PSA - eBikes require more frequent maintenance

CloneWerks

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PSA - eBikes should get more frequent maintenance

NOTE: The following advice presumes an “average recreational rider” scenario. Any bike subjected to harsher conditions (and this often includes commuter bikes) should have at least a basic visual inspection before every ride.

Wheels:

There is a three-fold reason why eBikes normally have thicker spokes on the rear wheels and those are weight, torque, and speed. A “traditional” bicycle rear wheel was designed to work with a steady torque of around 50-60Nm with brief spikes up to the 110Nm range while supporting an average frame weight of about 9-11kg (20-25lbs) plus rider weight at an average speed of 16-19Kph (10-12mph).

An eBike rear wheel can be subjected to a steady torque state of 70-80Nm from the motor AND an additional 30-60Nm from the rider which puts us in the 100-140Nm range with a potential spike up to around 190Nm plus a heavier weight range from 14-36kg (30-80lbs) and an average speed of 24-27Kph (15-17mph).

That boils down to a 160 to 190% increase in stress on the rear wheel components versus a traditional bike.

What this means in terms of maintenance is that any eBike wheel hooked up to a motor needs far more frequent “spoke-checks” than the “once or twice a year” inspection of a traditional bike.

Current best-practice is to evaluate spokes every 100 miles.

Related to this, on a traditional bike you could damage/pop one or even two spokes and still reasonably continue to finish a ride. With an eBike this is a really bad idea as all of the additional stress could easily lead to a catastrophic wheel failure.

Chains/Gear-train:

If you waded through the numbers for the wheels then you can easily understand that eBikes that use a mid-drive system also put significantly more stress on their chains and gears. The general rule of thumb for a traditional bike was to replace a chain every 2,000 miles. At this time there is no general agreement on chain life for an eBike (especially a mid-drive unit) so monitoring is critical.

Current best practices for eBikes is to visually evaluate and lube your chain and gear-train after every ride. If you have a Mid-Drive system it is also strongly recommended that you buy a “chain-check” tool (the Park Tool CC-3.2 is considered excellent) and do a check on multiple points on your chain every 200 miles as a worn chain will cause a Mid-Drive system to wear on the cassette and crank at a drastically increased rate.

Brakes:

Current brake systems for eBikes are still mostly based on components designed for traditional bikes. Again we run into a serious difference in number if we do the math. Traditional average bike numbers come out to something like 20lb bike + 190lb rider (210lb) + 10mph = 951 Joules of Kinetic Energy to stop the bike. On an ebike the numbers are more like 70lb bike + 190lb rider (260lb) + 16mph = 3060 Joules of Kinetic Energy to stop.

This is a 220% increase in the energy you would need to dissipate in order to halt the bike, a task that is being performed by fairly “traditional” brake systems resulting in some really astounding wear rates especially for people who live in hilly areas. Informal surveys seem to indicate that average brake life for an eBike is around 500 miles but some riders have reported needing to replace in as little as 300 miles, far more quickly than the 500-1000 miles for a traditional bike.

What this means in terms of maintenance is that eBike brakes and rotors should be carefully checked every 300 miles for wear.

Personal note, I'm a big guy by any standards, my bike (Addmotor Motan) is a heavy beast, and I have a long 16% grade leaving my house. At 150 miles my OEM Tektro organic/resin brake pads are showing a good amount of wear and I seriously doubt I'll make 500 miles on them. When I replace them I'm going to switch from organic to sintered pads.

Forks and Frames:

Again this is down to the additional weight of an eBike. Simply coming off a 4” curb puts a lot more stress on the average eBike frame vs a traditional bike.

Current Best practice is to inspect the frame and forks of your bike for any signs of stress or failure every 300 miles paying special attention to the areas around the Head Tube, Seat Tube and Chain Stay.

This link gives a good tutorial on inspecting your frame: https://hobbybiker.com/how-to-inspect-a-bike-frame/
 

CloneWerks

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Update... This afternoon I watched a guy bounce hard off a curb and pop a rear spoke on a hub drive eBike. He stopped and looked at it, then throttled off on his merry way. He got about 300 ft further and his rear wheel just collapsed. It was UGLY!
 

HillAversion

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Good points, particularly for kit builders.
Keeping chains well lubed is essential, as are brake and gear shift sensors. And blasting over 4” curbs is just dumb. I think wear and tear on spokes and drivetrains can be minimized by only using low-level pedal assist and laying off the throttle. Those throttles can really stress the system.
 
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