Whips and chains


Bicycle chains and chain-whip tools, that is. Why you should do a bicycle repair course.

The other day I did a little ride in the Western Cape with some colleagues and customers. Some guys were on the latest and greatest carbon 12-speed sub-10kg machines and some were on old-school 26-inch wheeled bikes. Yes they all had fun and nobody died. One guy, however, arrived at the rendezvous complaining his gears weren’t working properly. I’m no doctor, but I offered to take a look.

The conversation went like this:

Me: What’s up?

Him: I damaged the rear derailleur, so I bought a new one, and a new chain. The cassette is old, so the new chain slips, so I put the old one back. Now the shifting is terrible.

Me: Ok, let’s have a look, it’s not that hard to adjust gears.

So I fiddle a bit. I set the high limit screw and the low limit screw. I tweak the B-screw a bit. Cable tension looks ok, so I start shifting up and down the cassette, one click at a time. Wow this thing is terrible, I think. Shifts fine up one cog, then it takes 2 clicks of the shifter to move up one more cog. I check that the hanger is straight. It is.

After a minute of head-scratching it dawns on me. I count the cogs. There are 9. I look at the (new) rear derailleur. Shimano XT-M786. 10-speed. Eureka. The 9-speed shifter doesn’t pull the same amount of cable as the 10-speed derailleur needs. Incompatible.

Well, he rode like that, with inconsistent gears and clunky shifting.

bicycle chain

Like any good story, this one has a moral, actually more than one.

  1. Maintain your drivetrain, often. Buy a cheap chain-checker tool and replace the chain when it reaches 0.75% “stretch”. Your cassette and chainrings will last between 3 and 6 chains. That’s between 4500 and 9000km, approximately.
  2. Know about your bike and its various components. Is it Shimano or SRAM? Is it 8, 9, 10, 11 or 12-speed? This will determine what replacement chains you’ll buy as well as what your existing components will work well with when you have to replace a damaged derailleur, shifter, cassette, chain or chain rings.

So, either you can learn these things through trial and error, by solely relying on your bike shop, by watching random YouTube vids OR simply attend a bicycle repair course. It costs less than a major bike service and will give you the skills and confidence to be more self-sufficient and self-reliant.