Tuesday Tech Talk - Why 2X is better than 1X drivetrain. 1X isn’t that great it’s just marketing BS

4907

[EricPeelMusic]

Idk if anyone else has mentioned this but the teeth differences do not matter. Its the percentages between cogs that matter. A 16-18 (2t) step is 13% while a 32-36 (4t) step is the same 13%. 45-51 is not really a bailout gear since the step is a reasonable 13% even though it’s 6t. The 10-12 jump IS a massive jump at 20% even though only 2t. And the 18-21 is just stupid because it’s near the middle of the cassette and a pretty large 17%. Here’s all the percentages for 10-51 and 11-36:

20, 17, 14, 13, 17, 14, 17, 18, 18, 15, 13

9, 8, 8, 7, 13, 12, 11, 14, 17, 14, 13

If you’re doing a mix of hills and flats, the 2x 11-36 is better.

If you’re doing only hills with no flats, the 1x 10-51 is better.

If you want to make the best of the 10-51 on flats, choose a chainring that’s mostly keeps you in the 16t cog, since the steps surrounding 16t are the smallest on the 10-51 at 13% and 14%.

[michaelfasher]

The other factor is in fast shallow descents where everyone is in their top gear. The ten tooth cog loses about 2.7 watts over the eleven tooth cog

[keithadler]

Excellent explanation, I am a old fart who has older shimano on all my bikes. Compact and subcompact. On the gravel/touring bike have a 11-46 rear and a 30 46 upfront. the FSA ENERGY crankset let's you go way low. And doing a bit of moding with the rear derailleur wolftooth Tappan with a xt derailleur you can have silly low gears for bike packing and touring. Great YouTube channel. Thanks

[glenncoltman]

😊 I'm with you on 2x . You didn't take into account having 2 shifters and cables v only 1 but wouldn't add many grams. I also much prefer the straighter chain line you can achieve with 2x. Keep up the good work

[rivnuts]

Thanks for this tutorial. I don’t own a 1X but haven’t been compelled or convinced I need one. That said, I am always seeking simplicity and not having a front derailleur, shifter and cabling would be a plus but not enough to get me to change.

[johnlong]

I like a 3x with a road racing close ratio cassette👍

[letmein]

I have two bikes so I ridden both. SSevo 48/35 oval with 11-32, and another DIY bike build 44 oval with 11-46. There's pros to each. If I'm riding steep climbs, maybe i would prefer the 2x - i could just drop it to the small ring; if it's rolling hills, i hate changing the FD and RD; and so 1x would be my choice. i like the simplicity of the 1x when building the bike. I also didn't mind the ease of updating the SSevo rim brakes and exposed cables. cheers ☕😃😄

[aaronhamlen]

I have two road bikes with Sram and Shimano. I'm getting rid of my 10 speed Sram Red setup on my Tarmac. I have Ultegra on my Defy also a 2X setup on my Defy. You can't trim The Sram front derailleur on my Tarmac, I can with Ultegra. I use 52 x 36 on both bikes with an 11 x 32 cassette. This gearing works for me riding on rolling hills. I used to ride a 52 x 42 when I first started cycling. I had no issues with setup as a junior rider. The cycling industry is always trying to reinvent every thing. Keep it simple and just ride in my opinion.

[tweed]

Brilliant video, George! We were always taught that chainline is important. Get your chain operating at slant angle and your transmission wears out quicker. Having your "favorite" gear centered at the cassette was pretty important - that's why everyone was faffing around with cassette and big chainring combinations (or the small one if he/she rides in the mountains). SUDDENLY, when 1x drivetrains appeared on the market under SRAM incompetency to produce a decent front derailleur (SRAM front shifting was dreadful - I remember that vividly), the chainline is not the problem anymore. Which is total bull load. With 2x you get both easy gear and bailout gear. I used to ride 52/42 and 55/42 drivetrain with 11-something cassette (sometimes 21, sometimes 28, depending on cassette availability at my local bike shop) and I've spun out 55/11 gear only 3 times in the entire life cycle of that transmission. But anyway, it has been nice to have a ridiculously heavy gear alongside with climbing gears while having mild jumps between cogs. That's on a road bike.

