Merax Finiss w/ Luna Cylce Ebike Hub Motor w/ Craftsman 40v

I thought I would share the results of my ebike build from last year. After running into some troubles configuring the display, I was able to enjoy the bike.

https://endless-sphere.com/forums/viewtopic.php?f=2&t=80036

Here are the details of build with the costs...

Amazon Merax Finiss 26" aluminum mountain bike. $269.99 shipped.

https://www.amazon.com/gp/product/B016A59WPW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Luna Cylce 1000w rear hub ebike kit with tq arm. Just under $400 shipped.

https://lunacycle.com/motors/conversion-kits/

Craftsman/Greenworks 40v batteries Free? Well Kind of..

https://www.amazon.com/GreenWorks-29472-G-MAX-Li-Ion-Battery/dp/B00AW72Y2I/ref=sr_1_1?ie=UTF8&qid=1493237893&sr=8-1&keywords=greenworks+40v+max

Extra battery chargers for the holders. $50 on ebay.

Not including the batteries, which I already had, I have about $720 into the bike. Pics!



40v batteries ran in parallel. I also have 2 4ah batteries.


Replaced the OEM Tires w/ CST Rock Hawk 2.4" Wire Bead tires for mud'n.




One battery to rule them all...


So far, I have really enjoyed the bike. Being able to use the 40v batteries from my portable power tools is a huge plus. I put almost 200 miles on my ebike last year. Mainly short trips back and forth from my hunting spots a few miles down the road. I would throw my crossbow over the shoulder and take the bike right into the woods with me.

The Merax bike is holding up well. I have a nice Giant Mountain bike but it lacks disc brakes and a suspension. The Merax is cheap and heavy but being able to stop and having a little comfort was more important to me. Most of my trips were less than 4 miles each way but that seat has to go. I keep it on because it looks cool for pictures...

Max speed with the 40v battery is ~22mph on a flat surface. At full assist I get ~1 mile per amp hour which I have been happy with. I would like it faster and I need more climbing torque. I'm considering a mid drive kit but I'm not sure if it will give me the performance I'm looking for without upgrading the battery..

N E way. I just thought I would share my project.

The finiss is a lot like the blueks. Here is my merax blueks bike. It is still not finished.

RonnieBrowen2106 said:

The finiss is a lot like the blueks. Here is my merax blueks bike. It is still not finished.

Click to expand...

It appears they don't deviate too far from the mold!

GMRedline said:

RonnieBrowen2106 said:

The finiss is a lot like the blueks. Here is my merax blueks bike. It is still not finished.

Click to expand...

It appears they don't deviate too far from the mold!

Click to expand...

Yup. Pretty much. Probably better components though. The finiss is $269 and the blueks is $200 (on sale for $150). At least I hope it has better parts. My rear derailer broke within a block and a half of riding. I replaced it with a Shimano tourney derailer. The cranks are plastic. I am replacing those as well.

Nice build by the way. Is it still working well?

My rear derailer won't downshift by itself. It will move one gear by itself and then I will have to manually pull the derailer to get it to click. Then I can shift it one more gear. It's probably because I had to adjust the derailer so much to get it to match up with the rear cassette on the hub motor. Or it could be full of mud. It's not a huge deal because I typically leave my bike in one gear.

Overall the bike has been working fine. The ebike works great for 90% of what I use it for. The 36v/40v battery has just enough power.

HOWEVER, it's the remaining 10% of use that has me looking for other options. One of my hunting spots has a pretty steep unpaved hill. It's probably at least a 30* slope. If I build up enough speed before the hill I can make it about 1/3 of the way up before I have to stop and walk the bike the rest of the way. I would REALLY like to be able to ride the bike up the entire hill.

Last night I added a 20v battery in series with a 40v battery to create one 60v battery (55.5v nominal).


The performance increase was notable!

My top speed increase from ~22mph with the 40v battery to ~27mph with the 60v setup on a flat road even with those noby tires. There was noticeably more low end torque because the bike got moving much quicker. But it wasn't enough to make it up that hill. My Frankenstein battery was the equivalent of a 60v 2ah. If I were to increase the ah from 2 to 4 or 8 that would improve the low end tq but I still don't think it would be enough for that hill.

So now I'm contemplating a mid drive unit.

