Can someone explain to me e-bike maintenance

[hellen]

Hi everyone,
Great topic! E-bike maintenance can seem overwhelming at first, but once you get into a routine, it’s pretty straightforward. I’ve been riding electric bikes for a while, and here’s what I’ve found to be essential:

1. Battery Maintenance
2. Chain & Drivetrain
3. Brakes
4. Tires & Suspension
5. General Checks
Would love to hear what everyone else does for maintenance! What's been your worst maintenance challenge yet?

 

[gromike]

The devil is in the details, ain't it?

 

[Stefan Mikes]

The devil is in the details, ain't it?

Indeed. The first question to be asked is: Is the e-bike in question an inexpensive online or a premium product bought at an LBS?

 

[Base]

just some random tips,

You could buy a "special" tool from an UK brand to be able to backpedal with a clutched mid-motor to clean/lube etc of the drive train. You could also use a cheaper and "better" solution and that would be a Wera Stubby or Hultafors Stubby bit holder tool. That dose a better job and you have a good tool to drag along a ride. Or just put a rubber sleeve around an Y-tool.
you would stick this tool in the chaingring bolt and use the cranck placed against this tool to backpedal and move the chain/cassette for cleaning.

Do not use a pressure washer on your bike, it will cause issues. (open door I know)

Clean your bike before working on it, than you already had your fingers and eyes around your bike so you already know what could be the issues to work on. And also a clean bike is easy to work on.
I do use polish wax to keep the bikes nice and clean, just be ware of the rotors....

Invest in a workstand, this really saves a lot of time and hassle, or workout a way to hoist you bike of the floor using a lift or system with hooks and rope/tension straps. For longer road trips I always bring a few tension straps to attach gear to my bike but also so I can work on a bike by hanging it in the air. Mostly used on other peoples bikes.... you can always find a spot to lift the bike, trees, door frame etc.

Replace any worn-out bolts.... to many times as a pro I had to get crappy bolts out of bikes...

Get a list of torque specs for your bike's bolts and use a torque wrench.

Cheers

 

[spokewrench]

Invest in a workstand, this really saves a lot of time and hassle, or workout a way to hoist you bike of the floor using a lift or system with hooks and rope/tension straps. For longer road trips I always bring a few tension straps to attach gear to my bike but also so I can work on a bike by hanging it in the air. Mostly used on other peoples bikes.... you can always find a spot to lift the bike, trees, door frame etc.

Replace any worn-out bolts.... to many times as a pro I had to get crappy bolts out of bikes...

Get a list of torque specs for your bike's bolts and use a torque wrench.

I've had 3 e-bikes at once, but seemed to me that on 29 days a month, a stand would just be in my way. I don't even need a step stool to reach the rafters in my carport. That made suspension the obvious choice. I bought these.

https://www.amazon.com/dp/B07FX6L3NN

For each end of the bike, I used 2, about 2 feet apart. Run a rope through one, run it under lift point on the bike, and tie it off on the other eye screw.
Now I needed a way to secure the bight, where it would hang out of the way and wouldn't come loose accidentally. These work fine.

https://www.amazon.com/dp/B08RRQ16JN

When I'm not hanging a bike, I've got a couple of ropes neatly out of the way.

Torquing beyond the yield point will wear a bolt out. I've always torqued by feeling the elasticity in a fastener, occasionally checking with a torque wrench. That didn't work on the front axle of my Aventon because I couldn't feel the elasticity. I downloaded the specs. Many looked absurdly high. Often, they gave two figures. The second could be twice the first. Huh????

Apparently, American dealers wanted specs, so Aventon had somebody write down how many Nm it took to break loose various fasteners. That's not legitimate. They said 40 to 45 Nm for the M8 x 1 crank arm bolts. I knew that was far more than I applied by feel. Several youtube shows recommended using a torque wrench to apply about 45 Nm to M8 x 1 crank arm bolts when in fact they did it by feel.

All the modern bicycle bolts I remember have been class 8.8. In that class, an M8 x 1 takes 25 Nm, nor 45. Amazon has pages and pages of replacement M8 crank arm bolts. Maybe that's because so many are being damaged by following bicycle manufacturers' specs.

