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When to replace these 6 bike parts

Swap out old parts at exactly the right time

by Nick Di Cristofaro

Many items on a bicycle will need to be replaced, eventually. Cyclists who are keen on keeping their rides in tip-top shape should know what the most common wear items are and when it’s time to replace them.


Brake pads are probably the most important wear item for obvious safety reasons. Most cartridge-type brake pads have wear indicators. Replace the pad when there’s about 0.5 mm of material from the line. Look out for unevenly worn brake pads or pads with excessive glazing. You can sometimes rescue glazed-over pads by lightly sanding or filing the pad surface. Disc brake pads should be replaced when less than 1 mm of friction material is present.

Chain, cassette and drivetrain

Having a chain checker is nice to have for monitoring chain wear regularly. Replace the chain when it’s approximately 75 per cent worn to prolong the life of the rest of the drivetrain. As a general guideline, replace your cassette after three chains. Replace rear derailleur jockey wheels and front chainrings when teeth become pointed
and/or hooked.


First, look out for any gashes, cuts or holes on the tread or sidewall. You can remove the tire and check the inside to see if the cut goes completely through. Some brands of tire have wear indicators to indicate when the tread has become ineffective. Look for dry rot and cracking. Squeeze the removed tire with your hand to check. If the tire is really far gone, you will see little cracks and cuts you wouldn’t normally see with the tire inflated.

Bearing surfaces

A rough running bearing means it’s time to replace or overhaul. Check bearing surfaces are in the bottom bracket and wheels. With the chain off of the chainrings, give the cranks a spin. If everything isn’t smooth and quiet, it’s time to pull it apart for further inspection. A wheel with cup-and-cone bearings that are running rough after adjustment should be taken apart and inspected. The cone threaded into the axle should be replaced if it’s pitted. If the race in the hub is pitted, then it should be replaced if possible. Unfortunately, this part is sometimes not replaceable, which means it’s time to replace the entire hub.


You can drastically improve your bike’s braking and shifting by simply replacing the cables and housing. Sticky shifting and slow brake lever return indicates that it’s possibly time for replacement. Corrosion on inner cables and moisture will cause excess friction resulting in reduced performance. Always replace any housing that is cracked or cables that are frayed. Replacing cables once a year is good preventative maintenance. I recommend to always use Shimano SP41 shift housing and preferably Shimano cables. This is one area in which a more expensive product is not better, so don’t be fooled by all the fancy cable kits out there.

Handlebar tape

Handlebar tape is sometimes simply a cosmetic feature. But, your hands rest on your handlebars 99.9 per cent of your riding time, so it makes sense to make this a comfortable place for them. For that fresh look, replace the tape when it’s torn or discoloured. Riding on the trainer can be really sweaty and really destroy bar tape. It’s a good idea to replace the tape after a winter on Zwift.