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New EM3EV Mac 500 Front Kit, Photos, Mini Review

Mar 15, 2011
Inside New EM3EV Mac 500 Watt Side Cable Exit Motor

UPDATE MARCH 14: Motor did not fit my intended Fork (Surly Long Haul Trucker) so I'm installing it on my backup bike an Electra Townie. While trying to install the Grin Version 2 Torque Arms I encountered a problem. I have 2 Brand New Grin Torque Arms (One for each side) and a 3rd from my intended bike. On the Axle side opposite the cable exit all 3 fit perfectly. On the Axle side with the cable exit... none of the 3 will slide on. So it looks like my options are to either carefully file down the threads (Pretty worried about this) or to just live with 1 torque arm. The way the Townie Forks are Stamped and the thin drop outs makes me really want to put on both). So I'm at an impasse. This is "Chinese Quality" rearing it's ugly head. Very frustrating. I know FOR SURE the Grin Torque Arms are to spec... but the Axle... SHIT HAPPENS RIGHT? And yes the Nut fits, but it's just a little tight. I'm hoping I can file just a few threads near the end and then slide it on still.



Updated Photo of Installation of Torque Arms and Slight Interference from Cable Exit. I filed the Round Washer across the top... then decided instead to use the Torque Washer installed Backwards (Didn't reach the drop outs so the Washer is only being used as a spacer). Unfortunately for me the on the non Cable side of the Axle the Torque Arm fit perfectly... but on the Cable Side I had to file the Axle Flat in order to mount the Torque Arm. I have them on both sides (Advantage of Side Exit Cable). What should have been a simple procedure turned into an hour of hand filing and fitting of the Washer to make sure I didn't damage the Threads. In the end it all fit and worked out. And because I exposed the bare metal by filing, when I finished I filled the space between the Axle Nut and the Axle with a small amount of Permatex Black Silicone Sealant (I'll probably do a build post when I'm completely done)

I just wanted to post this photo so that people can see potential mounting problems in some forks with the washers and the cable exit.

These 2 Photos Added March 16, 2017 Potential Problems with Motor Rubbing against Fork

This is the Old 350 Motor in the Surly LHT Fork

On My Surly LHT Fork the Old 350 Watt had enough Clearance with stock washers and did not stretch the Fork past 100mm.


This is the New MAC 536 HF

Note how close the Motor Housing is to the attachment point. I can add spacers, but the motor is already a little wider than the old 350 Watt so I'm pushing past the 100mm spec. This makes the motor a lot harder to mount in the drop outs and stresses the fork some horizontally at the drop outs. The fork can probably handle the stretch, but the issue then becomes having to add matching washers on the other side to keep the wheel centered for Rim Brakes. Just something to consider when purchasing this motor. Make sure it will work with your Fork.


---------------------- ORIGINAL POST BEFORE NOTES ADDED STARTS HERE -----------------------------

I believe this is the 536HF Front built by http://www.macmotortech.com
I ordered mine from EM3EV (EM3EV uses different connectors).

You know that feeling you get when you are trying to put your new kit on your bike? And you have already had to stop and file down the C Washers, then another Washer, then you mount the motor and some of the wiring and you want to test it and make sure it works before you complete the build…all the little things to make the kit fit?

No Joy Much Frustration

You give it some power and nice… it’s working… oh except for the FACT that it is so damn wobbly you wonder how it ever even got out of the shop and who the hell built it that didn’t notice just how completely out of true it is?

And you have to STOP and wait until Monday and find a Local Bike shop to take it to and get trued so you can finish your build? That feeling?

Here are some photos.

View attachment 7

Now I will compare some between both Grin and EM3EV 9C 2806 vs MAC 500 with new side exit cable on front motor.

The Mac is lighter (obviously) and appears to be just a little bit higher in quality and fit and finish. The New Mac is a little more refined than the old version with the cable exiting out the axle. Keep in mind I am talking of front motors here… while I do also own a Mac 500 Rear that has been great.

