E-BikeKit.com Front Hub Motor Bearing Replacement?

Hi Everyone,

I am new to this site and looking for help in replacing the bearings in 2 of my front hub motors that I purchased from E-BikeKit.com. They indicated that these are 10x6 28mph direct drive motors. The bearings in my first motor wore out after about 2 1/2 years of use. I purchased a 2nd front motor wheel from E-BikeKit.com out of desperation, because it would have been time and cost prohibitive for me to send the original one in to them for repair, but now the bearings in the new motor also appear to be getting loose and wearing out after only about 4 months of use.

E-BikeKit.com was nice enough to send me two sealed cartridge replacement bearings. I asked for instructions or assistance in replacing these bearings, but so far they have not provided any, so I told the folks at E-BikeKit.com that I would reach out to folks on some of the electric bike forums for help. I spent a lot of time trying a lot of searches online and on this site, but have not yet found anything specific enough to help me to do this properly, and I want to make sure that I do it correctly. This forum appears to have a lot of folks that are very experienced with electric bikes and their components, so I have registered here with the hope that some nice experienced person here will be able and willing to help me to do this.

(I rely on my electric bike to commute to work 5 days a week and have no other practical way to get to work right now, so I am hoping to accomplish this quickly. I have about $3000 in this electric bike, and should have 2 complete kits to use, but I feel like I am now only about a week away from having nothing to use. This is by far the most expensive product that I have ever purchased, other than a car. It was a stretch for me to buy this electric bike kit, I don't make very much money, pretty much live pay check to pay check, rent a tiny nursery room from an old retired couple in order to be able to live and work in the Seattle area where I grew up so that I can stay living close to my family. I purchased this kit instead of investing in fixing my old truck or buying another car out of desperation for transportation to get to work. I also wanted to try to be more environmentally friendly, and ride an electric bike instead of driving. I new this was a gamble to try and rely on an electric bike for transportation after heavily researching electric bicycles online for a long time before purchasing something, since I was reading about how many things that can fail and go wrong with electric bicycles from folks posting on this forum and elsewhere, and mine has also had a lot of problems and failures of most of the components. Nonetheless, I hope to eventually be able to have 2 electric bike set-ups, so that I always have a back up. Over the last couple of years since I purchsed this electric bike kit, Alec at E-BikeKit.com has been great about helping me diagnose and fix things that have gone wrong with my kit...he deserves a big fat raise. I used to do all of my own work on my car for years and have always done all of my own work on my regular bicycle, so I feel like I am fairly handy with tools and do-it-yourself projects, although nowhere near as much as many folks on this forum seem to be after reading through a large number of posts here. Sorry, this is probably too much personal information to give out here for what I am trying to accomplish, but I guess that I am just hoping that someone might be more willing to help me. I know that most people are very busy, I know that I sure am, but I really hope to be able to do this myself without having to send things back to E-BikeKit.com. I also take great pride in being able to do things myself, and a lot of this has been out of financial necessity over the years. I am a longtime bicycle commuter, but am now 52 years old, have a lot of health problems that make it impractical and vitually impossible for me to commute to work 32 miles roundtrip 5 days a week any more, I can't really afford the health insurance or medical care that I need, and this do-it-yourself electric bike has really been a godsend for me when it is working. I have also discovered that it is probably the best form of exercise that I have ever experienced, particularly at my age and current state of health. I really hope to always be able to commute via an electric bicycle, and live within electric bike commuting distance of where I work!)

Thanks in advance to anyone that is willing and confidently knows that they can help me to replace these bearings properly!

(Sorry for the novel, this is my first time ever posting anything online anywhere....)

You have to remove the side covers from the hub, press out the bearings, and then press in the new ones. The process might be super easy with the interfaces on the axle ends and the side covers being free slip fits-- or it could be the opposite.

Let me see if I understand what you are saying, you had bearings go bad in your first motor, and now there going bad in your second motor. I would do I full stop and look at the bearings, what brand did they send you. It should say right on the bearing....if it doesn't say nsk, or skf...I myself would likely toss them and order in a more reliable brand as I suspect your not getting top quality bearings. Bearing numbers should be etched on the raceway, or bearing seal...likely a 4 digit number....I am partial to nsk myself....the googler should help you find a local stocking distributor.

A good mechanics machine shop would be able to pull out the old bearing and press in the new in ten min. Worth the cost, if one is nearby. A local bearing shop, or the internet, can also supply the right bearing to replace on your other motor.

Odd your new bearings are failing, Ive put many many thousands of miles on those EBK motors, and never had a bearing fail. Have killed bearings on other brands. Your older motor saw similar duty, before they finally failed. Nothing wrong with the first set finally wearing out years later than the warranty. 2-5 years hard use is typical bearing life.

If you can get out the old bearings, prying on them with something, then you can carefully tap in the new ones with a block of wood and a hammer. But I'd go to a machine shop, lest you risk damaging the new bearings installing them. Its easy to do that, that's what happened in your new motor unfortunately. Some guy in china, likely on his 70th hour of work that week.

Alec does deserve a big fat raise, even though a lot of the cost of those kits is that Jason pays a good living wage to all his employees. ( I was one for 3 years) The whole shop would lose half its productivity if Alec quits someday, so Jason does pay him well.