A set of ISO 2936 standard arm hex socket keys makes it simple. When a toolmaker designs a bicycle part, he'll specify a bolt with a socket for the size key designed for the required torque. I slowly pull the key tight until I'm at the maximum pressure I could comfortably maintain for 5 minutes.

 

[Base]

a few years ago a bigger tool brand had a test bench on the eurobike, to let bike-mechanics check their ability to determine if one could indeed gues the torque they use on a bolt. So they put a series of m5 and m6 bolts next to eachother wiht a torque measuring device underneath the setup. Using your discribed method you could fasten 5 bolts per size to check how close you could come to the bolt spec. Values all over the chart, nothing even close to what it should be.

Besides that, the toque spec is mostly concerning the material your are screwing the bolt into. And yes, in the bikeshops where I worked I've seen to many bolts worn-out which took us time to get them out.

On most DU's the crankshould be tightend at 35Nm, in a JIS BB the crancks go on 40 Nm, only Sram crancks go on with 50Nm, Cassette and centerlock lockrings also 40Nm, postmount bolts in general at 7Nm (between 6,8 and 7,4 Nm for most brands) so not that many values to remember.

And indeed, I am in the bike bussiness for almost 30 years now.(Trained in a differrent branche where would tighten bolts at 400Nm+... So bike tech is easy)

Hanging bikes under a carport is obviusly a perfect solution.

https://si.shimano.com/en/pdfs/dm/RAFC010/DM-RAFC010-02-ENG.pdf

Bosch BNI cranckbolts go between 40 and 60 Nm, just came upin my brain.

https://support.ethirteen.com/hc/article_attachments/360091979171

 

[teskow]

Dorkyman,​

I fully agree with you on solvent stripping away the lubrication from the bearing surfaces of a chain. The solvent has little if any lubricating quality to it so to get new oil/lube into those bearings the new lube would have to strip away the solvent before it can get in and lubricate the bearing surfaces. Would you strip all the oil from an engine bearings to clean it each time you oil change? Think how long it would be before the new oil reached the oil striped bearings. I know there is the thought that one should wash the grit and grindings from the deep internal bearing surfaces of the chain. But how to effectively do that I believe is difficult if not impossible. Maybe an ultrasound cleaning will do it but then you still have to displace the cleaner from the bearing surfaces buried deep inside the chain before oil/new lube can get there. Some have recommended using compressed air to clean a chain but I believe that only drives the crud deeper into bearing/sliding parts. Yes it looks beautiful clean when you do that especially when it has some solvent on it before blowing it dry.

 

[spokewrench]

a few years ago a bigger tool brand had a test bench on the eurobike, to let bike-mechanics check their ability to determine if one could indeed gues the torque they use on a bolt. So they put a series of m5 and m6 bolts next to eachother wiht a torque measuring device underneath the setup. Using your discribed method you could fasten 5 bolts per size to check how close you could come to the bolt spec. Values all over the chart, nothing even close to what it should be.

Besides that, the toque spec is mostly concerning the material your are screwing the bolt into. And yes, in the bikeshops where I worked I've seen to many bolts worn-out which took us time to get them out.

On most DU's the crankshould be tightend at 35Nm, in a JIS BB the crancks go on 40 Nm, only Sram crancks go on with 50Nm, Cassette and centerlock lockrings also 40Nm, postmount bolts in general at 7Nm (between 6,8 and 7,4 Nm for most brands) so not that many values to remember.

And indeed, I am in the bike bussiness for almost 30 years now.(Trained in a differrent branche where would tighten bolts at 400Nm+... So bike tech is easy)

Ten years ago I had a Nissan whose lug bolts required 60 ft pounds. When it came back from a shop, I needed approximately 250 foot pounds to unscrew them. The mechanic was concerned with speed. He wanted to be sure they didn't come loose. As long as he didn't strip the bolts or snap them off, it was fine with him. Bicycle mechanics could be in the same boat.

The principle of torquing lug bolts is to take up elasticity so that the elasticity will keep it tight, but not to go beyond the point where the elasticity stiffens sharply because now you could permanently deform the threads, causing them to loosen more easily. I'd never used a torque wrench on those bolts. This time, I tightened them by feel, put on a torque wrench, noted where the handle was on the tire sidewall, backed off a quarter turn, and tightened until it read 60. The handle was in the same position as before I'd backed off.