I already complained about the horrible wheel build above. It’s on an Alex DM24 26” Rim Brake (A wheel I already own and like a lot) with black 13g Sapim Spokes. I had the same set up from Grin with the 9C 2806. The Grin Wheel Build was better, but not great. I believe the 9C being larger makes it harder to true the wheel. Ebike Quality "True", but not really what one would consider "True" on a normal bicycle wheel. Grin build was usable, EM3EV recent build sadly... not even close to usable.

I expected so much more from EM3EV as their last 2 wheel builds were not perfect, but were good enough. This one… yikes I’m complaining again…. Just horrible, horrible, horrible. Wasted Saturday. I think I’m mostly unhappy because of all the time I have to waste now getting it trued before I can finish up. It's the build equivalent of Blue Balls.

Lets talk about the New Battery EM3EV I bought along with this kit.

14S5P Samsung 25r in new waterproof hardshell case. Will need to fins another carry solution as I'm sure the sharp edges will not play well with the fabric on my Rack Bag if it shifts around... more on this below. The battery was ordered on Feb 15th. The paperwork that came with the battery said it was tested on Battery October 18, 2016. That’s about 4 months after my order was placed. It was my understanding these are built to order? Makes me wonder if anyone is ordering the Samsung 25R’s? And why it took so long to ship if it was already built? Only questions God and EM3EV can answer. Not really important as long as it does it’s job. Just seems odd to me.

I already own a 14S 5p 14ah EM3EV battery that has been good to me over the past 5 years even though it never took a charge beyond 90% (This has been beat to death on ES already… not that big a deal). So as soon as I got the new 14S 5p with the Samsung 25r cells I tested it. 52.9 volts. Then I charged it. Let it sit over night and it’s resting at 58.6 volts so it appears to be fully charged.

Joseph at EM3EV said the “New” batteries in 5p and 7p would have a new case. So with the political climate being what it is (Don’t want to pay a possible tariff) I added it to my order.

Time to Deliver from China to West Coast USA

I ordered everything on Feb 15, 2017 and the packages arrived (Kit on March 8, and Battery on March 10). I had to pay for DHL/FEDEX because of the battery so I do not believe I could have purchased a faster option. Not really fast at all... but I didn't expect it to be fast.

In hindsight as great as the new case/packaging might be I kind of wish I would have ordered the old shrink wrap version. Why? Because the new battery has really sharp edges on it’s hard plastic case and the cable exits out the end making it even longer It weighs 9lbs and is 9”x3”x5.75” so it just barely fits my existing rack bag, but I’ll probably have to find a new carrying solution because it will likely tear the fabric. But the old Shrink Wrap version has nice smooth edges and the cable exit is on the top. It’s basically a 6” square and is 14ah and weighs 11lbs with the Samsung 22p cells. Personal Preference.

Good Packing for Protection during Shipping

EM3EV did a pretty nice job of packing the components to prevent damage, but there is a lot of tape and plastic and grease on the plastic. Also the Styrofoam kind of dis•in•te•grated in the motor. A little air blew the tiny pieces out of the motor. I can only imagine what they packages must endure while traveling the world.

Little Extras

EM3EV accommodated my cable length wish and gave me some extra screws needed to repair the old motor (I also purchased a clutch with blue gears which they put together as on their site the gears and clutch are separate pieces).

A few Build Notes You may want to know if considering this New Model Mac Front Hub Motor

* Cable Exit interferes with washer slightly so I had to grind it down a bit to get it to not rub the cable housing.

* For some reason the Cable Exit aligns with the Axle making it harder to mount the wheel.

* The width of the motor is such that it is a real tight fit… I’d guess just past 100mm if you use the supplied washers.

