Which bike should I UPGRADE for conversion?

Donor bike dilemma:

I have two bikes -
1. an 1985 Panasonic MTB which has pull type rim brakes. It needs a new rear wheel anyways.
2. a 2012 Trek 8.2 DS with caliper rim brakes but can be upgraded to disc.


I'm planning a commute of 11 miles round trip a day for work on inner city streets and longer range for the recreational weekends on paved bike paths and roads.

The hubmotor I'm considering is a 4840 Crystalyte with either a 36 volt 20 amp or a 48 volt 20 amp Lithium Manganese pack.

The game plan was to install the motor and new 700c wheel on the Trek and eventually upgrade to disk brakes but I love that bike and enjoy riding it as a regular pedal bike and in fact would use it for my commute if I wasn't wanting to get to work without having to take a bath when I got there and deal with a longer commute with my sub 15mph pace I prefer when riding easy.

I would like 20+ mph without effort on the way to work and I'm not to worried about pedaling on the way home to help.
I know the Crystalyte motor is not one for pedaling without power so I need to accept that this bike will be essentially an electric moped once the conversion is done. So I wonder should I convert my old mountain bike instead? I'm worried about not being able to upgrade to discs yet I'm pensive about modding the Trek. I have priced cheap donor bikes but I cant find anything worth buying and the obvious choice appears to be starting out with the newer Trek.

I even considered purchasing a IZip Path+ and as fine a bike as that is, I'm not keen on the 10amp battery and lack of upgrading potential in the future (battery, controllers, bike frame etc...)

I guess I'm just hemming and hawing before pulling the trigger on the kit. Advice?

...not sacrifice, a new life. Take your time, do your research before spending your money, don't skimp - especially when it comes to your mechanical components such as brakes... rims and spokes.... and dropouts.

power on.

When I first started motorizing bikes I would grab a cheap donor and was fairly happy. Then I motorized a nice bike and wow what a difference. Between a good frame and better components the payoff is greater period. If you love the Trek look for another donor something that has the components you want to start with it will save you money in the long run.

I wouldn't be in a huge hurry if your just starting out you'll more than likely change your mind a 100 times before deciding exactly what you want.

One hint I'd pass along to you is look at the yescomusa kits. They have a website and they are also on eBay. For your needs I think the 4840 is overkill. My wife's bike has a yescomusa styled dd and on a 48v 10ah and it tops out 32mph. I've been eyeing the 4840 but I want to go 35+mph.

Dan L.

That 8.2 is a nice bike, and will convert well. However, it's also a nice ride, so convert the old Panasonic for now. It'll also convert well and leave the nicer bike for pedaling. The things that make a bike nice to ride don't always make it nicer when it's converted.

You're been looking at Electric-bikes.com I see. They tend to invent their own names for motors which makes things a real b!tch when comparing them. That"4840" is really a Crystalyte HS3540. The HS3540 is a whole lot of motor, and would be a total waste on a controller like a 36 volt 20 amp unit. Its a big, heavy motor what can make a whole lot of power when it's supplied by a big powerful battery and a controller that can feed it properly. Like a 72 volt battery and a 40 amp controller, just to start.

Your goal is 11 miles and 20mph minimum. That part is easy. A 36 volt 10 amp battery and just about any >500 watt motor will get that for you, reliably. Yes.com for the motor, Ping for the battery, and basic goals met cheaply with quality parts. So the question is, how much more do you want?

I have some nice MTBs that I've converted, but I needed something in a hurry for my last project. Somebody gave me a cheap Wally bike, which I thought would be OK for testing. It had two worn out tyres, an unusable BB (no balls in one side), and the brakes didn't work.

I installed my electric stuff, a cheap Shimano cartridge BB, and the one thing I wouldn't skimp on - hydraulic disk brakes. So far, I've done about 300 miles on it. The forks clatter over bumps, but apart from that, it's perfectly adequate as a commuter. The steel frame makes installation a lot simpler and stronger.My Rocky Mountain has everything Shimano XT on it and proper air suspension. Everything works very slickly, but somehow I like riding the Wally bike just as much, and it has the big advantage that it's not nearly so desirable for thieves.

Moral of the story. The most important thing (for me) on a donor bike is the disk mounts. A steel frame makes things easier for a hub-motor. Wally bikes rule!

