Review: Mac + BD Elite + Lifepo4

George S.

Well-Known Member
I started out with a Bikes Direct Elite Adventure, which seems to be in the Motobecane series of frames. It is a hybrid frame and they offer multiple sizes. I rode the bike for a year, but didn’t ride it much once I bought an ebike, a Prodeco X3. The X3 basically defines my previous experience with an ebike.

I have, or had, no real problems with the X3. The problem was that the Elite was sitting around and I wanted to build an ebike, just to gain an understanding of how e bikes work. What annoys me about the X3 is that it is mostly locked down. I wanted to put a watt meter on it, but that would void the warranty. I wanted to know what the bike was really doing, and what e bikes need to do, to be good bikes.

In the end, converting the Elite came down to either the BBS 02 or the Mac, front hub version. The BBS 02 has been controversial, much more than the Mac. I don’t want to say anything bad about the Bafang motor. Most of the problems have been when vendors sold very high power versions into the US market. It is a question of the controller, basically, and the FET units that are on the controller board. This problem may have been solved and this problem might not exist if people used ‘reasonable’ power levels.

I bought the Mac partly to avoid any issues with the BBS 02, but mostly because it seemed like a very easy conversion. It is, sort of. The two issues that emerged sort out to (1) the Disk Rotor and (2) the fork integrity of the original Elite fork, a cheap suspension fork.

The rotor is a problem because of clearances. It isn’t the rotor, per se, but the original caliper when it aligns with the rotor, which is basically fixed relative to the motor. With a spacer, you can move the rotor out. Beyond this, there are narrow profile calipers that are easily swapped. This is something for a front Mac builder to consider, if only because you don’t want to have to stop the conversion and wait for parts. A member here, @flymeaway, sent me some spacers. I believe he has access, or owns, a machine shop. For the cautious, you can buy the spacers from EM3ev, which is where I bought the motor.

The final version of this bike has these parts;

  1. The Bikes Direct Elite Adventure (420)

  2. The Mac 350w Front Hub (350)

  3. An aftermarket narrow disk caliper (40)

  4. A Surly front fork (steel) (100)

  5. Grin Torque Arm (Ebay 24)

  6. A 15 AH 36v LifePo4 brick battery (Ebay 260)

  7. A seat post rack with a compatible rack bag (55)

  8. A Brooks saddle (OK, not essential 125)

  9. Total is around $1350
I owned the bike, and had gotten a lot of use out of it. All I wanted was to try to create a ‘good’ bike for a small enough amount of money that I wouldn’t feel bad if it was a ‘failure’. For testing,

I bought some LiPo cells, and used them for around 4 months. I also used them on the X3 to measure how efficient that ebike is, since it was easy to run the battery into a meter and connect it to the X3. I don’t really recommend the LiPos. They work, but they are prone to fires and the safety procedures are annoying. The Lifepo battery is essentially on the bike, on the rack, and I swap the connector to charge the bike.

Ease of Building

This is a very easy kit to build. If I hadn’t found that the disk caliper was rubbing against the motor, I might have called it an ‘afternoon’ project. As it was, I waited several days to get two parts, the spacers and the slim caliper. Along the way I ran the ebike with just a rear brake, and quickly learned that the motor outputs 1000 watts, at least going up hills. That led me to replace the fork, going from aluminum to steel. So it was a couple of weeks to get everything done. The last, hopefully final, mod was the Lifepo4 battery pack.

Essentially this is a kit where you pull the front wheel, and then pull the tire/tube off that wheel. I wanted to go with Marathon Plus tires, so I just put a new tire on the Mac wheel. That was very easy. At this point you have a wheel with a big cable coming out of it, a controller with a lot of connectors, and, hopefully, a battery.

I modified my battery pack, the Lipo, with XT60 connectors. I also used these for the charger. When I got the wheel, I put these connectors on the power leads from the controller. I believe the kit came with Deans connectors. There are a considerable number of connections from the motor to the controller, and then off to the battery. But everything is coded by connectors that only go to one connector, and only ‘one way’. This is nothing to even think about. Just think about how to connect the battery.