* My Surly Long Haul Trucker Fork is rock solid for hub motors... but with this 500 Watt the Axle size increased and now the C-Washers don't fit correctly without more filing, and the housing is nearly rubbing on the fork leg. The wheel housing only clears the fork by .5mm. So you want to check your fork closely. This may not mount in every fork, especially forks like the LHT which the drop out are centered are really close to not working. Sadly I'll be using this motor now on a different bicycle, and putting my old repaired 350 Watt back on this bike. No Joy as this is the bike I enjoy riding the most. I guess the Bafang Mid Drive will someday be on this bike if they ever fix the mounting issues.

* Screws for case cover are larger and easier to assemble

* New Blue Gears vs old Grey Gears. I had no problem with the Grey Gears on the 350 Watt Mac… so no worries. I did have the clutch fail… no real idea if this clutch is any better.

* Doesn’t seem to freewheel as well as 350W version… will have to wait and see if it “breaks in” a bit. Have not ridden it yet due to weather and the fact I can't get it installed because YEP complaining again - it's not even close to true.

* Controller mount was bent so I put it into the bench vise an a few twists of the handle and then it was straight again. But why bent in the first place? Who knows? Just cosmetic so not really an issue. But again should you have to straighten brand new parts? Attention to detail? Chinese Quality? Quality Control? Giving a frock about what you are selling? You choose.

Let me Wrap up my Rant and conclude… this is getting long enough.

Did I mention the terrible wheel build yet… oh yea about half a dozen times. I'm not going to be happy until I get it trued locally... no wait that won't make me happy either... really? Yup. These things shouldn't ship until/unless they are trued.

EM3EV Vs GRIN Ebikes Canada

Where should you buy? I dunno. But here is my take having dealt with both.

EM3EV - Paul "Cellman"


• While I don’t know him personally Paul has always been upfront in what he does and has been willing to make the "little extras" happen, but he isn’t the person that deals with email any more… I corresponded with Joseph… who does a pretty good job, but communicates in a more matter of fact manner… and I was not not sure I was always understood.
• Good luck with batteries so far I have purchased 2 now
• Pretty good quality for Chinese Parts… I had a brake set arrive broken. Not worth the money to do anything more than trash.
• Much better than trying to order from a Chinese Run Site that is just there to push product. (I won't name names).


• Dislike having to assemble motor into wheel, but understand it saves a lot on shipping
• Connectors on Controllers are not labeled and not much in the way of assembly instructions (Could use some Tutorials).
• A little bit slow to get product out
• Latest wheel build was a disaster of wobble. Will have to pay to have it trued locally.
• Website is new… but not sure it’s really better from a customer perspective, but it is easier to look at. Really need to work on getting some new photos and instructions up and then link to them.
• Not a lot of selection if you don’t want a MAC or Bafang Mid Drive
• Maybe they are growing to fast and not taking the time to assure things are good before sending out?

GRIN Ebikes Canada


• Justin – very patient, super knowledgeable, likeable. In my view the best guy in the business. Dedicated beyond the norm.
• Cycle Analyst!!! Get it! Everyone needs to know what is happening with their battery and little LCD 4 or 5 Dot Battery Displays just don't cut it!
• Solid and pretty timely customer service. I couldn’t find a geared motor for my application so I tried the 9C and really didn’t like it. The Bafang they sell just seemed too wimpy for what I wanted. The wheel build wasn’t great, but certainly within spec considering it is probably a very hard wheel to true given the size and way it’s built. But Justin did go out of his way to try and help me make it work. He is very honest about “Chinese Quality”. In the end I returned it and ate a ton of shipping cost and a small fee. Kind of killed my budget for getting something better. One of those it is what it is things.
• Lots of selection.
• Controller was not a wire mess and connectors were labeled so much better than any I’ve encountered.
• Torque Arms are really nice.
• Website Navigation is pretty good, but I still find myself lost a bit when trying to navigate to certain parts.
• Doing a pretty good job of squeezing the highest quality out of Chinese Stuff.
• Much better than trying to order from a Chinese Run Site
• Used Schwalbe Rim Tape on the Wheel Build - COOL! Love Schwalbe.


