Planned build

jfny1978

Active Member
Region
USA
Thanks to everyone who has helped me so far on another thread I started

Today I bought a used Trek Marlin 5 in great condition and I am planning to take it apart and put it back together again, without any changes, to learn the bike inside out, since I am not experienced with bike mechanical work. I will buy all the necessary tools including a work stand

Assuming this goes well, I want to install a Bafang Mid Drive conversion kit.

I am confident I can do this. Does anyone see any flaws in this plan?

Thank you.

IMG_20210226_173548383.jpg
 
Thanks to everyone who has helped me so far on another thread I started

Today I bought a used Trek Marlin 5 in great condition and I am planning to take it apart and put it back together again, without any changes, to learn the bike inside out, since I am not experienced with bike mechanical work. I will buy all the necessary tools including a work stand

Assuming this goes well, I want to install a Bafang Mid Drive conversion kit.

I am confident I can do this. Does anyone see any flaws in this plan?

Thank you.

View attachment 80163
Just curious , why make the extra work?
You can learn about the bike mechanics AND install the midrive at the same time, instead of taking it apart , putting it back together again, then taking it apart again for the install.
 
Just curious , why make the extra work?
You can learn about the bike mechanics AND install the midrive at the same time, instead of taking it apart , putting it back together again, then taking it apart again for the install.
Good question I want to be confident I can do it before spending the money on the conversion kit. I also want to learn about the entire bike, not just the parts I would need to change for the ebike conversion. I decided I want to be someone who understands my bike in all facets, and I figured that the best way to do that would be to take it apart. :)
 
Good question I want to be confident I can do it before spending the money on the conversion kit. I also want to learn about the entire bike, not just the parts I would need to change for the ebike conversion. I decided I want to be someone who understands my bike in all facets, and I figured that the best way to do that would be to take it apart. :)
Oh, I see, you said you were confident you could do this, so I just went by that statement.
If you're not so confident, you could always install a rear hub motor, which is super simple, AND you can always take the rest of the bike apart to learn about it.
It's all a matter of your level of confidence, and if you can live with a hub motor.
Good luck
PS running a middrive requires quite a bit more skill than a hub, otherwise you will damage your drive train.
 
Oh, I see, you said you were confident you could do this, so I just went by that statement.
If you're not so confident, you could always install a rear hub motor, which is super simple, AND you can always take the rest of the bike apart to learn about it.
It's all a matter of your level of confidence, and if you can live with a hub motor.
Good luck
Thanks! I guess I meant I am confident that I can learn how to do this. :)
 
No need to take it apart just for the sake of it unless you really want to. Bikes are pretty simple machines to work on especially if you are willing to spend the money on good tools which will last you a lifetime, I didnt always follow that advice and bought several tools many times. After going thru 3 bike stands, I finally settled on a Park PCS 10.2 and must say its the last stand I will ever need. Other tools like headset presses can be made out of simple things like nut/bolts/washers. There is so much info available on youtube these days. I have always done all my bike maintenance but I have wrenched on cars since I was a teenager.

For lots of BBS conversion info/ideas check out endless sphere. These forums are not as much DIY but that seems to be changing.

Nice clean bike there. I would say your biggest issues are getting the BBSxx to fit and the chainline. Who knows what kind of problems you will encounter. Easiest thing would be just to just get the kit, and try to install it and see what problems you encounter.

It looks like the trek marlin is using a threaded BB which is essential. It looks like it may have internal routed cables/brake lines. Without going into all the details, these lines/cables might interfere with your BBSxx installation as the BBSxx uses a thicker BB which was how BB was done years ago. Back then, you bought a BB cartridge that looks like the BB cartridge on the BBSxx. These days, the BB bearings are larger and actually external with alot of clearance between the frame and the crank axle. Trek is likely utilizing this clearance to run the cables/brake lines so you will likely have to run external cables/brake lines with zip ties.

Other than that...buy a good battery up front
 
Oh, I see, you said you were confident you could do this, so I just went by that statement.
If you're not so confident, you could always install a rear hub motor, which is super simple, AND you can always take the rest of the bike apart to learn about it.
It's all a matter of your level of confidence, and if you can live with a hub motor.
Good luck
PS running a middrive requires quite a bit more skill than a hub, otherwise you will damage your drive train.
The only potential problem with using a hub motor on a modern MTB is one of standards.

Hub motors are usually designed around older bike standards (135mm rear hub spacing, 9mm quick release). Many hub motors are actually 138mm which can fit into a 135mm rear spacing frame.

Many more modern mountain bikes these days are using wider rear spacing(142mm or 148mm boost) to accomodate wider tires as well as thru axles (no hub motors are doing thru axles yet)

There are frame/bike manufacturers which can accomodate multiple standards like surly on their bikepacking frames which is why I recently did a build based off a surly frame.
 