GMRedline said:

My rear derailer won't downshift by itself. It will move one gear by itself and then I will have to manually pull the derailer to get it to click. Then I can shift it one more gear. It's probably because I had to adjust the derailer so much to get it to match up with the rear cassette on the hub motor. Or it could be full of mud. It's not a huge deal because I typically leave my bike in one gear.

Overall the bike has been working fine. The ebike works great for 90% of what I use it for. The 36v/40v battery has just enough power.

HOWEVER, it's the remaining 10% of use that has me looking for other options. One of my hunting spots has a pretty steep unpaved hill. It's probably at least a 30* slope. If I build up enough speed before the hill I can make it about 1/3 of the way up before I have to stop and walk the bike the rest of the way. I would REALLY like to be able to ride the bike up the entire hill.

Last night I added a 20v battery in series with a 40v battery to create one 60v battery (55.5v nominal).


The performance increase was notable!

My top speed increase from ~22mph with the 40v battery to ~27mph with the 60v setup on a flat road even with those noby tires. There was noticeably more low end torque because the bike got moving much quicker. But it wasn't enough to make it up that hill. My Frankenstein battery was the equivalent of a 60v 2ah. If I were to increase the ah from 2 to 4 or 8 that would improve the low end tq but I still don't think it would be enough for that hill.

So now I'm contemplating a mid drive unit.

Click to expand...

At 48v 20.0833333 Ah is needed to make 1000W. If your battery is rated at 2C then it will take 10.04 Ah to produce 1000W. I just think you are not getting enough power to the motor. I live in a very steep and hilly place. My 1000W Direct drive motor can climb some steep hills on its own. Only at 11 MPH, but if you help it it goes much faster. I know this because I went downtown to a bike shop and back with NO derailer. I could not pedal at all. I was just crossing my fingers that the bike could get me back home without having to do the walk of shame. Try adding more capacity.

General rule of thumb from what I can understand is Voltage = Speed, while Amps = torque

Also, another thing you could try is get a controller that can supply 1500W of power to your 1000W motor. It should be fine if you don't run it at 1500W the whole time, for if you do the motor will overheat. That should help you up that hill. Pretty reasonable upgrade. Doesn't cost too much either.

RonnieBrowen2106 said:

At 48v 20.0833333 Ah is needed to make 1000W. If your battery is rated at 2C then it will take 10.04 Ah to produce 1000W. I just think you are not getting enough power to the motor. I live in a very steep and hilly place. My 1000W Direct drive motor can climb some steep hills on its own. Only at 11 MPH, but if you help it it goes much faster.

Click to expand...

Certainly.

This was just a quick test with different batteries I had on hand. The 40v battery uses Sanyo UR18650RX 22a cells and the 20v battery uses Samsung INR 20Q 20a cells. So they are quality high output cells. I matched up the 40v 2ah battery (80wh) with a 20v 4ah battery (80wh) to make sure I wouldn't drain and damage one battery faster than the other. But an 80wh battery at any voltage is absolutely tiny... I also tested the hill climb after the full speed test and my little battery was already 40-50% discharged.

I have 2 20v 4ah batteries I could pare with an 40v 4ah battery for a total of 160wh. But I don't have another make shift holder for the 20v battery.

RonnieBrowen2106 said:

I know this because I went downtown to a bike shop and back with NO derailer. I could not pedal at all. I was just crossing my fingers that the bike could get me back home without having to do the walk of shame. Try adding more capacity.

Click to expand...

And one of the great things about a hub drive motor. You really don't need a derailer or chain for that matter...

RonnieBrowen2106 said:

Also, another thing you could try is get a controller that can supply 1500W of power to your 1000W motor. It should be fine if you don't run it at 1500W the whole time, for if you do the motor will overheat. That should help you up that hill. Pretty reasonable upgrade. Doesn't cost too much either.

Click to expand...

The controller is "advertised" as 25 amps with a max of 1450watts @ 52v. Given all the details I think you are on the right track that my '60v test' was invalid because I didn't have a large enough capacity battery. I could sacrifice another one of my old craftsman tools to make another 20v battery holder to create a 160wh battery and re run the hill test.

hmmm

I am glad that I could help. I am new to this electric bike stuff, but I have learned a lot. So I try to help others as much as I can. electric bikes are fun, I encourage everyone to try them out. I let the people I know try mine out. Most of them probably wouldn't want to build their own, but that means more for me to build and some money too. I love keeping busy.

Hello I'm starting my ebike build and was wondering did anyone have any problems with the rear hub motor fitting with the disk brakes?