I tried it on a Cadillac from the 1950s. It used lug nuts instead of lug bolts. They were SAE instead of ISO but required the same size socket. This time, the required torque was something like 100 foot pounds, which shows you can't estimate torque by the size of the fastener. Again, I torqued by feel, then used a torque wrench to back off and bring it to the specified torque. Again, the position of the handle showed that I'd been accurate.

The polyethylene chain guard on an Abound is screwed to brackets of sheet steel. As you say, the material you're screwing into matters, and I find Aventon's specs way too high. An ISO 2936 3mm hex socket key makes it easy.

You posted torque specs for crank bolts that aren't M8 x 1. The spec for this bolt is 17nm. I put a plastic handle on an ISO 2936 8mm hex socket key so I could torque by feel and see how many Newtons it put on the pedal. Then I took the handle off to see how many Newtons the key would let me apply to the pedal. It was almost the same as when I torqued by feel. Then I did the math. Both were slightly over 17 Nm, the spec for that kind of bolt.

is

 

[PedalUma]

On the Abound it is important to remove the O-rings from the calipers, or they will never be right. Torque everything down every 400 miles. Degrease a new chain, rinse, dry, and dip in hot paraffin, and it will never need attention again.

 

[Base]

Ten years ago I had a Nissan whose lug bolts required 60 ft pounds. When it came back from a shop, I needed approximately 250 foot pounds to unscrew them. The mechanic was concerned with speed. He wanted to be sure they didn't come loose. As long as he didn't strip the bolts or snap them off, it was fine with him. Bicycle mechanics could be in the same boat.

The principle of torquing lug bolts is to take up elasticity so that the elasticity will keep it tight, but not to go beyond the point where the elasticity stiffens sharply because now you could permanently deform the threads, causing them to loosen more easily. I'd never used a torque wrench on those bolts. This time, I tightened them by feel, put on a torque wrench, noted where the handle was on the tire sidewall, backed off a quarter turn, and tightened until it read 60. The handle was in the same position as before I'd backed off.

I tried it on a Cadillac from the 1950s. It used lug nuts instead of lug bolts. They were SAE instead of ISO but required the same size socket. This time, the required torque was something like 100 foot pounds, which shows you can't estimate torque by the size of the fastener. Again, I torqued by feel, then used a torque wrench to back off and bring it to the specified torque. Again, the position of the handle showed that I'd been accurate.

To check a bolt on torque applied when fastening you would use a wrench like this:

Those are designed for that type of work, a "normal" torque wrench is used to fasten a bolt at a given torque. A release force to break a bolt free is in fact something different.

Sorry to say its my daily job to check built bikes on bolt torque spec. amongst other things.

 

[PedalUma]

I use one of these 50 times a day. The big ones are mostly for cranks and some axle nuts.
@Base, What do you do and where about? I am in Nor. Cal and work on eBikes.

 

[Base]

Morning,

Good question, at this moment in time I am a Q-engineer at one of the big bike manufacturers in the EU, I've been working at/with the big three American brands for years and been working in bike shops since the start of e-bikes in the BLX. My current role is mostly on E-bikes and Cargobikes.

These small click-keys are ok, not very accurate but it give's a good idea what you are doing. Just get them checked every now and then, I do own a row of torque wrenches and get these tested in our toolshop.

 

[gromike]

I suppose we should all get our torque wrenches calibrated -- and yearly at that.
Like when is that ever going to happen?

 

[Base]

For private use that would be a hassle indeed, although you could build yourself a test rig

Beam style versions do not need calibration

TW-2.2 Beam-Type Torque Wrench — 0–60 Nm

A straightforward tool for properly tightening components and fasteners with torque values up to 60 Newton meters.

www.parktool.com

Torque Wrench Use and Care

Best practices for how to operate and maintain Park Tool torque wrenches and torque drivers.

www.parktool.com

Beam-Type Torque Wrench Use and Calibration

This article will discuss the use and calibration of beam-style torque wrenches such as the TW-1.2 and TW-2.2, as well as the TW-1 and TW-2 (discontinued).

www.parktool.com

just have been through some documents, these small t shaped fixed torque wrenches typically have an accuracy of +/- 10%, ratchet style wrenches are usually +/- 3% for a quality tool