Is crossing-chaining possible with a single chainring

[CharlesF]

I was pootling along to work and for some unknown reason started thinking about cross-chaining. I found the website byclechainrings.com which had this definition - "Cross Chaining - We defined Cross Chaining (above) as the condition where the chain is running across the drivetrain centerline. In truth, it's more like running to extremes across the drivetrain centerline."

I understand what happens and why it should be avoided, but I'm unclear, does cross-chaining happen if you have a single chainring.

 

[Smokin Joe]

Not to the same extent because the chainring is aligned with the middle of the cassette and the angle is not as great when it is running to either end sprocket as it would be on a multi chainring set up.

However, I personally don't think cross chaining on a double causes anywhere near the increased wear that people make out. The chain is made to flex sideways and I have never seen anyone do any research into chain wear to see if it does make any difference to chain life. I suspect you are not talking very many miles if it does.

But when repeated often enough on the internet all sorts of myths become facts.

 

[Dogtrousers]

However, I personally don't think cross chaining on a double causes anywhere near the increased wear that people make out. The chain is made to flex sideways and I have never seen anyone do any research into chain wear to see if it does make any difference to chain life. I suspect you are not talking very many miles if it does.

But when repeated often enough on the internet all sorts of myths become facts.

That's my opinion too, but I have no evidence either way. It's pretty low on my list of things to care about. I don't do it intentionally, but whenever it happens (normally big-big) I get a bit of front mech noise reminding me it's not entirely happy, so I rectify matters.

 

[Sharky]

Maybe, but this year I have been experimenting.

Through the winter commutes, I got fed up with the double 34/54 chain rings. Always needing to change up/down and in the dark not quite knowing which gear I was in and often running into the small/small combination and rubbing on the front changer.

So I ditched the front changer and replaced the 34 with a 40, so effectively running a 1x9 drive. But I left the 50 on, but I was getting rubbing when on the tiny cogs.

So I removed both chain rings and replaced them with a 40 narrow/wide chain ring and optimised the chain length for the 40, by taking out a couple of links and bingo. The drive now works across the full 1x9 range, with a 13-26 cassette.
All very smooth.

I suspect the future will see 1x11 drives taking over and the compact chainrings will be history.

Cheers
Keith

PS my TT bike has been running with a single chain ring and not had any cross over problems for over 20 years, however I only have a single sprocket at the back as well!

 

[Smurfy]

Chain lines have got progressively worse over the years as more sprockets were added.

On a five speed, the cassette width is 24mm, so the worst cross chaining would be 12mm.
On eleven speed, the cassette width is 40mm, so the worst cross chaining would be 20mm.

This is a good reason to stick to 7 or 8 speed, the other reason being that the chain is full 3/32 width, and can take more of a beating, unlike the super narrow 9, 10 and 11 speed chains.

http://www.sheldonbrown.com/cribsheet-spacing.html

Edit: The third reason to use lower sprocket counts is that more sprockets means more dishing = weaker rear wheel

 

[ianrauk]

However, I personally don't think cross chaining on a double causes anywhere near the increased wear that people make out.

Agree 100%. I used to never cross chain as it was the given advice I found yonks ago. I now cross chain on my compact double commuter all the time and have found that the chain and cassette last just as long as when I didn't cross chain.

 

[fossyant]

It's not a big issue generally in the short term, if you accidentally cross chain, but long term it will wreck the drive chain faster.

If you are using a single front chain ring, it does need to be bang on middle though.

 

[earlestownflya]

modern chains are just fantastic pieces of kit,incredible what you can do with them.

 

[CharlesF]

Not to the same extent because the chainring is aligned with the middle of the cassette and the angle is not as great when it is running to either end sprocket as it would be on a multi chainring set up.

However, I personally don't think cross chaining on a double causes anywhere near the increased wear that people make out. The chain is made to flex sideways and I have never seen anyone do any research into chain wear to see if it does make any difference to chain life. I suspect you are not talking very many miles if it does.

But when repeated often enough on the internet all sorts of myths become facts.