The only potential problem with using a hub motor on a modern MTB is one of standards.

Hub motors are usually designed around older bike standards (135mm rear hub spacing, 9mm quick release). Many hub motors are actually 138mm which can fit into a 135mm rear spacing frame.

Many more modern mountain bikes these days are using wider rear spacing(142mm or 148mm boost) to accomodate wider tires as well as thru axles (no hub motors are doing thru axles yet)

There are frame/bike manufacturers which can accomodate multiple standards like surly on their bikepacking frames which is why I recently did a build based off a surly frame.
I am definitely thinking that mid-drive motor is the way to go. I found a video on YouTube where someone had put a mid-drive on the same model of bike that I got and it seemed great.

I also love your thoughts on getting a good stand and a good battery! I will do that.

Thanks so much
 
I am definitely thinking that mid-drive motor is the way to go. I found a video on YouTube where someone had put a mid-drive on the same model of bike that I got and it seemed great.

I also love your thoughts on getting a good stand and a good battery! I will do that.

Thanks so much

The only potential problem with using a hub motor on a modern MTB is one of standards.

Hub motors are usually designed around older bike standards (135mm rear hub spacing, 9mm quick release). Many hub motors are actually 138mm which can fit into a 135mm rear spacing frame.

Many more modern mountain bikes these days are using wider rear spacing(142mm or 148mm boost) to accomodate wider tires as well as thru axles (no hub motors are doing thru axles yet)

There are frame/bike manufacturers which can accomodate multiple standards like surly on their bikepacking frames which is why I recently did a build based off a surly frame.
Maxom; Bafang and many others make thru axle motors and thru axle adapters up to 148 mm.
 
It's only a bike. You'll learn enough as you go, installing the BBS02. Buy the special wrench for it. Get a crank puller that suits your bike. Get a chain breaker and some quick links (needed to remove the front derailleur). Learn how to patch an inner tube. Go have fun.
 
jfny1978,
looks like you got a good start: Trek, disc brakes!, suspension front.... these are things that I like.
Mid-drives are a little extra $ and takes a bit more technical knowledge, but I think you will be happier with a mid drive because it is more like riding a bike, than driving a bike, if you get what I'm saying.
Keep us abreast of your installation process
 
jfny1978,
looks like you got a good start: Trek, disc brakes!, suspension front.... these are things that I like.
Mid-drives are a little extra $ and takes a bit more technical knowledge, but I think you will be happier with a mid drive because it is more like riding a bike, than driving a bike, if you get what I'm saying.
Keep us abreast of your installation process
Yes it's completely a matter of taste and how much work you want to do.
Myself I absolutely love rear hub drives. To be honest , with PAS, I don't see any difference from riding the many un powered bikes I have had....just way more power.
I have two more discarded bikes that I plan on putting even more powerful hubs on but I would never consider putting a mid drive on any of them, so it's totally personal tastes.
 
I'd kit it with an Ezee, Mac, or Bafang 310 if not riding in a very hilly area. In that case, I'd go for the BBSHD. BBS02 is a great choice but is better suited to an active rider. The BBS02B can overheat if the rider isn't actively shifting as one would on an acoustic bike. I'm in the camp that wants parts to support any build.
 
I'd kit it with an Ezee, Mac, or Bafang 310 if not riding in a very hilly area. In that case, I'd go for the BBSHD. BBS02 is a great choice but is better suited to an active rider. The BBS02B can overheat if the rider isn't actively shifting as one would on an acoustic bike. I'm in the camp that wants parts to support any build.
Great. I do have a lot of hills I would like to conquer but I am willing to pedal. I was thinking of the 500 watt Bafang
 
Nice bike
Choice depends on what compromises you are willing to accept
Want to keep 3x7 drive train = hub drive
Want to keep QR axles and a light wheel for easy wheel removal for flat repair = mid drive
For road use, either will probably work depending on your preferences
For trails, depending on your use, the mid drives might be better for transmitting torque through your gears, but then you do lose the advantages of your triple chainring.
Neater installation, for me a mid drive because the controller is in the motor housing and overall the wiring is less of a rats nest.
Some of the Bafang mid drives are torque/power monsters but don't seem to have torque sensing, if that is important to you. Tongsheng mid drive has a good, natural feeling torque sensor function.
Ease of installation: if whatever you choose fits your bike and if you can handle removing your crank assembly it's not a significant issue IMO. No need to hurry on a project but for a standard bottom bracket bike I can fully install a Tongsheng mid drive in less than an hour and I'm not a mechanic by any means. Cost of bike specific tools needed is maybe $25. FWIW I bought a $40-$50 bike stand from Amazon a few years ago and it has been one of my best bike accessory purchases. It had great Amazon reviews, is very sturdy and easily holds heavy ebikes.
 
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