My chainline is super-sexy.
It would definitely get you hot just looking at it.
Especially if you are a campagnolo man.

They may be expected to introduce a road version based around an 11-36 11 speed.
It will not do very well, though.
Sram has a romantic approach to engineering matters and that is not good.
When I buy sram components it is a given that I will have someone else's design messes to clean up.
That is fine. I still like them.

xx1 is cool.
but, no road shifters, that was the personal deal-breaker.
Also, chain cogs begin a rather rapid drop-off of efficiency below 11t
is neat stuff though.

I wouldn't count on 11-36 for the 11spd road version. The amount of chain wrap that would involve would require a very long cage der indeed.

Xx derailleur I use has mid-length cage that is precisely same dimension as sram red rd it replaced.
Rated for 36t.
Could go 40 easy.

problem was there was no integral barrel adjuster as we road cyclists are accustomed to.
I had to build one in, for I hate and despise and detest in-line barrel adjusters.
If you enjoy being a ball of nerves, buy a 300 dollar derailleur and start drilling and threading holes in it.
Thank god it worked perfectly. But Lord I hate having to do things like that.

But that is for a single front chainring not a 39/53 road crank. That means A LOT more chain wrap.

What? You don't like cut and paste?

Well, not really...but then again, this phrase is often saved for situations in which it doesn't apply.

Additionally, your interpretation of what constitutes a "transmission" is far narrower than the accepted definition. Whether it has one, two, or three chainrings, there's only one transmission.

Regardless, I appreciate your novel approach.

I think it really boils down to your smallest and largest cassette rings; what is in between is a personal preference as to how much of a jump you can handle. I have found the 8 speed to cover this amply. You need a climbing gear and a spinning gear and the rest is somewhat necessary filler, even in mountainous Colorado. 1x10, 1x11 seem a bit overkilly to me - that's just working your right hand harder than a 13 year old who discovered his dad's nudie mag stash. Not that this ever happened, just sayin'.

This is all technical info for someone who wants to make one. I don't want to waste time arguing a 'case' for it- so the below is relevant only if you're interested in how to do it. If you're more interested in the controversial aspect of things, don't waste your own time reading it.

Here are the little engineering problems that have to be solved if one requires a Dura Ace level of quietness, reliability and performance. Most issues arise out of the expanded range of chainlines. If the installation is on a TT bike (such as the poor Cervello P2 in the photo), your chainlines will be even worse. The shortened distance between crank and rear hub are responsible for that. The chainline in extreme gears are a strain even for a 2x10.

If you're doing this to a town bike or a hybrid with nice looong chainstays, hell, your chainlines with a 1x10 will be better than a 2x10 road/tt bike has. You got no worries and can ignore most everything that follows. You replace your stock square taper BB with a 108mm, buy a Tiagra 11-36 with rear d, a fancy Paul's chainkeeper and GO. And if you like 8 or 9 speeds like the fellow in the previous post (and that's my own sentimental preference actually, but I am forcing myself to live in this century now) so much the better. 9 speed chain and cogs don't give a damn what you do to them. Bizarre chainlines, splicing different cassettes together, they just don't care.

For a road/TT bike with outboard crank bearings you've got to find a bottom bracket that includes 2-3 mm of spacers because that's about how far the big ring has to come in. And now your problems are just beginning. Did you have ankle/chainstay clearance problems before? You might have them now. Didn't think about that, did ya! I didn't. Or suppose the spacer-jiggering will not get you where you need to go. Willing to go after your bottom bracket shell with a rotary sander to knock a couple mm off? On a carbon frame you just bought two weeks ago? You can, of course, have it professionally done with the proper tools, but think of the looks you're going to get when you walk into the LBS and request 2mm of perfectly good bottom bracket shell be destroyed. Personal vanity determined this particular deed be done in the secrecy of my own home.

For derailleurs, you have two options: buy an mtb rear d that is compatible with a road group (if you weren't a sram man before, you may have to be one now) or, swap/fabricate a new cage for your present rear der that is a) longer and b) has greater eccentricity of rotation about the pivot. I've done b) before and although it's lovely when you're done, I don't recommend it. You'll go through two or three derailleurs before you get it right, and that doesn't include the ones you'll buy just to rob their cages and return springs.