Links would help us look up your Trek.. Off to hunt it down.

http://www.trekbikes.com/us/en/bikes/town/dual_sport/ds_series/8_2_ds/

That trek is sill a 7 speed bike. Perfect for a rear hubmotor. So I'd convert the trek, unless you love pedaling so much you want to keep it as your regular bike.

However, I wouldn't put a big honking clyte motor on it. Put a slightly less powerful motor on it, that might run more efficiently. Basically, if you have the extra power you'll use it.

Mabye a mac 10t on 36v? Or some other lighter motor than a big clyte? A mac is about 9.5 pounds.

Maybe I'm wrong, what does that motor weigh? 15 pounds for a 9c type motor, and one of those would do all he wants at 36v.

Danschutz said:

When I first started motorizing bikes I would grab a cheap donor and was fairly happy. Then I motorized a nice bike and wow what a difference. Between a good frame and better components the payoff is greater period. If you love the Trek look for another donor something that has the components you want to start with it will save you money in the long run.

I wouldn't be in a huge hurry if your just starting out you'll more than likely change your mind a 100 times before deciding exactly what you want.

One hint I'd pass along to you is look at the yescomusa kits. They have a website and they are also on eBay. For your needs I think the 4840 is overkill. My wife's bike has a yescomusa styled dd and on a 48v 10ah and it tops out 32mph. I've been eyeing the 4840 but I want to go 35+mph.

Dan L.

Click to expand...

Yes, I agree about the "100 times I'll change (my) mind!" I think I've changed it twice while writing this reply.

Save the Trek for just pedaling? Yes, I also agree. I just took my bike for a spin this weekend and decided not to electrify it. If I did, I'd loose the bike I use for excersise and riding with my wife. I'm currently leaning toward buying a bike with a decent frame and so-so components which I can upgrade. I'll keep the speed down until the upgraded brakes are up to, well- to put it bluntly "up to speed."
For the detours, sidewalks, unimporved paths, parking lots and curb jumps, I think a full suspension bike is in order. So, off to wally world to check out the 29er xr-pro from mongoose. The rear suspension is nothing but a spring, forks low-end and the brakes are meh. But reports are that the frame is strong. Problem with using the triangle for battery as this has limited space. So, its either a rack which can support 10 lbs of battery or I'll consider mounting the battery hanging off the front of the handle bars. In the future I suppose I could fabricate some sort of battery compartment that can use the frame with a geometry which would not interfere with pedaling. I'm still browsing Craigslist for perhaps an older used frame which would suit me well and would be beter suited to the task. I built a cardboard mock up of the battery I'm thinking of using and take it with me when checking out bike frames. I bet people are wondering what kind of clown is putting a rectangular block in a triangle opening on bicycles when I'm checking out potential frames. "Why yes, I am Neanderthal."

dogman said:

Links would help us look up your Trek.. Off to hunt it down.

Click to expand...

Yes, sorry about that.

dogman said:

http://www.trekbikes.com/us/en/bikes/town/dual_sport/ds_series/8_2_ds/

That trek is sill a 7 speed bike. Perfect for a rear hubmotor. So I'd convert the trek, unless you love pedaling so much you want to keep it as your regular bike.

However, I wouldn't put a big honking clyte motor on it. Put a slightly less powerful motor on it, that might run more efficiently. Basically, if you have the extra power you'll use it.

Mabye a mac 10t on 36v? Or some other lighter motor than a big clyte? A mac is about 9.5 pounds.

Maybe I'm wrong, what does that motor weigh? 15 pounds for a 9c type motor, and one of those would do all he wants at 36v.

Click to expand...

Yep, I'm going to keep the trek as is and I realize that my old mountaing bike is probably a poor candidate for ebike with it's marginal brakes for slowing down from that kind of speed. So, I'm researching bike frames to use in the meanwhile untill I feel comfortable buying a purpose built ebike frame like the raptor or greyborg.

As for which motor: I am thinking of keeping the motor but going with a 48 volt system. Yes, it does more than exceed my originally stated minimum requirments. But heck, I'll probably use it more for adventuring about the city down alleys and long service roads. I'll be able to use the range of the 20 amp 48 volt battery when run at slower speeds. The extra speed capacity would be eventually be used as the components of the bike are upgraded over the course of the year.