It never hurts to take your time running the cable up from the hub motor to the controller. My controller ended up in a handlebar bag. That means there is not much distance. It isn’t terribly neat (there are coils of wire on every connector) but it works and it is more or less ‘stealth’. I don’t think the overall effect is bad. I run power cables to the Watts Up meter, and let it sit below the handlebars. I carry a smartphone on a mount, along with a basic wired bike computer. The smartphone lets me get constant live updates from EBR. (Well, no, not really, but I could.) It’s a little over the top, but all the information is useful, especially for testing.

I had a loose connection which shut down the motor. That was my fault. It was easy enough to troubleshoot, once I got over the annoyance. (Sorry, Paul). Anyway, my initial tests convinced me to replace the fork and then do the real testing. Everything seemed comfortable when the fork was swapped, and I never thought of the bike as a test platform or prototype after a few rides.

The front hub is different, because the power and the wheel are not fixed. The motor can hit soft spots and turn with considerable force. It helps to stay on top of it. The power tends to spin the wheel easily, which obviously doesn’t do any good. Other than that, the motor pulls you through turns, which is pleasant enough.

The Mac proves itself climbing hills. As a geared hub, it is a better design for maintaining efficiency at lower speeds. I climb 8 percent grades, long ones, every day, and the bike will go almost any speed I want, up to around 15 miles per hour. The bike will climb 12 percent grades, but it helps to have some speed when you hit the hill. The motor never really gets warm.

For the first 100 miles, the motor seemed to make some noise, perhaps a slight chattering. That is gone, now. There is a mild whine of the gears, and the clutch will be noticeable if it is close to engaging on a downhill.

I run the bike with a throttle and no robotic power assist system. None of that black magic, bionic rider stuff, for me. I generally pedal as hard as I want and use the throttle to set the speed. On this bike, 18 mph feels safe. The brakes are the real hard limit. There is not enough stopping power anywhere in the 20’s. The hydraulic brakes on the X3 put these brakes to shame, but these basic Tektros are good enough at moderate speeds.

If anything, the bike is much better with the motor. The shifters are great for the few times I need to shift. I can do a big shift on the front derailleur, for hills. This bike has two completely separate drive systems, which is great. It is a two wheel drive, adding some traction advantages. On the X3, the motor will sometimes create skips where the chain loses power. I think the front hub is an advantage, here.

This is an exceptionally easy system to maintain. I carefully inspect the fork every week. I bought a ‘ball’ torx screwdrive, so I can tighten the screws in the motor housing. The disk rotor gets in the way, and the ‘ball’ doesn’t strip the screws at an angle. (Ebay $10). I check every fastener regularly, but there are not that many things to put a wrench on. My $7 Hong Kong kickstand seems to loosen, over time, but it does a nice job of holding the bike up. I lube the chain.


Hard Data

I have a tremendous amount of hard data for this motor. Because the motor will draw about 25 amps, or 1000 watts, it will climb hills with relative ease. I generally pull hills at 600 watts and maybe 13 mph, which is a nice speed, but I pedal and downshift a bit. The LiPo batteries were great for instant power, but the Lifepo set is almost as good.

This controller (and motor) will work with up to about a 60v system. The next logical upgrade would be from my 36v to a 48v, since that is becoming almost the new standard. I don’t even want to know how many watts this motor would pull with a bigger battery, but I assume it would still draw 25 amps, so do the math. It’s not necessary. This motor always seems to run cool, and there is nothing it won’t do, for me, with 36 volts.

I pedal 95% of the time. When I don’t pedal, it is for maybe 30 seconds or going over very rough terrain. In order to pedal and not go too fast, for the bike components, I don’t use much battery. I get about 3 miles per amp hour, which I figure will give me about a 40 mile range with the battery pack I am now using.

