Chain rubbing on front derailer

[fossyant]

Ohhh 'internet wisdom', I like that.

 

[Yellow Saddle]

Ohhh 'internet wisdom', I like that.

Present party's wisdom excluded, of course.

 

[simongt]

Always been a disciple of not cross chaining; 'rule of threes' as I call it. However, it's surprising how common it is among cycling folk who you would maybe expect, by their mount and attire, should know better, but obviously appearance and kit has no correlation whatsoever to their understanding of care of the drivetrain - !
Saw a manny last summer who had some fancy MTB that had a single chainwheel and an 11 speed cassette. He insisted that chainline wasn't an issue - !

 

[fossyant]

Always been a disciple of not cross chaining; 'rule of threes' as I call it. However, it's surprising how common it is among cycling folk who you would maybe expect, by their mount and attire, should know better, but obviously appearance and kit has no correlation whatsoever to their understanding of care of the drivetrain - !
Saw a manny last summer who had some fancy MTB that had a single chainwheel and an 11 speed cassette. He insisted that chainline wasn't an issue - !

1x is the thing on MTBs now. 12 speed at the back too. Also eye wateringly expensive cassettes

 

[youngoldbloke]

Always been a disciple of not cross chaining; 'rule of threes' as I call it. However, it's surprising how common it is among cycling folk who you would maybe expect, by their mount and attire, should know better, but obviously appearance and kit has no correlation whatsoever to their understanding of care of the drivetrain - !
Saw a manny last summer who had some fancy MTB that had a single chainwheel and an 11 speed cassette. He insisted that chainline wasn't an issue - !

Isn't the 11 (or 12) speed cassette the same depth as a 10 speed, and the chain narrower and more flexible, so the chainline effect less?

 

[Ajax Bay]

A scraping FD is actually a blessing because it warns you of you doing illegal stuff with the chain. Put it out of its pain and shift.

This.
Compact with 10sp cassette set to 2.1 degrees allowed - four combos are out of angle: large chainring to largest two sprockets and small chainring to smallest two sprockets. Noise from the FD cage will give the rider the top tip to shift chainrings.
gear-calculator.com
1x with 11sp cassette set to 2.1 degrees allowed - out of angle: chainring to the largest and the smallest sprockets.
Using all 11 sprockets requires 2.6 degrees. Though there's no front derailleur, using top or bottom gear requires some cross chaining.
gear-calculator.com

 

[Jenkins]

SRAM Yaw front dreailleur with wi-fli gearing - no rubbing when 'cross chaining'.

 

[Ajax Bay]

SRAM Yaw front dreailleur with wi-fli gearing - no rubbing when 'cross chaining'.

Point I was trying to make is that 1x set ups require cross chaining in top and bottom gears, or at least as much cross chaining as a large to large or small/small would be with a compact chainset. SRAM's Yaw design elegantly avoids cage/chain interference while keeping the cage reasonably narrow (for crisp chainring shifting).

 

[Nigelnightmare]

Isn't the 11 (or 12) speed cassette the same depth as a 10 speed, and the chain narrower and more flexible, so the chainline effect less?

Just because it has LESS EFFECT doesn't mean it has NO EFFECT at all.

 

[youngoldbloke]

Just because it has LESS EFFECT doesn't mean it has NO EFFECT at all.

Very true. I didn't say NO effect. I'm suggesting that (perhaps) a 1 x 11 or 12 setup may suffer no increased ill effects from cross chaining than (say) a 2 x 9 or 10, given the flexibility of the 11/12 speed chain. Any one know? Yellow Saddle?

 

[Yellow Saddle]

Very true. I didn't say NO effect. I'm suggesting that (perhaps) a 1 x 11 or 12 setup may suffer no increased ill effects from cross chaining than (say) a 2 x 9 or 10, given the flexibility of the 11/12 speed chain. Any one know? Yellow Saddle?

I haven't done any measurements on 1 x systems but I think they will be better than 2 X systems. Reason being, that the single chainring can be placed exactly in the centreline for a perfect chainline in the middle sprocket at the rear, with 5 sprockets either side of it. Contrasted to a 2 x system the chainline falls between the two front sprockets, biasing the chainline upwards and downwards at the rear. In the extreme, a cross-chain would be worse than in an extreme in a 2 x system.

