Monday, 28 November 2016

Daily Drivetrain Care

Dirty Drivetrain

How often do you lube your chain; after each and every ride, once a week or only when it starts to squeak? And what about cleaning; how often should the chain be degreased? Did you know, you're lovely bicycle performance will turn to be poor and cost you more when you doesn't care the chain, sprocket and chainring.  

Let’s start by looking at what drivechain wear actually is, beginning with the chain. Each link in the chain consists of two inner and two outer plates, a pair of rollers and pins to hold it all together. There are also bushings that the rollers sit on, but on a modern chain these are formed as part of the inner plate. You’ve probably heard people refer to ‘chain stretch’. This is when the individual chain components wear; the pins, rollers and the bushings are ground away. A tiny amount of play in these parts means the chain gets longer—that’s the stretch that people refer to. 

Top, chain wear within limit, better change the chain

As the distance between each pin grows, the other drivetrain components wear to match the ‘stretched’ chain. With this, the ‘valley’ between each tooth grows wider and the teeth themselves become more pointed with a slight hook on one side. A chain can be quite worn and it’ll continue to function, so long as the chainring and cassette are worn to match. The problem occurs when you decide it’s time to fit a fresh chain, as it won’t mesh well with the worn teeth.

Worn Sprocket, time to replace it

If the drivetrain is too worn, the new chain may run rough and will suffer accelerated wear. If the teeth are really worn, the new chain will slip under heavy pedalling load—a potentially dangerous issue. It’s certainly possible to fit a new chain and retain your existing drivetrain components. The key is to replace the chain before it wears too much. To do this you can track the chain wear with a purpose built tool. Chain checkers come in many different styles and you’ll find wideranging opinions on which is best. Some devices provide a simple ‘good’ or ‘replace’ indication of the wear while others show the wear incrementally and let you decide how far you’ll push it.

With 1X drivetrains it’s equally important to keep a close eye on chainring wear, as it cops all of the wear, all of the time. They aren’t the most expensive item so it’s good practice to fit a new one every now and then; a new ring with your third replacement chain is fairly safe.

Wiping the chain

Tracking chain wear is one thing but minimising it to begin with is of equal importance. Start by wiping the chain over after every off-road ride. Backpedal whilst holding a rag around the chain and apply some lube to assist with flushing any crud from within the rollers. This works best with a lighter viscosity lube. Keep wiping and lubing until the rag still looks reasonably clean after coming in contact with the chain. You want the lube inside the pins and rollers, not on the outside where it’ll attract dirt. By following this post-ride cleaning regime, you’ll have less muck build-up and you’re less likely to need a full drivetrain degrease. 

Chain soak in a tub of degreaser

In time however, the drivetrain will need a more thorough going over. The best way to do a full degrease is to remove the chain completely and soak it in a tub of degreaser. It’s vital that you get any residual degreaser back out of the chains. With regular care you will be more familiar with how your chainring should look and you’ll be better equipped to spot drivetrain wear.

Problems to Watch for When Cleaning

Tight Links 
These are links that no longer bend smoothly. To spot them, pedal your chain slowly backwards and watch as each link passes through the tight turns of your rear derailleur. Most are caused by dirt or corrosion between link plates; these can be fixed by cleaning, lubricating and a little flexing back and forth. Others are the result of improper pin installation or serious chain damage. Damaged chains should be completely replaced. 

Chain Stretch 
As chains wear, they become longer. This is called stretch, which is a misnomer because nothing actually stretches. Chains lengthen as wear occurs between the rollers and the link pins. This creates slop or free play that leads to gear "skipping" in some cases. It also causes extra wear and tear on your chain rings and rear cog teeth.

Clean and ready to roll

Mountain Biking Australia Nov-Jan 17

Ride On!

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