Thanks for the suggestions!

d8veh said:

I have some nice MTBs that I've converted, but I needed something in a hurry for my last project. Somebody gave me a cheap Wally bike, which I thought would be OK for testing. It had two worn out tyres, an unusable BB (no balls in one side), and the brakes didn't work.

I installed my electric stuff, a cheap Shimano cartridge BB, and the one thing I wouldn't skimp on - hydraulic disk brakes. So far, I've done about 300 miles on it. The forks clatter over bumps, but apart from that, it's perfectly adequate as a commuter. The steel frame makes installation a lot simpler and stronger.My Rocky Mountain has everything Shimano XT on it and proper air suspension. Everything works very slickly, but somehow I like riding the Wally bike just as much, and it has the big advantage that it's not nearly so desirable for thieves.

Moral of the story. The most important thing (for me) on a donor bike is the disk mounts. A steel frame makes things easier for a hub-motor. Wally bikes rule!

Click to expand...

Sweet conversion! I'm probably going with a WallyWorld frame too. Brakes will likely be the first of the upgrades.

Drunkskunk said:

That 8.2 is a nice bike, and will convert well. However, it's also a nice ride, so convert the old Panasonic for now. It'll also convert well and leave the nicer bike for pedaling. The things that make a bike nice to ride don't always make it nicer when it's converted.

Click to expand...

True. I decided it's best to leave both of these bikes un-asssisted and look for a reasonable frame for upgrading and conversion.

Drunkskunk said:

You're been looking at Electric-bikes.com I see. They tend to invent their own names for motors which makes things a real b!tch when comparing them. That"4840" is really a Crystalyte HS3540. The HS3540 is a whole lot of motor, and would be a total waste on a controller like a 36 volt 20 amp unit. Its a big, heavy motor what can make a whole lot of power when it's supplied by a big powerful battery and a controller that can feed it properly. Like a 72 volt battery and a 40 amp controller, just to start.

Click to expand...

Yes, I'm beginning to learn the name game bit by bit. The current gameplan has changed even though my min requirments will be certainly be surpased. 48volt 20amp Lithium Manganese battery with that clyte HS motor is likely what I will go with.

Drunkskunk said:

Your goal is 11 miles and 20mph minimum. That part is easy. A 36 volt 10 amp battery and just about any >500 watt motor will get that for you, reliably. Yes.com for the motor, Ping for the battery, and basic goals met cheaply with quality parts. So the question is, how much more do you want?

Click to expand...

More is the operative word I suppose. I probably would want to upgrade almost right away so I've upped the requirments after thinking a bit more of how I will actually use this creation on the weekends. But will I change my mind again? :?

Willow said:

...not sacrifice, a new life. Take your time, do your research before spending your money, don't skimp - especially when it comes to your mechanical components such as brakes... rims and spokes.... and dropouts.

power on.

Click to expand...

Agreed! I'm learning bit by bit and will put off buying until I learn a bit more about what is available and falls within my skillset.

That's a nice clean ebike build shown above. That's the ideal type of ebike to build in my opinion. No wires/batteries hanging out or anything to get attention from police or bike thieves.

lester12483 said:

That's a nice clean ebike build shown above. That's the ideal type of ebike to build in my opinion. No wires/batteries hanging out or anything to get attention from police or bike thieves.

Click to expand...

He certainly does have a very stealthy rig. I on the other hand will likely be to excited to wait to dress up the wires and try it as soon as I bolt the motor on the frame. I'll probably be holding on to the battery with one arm while the other is on the throttle.... just before I hit something.

I've given this some thought and indeed changed my mind several more times!
The current plan is to convert the Trek for now and upgrading front brake first (New wheel needed and of course brakes,) then a month or two later adding the rear brakes with the possibility of upgrading the rear cassete (8 gears?) to 11-34 (again, new wheelset needed.)

To avoid the "cogging" motor drag issue of a non-geared hub if ridning without power, I've changed my mind as to the motor. I'm thinking a geared mid-drive Bafang BBS02 rev2 would do the trick. I'm thinking that not having to find a mounting point for a controller eases layout and build. I'm giving up some speed but my first build is not going to be a speed demon anyways. From this project, I'll learn which what I like and would change on a future bike.