Thanks for explains, now that you have I can see it, which I couldn't when thinking about it on the ride.

A range of views, and interesting, I try not to cross train but do so usually in traffic when I'm not paying attention. I get more noise if in small/ small which reminds me to sort it out.

 

[Levo-Lon]

The 11 speed chain on my cube is 5.4mm wide and as its single up front i dont see or hear the chain being stressed.
It works faultlessly even going from 36 to 42.

 

[Spoked Wheels]

Edit: The third reason to use lower sprocket counts is that more sprockets means more dishing = weaker rear wheel

Interesting comment. I find that I have to use more tension on the drive side spokes to be able to get sufficient tension on the non drive side spokes. It's ok with H plus Son Archetype rims but I don't like it with Open Pro rims to mention one rim. All thanks to 11 speeds.

 

[Smurfy]

Interesting comment. I find that I have to use more tension on the drive side spokes to be able to get sufficient tension on the non drive side spokes. It's ok with H plus Son Archetype rims but I don't like it with Open Pro rims to mention one rim. All thanks to 11 speeds.

You can calculate the tension difference if you know the angle of the spokes and amount of wheel dish. As a general rule, the greater the dishing, the higher the disparity between spoke tension on DS and NDS, although varying the number of spoke crossings will modify this, as it changes the angle of the spokes.

Edit: And greater disparity in spoke tension between DS and NDS makes weaker wheels.

 

[Spoked Wheels]

You can calculate the tension difference if you know the angle of the spokes and amount of wheel dish. As a general rule, the greater the dishing, the higher the disparity between spoke tension on DS and NDS, although varying the number of spoke crossings will modify this, as it changes the angle of the spokes.

Edit: And greater disparity in spoke tension between DS and NDS makes weaker wheels.

Yes, it's possible to calculate the tension difference, in fact there is one spoke length calculator that I know of that also calculates the tension difference for you.

I don't think that varying the number of spoke crossings will modify the tension difference, the bracing angle remains the same.

In practice I have a good idea of what kind of tension I want for my DS which will give me an acceptable tension for the NDS. With greater dishing it's now necessary to increase the tension on the DS to have an acceptable tension on the NDS. I can only see more wheel problems in the future. If you don't have enough tension you have a weak wheel but if you have to increase the tension, because of the greater dishing with 11 speeds then some rims will be cracking. I heard the other day that Open Pro rims are suffering from a higher rate of failure due to cracks, I think it may be the 11 speeds hubs that need more tension on the DS that are causing this unusually high rate.

 

[Smurfy]

Yes, it's possible to calculate the tension difference, in fact there is one spoke length calculator that I know of that also calculates the tension difference for you.
Haven't seen that one before. Do you have a link?

I don't think that varying the number of spoke crossings will modify the tension difference, the bracing angle remains the same.
Maybe it only works on high-low hubs with different flange diameters on DS and NDS. These hubs were designed for different numbers of spoke crossings on DS and NDS to try and even out spoke tension.
Try it on the spoke length calculator you mentioned.
1. Set the same number of spoke crossings for DS and NDS
2. Set different numbers of spoke crossings for DS and NDS.
3. Compare tensions for 1 and 2.

In practice I have a good idea of what kind of tension I want for my DS which will give me an acceptable tension for the NDS. With greater dishing it's now necessary to increase the tension on the DS to have an acceptable tension on the NDS. I can only see more wheel problems in the future. If you don't have enough tension you have a weak wheel but if you have to increase the tension, because of the greater dishing with 11 speeds then some rims will be cracking. I heard the other day that Open Pro rims are suffering from a higher rate of failure due to cracks, I think it may be the 11 speeds hubs that need more tension on the DS that are causing this unusually high rate.
Eleven speed is great for TdF, who really do need close ratios to optimise their cadence/speed relationship. But they also have pro mechanics and spare wheels following them everywhere. For the rest of us, I'd say 7-8 speed was the optimum combination of gearing choice and keeping the dishing to a reasonable level. Of course manufacturers and bike shops love eleven speed, because they charge a premium for a product that doesn't last as long.