About the Battery

The battery on the Elite is the same type as on the X3, but I think Prodeco is phasing out the LiFePo4 chemistry. The X3 has gone about 1500 miles over 18 months, and the pack seems about as strong as it did new. Lifepo are rated for a lot of cycles, maybe 2000, and that number rises if you don’t fully discharge the pack.They are also the safest chemistry. The downside is size and weight. My pack weighs 13 pounds and it is roughly twice the size of a LiOn brick made with, say, a standard Samsung ebike cell. To me, with a pretty heavy front motor and a rear rack battery pack, the weight distribution is fine. It merits zero concern. It looks OK and it works fine. The range is fantastic. If it lasts two years, it’s $10 a month. At that point, something else will come along, probably another bike. But, who knows, maybe I would use this pack on another bike.

I bought the battery pack (marked Sun Thing) from China for $260, including very slow ocean freight shipping. It includes a charger and the battery has a BMS. There is one set of leads, postive and negative, so the charger and connection to the bike will be the same. I removed the connectors on the pack and the charger, back to XT60’s. Unfortunately, I don’t have much time with the battery. The seller is rated 99% on Ebay, and he has sold a lot of packs. Other forum members are using this basic pack, the Lifepo chemistry in a ‘brick’.

The battery pack is now sort of an integral part of the bike. I can remove the rack bag in half a minute, to put the bike on the vehicle rack (a 1upusa). That’s just for safety and to reduce weight on the rack. I bring the bike inside, where it is stored, so I charge the battery on the bike. It would be very easy to calibrate this pack for an exact 90% charge because I always know the amp hours I use with the bike. That is what the Watts Up meter does. I would just use the meter between the battery and charger.

There is incredible flexibility with a kit and a bike you know and understand. I know exactly what the motor does, exactly what it is supposed to do. I know how the battery is being consumed, or how it is being charged. I know how my speed affects the discharge. I can swap for any compatible battery I want, or use a reserve battery. With a kit you are completely in control.

I guess people say there are reliability issues with a kit. I’m not sure why. I solder good connectors to the charger, controller and battery. Every connection with the kit is a pretty bulletproof situation. Yes, carefully connect everything and put everything in a safe place, but that’s it. If there are bad connections, it is bad design. It’s 10 dollars in parts and an hour of your time, a bit of solder, since I solder connections.

As for the motor, the Mac seems to be a premium motor. The controller is a recognized controlled, fine for the wattages where it specs out. It’s not a 2,000 watt controller, and I don’t want to run the motor over 1,000. The legal limit in Utah is 1000 watts, 20 mph hard limit on assist.

Compromises

I can see why Lifepo chemistry is not in favor. It makes for a heavy and bulky battery. But, if you can live with that, you may get an incredible number of cycles from a very safe battery. The real feature is probably the price. This is a 36v 15 ah battery for $260. I hope it lasts. And lasts.

Weight and balance are not ideal with a heavy battery in back, and a fairly heavy motor in front. The balance is OK, but everything is outside the frame, so ‘unsprung’. Should you worry about this? It depends on how you ride, and how much speed you need. I tend to be extremely conservative in turns. There is always loose gravel or sand where I live.

For me the bike rides about the same with the added weight of the power system, compared to how it rode without that weight. I felt the bike rode slightly better, when I added 8 pounds to the battery weight (Lipo out, Lifepo in). It’s all subjective. I added about 4 inches to the handlebars with an extender. This sort of moved the bike toward the comfort or cruiser category. It was a cheap but effective solution to numbness issues.

The Brooks seat seems to absorb a lot of hard bumps, and I would not go back to the previous cheap seat, nor would I buy a suspension post. With the extender and the Brooks, the bike is fine for a 90 minutes ride.

Overall, this approach has some real advantages if you already have a bike. There are several motor choices, and none are terribly difficult. Power is something to consider carefully. A mid-drive may be better for hills, and you can climb hills with modest power levels, using the gears. If you want speed, be careful with components. Reliability will depend heavily on making good connections, waterproof connections, and carefully laying out the cable to avoid any chance of rubbing or pulling. Do it right once, and everything should be great. These are simple systems. Simple is generally reliable. Have fun!
 
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