ArgoMan

"...cross chaining consequences will not be mitigated by the non-existent 1x chainring that was invented to split the difference in position of the 2 existing rings."

Okay, this is where I get lost. I don't think I have any issues with "chain retention duties", as the chain has never jumped off the large chainring. I ride fantastically flat and well paved desert roads, so I've got that going for me. But can you elaborate on "cross chaining consequences" for my education? Thanks!

zandoval 

I understand. I have a rear freewheel that goes from 14 to 34 teeth. Do I really need more then that? I usually only use about 4 gear combinations on non-indexed friction shifters. I could probably get away with a 38 tooth single ring on my crank and ditch my front derailleur.

Ok... Maybe 36... I am getting old and my rides are Up and Down...

base2 

The inboard ring is intended for the inboard half of the cassette.
The outboard ring is intended for the outboard half of the cassette.
Small/small & Big/big are considered no-no's because the angle the chain travels is taxing on the components. It simply causes excessive wear from excess articulation. Big/big places undue stresses jockey wheels. The higher tension can erode them prematurely or even crack them. Chains tend to wear faster, from the side-to-side offset angle. The chainring teeth will become shark toothed sooner because of friction with the inner edge of the plates instead of interfacing with the chain roller square-on. Undue stress is placed upon the hanger and derailleur springs. In extreme cases like with triples there is a risk of breaking a chain link. (ask me how I know) And in the case of poor component choice, there is the risk of the rear derailleur and hanger hanger being ripped off the bike.

In small/small the shifting pickups on the adjacent chairing will rub and try to pick up the chain. The derailleur is much more relaxed and may not provide enough tension to retain the chain. And some of the above remains equally true. But it is definitely the less destructive condition.

In either condition you'll lose a couple of watts efficiency of power to the wheel while having straighter chain alignment options that yield a comparable gear ratio

The bike will unhappily run "cross-chained" because the penalty is permanent destruction. The full measure of safety margin is being used when you do so. But it really isn't meant to ride that way frequently or for any duration. Derailleur rub, even with perfect adjustment and proper trim is almost guaranteed.

A 1x ring splits the difference between the 2 keeping things better aligned.

Groasters

I'll give you a few upsides. I recently switched to 1X on my winter road bike, a bike typified by its weather protection (ie full length mudguards/fenders) and the fact that you don't need to clean it regularly. But, when you do, it is invariably filthy and anything that can help to make this easier and quicker is very welcome.

This last point pursuaded me to try 1X, after yet again spending ages cleaning the front mech and crankset, the latter being possible to achieve properly only by removing the chainrings, cleaning them and refitting.

So, here we are:

1. MUCH easier and quicker to clean the crankset and the whole BB area around where the front mech usually is.
2. No front mech to purchase/install/clean/service/adjust!
3. Weirdly liberating to not have to change gear up front nor trim the mech nor even have to think about it at all, just go up and down the cassette. The usual double change when approaching a hill where you click down to the small ring and simultaneously drop onto a smaller sprocket out back is just a task no longer needed.
4. Saves a wee bit of weight (said the weight weenie).
5. A bit quicker to remove and refit the chain when cleaning the bike.
6. Never a crosschaining concern.
7. Never the annoying sound of front mech rub.
8. Never a derailed chain (with those narrow-wide teeth profiles).

I'm a convert. I use 40t chainset with 11-34 and I have been surprised that I've not been irritated by the bigger ratio gaps nor the fact that 40-11 spins out before 50-11 does but in the real world on a winter training bike 40-11 is actually fine. And 40-34 is not far off 34-28 for a low ratio.

mstateglfr 

Wasn't suggesting there is never a situation where 1x is beneficial. Just saying that based on what the OP posted for their situation, I don't see a benefit.