Salted winter roads?

(otherwise, I dont' know what would cause them to fail like that; I use motors hard on heavy cargo bikes and trikes, and I've only damaged one motor's bearings that I know of, and it came to me well-used already in unknown conditions....)


To get bearings out of covers, as long as you don't need the bearings (cuz this will damage them), you can use something like a socket (from a socket wrench), that's of the right size to fit into the axle hole in the cover from the outside, and to sit against the bearing itself. Then hammer the socket to tap the bearing out. Don't hit it so hard that it breaks the cover....

To install the new bearings without a press, without damaging them, you can freeze the bearing (put it in a sealed ziploc and stick it in your freezer overnight, deepfreeze is better than regular freezer), and then heat up the side cover, but not so hot you can't touch it. Get out another socket from the wrench set, but one that has it's open end the same size as the outer ring of the bearing. Set the bearing in the cover hole, then tap it in gently with the socket between it and the hammer. Don't slip with the socket positioning, as if you hit the bearing anywhere but on the outer ring, it may damage the side seals, or the bearing cage inside, or the bearings themselves.

Any tips for getting the side covers off without damaging anything after removing the bolts that hold the side covers on?

Doesn't seem to be any room for my gear puller between the cover and the motor housing. Looks like it would be tough to get anything in between the covers and the motor housing to attempt to pry them off, particularly if there was any sealant of any sort used to keep water out.

Finally getting around to working on this after a freakish 2 weeks of snow in Seattle that sucked up all of my time tryng to get to work and back without being able to bike commute.

Thanks for the advice so far.

The bearings that they sent to me from E-BikeKit.com do say NSK. A tech at a local bike shop said that I should use ceramic bearings instead. Not sure what these are that I have.

Only road a few days just recently where they had salted the roads. Very unusual for the Seattle area. Definitely not what caused the bearings in the new motor wheel to wear out prematurely.

As a side note: I asked a lot of questions of E-BikeKit.com both over the phone and via e-mail before purchasing this kit. One very specific question that I asked was if the bearings where replaceable, since I have had to replace a lot of bearings over the decades is my normal bicycle wheels. They told me that the bearings were not replaceable, and that they would never wear out. I was very skeptical, but they insisted that this was the case.

davidm said:

Looks like it would be tough to get anything in between the covers and the motor housing to attempt to pry them off, particularly if there was any sealant of any sort used to keep water out.

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Cheap chef's knife from the thrift store (or one you're tired of looking at, that isn't worth resharpening). Gently tap on the back edge with a hammer if necessary.

You don't pull the cover off. You push the whole core of the motor out, including the cover on the other side. That removes one cover. undo all the cover bolts both sides, then hook the arms on the spoke flange. this will then push the core out the other side.


Then with the core and the other cover out, you can then pull off the cover.

Well, the technique of pressing the whole motor out one side with my gear puller did the trick to get everything apart and provide access to the bearings for replacement.

Unfortunately, there was a ton of corrosion everywhere inside of the motor. What happened as it started to come apart, was that just one side of one of the cover plates came free first, probably due to all of the corrosion everywhere. As it did this, the force from the gear puller appeared to bend the main "wheel-like" structure that the axle goes through inside in the middle of the motor, so now the axle is not perpendicular to the wheel...bummer. Maybe a combination of the gear puller and the kitchen knife techniques might have worked to get it to come apart evenly and straight without bending anything? Hard to know without trying it, and I guess that I felt like I definitely had to try this.

My guess is that this thing is toast?

While the E-BikeKit.com webiste says that their motors are well sealed in a number of ways and have grease on both bearing surfaces to keep moisture out, I saw no evidence of that at all. I'm definitely a relative newbie with ebikes and am far from an expert, but I am thouroughly unimpressed by the design and manufacturing of this kit.

I do ride this in the rain a fair amount, however, my bike has never been left outside and is always inside when I am not riding it. Before I purchased this kit from E-BikeKit.com they insured me that their kits were fine to ride in heavy rains a lot. They even said that they wouldn't be in business if their kits didn't hold up to riding in the rain. There's no questions that it rains a lot in Seattle! It seems likely that the corrosion inside of the motor might have contributed to the failure of the bearings.

https://www.youtube.com/watch?v=gwlbAJLzI_w It's easy to assume that the moisture is leaking in through the bearings. Here is a study that shows that heating and cooling in the motor causes moisture to be drawn in through the wiring.

davidm said:

While the E-BikeKit.com webiste says that their motors are well sealed in a number of ways and have grease on both bearing surfaces to keep moisture out, I saw no evidence of that at all. I'm definitely a relative newbie with ebikes and am far from an expert, but I am thouroughly unimpressed by the design and manufacturing of this kit.

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There's no way to keep *all* water out of a motor. If nothing else, it'll get in there via the wires, and thru the bearings (even "sealed" types); heating and cooling can cause it to be sucked in, then it can't get out because of the sealants.

The very best way to keep a motor dry is actually to have vent holes (at least one) that it can drain from when it does get in there, preferably at the very outer lip of a side cover, so you can put that at the bottom of the wheel and let it sit in a dry place to drain out. If you need to to be "sealed" for riding just thread the hole and put a short screw in it.