• C Washers did not fit well on either the 9C or the Mac 500 and had to be filed. It seems like a little thing, but it’s a huge time suck to file them down. Maybe there should be 2 versions for different axle sizes. I think the blame lies with imperfections in the Chinese Built Axles.
• Shipping is actually just about the Same as EM3EV although it is so much closer to where I am on the West Coast.
• I would like to see more flexibility in the Kits when purchasing. Like being able to substitute or eliminate parts wanted or not wanted. Too structured in my view. The intent of course is to sell only parts that work with each other. For example if I want to add and additional Torque Arm have to go and find it and add it separately instead of just selecting quantity 2. Or if I want a CA3 on a Kit that only has a CA2 option I have to subtract it then go find it and add it to the cart. I'm nitpicking as it is still much better than the competition.
• IMHO not really a good option for “affordable” geared kit. The Ezee maybe great… but it’s out of my budget. So this is a price con for me. And while the tire it ships with is of good quality, it's a size I never ride... so it's wasted money.
• Not a lot of Battery Options
I'm sorry to hear about your issues with the wheel build. We will offer you a refund for the cost of the wheel build and the ebrakes. It seems to be clear that your items were damaged in transit. I can assure you that these parts would have been checked prior to shipment. The fact that you state the controller mounting plate was bent, the ebrakes broken and the issue of the Styrofoam packaging are strongly indicative of damage that occurred during shipping.

It normally takes us about 1 week to do a wheel build and shipping a battery pack usually takes 7 to 10 days upon leaving us. Your order was a little more complicated as you required custom cable lengths exiting the motor (which we were happy not to charge for). This would would have added some extra time onto your order.
Thanks for the email and the reply. I hope people who are looking for a Geared Motor will be helped by the post. I think the MAC offers a lot of value for conversions.

I can tell you that the boxes looked pretty good on the outside, but the inside of the motor box the Styrofoam was in pretty bad shape. Maybe it was dropped in shipping. But the motor itself does not look damaged in any way and it spins up just fine. But the wheel box also looked pretty good, on the outside. It's so hard to tell and no way to know how these packages are handled in transit.

I was a little surprised at how far the wheel was off because both my prior builds from EM3EV were pretty good. I took it to a local shop and they are going to fix it up... so it should work out fine in the end.

As you know I'm not complaining about the time... rather setting an expectation for how long one would expect for a package to arrive to the West Coast of USA from China.

I did receive your email, and really appreciate what you guys are EM3EV are doing.

I really wish the new motor had the new side exit cable, but with a thinner profile like the old version because it's just not going to work on my existing fork... just not enough clearance on the disc side (I use rim brakes so disc isn't needed in my application). So I'm going to put it on a different bike. Kind of a bummer... but this is a Mac Issue vs My Fork Design issue and nothing to do with your service.

I'm very impressed with the power and speed of the 350 actually, maybe they will offer a side exit 350 Watt Version with a Thinner Stator Version and that would solve the clearance issue for forks that have centered drop outs like the Surly LHT.

My 500 Watt Rear has been great as well.

For the record my bike fully loaded with me on it is about 240lbs and the 350 Watt on the front has no issue climbing hills at 6% for half mile or so in normal riding weather (Not exceeding 85 degrees Fahrenheit). I never intentionally push it hard... and I always pedal when starting from a stop before hitting the power (For some reason in my mind I think this may make them last longer... who knows?). I got a little over 3,200 miles before the clutch completely failed (Some warning signs a few months prior to failure). The new Blue Gear clutch installed perfectly. The old Grey Gears were not damaged at all... just failed clutch and a little bit "sticky" on the planetary gear bearings.

Thanks Again.

Great Service, very nice kits.

As noted above I can highly recommend what you guys are doing and the services/products provided.

FYI: Custom Requests and small parts were noted in Original Post above, a great service. Both EM3EV and Grin were very accommodating to my needs n this regard.