 

[screenman]

Always been a disciple of not cross chaining; 'rule of threes' as I call it. However, it's surprising how common it is among cycling folk who you would maybe expect, by their mount and attire, should know better, but obviously appearance and kit has no correlation whatsoever to their understanding of care of the drivetrain - !
Saw a manny last summer who had some fancy MTB that had a single chainwheel and an 11 speed cassette. He insisted that chainline wasn't an issue - !

I hope you took the time to educate him, maybe he was new to cycling.

By the way an 11speed single ring works great.

 

[robgul]

Yep - all the above comments about cross-chaining apply - this is the text from the (home created) "manual" for how we do it from my shop

Rob
=============
Gear set up

Rear derailleur

1 Barrel adjuster at minimum
2 Chain on largest chainring and smallest sprocket - align jockey wheels with limit screws
3 Adjust cable to be just taut (on default spring for mech)
4 Chain on smallest chainring and largest sprocket - align jockey wheels with limit screws
5 Fine tune with barrel and/or inline cable adjuster

*** check hanger alignment

Front derailleur

1 Loosen cable, inline adjuster at minimum
2 Chain on smallest chainring and largest sprocket - 1mm on inner (frame) side of cage from chainring - adjust with limit screws
3 Adjust cable to be just taut
4 Chain on largest chainring and smallest sprocket - 1mm on outer (non-from) side of cage from chainring - adjust with limit screws
5 Fine tune with inline cable adjuster

 

[Ajax Bay]

I'm suggesting that (perhaps) a 1 x 11 or 12 setup may suffer no increased ill effects from cross chaining than (say) a 2 x 9 or 10, given the flexibility of the 11/12 speed chain. Any one know? Yellow Saddle?

I haven't done any measurements on 1 x systems but I think they will be better than 2 X systems. Reason being, that the single chainring can be placed exactly in the centreline for a perfect chainline in the middle sprocket at the rear, with 5 sprockets either side of it. Contrasted to a 2 x system the chainline falls between the two front sprockets, biasing the chainline upwards and downwards at the rear. In the extreme, a cross-chain would be worse than in an extreme in a 2 x system.

On a 1x11 system you need to tolerate a 'cross-chain' angle of 2.6 degrees to use the largest and smallest sprockets (which of course one needs).
On a 2x11 system you need to tolerate a 'cross-chain' angle of 3.0 degrees to use the large/large and small/small (which of course one doesn't need).
On a 2x11 system you need to tolerate a 'cross-chain' angle of 2.5 degrees to use all sprockets (in either chainring) except the large/large and small/small combos. (which one doesn't need).
On a 2x11 system you need to tolerate a 'cross-chain' angle of 2.3 degrees to use all sprockets except the top two large/large and and the bottom two small/small combos (which one might wish to avoid)
http://www.gear-calculator.com/?GR=...1,24,27&UF=2135&TF=100&SL=2.1&UN=KMH&DV=teeth
(In)Efficiency of cross-chaining (and use large/large in preference to smaller chainring/middle sprocket)
For a given ratio, using the large chainring and a large (even the largest) sprocket (say 50/25) is more efficient (eg 11t > 21t = +3%) than using a smaller chain ring and a smaller sprocket (say 34/17). This advantage dwarfs the cross-chaining issue (from an efficiency PoV).
"Human Power" Number 50 Spring 2000 $5.50 TECHNICAL JOURNAL OF THE IHPVA
"the effect of chain offset can be estimated.
These data were obtained with
the 52–11 and 52–21 configurations in
the offset condition while those in the
long-duration tests were taken with no
offset. Comparing the data for 60 RPM
100 W tests shows that the offset lowers
the efficiency by, at most, 0.5%
when measurement precision is considered.
Additionally, if the efficiencies are
normalized by efficiencies measured in
the 52–15 configuration (both sets of
data were obtained with no offset),
then it appears that the offset has a
negligible effect on efficiency."

 

[simongt]

WOT - ???
Think I'll stick with my five speed Sturmey - !