After doing some reading on here my self...I made the switch. I really like it so far.

The crankset doesn’t matter as much...but my advice would be to get a specific 1X chainring, as the teeth are different...I am using all SRAM stuff...and I really like the clutch RD...if you get the chain the right length...I don’t see how you would ever drop it with that RD...and it has a button that helps loosen everything up if you need to change the rear wheel...super easy.

If you are going with the SRAM rings...just look at your current crank and determine what the bolt pattern is...because that will determine which rings you can use up front....you can find that info on SRAM’s website.

I’m also using the R2C shifters...and I like them...good luck whatever you do.

The B.B. is determined by your frame/crank...the 1X setup won’t have any effect on that.

You can keep your existing bottom bracket and cranks. Just purchase a SRAM X-Sync 1x chain ring.
And then get a 1x rear derailleur (you do not NEED this, but it helps chain retension). Like a SRAM APEX1/Rival1/Force CX1

That’s all you’ll need for the conversion.

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Alex Arman

Strava

Thanks heaps for the info. Helped a lot. Will post the bike once it is done. Thanks again

Perfect, thanks very much!

I have a Gen 1 Speed Concept that I had re-painted. They removed the front derailleur mount and patched the hole before painting it and it turned out great (but there’s no going back to 2x).

I’m using Sram parts - Quarq with X-sync chainring, Force 1 RD and cassette, R2C shifter. My bottom bracket is Trek’s BB90 for GXP.

I used to have a 1x on a gravel bike. For gravel (with big bumps which the clutch rd helped with), I liked the system a lot. But here's why I won't do 1x on a road or Tri bike . . .

. . . First, the clutch rd creates drag on the system. In other words, it robs power and slows you down, just a tad. On a gravel bike, chain security was (maybe) worth the extra drag. Thinking back on it, I'm not even sure I would use a clutch rd on gravel again.

. . . Second, in a TT or Triathlon, having my cadence at its optimum speed seems a lot more important than on gravel. On gravel, cadence varies almost constantly. In a Triathlon, I want to get to my optimum cadence and keep it there. With a 1x, there aren't as many gearing options available to bring and keep my cadence "just right."

But your mileage may vary. Be sure to let us know how it goes!

People come at this from different angles. My angle is always start with what you've got. As you think about 1x think about what rides you'll be using it in. Can you replicate those kind of profiles near you? If so then ride there a bit and be extra mindful about the gear ratios you are using. The one bit I didn't see anyone here mention (sorry if I missed it) is the Chain ring size. In some situations you go with a chain ring smaller than the larger one in a 2x so that the overall range is right. But in making that decision you want to be confident the range you will have covers what you need. Which is why I'd suggest getting to know your ratios. For instance how much time do you really spend at 52x11 (or whatever your largest current ration is)? A 1x will be giving up gear range somewhere the question is how much to give up at each end of the spectrum.

So my suggestion is make some notes on the ratios you need for your target rides - through testing not guesstimating. Then get a cheap narrow/wide tooth 1x that fits your current cranks and gets you the range that fits with what you have worked out you need. Ride to check it's all good. Changing rear derailleur can wait until you are happy with everything else and you find you are very unlucky and having chain drops .

You'll get the correct product if you search for "1x" stuff, but don't accidentally just use a big ring for a normal double.

You need the narrow/wide aspect to get rid of the FD.

Also consider buying some spare cassettes in different configs so you can swap out and play with stuff depending on the ride. Takes all of 5min to swap one. Also, the largest cogs are on the spider but you might be able to play with tossing out the 11t for an even numbered cog somewhere else. Either the jump right before the spider or the jump right after it goes from 1-tooth increments to 2-tooth.

A SRAM 1X chainring is the one essential thing you'll need. It uses a wide/narrow tooth pattern that holds the chain tight.

Does anyone have any experience doing One X in a di2 setup with the RX 805 rear derailleur

My gravel/cross bike has an XT (MTB) Di2 rear derailleur. The utility of di2 with 1X is less, since the difference between electronic and mechanical rear shifting is much less than in the front.
The Shimano clutch RD is nice, since the clutch is lever operated. Someone above mentioned the power robbing from the clutch. So, if you are on a smooth course, simply disengage the clutch. If you are on bumpy stuff, put it on.

I've done a load of Shimano 1 builds, mostly on OPEN U.Ps or UPPERs, and we tend to make the left hand lever replicate the right, so if you crash and smash up your lever, you're possibly still good (shifting wise at least!). As these are Gravel bikes, they normally have the XT or XTR mech for its capacity. We have built a couple now with the (Ultegra) 805, but it doesn't have the same sprocket capacity, it does have a clutch though, so you can have a clutch and X2 which you couldn't before.
I'd say, as posted earlier, spend some time being particularly aware of your gearing and terrain, if you're considering the 805 with its 'limited' largest sprocket size (34T).

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'to give anything less than the best is to sacrifice the gift'...Pre

The worst of the climbing I do requires a a 34 /28. So I was wondering or thinking I might be able to get by with a 50 big ring and a cassette that has a 34 on the back. With those 1X setups can you cross chain fairly easily

Hate to burst your bubble but if you need 34/28 for a section then 50/34 isn't going to do it. 42/34 would be about the same ration.

The whole point of a 1x is that the whole cassette is available with the one front ring.

Specific darts and brakes too

1xaerobars
Aero or die set up

kona champ Greg welch had some called Scott y1
https://goo.gl/images/G2KLrd

But I guess the modern iteration would be more like a use tula with a mono extension
https://goo.gl/images/CNQFcW

1xbrakes
In new Zealand a guy one the coast to coast with a bike with only a rear brake but with leaf brakes like on the Storck Aero2 make that unecessary

1xbottle?

1x seat rail?

You can also remove every second bearing in rings and Rolf wheels to skip spokes and the only next option is drillium.... Don't get me started on drillium

Thanks for this. All races are pancake flat where I am. I am using 10 sp atm, was thinking a 11-36 in training for enough gearing for hill work, and 11-28 for races. Maybe a 52T front ring?

That's probably the easiest setup to workout what ratios you need. Most 2x bikes have something near a 52 to begin with. So then you can bike around, decide not to use the small chain ring on that ride, and see where in the cassette you are spending all your time. For me 52x11 would be a complete waste. I'm targeting longer rides and tend to over bike. So I don't need to hammer it when there is a tail wind or a favorable slope. Equally a bit of room on the easy side of the spectrum means I can spin a section and save that match. So for me it's a smaller chain ring than that on a 1x. But it's all individual and depends on your context. If you are a stronger biker than me then you may well need that 52. But it's easy to test that setup before buying anything.

If it's pancake flat, when would you use 52/11? I use 52/11 on my road bike occasionally when on the flat when I'm sprinting, but you won't be doing much of that on a tri bike. On the other hand 52/28 is a big gear. It would be approximately equivalent to having a 34T small chainring on a 2x compact and never going bigger than 18T at the back, or 36T and never going bigger than 19T at the back. Probably fine on a pancake flat route, but I'd rather have some smaller gears than an unnecessarily big one. If your big is not big enough you may lose out on a very small amount of potential speed, briefly. If your small is not small enough, you may lose a little on acceleration at the start or from very tight corners, but you may also seriously struggle or even have to get off the bike if the gradient increases more than you anticipated.

I don't have experience with 1x but I'd expect something like 44/11 will be enough to lose out very little on most non-mountainous routes. Equivalent to restricting yourself to a 13T at the back on a 52T chainring.