Rear Hub Trek 7300 Build (hybrid Hybrid Bike)


New Member
Hey All! I just got done ( well %90 complete) my new build. I was originally goin to take the advice of most people and use my existing Northrock XC6 Bike and replace it with new components, new motor, and a new battery. I ordered a new 26' Black Magic 5 Rear Hub (Magic Pie 5) from LunaCycle. As always with Luna, the information, value, and cumstomer service was spot on! I paired the MP5 with a 52V 13.5ah Shark Pack with Panasonic GA Cells.

In the time that I was waiting for the motor and battery, I was at my Dad's house in the garage one day. I saw his Trek 7300 Hybrid 700c Bike that he had used for maybe a couple months when he was on a health kick a few years back. This beauty was hangin on the wall collecting dust. Knowing that it was not the correct I didn't get my hopes up too much. But I asked him what he was going to do with the bike and he responded, "nothing." So, needless to say, I ended up with a almost new Trek 7300 for FREE! My favorite kind of deal haha.

However, now I was faced with the issue of having a brand new 26' wheel laced with the new hub motor. I could have returned it and taken a small hit on the shilping fees and a heavy hit on the turnaround time to get the new motor. I also could have had the new MP5 re-laced into the proper 700c rim to fit the bik. That certainly would have been accompanied by a decent price tag.

As I was very close to giving up on using the Trek at all for an ebike setup, I decided to remove the rear wheel off of it and tinker around a bit. As soon as I got the wheel off, I was very suprised at how wide the rear of the bike was. Because the Trek frame is aluminum, I did not want to do ANY bending of the frame at all, as not to lower the integrity and the stregth of it. Many 700c frames tend to have narrower gaps in the rear due to the small width wheels they use. This frame though, was literally just as wide as my 26' Northrock Mountain bike frame. This got my creative juices flowing and the research began and "true hybrid Hybrid Electric Bike" build began.

In doing much reading and research I found that the overall diameter of the 700c and 26' wheels are not terribly far apart. Since I now knew that the 26' wheel laced with the motor would physically fit, how would the change the geometry, handling, and speed of the bike. I did more reseach on "Rolling Diameter" and came to the conclusion that if I chose appopriate tire sizes that this build will work. I decided to mount a 2.2 inche wide knobby tire on the rear 26' rim. On the front I chose a 35mm (1.378 inches) for the 700c rim in the front.

I am amazed at the handling and feel of this bike so far! The larger width tire with more "meat" gives amazing traction and handles shocks and bumps very well. The 700c wheel in the front also takes bumps suprising well and handles like a dream. The geometry of the bike is really something cool to feel. I can truly "feel" the read via the front and ride in complete comfort and safety due to the rear.

I will certainly have more pictures to come. I would also love to hear feedback from everyone!! I am also willing to answer any questions you may have about the bike or the build. :) Ride On!!

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George S.

Well-Known Member
I have a Trek 820 with the same motor. The MTB tires and basic front suspension fork are enough, for me. The bike has a lot of power. The weight on the rear isn't ideal, but sometimes it helps with traction. Given the cost, power, and basic simplicity of the Pie, I'm not sure why more people don't do that conversion.

I ended up with a step through frame, so the battery is more of a challenge. The geometry works for me and it ends up very upright with the bars I use. You can play around with this stuff.

Looks great to me.

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