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For cranks designed for 2x, are the two rings in the same position as the little and middle on a 3x chainset? Or slightly further out?
[url= http://www.oneupcomponents.com/pages/understanding-chainline-for-optimal-1x-conversions-boost-and-non-boost ]http://www.oneupcomponents.com/pages/understanding-chainline-for-optimal-1x-conversions-boost-and-non-boost[/url]
May help
2.5mm further out on the wife's 2x SRAM cranks. Stupid piece of design too.
Am going to replace with a stripped down triple to allow full gear range from the "middle" ring.
Dedicated 2x cranks, along with direct mount FDs, have to be one of the most irritating piece of unnecessary redesigning of modern drivetrains. grrr.
Shimano 10 speed ones were not - the chain rings were spaced sort of in between the 3 chainrings on a triple without having either chain ring dead center. Triples were better for singer ring setups.
Don't know about 11 speed ?
On Shimano's recent 2* cranksets, the centre chainline is in the middle of the two chainrings, usually at around 48.5mm. This make the outer ring the default choice for single ring as the chainline will be ~50mm which is usually perfect for the cassette.
Am going to replace with a stripped down triple to allow full gear range from the "middle" ring.
So you're saying the chain line on the larger ring and largest sprocket was too much?
I'm more concerned about the ex-middle ring and smallest sprocket. If I were to remove the big ring and fit a bash (yes, I am that far behind the times) then I'd need 32/11 as a top gear, and that rubs currently.
Am going to replace with a stripped down triple to allow full gear range from the "middle" ring.
So you're saying the chain line on the larger ring and largest sprocket was too much?I'm more concerned about the ex-middle ring and smallest sprocket. If I were to remove the big ring and fit a bash (yes, I am that far behind the times) then I'd need 32/11 as a top gear, and that rubs currently.
Yep. Currently the chain climbs off the inside of the 32t front ring when in 36t sprocket at the rear. Not all the time but often enough to be infuriating for her as it usually happens under load i.e the climbs where you would be in this gear. It may work better with a larger front ring but I wouldn't bet anything on it.
My 3x9 setup as double and bash is as you describe you want. I get a bit of rub but it is from the dérailleur. I use a 3x front shifter and have set it so that I can move the mech over far enough to stop the rub but not enough to shift to the big ring/bash position on the 3rd click. I don't spend much time in that gear so it may not bother me as much as you.......
Currently the chain climbs off the inside of the 32t front ring when in 36t sprocket at the rear
Surely you shouldn't be in that combination in the first place? Use the little ring?
If it works for 1x10 why shouldn't it work for 2x10?
The only thing currently different is chain line.
If it works for 1x10 why shouldn't it work for 2x10?The only thing currently different is chain line.
You've answered your own question.
I mean, why would you use it when you have a smaller ring and could get a better chainline?
Severe chanlines are never a good idea for several reasons, one of which you've discovered.
OK, I'm now well confused. Are we arguing at cross purposes?
Quite possibly.