bigmark100

The chain on my Bike broke the other day. On taking it to the bike shop - they have said that the cassette , and crankshaft and chain all need replacing.
Ive done about 2000kms on the bike,
is it possible that after this mileage I already need all of this replaced.
Its a Shimano 105 set.

should I get a second opinion - who go withwhat the shop says.

Deanster04

Second Opinion.

KevinF

I don't think you could possibly ruin a crankset in 2,000 kms if you were trying to. Chains do wear out, and as they wear out, they wear out the cassette and the chainrings with them. The chainrings have so many teeth to support the load though that they take a long time to wear out. If you're good about your chain maintenance you can easily get a thousands and thousands of miles out of cassette though. Sheldon Brown has an excellent article on how chains wear out, etc. here: https://sheldonbrown.com/chains.html.

Bottom line: your shop is full of it.

HillRider

Unless the broken chain mechanically damaged the crank and cassette there is no way they would be anywhere near worn out in less than 2000K (1600 miles). Your shop either saw a lot of damage or is really trying to gouge you. Under normal conditions, a 105 crank and chainrings will last 40,000K under a strong rider and even longer under most of us. Certainly take it to another shop for an appraisal.

BTW, again unless it was improperly installed (which is my guess) or was damaged by an outside obstruction, the chain should never have broken in that distance either.

operator

Broken chain barring damage from external causes or manufacturing defect is almost always installation error. I would NOT trust your LBS... yet. Start by measuring your chain wear and tell us what this number is.

slowandsteady

Replace all that every 2000kms?!?!??! Boy that would sure get expensive.

myAWESOMEbike

There are several ways to tell whether your drive train is ready to replace, first check to see if your chain has stretched (park has a tool, or you just measure the length of two links and it should be an inch rivet to rivet). If it has stretched, replace it...easy. Usually you will find that your middle (in the case of a triple) or your lower (in the case of a double) chainwheel in the front wears more because you are in it more. When the chain comes on or off the teeth it wears a little bit on the side that it pulls from and eventually the teeth become 'shark tooth'. If this is the case, the chain will not engage the teeth all the way and perhaps should be replaced. This is the same for the cassette. Shifting will also be affected, especially in the rear, if the teeth are worn. To check, see if your chain will sit on 10 or so teeth without a gap between the chain and the teeth.

TO11MTM

Cassette life can vary a lot depending on cleanliness of drivetrain, gearing you push.

I killed a chain and cassette in 1000 miles once on a 9 speed setup, because I typically only rode in one gear on it for 90% of my ride.