9X derailleur, 1X crankset with BB and a lot of other parts in the attic. I simply don't need more gearing than that. I suppose spacing could be a little bit of an issue if I was pedaling against a stiff headwind. It'd be a fun and unique build. With the parts I already have laying around, I could do it for less than a grand. I've got this idea that I would use use a lot of colored parts to make it look really gaudy.

trailangel

What ya gonna do with a 126 inch gear?

Drew Eckhardt 

Advantage: You're unlikely to accidentally dump the chain to the inside and loose a fraction of a second as it bounces off your chain catcher.
Disadvantage: You need to be strong enough to spin a 39x21 up most of your hills and manage the rest if you also want decent spacing. You need a decent spin.

Ex: 42 x 11-12-3-14-15-16-17-18-19-21-23

Good for cruising about 30 MPH and sprinting at over 40.

bikebreak

You are right for race bikes that need a steep gear to stay in the pack at 30+ mph and a still need a good climbing gear for spinning up mountains.

For a general purpose bike the 1x is enough!

I recently got a Tricross with 1x11, 43t front 11-32 rear. The fastest gear is a just a hair less steep than the classic race gearing of a couple decades ago (52x13). It will do over 31mph @ 100RPM. If you need more speed just spin a bit faster. It worked for Merckx with the 52x13.
The lowest gear is 36.3 inches, a tad lower than a compact 34x25. Fine for hills.

The gearing is fine for group rides, as shown:
https://www.strava.com/activities/267617493
I used the 11 on a long descent https://www.strava.com/activities/26...nts/6264159079
and for maybe 30 seconds doing fast paceline with a couple guys
https://www.strava.com/activities/26...nts/6264159337
the 32t bailout gear I used on a 7% long climb and 9-11% short climb

Gearing is fine for my short spring training (aka chatting) rides
https://www.strava.com/activities/266689624
https://www.strava.com/activities/252334244

After spring, I'm going to make the Tricross my commuter and ride a normal 2x10 for group rides. It's under 19 pounds now but once I get fenders, rack, and fat tires on it will be ~23 pounds, I plan to swap the chainring for a 39.

pics here
https://www.bikeforums.net/commuting/...5mm-tires.html

Darth Lefty 

An "alpine" geared classic 10-speed went from 40-32 low to 52-14 high, about 34-101 gear inches. An 11-32 cassette of any number of speeds and a single 40 chainring can accomplish the same thing (or maybe 42 to compensate for smaller, faster wheel and tire). At up to 10-speed there are some solutions to get a bigger than 32 cog without any extraordinary expensive parts. More speeds is nice, wouldn't complain, sure, 11, why not, fewer solutions but do-able. If there were any serious disadvantage I could think of it would be cosmetic and not technological.

AlmostTrick

My latest commuter runs a 1x9. 42x 12-26. I have a couple steep hills, but they're not too long. Already hit 32 mph in 8th gear, haven't even spun up 9 yet.

After riding a 32-42-52 triple primarily in the center ring for years, I figured why not ditch all the extra parts.

bikebreak

PS I really enjoy the spacing in the middle of the shimano 11-32 cassette, 16-18-20-22-25

I wish they made a 10 speed cassette like that, as I find the 16-17t shift fairly useless anyway.

Darth Lefty 

Look at different models and different makes of cassettes. The Deore is different from the Tiagra is different from the Apex, I recall. Don't have time to research now.

Darth Lefty 

If you're commuting the 1x will let you run a chain guard. On your 11-speed. Giggle

fietsbob

the $300+ Replacement Cassette OK by you?

79pmooney

You can do a lot with a 42t chainring. I rode Cycle Oregon 2012 and last fall on a 42. 12-23 12 speed except each morning I would decide which three cogs I would ride that day and leave the rest with my tent. I would have loved an 11 for the descent into Ashland in '12 but they do not make one for my hub. Still, pedaling the 12 was quite doable on almost all the descents.

Some folks use index shifting. That bike shifts with biceps. And a large wrench. Never coasts. And is my all time favorite ride.

Ben

79pmooney

My "12 speed" has close to $400 in cogs as I have to purchase them individually. But since those cogs last an average of close to 10,000 miles each, running costs are too bad. (I will thank the engineers who came up with that really good drivetrain, the 1/8" roller pin chain and sprockets. Funny that for most of my lifetime, it was only used for kid's bikes while the adults used far inferior designs.)

Ben

fietsbob

my 1 by 14 speed only has 1 cog on the hub..