ArgoMan

Okay, all. I took my bike out today (it's a second bike) and am now determined to switch to a 1x. Here's my plans. It's presently set up with the older Sora crankset (FC 3550.) That's a 5 bold chainring. I want to switch the front chainring to a Wolftooth 110 BCD. The Sora is a 9-speed. So I also now want to swap to an 11-speed cassette and replace the rear derailleur with a 105. I think the difference between my bike equipped with the newest 105 and the one with the older Sora is really bigger than I wanted to admit. The 105 is so quick and effortless, so smooth. the Sora is fine. But I'm just realizing how nimble and nice the bike is. It deserves a better drive train. Does anyone have any thoughts as to where I'm going wrong with my idea? Thanks and Merry Christmas!

base2 

Presumably because your bike came with Sora from the factory, your free hub is a Shimano standard 8,9,10 (mountain 11) free hub. So a cassette of any of those speeds will work. There is a "road" 11 speed 11-34 cassette that will work because it sits in the crossover point between roads biggest cassette and mountains smallest.

The deciding factor is the free hub bodies length as it compares to the cassettes depth. Look for verbage similar to: "Compatible with GS cage rear derailleurs, the HG800-11 cassette offers low climbing gears perfect for mixed surface riding. It is compatible with both 10 and 11-speed freehubs." &/or "Spacer required for 11 speed freehubs." The spacer is the tell that indicates the cassette has the short depth your 8,9,10 speed frehub requires.

After that, as long as the latest generation 11 speed derailleur is mated to a 11 speed road shifter you should be good to go. The derailleur max capacity is more capable in the latest 6,7,8000 series & GRX. The older 11 speed 5800, 6800 series topped out at 11-32 with the long cage derailleur.

t2p

^^^^

because of this above - the uncertainty etc - I transformed a Sora 9 speed bike into a Frankenstein Tiagra 4700 10 speed bike (4725 brake/shifters and 4770 hydraulic brake calipers - with GRX RX810 crank, Ultegra R8000 RD, and XTR M970 11-34 cassette)

I did not want to change the rear wheel or rear hub or free hub … did not want to be limited with cassette (size) …

later began to second guess the decision to go 10 speed (10 speed has been dead for some time) - but the bike really works well and now no remorse with 10 speed … and I was able to get the Tiagra 4700 components (new take off) for much less $$ compared to current end / higher end stuff

I have two other 11 speed bikes (SRAM 1x and Shimano 6800) - this 10 speed bike works as well as those bikes … actually rear shifts better than the 6800 11 speed bike (not as sensitive / quirky with cable adjustment)

still not sure I would recommend an upgrade to 10 speed instead of 11 speed - but it did work well for me

ArgoMan

Thanks, base2 and t2P. The bike is built off of an older "Motobecane." I place the name in quotes because it's a BikeDirect frame, not an original French Motobecane. But it's an excellent aluminum frame made by Kinesis in Taiwan. 7005 aluminum, very stiff, racey geometry. The head set is an older 1.5 caged bearings Cane Creek. Works beautifully. Makes me believe that fancy headsets are overrated. The bike originally came with 3x Tiagra about 18 years ago. I had a Sora 3550 group put on it during Covid. It's never worked 100%, so I assume my local LBS didn't do the greatest job installing it. Just noticed for the first time yesterday that it will not shift to the smallest rear gog. I have a set of cheap Superteam carbon rims on it; the UCI approved version. Very few miles on them and I believe they came ready to handle up to an 11 cassette. I think they're very nice.

So, do either of you see a problem going with the Wolftooth BCD 10, new 11-speed cassette, the appropriate 105 rear derailleur and shifter? I may even switch out the front brake caliper to 105, as I find them to be excellent. Any thoughts are greatly appreciated.

ArgoMan

"I'm a convert. I use 40t chainset with 11-34..."

Thanks Groasters. I'll be doing this. My bike is for roads, mainly flat. No hills whatsoever. I plan on switching from a 9 to 11 cassette. My present large chainring is 50T. Any recommendation on what size chainring I should be looking to install, toothwise? I see a large range out there.

Groasters

Unlike you, I live in a hilly area, so the 40t works for me, with that wide range cassette. I'd think you could possibly go to 42t or 44t, but what I'd do if I were you is look at which ratios you tend to favour (you said there are four cassette ratios that are most used) and try to replicate these with your new set up, but err on caution in allowing a lower gear or two for hills, even if they're occasional.

Enjoy your new set up!