How do you tell when it is time to replace a crankset? Is there a mileage limit to go by or years? Thanks
The crank arms will usually have a useful life at least as long as a frame ie. unlimited unless damaged. Chainrings may need to be replaced if they are worn, but I’ve never had to replace chainrings even on 10 year old bikes. Bottom brackets (bearings) may need to be replaced every 1-5 years depending on wear and the weather conditions/maintenance they have been subject to. I have only ever replaced bottom brackets but never chainrings or crank arms.
The crank arms will usually have a useful life at least as long as a frame ie. unlimited unless damaged. Chainrings may need to be replaced if they are worn, but I’ve never had to replace chainrings even on 10 year old bikes. Bottom brackets (bearings) may need to be replaced every 1-5 years depending on wear and the weather conditions/maintenance they have been subject to. I have only ever replaced bottom brackets but never chainrings or crank arms. I need to replace the drive train every year.
cog chain and chainring.
Sure 5 years… just sitting in the box wears out cranks… doh.
Or maybe they get better as they age? Does the ozone break down the carbon matrix? Is sun exposure a factor?
How do I tell? When they break usually. Some last forever, and some not long at all… especially if you crash a lot. I have around 35k miles on my IRD carbon octalink cranks. I’ve considered refinishing them, but not getting rid of them.
I expect my SKF Isis bottom bracket to last 100,000 km.
Chainrings normally last me a year on the commuter bike (6,000km/year)
I have yet to break an aluminium crank* but I have seen ones cracked at the pedal thread
*thinking about it, I actually did break a crankarm when I was 12 on my Raleigh racer. I must have been putting out some serious watts.