Koga Miyata e bike fixer up.

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Sep 16, 2018
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I got myself a Koga miyata e bike that was e bike of the year 2010 and the frame is based on the hand made bike from 2007.
I am working on it to fix it again. Not that it was a bad bike, but the battery was gone and some things need to be fixed or replaced.

I got it to replace my gazelle. Reason is simple, this bike is way better. It needs some work, but it rides good, especially now I replaced the chain, cleaned the derailleur. Even with the rear hub motor not connected, the bike rides smooth. It rides easier than a bike with a mid motor that isn't connected to a battery.
I now get more gears, what helps me riding on different speeds.

Ad the moment I am rewiring the bike. It has a new controller, lights and display.
That is the thing I needed to replace to get the assist working without getting an original battery that is way to expensive.

Tomorrow I get a new cassette that has 11 28, instead of 14 28. A bit wider range that gives me a higher top speed. Front I am looking and 44 or 46t to replace the 42t.

End of the month I get my front and rear fender. After that I only need to get new grips, new pedals and new tires. After that it is ready.
 
Joined
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That is the best image of my frame I have ad the moment.

This is the bike how it is all build with battery.

I replaced the rear rack for the version without battery. But the bike on the foto is on some small details like saddle and front light, the same how I got it.

I will post more images as I have the wires fixed.
 
Joined
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A very clean looking frame with that internal routing for the cables.
Yes that looks great and I love it.
The bike is also from high quality and that is why I am looking online for more Koga bikes.
This is the Koga e-light, but there is also a Koga e-xlight. That is a very light version of this bike and this is already a light bike.
 
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Just got back from a test run. Motor runs good and everything seems to work good. Lights are very bright, so that is just perfect.
I noticed a big difference in the 5 assist modes.
Also it takes a bit longer to respond by pedaling away, but after that it is fine. Motor has it a bit heavy as you ride away, but other than that it is fine.
Speed is about the same as my gazelle with the tsdz2 motor. Gearing is not the same, so the gazelle goes a tiny bit faster. But gearing will be changed and then is that solved.

Only one thing that I need to see if I can adjust it and that is the speed. The controller uses the motor to find its speed. As I set it as it should, it is showing about 5.5kmh slower speed than my gps, where my tsdz2 gives about 3 to 4kmh higher speed.
I changed the magnet count of the motor and that made the difference about 3km slower than the real speed.
So I changed it back. As I ride 20, I know that I go 25 and so on. Easier to count. 32 to 33 I did today and with some other gearing, this will be about 35 to 36kmh.

The display shows in the beginning no speed. This comes after 5 to 10 seconds.

The bike it self does great. Smooth ride and rear gears work flawless. No adjusting needed.
Only thing I want is seat suspension. With the speed numbs out here and the speeds I ride is it a must have.

Only have to clean up the pass wire, display wire and rear light wire. But I do that tomorrow or when I get my rear fender.
Mounted the old fender for now, so I can use the bike. Next week I start working on my gazelle, so I can give it to someone else. Give it a final checkup and clean it. Motor goes off the bike and I will check the brakes.

I am already very happy with my Koga. It has good power and shows better the value of what my battery power is and the amount of watt the motor pulls than my Bafang does. I find the feeling about the same. Bafang a bit smoother low and this one mid and top better.
 
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Yesterday i did soms work on the bike. This is how it looks like now.




I didn't shorten all wires het, this because I neet to replace the rear fender and i want the rear light, hall sensor, front Light and display cable all togheter.

The rear fender is now mounted, but I moved the read lugage rack a big forward. This be placed back as I have the new rear fender.



The controller is mounted and stays very nicely on its place.

All the yellow/green tape Will be vond and those wires Will be cleaned and shortened.


Thr front and rear Light are turned on and off by that switch. I remover the horn and placed a switch in it. Works great and no extra cables to the handel bars. I don't need a button om the handkebars to turn on of off The lights.
That Black rond thing on the brake cable is abs on the front wheel.


The display is in color and even in the dun, good visible. Nog on the photo, but i van read everything, even in the sun.
5 brightness levels to set.

I made soms setup changes today. This helped with the speed values it seems. I neet to test it, but the walk mode now didn't start ad 16kmh on the display and 21kmh on the GPS. It now starts at 6kmh and looking ad the speed of the wheel, this seemed to be a lot closer to what it really is.
I also changed the hall sensor sensitivity. This is now responding a lot faster. Changes a setting for a throttle. As i connect the throttle, it Will now start at 6kmh till i start pedaling. But That is nog connected and i think that i will nog connect it.
The controller starts now in assist level 3 as i turn it on. I can choose from 0 to 5 of set it, that it remembers the last setting.
One mode that i mept ad the middle, but werd i can plat with, is the assist power. It has 3 modes. Low medium high. I have it now on medium. That makes how high the assist level is in the power setting. I krot it medium, because on level 5 i have the max assist if needed. On low i have the biggest range if needed.



I remove the smallest chainring to place the magnets and i placed the sensor zo as the chain cones off, it Will mot hit it. I Will probably get an other chainring and place that back.
But for now it is ok.
I found a chain protector for cheap and that fits with the sensor, so i will het that one.




The cassette will be replaced.
I now reach 32kmh and neef to pedal very fast.
I go from 14-28 to 11-28. That is about the dame as on my trike and a cadense i like.


The cable of the lamp goes trough the frame and site nicely now. Finally got it trough the frame.



One mount is broken, but i will get a new one.

As you van zee, mot finishes yet, but it rides goof and after the changes to the controller, it deels even better. I will test the speed, tonight.
 
Last edited:
Joined
Sep 16, 2018
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I tested the Koga with the new settings.
Things that are changed are that it is way smoother now, the motor picks up faster and the speed indicator starts working way faster now.
It didn't solve the difference between the speed on the GPS and what the display says. It is still 5kmh slower than in real life. But that isn't a problem.

The hub motor is ad high speeds equal to my tsdz2 and with shifting it is by far the best. Chainging gears goes so smooth with the hub motor.
 
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