Chain line on 1x drivetrain

[Duckfoot1606]

Ok, let’s set the scene. I’ll freely accept I’m a Luddite and still use both a triple crank on my Audax bike and a compact double with an 11-34 cassette on my everyday steed. But I see lots of article copy about these new fangled 1x drivetrains, something like a 42 on the front and an 11 speed 11-40ish on the rear. I understand the rationale behind a wide gear range, my question is that the chain line must be absolutely tortuous when running towards the extremes of this set up, so what are they like in use from the perspective of noise and durability of the chain/cassette?

Thanks in advance.

A

[salar55]

All depends what you want, on MTB /ROAD chain has an easier life changing at the back compared to the front. Some people only renew when the chain skips on standard setups. Chains have they not improved compared to the 5-6-7 ones.

[salar55]

Campag have 13 on the rear now for the Gravel bikes.

[Ian H]

There's nothing 'Luddite' about wanting decent close ratios.

[grams]

my question is that the chain line must be absolutely tortuous when running towards the extremes of this set up, so what are they like in use from the perspective of noise and durability of the chain/cassette?

The answer is obviously "within acceptable levels", as with any trend that makes it past early-adopter over-enthusiasm.

The same as tubeless won't kill you and Di2 and hydraulics won't inevitably leave you stranded.

[rogerzilla]

The cassettes aren't appreciably wider than an 8-speed but the chains are thinner.

[zigzag]

1x works fine regarding noise and durability. a tiny bit less efficient and noisier at the extremes, but it's not where you'd be spending most of the time riding at. i did most of my early audaxes on 1x, before it was even a thing.

every setup has its compromises, choose what's important to you and accept the downsides.

[nuttycyclist]

There's nothing 'Luddite' about wanting decent close ratios.

Many years ago, when I bought "proper bike", I got the LBS to supply it with a triple instead of double at the front, and a suitable cassette at the back.  Chain was a decent strong one, not thinner.

That bike served me many thousands of miles, and I really need to pump the tyres up and get back on the road.

I had low gears for slogging up hills with panniers (I was chatting in a Bristol hotel once with a chap doing Lands end to John o Groats, he was running a double not triple, with partner in car to carry luggage, and already struggling - He couldn't believe I'd ridden a 300km DIY audax there for a meeting, and was doing another 300km  DIY back the next day).

I had high gears for downhills or flats with tailwind/group riding. 

I knew when to flick gear changes on both front and back to get the close ratios required.  Need to go up half a gear?  fine, up two on the back and down one on the front.   etc.  Just get to know the mappings.

[bobb]

I wouldn't bother with 1x for a road bike. The only reason (the modern) 1x exists is so MTB manufacturers could get rid of the front mech and do whatever they wanted with the whole seatpost/BB/chainstay area - which can get pretty weird on full-sus bikes and bikes with massive "plus" tyres. They may claim "No more front mech to go wrong", but that's not the reason they did it.

1x on a gravel bike - fine. Can make more room for voluminous tyres. But a road bike - nah, it's all marketing hype.

[rogerzilla]

The biggest downside is the risk of dumping the chain during shifts.  So you may need a clutched rear mech, narrow/wide chainring or even a chain catcher.  I say "may" because some bikes get away without any of these.  A strongish rear mech spring can be just enough to tip the balance in your favour.

[FifeingEejit]

I wouldn't bother with 1x for a road bike. The only reason (the modern) 1x exists is so MTB manufacturers could get rid of the front mech and do whatever they wanted with the whole seatpost/BB/chainstay area - which can get pretty weird on full-sus bikes and bikes with massive "plus" tyres. They may claim "No more front mech to go wrong", but that's not the reason they did it.

1x on a gravel bike - fine. Can make more room for voluminous tyres. But a road bike - nah, it's all marketing hype.

Aye, the amount of times I've had that quoted at me and can counter it with
Front Mech Failures = 0
Rear Mech Failures = 5

[grams]

Recent generations of cable Shimano front mech have been near impossible to adjust satisfactorily, at least on some frames.

