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Tim Hall

Guest
Location
Crawley
Does cross chaining have a moral dimension?

Once upon a time, in the early days of multispeed freewheels there may have been good technical reasons to avoid it. But things have since moved on.

Flat tyres, cross chained, bso, slack chain, poor technique, etc, dont care so long as they are riding bikes.
But I draw the line at pie plates.







(no I don't acksherly)
 

GrumpyGregry

Here for rides.
I'll offer another reason for avoiding cross chaining.

If you are large-large and you need a lower gear then, probably on lower than normal cadence and higher than normal force straining up a hill, you're faced with a sudden 'dump' of 32% using the FD (going from 50 > 34). Sure you can double shift (eg 27 > 21) on the RH STI simultaneously, but if you're that capable, look ahead and be skillful: drop on to the smaller chainwheel ahead of need and give yourself the option of several sprocket shifts up or down from mid-cassette.

If you are small-small and you need a higher gear then, you're faced with a sudden 'rise' of 47% using the FD (going from 34 > 50). Sure you can treble shift (eg 12 > 15) on the RH STI simultaneously, but if you're that capable, look ahead and be skillful: step up to the larger chainwheel ahead of need and give yourself the option of several sprocket shifts up or down from mid-cassette.

Maybe there's a 'real men don't use the small chainring' syndrome coming into play here. I suggest the only rationale for not changing from one chainring to the other in good time is the laziness/ cba factor (underpinned by denial of the physics and/or the effect on chain durability and efficiency). And that's not a rationale; it's irrational.
if you are in one gear and you need another gear you change gear. You may even change gear more than once on a particular journey. It really isn't more complex than that.

For 99.9999% of folk riding bikes the physics and the theoretical effects of wear and efficiency don't enter into it. Only Cyclists care about that sort of anal nonsense.

Just ride your bike.
 

Ajax Bay

Guru
Location
East Devon
Original post:
running big front to big back ( or small to small) puts lots of lateral stress and can cause excessive wear, but my question is what would be the max recommended number of cogs to go up to if on big front? ( am on 105, 11 spd)
Recommendation: use the first 9 but not the largest 2 sprockets (reasons explained up thread).
Once upon a time, in the early days of multispeed freewheels there may have been good technical reasons to avoid it. But things have since moved on. . . . dont care so long as they are riding bikes.
Good technical reasons to avoid cross-chaining remain and these have not 'moved on'. What are these 'things'? I'm happy people are riding bikes too, but not sure that's relevant.
 

outlash

also available in orange
+1

You can over-think these things. I think of cross chaining as being a bit like having your flies undone. It's not something that you go out to do, and if you notice, you rectify the situation. Habit makes sure it doesn't happen too often.

If you're riding a double, then use the little ring for lowish gears and the big ring for high-ish gears. Change when the terrain/situation demands. That will generally keep you from cross-chaining. Life's too short to be constantly looking back at your cassette and counting sprockets.

A little bit of cross-chaining on a double now and then isn't going to wreck your bike. Riding for long distances cross chained will do it no good, but you'd have to actively go out and decide to do that to have any real effect.

This. I'm sure most of us have been in the position of being on the last section of a climb, finding out you're almost out of gears in the big ring. To drop down to the small ring and 3, maybe 4 changes on the rear will result in a loss of rhythm, momentum and possibly balance if you're crawling up a steep like I normally do.
I'm sure hammering on mile after mile cross chaining doesn't do the drivetrain much good, as using anything to it's extremes isn't, but surely going big/big for that short distance to crest a climb is preferable is it not?
 

Ajax Bay

Guru
Location
East Devon
a loss of rhythm, momentum and possibly balance if you're crawling up a steep [hill] like I normally do.
If you're crawling up a steep hill 'as normal' why on earth would you try to do that in the large chainwheel? Are you trying to make it extra difficult?
but surely going big/big for that short distance to crest a climb is preferable is it not?
Yes, in the scenario you describe, into which you've forced yourself, that's preferable. Until you don't make it; then you're stuffed and faced with banging down onto the small chainwheel and banging the chain too, and thinking to yourself "why didn't I change down when I had the chance." Changing down (FD) before getting into that scenario is preferable, is it not?
 

outlash

also available in orange
If you're crawling up a steep hill 'as normal' why on earth would you try to do that in the large chainwheel? Are you trying to make it extra difficult?

Yes, in the scenario you describe, into which you've forced yourself, that's preferable. Until you don't make it; then you're stuffed and faced with banging down onto the small chainwheel and banging the chain too, and thinking to yourself "why didn't I change down when I had the chance." Changing down (FD) before getting into that scenario is preferable, is it not?

Without knowing how you climb, if it's a climb I don't know I'll use my usual 80% effort rule. Now, 9 times out of 10 I'll winch myself up and I'll ride on, but there is the odd time where I'll find myself running out of steam and I'll be in that position. So while I could be thinking 'why didn't I change down when I had the chance', I'll be more likely thinking 'it's only 100 metres or so, let's just get up it. Spin to win etc etc'. While I might have 'forced' myself into that 'situation', it's not something I'm going to worry about.
 

DaveReading

Don't suffer fools gladly (must try harder!)
Location
Reading, obvs
Worth pointing out that if you chain is the correct length, the right type, your RD, and other transmission components are setup properly and matched correctly not least to your gear range, you will probably get away with big-big.... forever. ;)

Yes, I suspect most people would have been able to deduce that from my post.
 

Dogtrousers

Kilometre nibbler
Yes, I suspect most people would have been able to deduce that from my post.
But the problem wouldn't be cross chaining per se, but riding with the wrong length chain. Although I do believe that some competitive MTBers do knowingly ride with short chains, but they need to knoow what they're doing.
 

Dogtrousers

Kilometre nibbler
I managed to crash my derailleur into my wheel coming up a hill under power practicing for a TT. Big front to biggest rear. Made quite a mess, broken hanger, broken deralier, bent chain, stretched cable, couple of bent spokes and buckled wheel, oh the shame.
Lesson learned, I always leave one cog spare now unless I'm really not under load then it's ok to use.
I don't see how cross chaining would put your mech into the spokes. That sounds to me like your low limit screw was not set properly. Surely cross chaining would, if anything, pull the mech slightly away from the spokes.

I'm not advocating it, mind.
 

GrumpyGregry

Here for rides.
Greg, you seem to quote 'moral dimensions' a lot, when no one has mentioned any such thing. I wonder why that is? I believe something, you believe something different. Now off you go and ride your bike.
good things v bad things = using the language of morality for choices that have no moral dimension.

rental bike today btw. cba to put mine on the train.
 

GrumpyGregry

Here for rides.
Good technical reasons to avoid cross-chaining remain and these have not 'moved on'. What are these 'things'? I'm happy people are riding bikes too, but not sure that's relevant.

Why is my 11 speed chain so much more laterally flexible than the one on my fixed or, indeed, hub geared bike?
 
Why is my 11 speed chain so much more laterally flexible than the one on my fixed or, indeed, hub geared bike?

The chain is a different thickness

As you increase the number of cogs in the same space, the distance between becomes smaller, and to tuck into that space the chain width decreases.

This is achieved with narrower rollers, but also narrower plates. narrower means a loss of lateral stiffness

This picture shows a single speed chain, and a multi speed chain next to each other

Figure%202.jpg
 
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