When I've bought 29+ MTB specifically designed around 1x transmission (Trek Stache), I thought, well, I will eventually come to terms with bigger jumps between gears on trails. Wrong! I never did. I dislike those 3-tooth and sometimes 4-tooth jumps between gears now as I disliked them the very first day. Chainline is messy.

Gimme the double chainring and a nice mechanical front derailleur any day of the week.

[mattharding]

🙂 seeing those huge cassettes on a 1x drivetrain made me suspicious. Nice to see someone do the work and present some hard numbers. My road set-up is a 90s 9-speed Ultegra 6500 53-39 & 12-23 cassette. Gravel set-up is 8-speed 2x 46-32 & 12-23 cassette with short cage road derailleur. I can climb very steep hills with both set-ups and still have comfortable gear steps and maintain a straight-ish chain line.

[gc]

Nice one George, 2x all the way, I have no shame I’m running a grx 46-30 and 11-42 cassette on my road bike, what can I say I’m a softy

[ian_pedalz]

😊😊😊😊
A lot of people defending 1x probably because they wish they had 2x 😂

If you do any type of long distance riding whether on or off road I find 2x to just be superior. Mechanical front derailleurs are so inexpensive to own, I couldn’t imagine cost or weight being a thing. So many rando riders I know are still rocking 3x up front and they arnt complaining lol. Great video George and excellent points!

Only one problem with the grx mechanical 12 speed… lack of rim brake option 😫

[lecoachdefrancais-]

I tried 1x for about a year on road. The weight difference was indeed around 50gr, ridiculous. Bigger jump between gears as you mention. I also experienced more chain drop than a 2x set up (I didn't have any chain catcher on the 1x set up). But the biggest problem in the 1x set up is the efficiency loss. Even if you don't care about speed and few watts loss, those particular few watts loss in the drivetrain result in a very fast wear of the chain. As i'm doing a lot of climbing, I had to change my chain every 2 or 3 month with my 1x set up against once a year in 2x set up (I'm riding more or less 1000km per month). The 1x set up were crazy more expensive to run than the 2x! I came back happily to a 2x set up after this terrible experience.

[thomaskuhn]

I always wonder if, when talking about jumps from one cog to the next, it's appropriate to look at the number of teeth or the percentage change. So just looking at the 4 lowest gears: on the 1X setup, going from the 33 cog to the 51 is an average increase of 15.6% in the number of teeth; on the 2X 11-36, going from the 24 cog to the 36 is an average increase of 14.5%.
So over those 4 biggest cogs, 1X vs 2X, I look at 6 tooth vs. 4 tooth jumps and think that's a huge difference. But if I look at it in % terms, it's 15.6% vs. 14.5%, which is still a difference, but doesn't sound nearly as dramatic as 6 vs 4.
What about comparing the 5 smallest cogs, where the average increase in the number of teeth for the 1X is 15.8% (10-18) vs 8.1% for the 2X (11-15). Isn't that difference in gapping going to be more noticeable than what's happening with the climbing cogs?

[drooghead]

You can't beat a triple chainring for range of gearing.

[plantfuelled]

The thing people always forget is that a front derailleur also makes the best chain guide you can get. For the weight of a shifter cable and chain ring you get 2x the gears, no brainer.

[robertshunter]

😁 This is just the kind of nerding that brings me back. I'm always up for cold, hard numbers.

And a very happy birthday to you, George!

[travelersimports]

It depends on the terrain. In Wisconsin, there is no reason to have 2x setup. 52 or 53 chainring with 11/28 cassette ( better for short cage force 1 clutch derailleur), or 11/32 cassette with mid size cage. In Colorado, I would use 2x standard setup.

[kyqx]

Great info, George but I'm good:). I can do all of my usual routes with 11 speeds. I can adjust with a differently geared bike if needed (twice a year to Colorado) as I have too many of them (12) but I'll never in my life own a front derailleur. I'm either ahead of my time or penalizing myself. If the latter is true, I like the pain.

[michaelcapilla]

Great breakdown of weights and ratios. Currently using GRX 11 w/ 48/11 and 11-34. I live in hilly area, but it is still so rare that I use 31x34 so the 11-36 just doesn't make sense. I do like the even smaller steps with the 12 speed 11-34. That'll likely be my next groupset.