Also if you count "front mech set to the wrong fuxxing chainring once again" as a failure, which I do, then in rolling terrain they're the worst part of a bike.

Both are also solved by Di2 synchro shifting.

[lissotriton]

I've had several front mechs fail on my mountain bike. Mostly due to them clogging up with mud and other crud. Maybe because I don't change gears at the front very often.

[bobb]

I've had several front mechs fail on my mountain bike. Mostly due to them clogging up with mud and other crud. Maybe because I don't change gears at the front very often.

But like I say - that wasn't MTB manufacturers motivation for getting rid of them. If they were worried about knackering mechs, why do they still have rear mechs? Rear mechs with super long cages that get ripped off at the merest sniff of a rut, rock or loamy berm!

[lissotriton]

If they were worried about knackering mechs, why do they still have rear mechs? Rear mechs with super long cages that get ripped off at the merest sniff of a rut, rock or loamy berm!

Because there aren't any better alternatives. And most of these new rear mechs are lower profile, so less likely to get bashed. Plus the fad for bigger wheels...

[FifeingEejit]

I have somehow succeeded in making 3 SRAM MTB rear mechs rotate their cage entirely past the stop thus rendering bugger all chain tension at the trail side.
At least rocks were involved with the 2 destroyed Shimanos.

[mzjo]

Ok, let’s set the scene. I’ll freely accept I’m a Luddite and still use both a triple crank on my Audax bike and a compact double with an 11-34 cassette on my everyday steed. But I see lots of article copy about these new fangled 1x drivetrains, something like a 42 on the front and an 11 speed 11-40ish on the rear. I understand the rationale behind a wide gear range, my question is that the chain line must be absolutely tortuous when running towards the extremes of this set up, so what are they like in use from the perspective of noise and durability of the chain/cassette?

Thanks in advance.

A

No not Luddite Luddite is using 1xn where n= 4 or 5 (could be 3 but certainly not 6).

I would think (from observation and experience) that front mechs seem to require much stronger springs than rear mechs which does play hell with the shifters. As Grams says, "solved by Di2" (also solved by non-indexed friction shifters - the luddite solution). I have one bike with a 1x transmission, it's the folder with 1x6 which works just fine and not noisy, I see no reason why 1x 11,12 or 13 should be particularly noisy but knicker elastic chains would put me off (but I'm a luddite at heart!)

[quixoticgeek]

The problem with 1x on a road bike, is it just does not have the range. My bike has a 28/38 front, and an 11-40 cassette. I'm using Shimano Di2 with syncroshift, which effectively gives me 13 years. 13 gears that are spaced pretty damn near perfectly (for me at least). The lowest gear has a ratio of 0.7, which gives me an effective gear of about 1.5m. Whilst the highest gear is about 3.45, and gives me 7.6m. This means that at 90rpm in the highest gear I can do 40kph, and in the lowest gear at 60rpm, I'm doing about 5.7kph. That's a good range, and for the cycling I'm doing, if I'm doing more than 40kph, it means it's down hill and I should stop pedalling and save energy.

It's interesting that one of the world tour teams had a 1x setup a couple of years back, and the riders hated it. Just didn't meet their needs. Which kinda pisses over my original theory that it was only good for big strong mens pro riders who could climb in such a large gear.

1x on a mountain bike makes sense from the whole "where the hell do we put the front mech on this haunted devil geometry", but on a road bike or a gravel bike, I just cannot understand the advantage. I have to conclude it's a fashion thing...

I have ranted at great length that I believe that the gears offered on most production bikes are too big. I am really pleased that Shimano brought in 30-46 on the GRX range, but it's such a shame you can't use it with anything bigger than a 34 on the back, giving you a ratio of 0.833 and a gear of about 1.8m which is about 6.6kph at 60rpm. That extra 1kph on a 10% gradient could easily be 20+watts. If the GRX 30/46 could work with an 11-40 cassette it would be perfect.

Alas.

Anyway, you've all heard my rants before, thank you for letting me get it off my chest once more.

