Chain Wear on Electric Bikes

Hi Richard here from eBike Sussex, here is a short article about chain wear on electric bikes and some things you can do to slowdown chain stretch. We have been selling ebikes for long enough to know that chain stretch is inevitable, and kind of annoying! We have some amazing stretch proof chains, most of our ebike specific chains are triple stretch proof.  So you will get longer from our aftermarket chains than the factory fitted ones that most electric bikes come with.

It is FREE for us to check your chain for chainstretch, we also have a nifty chainring wear tool. Bring your bike in and we can check whilst you wait and advise if you need a replacement and based on your odometer reading and usage how long your chain should last you. We recommend checking your chain for stretch every three months. This is FREE in store whilst you wait, or we can sell you a chain checker.

So why is the chain so important, and why does it stretch? The chain is transferring the energy from your pedal stroke and the motor (on the crank drive ebikes we sell) to the rear wheel. Sometimes this is through a gearing system too.

So you have your pedal force, which can be your whole body weight if you stand on the pedal. You also have the motor assistance, which can be over 300% on some of our models. Finally you have the gear you are in, which can be either harder or lighter stress on the chain depending on if it is a higher or lower gear.

Phew! Hope that makes sense!

So if you pedal 500 miles on an ebike in 300% assistance you have actually worn the chain to a 2,000 mile mark. Because of this we usually anticipate a customer changes their chain at the 450 mile mark for one of our triple stretch proof models or extra stretch proof depending on the gear system you run. We stock these chains at all times for your convenience.

What happens if you don’t change your chain when it stretches?

Well this is a great question, you will basically start to wear the cassette and front chainring faster because a stretched chain will touch the teeth on the cogs in a different position and will therefore rub. After a while the cog’s teeth will look pointy and sharp like shark’s teeth. You can also get chain suck which really is a dangerous issue as the chain can bunch and can lock the wheels of the bike. This is another reason that we take chain wear so seriously.

To prevent chain wear on electric bikes you should do some or all of the following:

  • Lubricate the chain and gear system regularly.
  • Try and change to a lower gear before you come to a stop, so when you pull away there is less strain on the chain.
  • Get your chain checked for stretch regularly to reduce the need to replace your chainset and cassette cogs.
  • If your bike has a recommended gear indicator like our Bosch eBikes, don’t ignore it! Change gear when it says to get a longer battery range and to reduce chain and cog wear.
  • Have a Stretch Proof Chain fitted for extra durability, we have a range of ebike specific chains in stock. Visit us for details.

Fell free to contact us to book your ebike in for a service or repair if you have chain stretch. Also if you have just purchased a second hand electric bike, or have accomplished quite a few miles on your ebike, bring her down to th store so we can check for chain stretch. With new cogs and a chain you will have a much smoother ride, gear change and better power transfer.


Electric Bike Repair & Service Specialists

eBike Sussex