Suppose you get through that, you've got it pretty much set up and the chainlines in bottom and top gear really arent too bad, it shifts well. But you're fanatical about noise, or rather, hearing less of it. You also don't like it that when you backpedal in either the 11 or the 36, the chain jumps out of gear and that is no fun when the light is about to turn green. You've also got a bit of extra racket in those same cogs when you're rolling. Lastly, you've noticed that when your bike takes a weird bounce, the lower pulley has sounded like it's about to unchain itself. That would be very, very, very bad. Seen the photos of mangled Sram rear d's? That lower pulley is the cause, and you've just aggravated the problem with your oh-so-clever 1x10 set up. Lastly, you still drop the chain now and then - and one chain drop per season is one too many, for my money. Or, when you set the plates narrow enough to prevent that, you get chain rub when you're stomping on it. What is the point of getting rid of my fd if setting up a simple chainkeeper is so frustrating?

Here is where the real voodoo comes in, if you really want to stick to your objective of Dura Ace quietness, reliability, and performance. You've got to re-profile the teeth on your chain ring without taking too much away from the load bearing area. The 11 and 36 cogs will need a light chamfer in one particular spot to solve the backpedaling problem. The lower pulley wheel must be re-chamfered in order to eliminate its derailleur-exploding potential. And if you are perversely determined enough to figure out how to do that, there is still the g-d chainkeeper to deal with. In the end, that has ended up being the job that required an absolutely soul wearying amount of trial and error: design and positioning of the chainkeeper plates. Had it occurred to me earlier that a chain-keeper's job is entirely different from that of a derailleur, I would have gotten to the correct answer much quicker. But all the mistakes have yielded a more solid understanding of the configuration that works, as well as the principles behind it.

This week I'm taking the bike to the Cross Florida ride, and this should be the worst possible terrain for wide-range gearing. But the bike is weird enough apart from being a 1x10 and should probably be ridden as is.

This thread now needs to sink without a trace but the last word on the subject should definitely be these:

"1x10, 1x11, that just seems a bit overkilly to me. That's working your right hand harder than a 13 year old who just discovered his Dad's nudie mag stash. Not that this ever happened, just sayin'."

I admire your passion. Will be interesting to hear your report post-ride. Will you Strava it?

After reading all the above...I came away thinking...geee, what a waste of time. Not for me, because of the undeniable entertainment value but rather for you. But of course, you have deluded yourself into believing this waste of time has actually manifested some level of improvement. Great self deception I will add.
I was thinking...you should simply run a 2 X 10, save money and time and maybe go build a fence, or change the radiator hoses on your old car...that is if it isn't stuck in the front yard without a transmission...lol.

I have to say this reminds me of events that started a few decades ago in Marin County, CA. Guys like Gary Fisher, Joe Breeze and Tom Ritchey were tinkering with a new idea: fully functional off road cycling. Look what happened. No, don't get me wrong. I am not saying this is as important or will become a cycling revolution. I'm just saying this is how the new ideas get started. You don't have to like the gear spacing. You don't have to place any value on the lack of front shifting and its attendant problems. But I think giving Gerry credit for scoping out a different road bike gearing approach is really important. I think we are lucky to have read these posts. We should have learned something new from them, and that is a lot more than you can say from a lot of what we see here. Some day we may be thinking, "I remember when that idea was invented." Kudos to Gerry. Out of the box is a good thing.

I see at least one potential good product from OP's work -- the lower pulley that won't blow up the derailleur.

Curious why a chain keeper over the top of the chainring rather than behind wouldn't be more effective.

Point taken. First, 1 X 9...I run it on my 29er and 1 X 10 is 'nothing' new. If you spend time in the off road community you reference, this is a widely used practice. I enjoy my 1 X 9 bike. But with road cycling, if speed is the prize, there is a reason for 2 X 10. In fact, if living in the mountains with a lot of climbing, the average rider is well served with a 3 X 10 which mitigates the whole in gearing of a conventional 50/34 crank.