J

[rogerzilla]

If they were worried about knackering mechs, why do they still have rear mechs? Rear mechs with super long cages that get ripped off at the merest sniff of a rut, rock or loamy berm!

Because there aren't any better alternatives. And most of these new rear mechs are lower profile, so less likely to get bashed. Plus the fad for bigger wheels...

In the 90s, MTBers in the know used road mechs.  An experienced rider would never select big-big or small-small and, on the upside, you got more ground clearance, lighter weight and slicker shifting.

[DuncanM]

It's interesting that one of the world tour teams had a 1x setup a couple of years back, and the riders hated it. Just didn't meet their needs. Which kinda pisses over my original theory that it was only good for big strong mens pro riders who could climb in such a large gear.

AquaBlue had 1x11, because the bike didn't have anywhere to put the front mech, and their equipment sponsor didn't do 1x12. The riders hated it because of the big jumps in the middle that were necessary for them to have gears to pedal up and down mountains. The mechanics hated it because they had to continually swap chainrings and cassettes so as to try to give better gearing. Campag now offer 1x13, so it will be interesting to see if that makes its way from gravel back to road.
Even CX has a mix of 1x and 2x at the pro level (seems to be Shimano riders on 2x and Sram on 1x).

[salar55]

I have an old school 1* bike for dirt roods and tracks no problem with catching the rear mech on rocks or tree stumps it's a Rohloff. Going to try the bike packing with a lighter bike ( Rohloff has a lot of the bikes weight on the rear), looking at a. Orro or a Cannondale topstone.

[nuttycyclist]

If they were worried about knackering mechs, why do they still have rear mechs? Rear mechs with super long cages that get ripped off at the merest sniff of a rut, rock or loamy berm!

Because there aren't any better alternatives. And most of these new rear mechs are lower profile, so less likely to get bashed. Plus the fad for bigger wheels...

In the 90s, MTBers in the know used road mechs.  An experienced rider would never select big-big or small-small and, on the upside, you got more ground clearance, lighter weight and slicker shifting.

That reminds me, I must sort the seized headset out on my MTB .    Rigid MTB, massive knobbly tyres, and Shimano 105 race gears.

Some riders on an old Dun Run recalled me overtaking them as I chased down the YACF group on my backup bike (I trashed the audax bike 500 yards from home and had to go back to restart the trip to the station).    Apparently the road noise was what alerted them to my approach, overtake, and disappear into the distance.

[Defblade]

I've just gone from an old triple audax bike (with the inner chain ring dropped 2 or 4 teeth from the original) to a new 1x road bike.

It's SRAM with the 11 speed 11-42 cassette on the back; I've dropped the front from 44t to 42t to give a 1:1 as it's hilly around here.
The old bike has a slightly lower bottom end (about 2 gear inches less) but is heavier and expected to pull luggage at times.
The new bike is for pure good weather fun so I'll take the slightly higher bottom end; at the top end I'm still pushing as I go past maybe 35mph-ish so I'm not missing the decrease there.

Do I miss the tuneable flexibility of the triple? Not at all. I'm finding the 1x simple and natural. It may be a fashion thing, but it also works just fine.

I was thinking about it tonight as I did 12miles/1400ft climbing, and I did come up with 2 caveats for my enjoyment of 1x:

1) As I say, it's hilly around here. I spend a lot of time going from gear 3-ish to gear 8-ish as I go up and down (or down and up!). I'm rarely pushing along flats looking for the perfect gear for my favourite cadence.
2) On the subject of cadence, I'm happy with quite a large range - while I aim for 90rpm, I'm fine with anything from about 80 to 105 or more. In fact, the top big figure on my Bolt is set to cadence to remind me to aim for 90. But being ok away from that probably helps disguise the slightly larger jumps in the gears.



Oh, and I think 1x looks good/clean, too 

[quixoticgeek]

I've just gone from an old triple audax bike (with the inner chain ring dropped 2 or 4 teeth from the original) to a new 1x road bike.

