Gear Cassette, time to change?

[withiniswithout]

Would you change this gear cassette? It has about 6,300 km on it. The shop said don't worry about it until the shifting is noticeably rough. The chain was replaced a couple of months ago, and I wish they had gone ahead and put a new gear set on at the same time.

The front axle and bearings have not been replaced. They are original, 8 years old, 18,650 km. I don't feel any noticeable side to side play, or hear noises from it. Is this a "run it till it fails" thing with no worries, or should I have the axle replaced just because of age and mileage?

Also, I am thinking about asking them to thoroughly clean chain and the gears and putting on a wax lubricant and switching over to this.

 

[Stefan Mikes]

The only real need to replace a cassette is if a new chain skips on some sprockets (usually the smallest ones) during the ride.
I said "a new chain". It is as noticeable as you cannot miss it. The old chain wearing the cassette gradually damages it without any signs, so you wouldn't notice anything until the cassette were destroyed.

Now, there are two ways of approach by the riders:

• If the cassette is relatively inexpensive, both the cassette and the chain are replaced at the same time
• If the cassette is expensive though, the rider would occasionally inspect the chain stretch with an inexpensive chain wear gauge, and replace the chain whenever the chain stretch went past 0.5%.

6,300 km on an e-bike is a lot, your chain is probably stretched past 1%, and your cassette needs to be replaced together with the chain.
However, the wear is high on mid-drive motors and a way less prominent on hub drives. I suggest you get yourself a chain checker, for instance Park Tool CC-3.2 and check the chain. 0.5% stretch? The cassette is fine. 1%? The cassette is surely damaged.

 

[withiniswithout]

W

The only real need to replace a cassette is if a new chain skips on some sprockets (usually the smallest ones) during the ride.
I said "a new chain". It is as noticeable as you cannot miss it. The old chain wearing the cassette gradually damages it without any signs, so you wouldn't notice anything until the cassette were destroyed.

Now, there are two ways of approach by the riders:

• If the cassette is relatively inexpensive, both the cassette and the chain are replaced at the same time
• If the cassette is expensive though, the rider would occasionally inspect the chain stretch with an inexpensive chain wear gauge, and replace the chain whenever the chain stretch went past 0.5%.

6,300 km on an e-bike is a lot, your chain is probably stretched past 1%, and your cassette needs to be replaced together with the chain.
However, the wear is high on mid-drive motors and a way less prominent on hub drives. I suggest you get yourself a chain checker, for instance Park Tool CC-3.2 and check the chain. 0.5% stretch? The cassette is fine. 1%? The cassette is surely damaged.

View attachment 192778

When the chain was replaced it was near the outer limit of "stretch" as measured with a chain checker. Thus, based on your feedback (thanks!) I am going to get the gears replaced. The off the shelf cost of the gear cassette is around 45 euros, and the labor cost is only around 20 or 30 euros.

 

[Base]

Estrattore pacco pignoni shimano

Chiave estrattore Eleven per pacco pignoni shimano

www.cingolanibikeshop.com

https://www.cingolanibikeshop.com/bike-hand-frusta-smontaggio-pacco-pignoni.html

for the labor cost you could do it yourself.

 

[withiniswithout]

Estrattore pacco pignoni shimano

Chiave estrattore Eleven per pacco pignoni shimano

www.cingolanibikeshop.com

https://www.cingolanibikeshop.com/bike-hand-frusta-smontaggio-pacco-pignoni.html

for the labor cost you could do it yourself.

Si, although it's worth it to me to just bring it to the shop and have them look it over. Many times they've found an issue that wasn't on my radar, such as a cracked wheel. My mechanical aptitude is stupendously low and I eff things up quite often. The gear cassette tool is cool.

 

[indianajo]

Sprockets 4 & 5 are worn out. You may be able to buy those individually but it takes a special cassette tool to unscrew the retainer. Also takes a 1/2" breaker bar, a used chain to wrap the large sprocket and a large pliers to hold the large sprocket against the torque. I have found on used ones, they are usually rusted up and will not come apart. So a new cluster then becomes necessary.
Front axle, I open it up and lube the balls about every 5 years or 10000 miles. I use petroleum jelly, as NGLI #2 automotive grease is too thick and might slow me down.

 

[withiniswithout]

Thanks, I'll get it changed in the next week or so. Oddly it's shifting quite smoothly.