The essence of the OP's exercise can be reduced to the reason for 10 cogs in back, now becoming 11 which will likely become even 12 or 13 with next evolution to 135 axle spacing. So why do more cogs exist in back? For the simple reason of tight gear spacing. What the OP does is defeat this premise by reducing from 2 to 1 chainring in front. We as human's don't change our power output or cadence ability, but gearing changes the performance of the bike. By compromising the spectrum of gearing by limiting the no. of chainrings in front, the rear of the bike has to compensate for this compromise. A 11-36 rear cassette increases gear spacing pretty dramatically. Again, this completely flies in the face of why 9 speed, then 10s and now 11s cassettes came into being...for tighter gear spacing.

If you listened carefully to what the OP had to do to make this work..how sensitive set up is...and how cross-chaining creates greater friction and chain wear and noise, in combination with loss of tight gear spacing, it clearly states this is not an elegant solution if the priority is speed on a road bike. I believe 1 X 9 or 1 X 10 is fine for a knock around bike or a low maintainence bike for commuting etc provided the terrrain doesn't have too much climbing...but not for road or TT bike where speed is the priority. That is my counterpoint.

Well said^^^ It is more of a curiosity at this point.

Pully gear tooth profile and involute shape have been carefully developed by countless tolerance stackups and dynamically modeled on CAD with all possible gear combinations. That is how pulley tooth shape evolved to its present state. But there is more. Pully shape isn't just about X-chaining capability...it is about gear shifting efficiency and also propensity for pully wear due to reducing tooth cross-section. Countless hours have gone into the evolution of pully tooth shape and any modification of this will have consequences to parameters other than X-chaining capability.

Funny thing is I agree with you, not OP. I was just pointing out how valuable it is to have folks fooling around (AKA experimenting). We see so much of the same old, same old here, the change is refreshing. And the discussion on this has been very illuminating.

Invention occurs yes...and playing with the status quo...out of the box is so passe ...is how its achieved for sure. If you look back on the bike industry pretty much the whole bike has evolved...and many would say for the better...I do. In the mtb industry...the 29er in particular is an outgrowth...partly driven by the hybrid of cross bikes with mtb...and where 1 X 9 became popular on...starting with long cage derailleurs and pie plate cassettes...again popular in the mtb industry. Also the mtb industry has morphed toward 2 X 10 for racers and away from 3 X 9 which was popular for years. The 29er trend was a loooong slow slog and very slowly embraced because of the greater inertia of bigger wheels...big rubber on 700c hoops don't spool up like a 26" wheel does. Further...26" wheels are inherently stronger because of bigger spoke brace angle and shorter spokes...mtb's themselves evolved from 26" cruisers.
So yes the evolution will continue...electric shifting...and will likely go well beyond shift sensors in seats.

I like simplicity- but FDs are so simple, I'll keep mine. Although ultimately, I could be perfectly happy with 8 or 9 well-chosen gears.

OP, for your next project, could you make an FD that works on the non-tensioned side of the chain, and therefore could shift smoothly regardless of load? That might seem a next logical step.

Priority is definitely speed, bro, and nothing else.
In May, a Boone, N.C. event called the Black and Blue.
204 miles, 17,000 feet climb, three states. Ego won't get me to the finish there.
So I can't afford ideas that don't work. I'm not really the knock-about-town type.

To imagine one has an original idea for a bicycle:
Now that is self-delusion.
But very few of them, original or not, have been fully thought through.
That would include a great deal of what you are sitting on now. But
don't go start having night sweats about your pulley wheels, campag-man.
That is a sram issue, far as I know.
You're in the clear, dude.

Persistence in developing an idea is a worthwhile thing, always.
It builds tolerance for failure, at the very least.
It is certainly better than talking.

There's a few guys out there like you in cyber space gerry-man. Guys like you who don't understand the first or second law of thermodynamics and are constantly trying to invent perpetual motion machines...lol.
Hey, maybe your bike will be the human powered flying machine! All you need is mount a wing to the front.

I will look for your 1 X __ in next year's TdF. I am sure it will have caught on by then.
PS: I thought I heard you coming down the road where I live. I looked out the window and it was only a road grader running x-chained.

I have no issue with front derailure, not sure why you will gain 10 feet on anyone but ok. Saying that I truly believe one day we will all be subject to 1x15's.

Add Ferraris, Porsches, and a number of other cars with dual clutch transmissions, which essentially have 2 seperate manual transmissions side by side.

Smarty Pants