Generations of cyclists have known that cross-chaining is A Bad Thing. It's one of those rules you get taught very early on. Ride with the chain on the small chainring (on the chainset, the component your pedals are attached to) and the smallest sprocket on the cassette (the cluster of cogs attached to the hub of the rear wheel) – as in fig 1 above – or on the large chainring and the largest sprocket – as in fig 2 – and anyone you're riding with is likely to alert you to the fact in seconds. People love to point it out.
But is cross-chaining really all that bad, or does it just get a bad rap? We asked some of the biggest component manufacturers for their views. You might be surprised at some of the things they said.
The most efficient chain line occurs when the chain is running in a straight line. This minimises friction. When you run big-big you're pushing an uneven power transmission to the rollers, plates and bushings, especially at the points where the chain line alters (the points where the chain meets the sprocket and the chainring). This uneven load causes extra friction which increases the wear on the chain and longer term leads to less than optimum gear shifting.
For these reasons Shimano recommends avoiding extreme gear positions.
Ben Hillsdon, PR Officer, Shimano Europe
Shimano says you should avoid running the chain in this big-big combination (above).
Cross-chaining is a practice to be avoided as it is less efficient than a straighter chainline (increased friction, less free motion of links etc).
We all might find ourselves cross-chaining during the heat of the battle during a race. However, we shouldn't make a habit out of it as there is generally a similar metric development gearing position available on a larger/smaller chainring.
Extreme chain crossing can add wear and tear on chainring and cassette teeth as the severe angle of the chain brings the external or internal part of the chain in direct contact with chainring/cassette teeth as opposed to a straight chainline which keeps friction to a minimum and limits contact to the rollers located on the axles of each chainlink.
Joshua Riddle, Press Manager, Campagnolo
At SRAM we love big-big. Amongst mechanics on the NORBA and Mountain Bike World Cup circuit (many years ago!), we called big-big the 'pro gear’, because professionals would ride it all the time, no matter what their mechanics told them. The same applies to pro road racers. They'll stay on the big ring as long as possible.
There are very good reasons to stay on the big chainring, even as far as the big sprocket:
• Chain management on rough terrain.
• Access to tallest gears without have to shift in front.
• Front shifts are slower than rear and much harder on the chain.
So we would encourage your readers to ride big-big if they like, as long as they don’t experience chain rasp on the front derailleur cage. SRAM 2x11 drivetrains, specifically the Yaw front derailleurs, are designed to accommodate this.
Very little efficiency is lost when cross-chaining. And in the case of big-big, minuscule efficiencies lost to cross-chaining are offset by efficiency gained because of larger bend radii for the chain. Better chain management and easier access to tall gears certainly outweigh any efficiency loss.
A few words on efficiency measurements. There are enormous differences between the efficiency measured on a loaded drivetrain and an unloaded drivetrain (what your hand feels when spinning the crank on a bike in a workstand). The sluggishness that cross chaining sometimes appears to cause on a bike in the stand disappears when the drivetrain is under load. It’s analogous to lubes in loaded and unloaded mechanical systems. Light oil generally feels better than heavy grease when a system is worked by hand, but when the system is loaded the heavier lube will be more efficient.
Similarly, cross-chaining is not a concern for premature component wear unless of course your chain is wearing through your front derailleur.
JP McCarthy, Road Product Manager, SRAM
In the last decade cross-chaining has become increasingly common with many people running the chain in the big chainring and big sprocket, especially with the advent of electronics which is much more permissive regarding cross-chaining.
This means that today's chains are subjected to much higher stresses than in the past. That’s why we decided to invest in the development of much stronger chains.
We have a stable supply of raw materials allowing us always to offer a product with a very high level of reliability and performance.
Here at FSA we understand well the importance of cross-chaining. Our latest introduction in this field is the 48/32 Adventure chainset. This is a new super compact standard that allows combination like 48/21 – 48/18. It’s a possible solution to avoid crossing because the chain works more linearly.
We will have this new range of chainsets available in 2017, from the carbon SL-K to our entry level Vero Pro.
Maurizio Bellin, General Manager, FSA
There's a range of views from the big brands, then; what do you think? Is cross-chaining perfectly acceptable? Or do you avoid it because of greater inefficiency and component wear and a higher chance of dropping your chain? Let us know your thoughts and experiences.
Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.