Testing my rationale, I've ridden the Trek with the 48 gear ring in place and found it fine for general riding with the rear cassete (14-34) I have. So, this solution would be ok for riding normaly when leaving the battery home and I'm just tooling along with the family.

When a new frame comes along, I'll either strip the Trek back to its original form or look into HUB motors.

Battery: 48v 15amp Headway LiFePO4. The weight should be OK with the rear rack I have though I'd like to configure it for the triangle area of the Trek's frame. The construction of the pack allows me to reconfigure the geometry without too much soldering.

Anyway that's the current plan unless it changes up until I pull the trigger on an order this weekend.

Drunkskunk said:

You're been looking at Electric-bikes.com I see. They tend to invent their own names for motors which makes things a real b!tch when comparing them. That"4840" is really a Crystalyte HS3540.

Click to expand...

Do you have a link for this? Out of curiosity, I searched Electric-bikes.com but didn't see where they label their motors in this manner. I know there has been confusion with Crystalyte motors in the past, including the HS4040 I have, which ebikessf.com says is their "cruiser" model, previously known as the 4080, which is faster than their "torque" model, the HS4060, due to some strange labeling/ratings from Crystalyte.

Drunkskunk said:

The HS3540 is a whole lot of motor, and would be a total waste on a controller like a 36 volt 20 amp unit. Its a big, heavy motor what can make a whole lot of power when it's supplied by a big powerful battery and a controller that can feed it properly. Like a 72 volt battery and a 40 amp controller, just to start.

Click to expand...

I bought a HS4040 to run 20S lipo, but until I decide on a BMS I've been running it on 12S and I'd have to say that it runs very nicely at 20A, and really wakes up when I push 40A through it. What I like about these motors is the extra width that helps with the heat. I have some serious hills where I live and it's nice to not worry about the motor overheating anymore. Just because someone doesn't want to run this motor at 72V/40A doesn't mean that these motors are not a good choice for someone running them at lower volts/amps.

Well, the damage is done. I've ordered a Bafang 8fun Mid Drive BBS02 and a 48V 15amp battery with charger and I plan to start the conversion in a couple of weeks.

The first victim will indeed be my Trek 8.2 and I'm eager to see if my install is successful!

Thanks for your comments and advice.

0utrider said:

Well, the damage is done. I've ordered a Bafang 8fun Mid Drive BBS02 and a 48V 15amp battery with charger and I plan to start the conversion in a couple of weeks.

The first victim will indeed be my Trek 8.2 and I'm eager to see if my install is successful!

Thanks for your comments and advice.

Click to expand...

Please choose new lexicon for describing ebike conversions. Victim should be BENEFICIARY. And sacrifice should be UPGRADE.

Willow said:

...not sacrifice, a new life. Take your time, do your research before spending your money, don't skimp - especially when it comes to your mechanical components such as brakes... rims and spokes.... and dropouts.

power on.

Click to expand...

Nailed it^

cal3thousand said:

Please choose new lexicon for describing ebike conversions. Victim should be BENEFICIARY. And sacrifice should be UPGRADE.

Click to expand...

Understood! UPGRADE!!! Conversion Beneficiary! I should be less negative.

0utrider said:

The first victim will indeed be my Trek 8.2

Click to expand...

Whoops. Spoke too soon. Bottom bracket measured 73mm. The recommended installation is for a 68mm BB.
Back to stupid plan #3:
Find a Wallyworld XR-Pro for conversion and figure out how to mount the battery.

I installed a BBS02 on 73 mm BB before. You just can't install the last locknut over the BB nut.

But some loctite will handle the job. It's definitely doable

cal3thousand said:

I installed a BBS02 on 73 mm BB before. You just can't install the last locknut over the BB nut.

But some loctite will handle the job. It's definitely doable

Click to expand...

I understand there are also possible issues with the chain line. In the end, I'm sticking the motor on a bike with a 68mm BB. I'll see how it turns out this weekend on a WalGoose.

So far so good! Project Album

My next steps are cleaning up the wires, changing the brake levers, pulling the gear shifter wire from the new sram twist grip and installing the display unit. Than another non-powered test ride to fine tune the brakes and adjust gear shifter. Then the Battery puzzle!

Phew! Thankfully no one noticed that I placed the lock rings incorrectly on the bottom bracket.