It's SRAM with the 11 speed 11-42 cassette on the back; I've dropped the front from 44t to 42t to give a 1:1 as it's hilly around here.
The old bike has a slightly lower bottom end (about 2 gear inches less) but is heavier and expected to pull luggage at times.
The new bike is for pure good weather fun so I'll take the slightly higher bottom end; at the top end I'm still pushing as I go past maybe 35mph-ish so I'm not missing the decrease there.

Do I miss the tuneable flexibility of the triple? Not at all. I'm finding the 1x simple and natural. It may be a fashion thing, but it also works just fine.

I was thinking about it tonight as I did 12miles/1400ft climbing, and I did come up with 2 caveats for my enjoyment of 1x:

1) As I say, it's hilly around here. I spend a lot of time going from gear 3-ish to gear 8-ish as I go up and down (or down and up!). I'm rarely pushing along flats looking for the perfect gear for my favourite cadence.
2) On the subject of cadence, I'm happy with quite a large range - while I aim for 90rpm, I'm fine with anything from about 80 to 105 or more. In fact, the top big figure on my Bolt is set to cadence to remind me to aim for 90. But being ok away from that probably helps disguise the slightly larger jumps in the gears.



Oh, and I think 1x looks good/clean, too 

You're very lucky if you can climb in a gear with 1.0 ratio. As i outlined above. I have 0.7 as my lowest, and even then on the steepest hills, I'll still walk.

If you had a 30 tooth chain ring that's 0.71, which is close enough. Now consider what top speed you'd get with a 30:11 gear...

If 1x becomes the norm, it's going to be the less strong riders who are most adversely affected.

J

[Defblade]

You're very lucky if you can climb in a gear with 1.0 ratio. As i outlined above. I have 0.7 as my lowest, and even then on the steepest hills, I'll still walk.

If you had a 30 tooth chain ring that's 0.71, which is close enough. Now consider what top speed you'd get with a 30:11 gear...

If 1x becomes the norm, it's going to be the less strong riders who are most adversely affected.

J

I wouldn't call myself strong (except in very short bursts)... Currently 93kg so what I am is slow up hills! My FTP of 227 is, I believe, very very average for an untrained rider.
That 80rpm minimum I'm happy with quickly falls away to 60rpm I'm not happy with as the grade % runs into double figures.

Playing Devil's Advocate a bit:
The top speed on 30:11 would be around 24mph @110rpm which would see me be starting to spin out on slight downhills/false flats... but would a "less strong" rider be getting there anyway? And maybe they could accept freewheeling at that sort of speed and above for having such a low climbing gear?

I can't really see 1x becoming the norm if I'm honest. I do think it can probably suit, with some fine tuning for circumstances, far more of the "average" amateur riders than will ever be persuaded to try it, but it does force more limitation than a 2x or 3x... both stronger and weaker riders will still find more use in multiple chainring set-ups - see the comments above regarding pros and their mechanics.


Personally, I spent a fair bit of time drawing out gear inch charts for each of my triple's rings, then really taking note of which gears I actually rode in, and plotting all that against a chart for the proposed 1x gearing on the new bike. I was nervous about the change!
I found that:
The lowest 3 gears were very close between the 2 set ups. I use these quite a lot.
I never used the very highest gear as my old bike didn't like running in it after changing from 7 speed to 8 and I don't go fast enough to spin out the one below anyway (or I'm tucked, freewheeling, and probably going "wheeeeeee"  ); the one below was equal to top on the 1x.
I don't change perfectly stepwise (changing both chain and cassette to access the gears in ratio order) on the triple. On anything other than decent hills, I tend to stay on the chain ring I'm on and just change the cassette until I run down/up to maybe 2 or 3, or 6 or 7, at the back and then change chain ring if the road is obviously staying that way. So the jumps between gears as I use them are much the same as the jumps on the 1x set up.

Taking all that, I felt that although going to 1x costs me theoretical ratios, it shouldn't make much difference to the way I actually ride the 24 ratios I had on my old bike.
And it doesn't, and I like it