Test ride: MAC 10T / 48V setup

[footloose]

This spring I built a second electric bike, designed mostly to deal with the fairly extreme hills where I live.
Design is not cutting edge at all – the bike isn’t powered with recycled phaser cannon batteries or anything like that.
Instead I studied ES until I had a pretty good idea about a couple of tried-and-true build approaches, figured which one would work best for my need, then I used that recipe.
This post is basically a report on real-world testing of the bike, intended to help any other newbies who are interested in that particular setup.

Bike is basically:
- 1980s Trek mountain bike frame, 26” wheels
- MAC 10T motor
- 48v 12.6 Amp hour Samsung NCM battery pack
- 9 FET 3077 controller
- CA V2.5

Bought all but the bike from Cellman (EM3ev).

Bike turned out to be dynamite, copes with hills like a champ, tops out >30mph, hauls reasonable amount of groceries with no sweat.

Until this weekend, I mostly rode it on short trips around home turf.

This weekend I had a chance to do a real test. Thanks to my wife attending a conference at Squaw Valley (in the Sierra Nevada mountains, near Lake Tahoe) I had a free room and a couple of free days to ride. I went along, and brought the bike.

'Test track’ was the mostly flat, nicely paved bike path that runs along the Truckee river and west shore of Tahoe, for about 20 miles.
Beautiful ride, do it if you ever get the chance.
Got lucky and had beautiful weather too.

I divided the test ride into three segments: conservative riding, aggressive riding, and flat out riding.

Segment 1 was the initial ride from start-point to end-of-trail. Since I didn’t want to end up with a flat battery 20 miles from the hotel, I was conservative with power heading out. Basically, tried to keep the power to ‘EU / AU legal’ level of <250W. Here was a pleasant surprise: even when I was just sipping power (like <100W), the electrics gave a nice steady power boost, felt like I was riding with wind at my back. At 250W, plenty of power and speed on the flats. I goosed it now and then for laughs (max ~1500W) or when going uphill, but was pretty moderate. At the end of 20 miles, here are the numbers:
Distance: 17.96 miles
Consumed: 3.047Ah of power (9.4 Wh/mile)
Average speed: 11.1 mph
Max speed: 23.5 mph
Max amps: 30.01
Battery was still theoretically at ~75% of capacity.

Segment 2 was the return ride. I didn’t try to conserve power at all. Instead I went as fast as I safely could on bike path, and didn’t pedal much. Philosophically, it was “home James, and don’t spare the horses”. For the return trip, here are the numbers:
Distance: 17.92
Consumed: 5.507 Ah of power (15.5 Wh/mile)
Average speed: 15 mph
Max speed: 28 mph
Max amps: 33.13
Battery was still theoretically at ~30% of capacity.

I was pretty surprised that I’d done 38 miles and still had significant battery remaining. So I went on to Segment 3 – "just burn through the power".

Segment 3 was basically… ride it like I stole it, throttle wide open, use the pedals as foot-pegs, hunker down and go as fast as possible until battery was depleted. I wasn’t on the bike path at that point – I was riding on an open but quiet road and in a couple of huge nearly empty parking lots – so I could safely push the bike pretty hard. Here are the numbers for Segment 3:
Distance: 7.0 miles
Consumed 3.262 Ah of power (20.7 Wh/mile)
Average speed: 18.9
Max speed: 30.3
Max amps: 33.13
Battery was showing signs of depletion (voltage drop) by then. Maybe ~7% of theoretical capacity left? I didn’t want to abuse it, so I called it a day and headed home.

Very pleasantly surprised with how well the entire setup performed.
42.88 miles total.
24.92 of speedy to aggressive riding.
17.92 of mild touring style riding.
Only complaint: my wrist was getting sore from holding throttle

 

[oldtown169]

Nice! I should have my kit from Cell Man today. He estimates my Samsung 18.5 ah triangle pack to about 33 miles at 20 mph with little or no pedaling. Obviously there are lots of variables so it is just an estimate.

 

[deffx]

Thanks for the write up/review

Your getting great range. 42 miles out of 12.6 Ah is nice, and the way you did it can just be related to mixing it up like an everyday ride

I'm getting no where near that with my mac 8t, but im running a 12 fet and 45 amp peaks, which i need to tone down a bit to get some more range,

Thx

Deffx

I should probably pedal a bit harder too

 

[-dg]

NIce. Those watt/hr per mile figures are better than I would have expected, especially for such a strong bike.

 

[spinningmagnets]

This is an excellent review, I appreciate the three types of riding you posted results for, this would provide a really good profile of this systems capabilities.

 

[cal3thousand]

You must have some strong legs and light throttle hand. Good job.

 

[footloose]

Thanks to all for the feedback! Had a good time doing the test. Sweet ride plus an opportunity to analyze performance. Good combo.

If I could change anything about this bike, it would be this: I'd like a smoother throttle response.
The bike is pretty powerful, and even with battery mounted forward in the triangle, the front wheel can get very light when accelerating.
Takes a very careful touch to hit the sweet spot. A touch too much throttle and the front wheel lifts off ground, especially on hills.
Any suggestions for getting a smoother throttle ramp without compromising top end would be appreciated!

 

[el_walto]

I have the same setup and would also like a softer start on the throttle, especially when someone else is trying the bike. I think it might be possible using Cycle Analyst Version 3, but i havent looked into the details yet.

 

[footloose]

... especially when someone else is trying the bike.

Hear you on that. I've loaned the bike for test ride to half a dozen friends. With the exception of -dg (who I figured knew home-brew ebikes well enough to be cautious for a while, then probably flog it hard once he got the feel of it :wink: ) each ride worried the heck out of me. Even after coaching them about 'max torque from zero mph, careful with the throttle, when you twist it the thing just goes, no clutch, etc etc' I pretty much had my phone ready to dial 911 if they didn't arrive home pretty quick. Fortunately, no problems so far. Just big grins when they got back, and instant converts to the concept.

 

[-dg]

... especially when someone else is trying the bike.

With the exception of -dg (who I figured knew home-brew ebikes well enough to be cautious for a while, then probably flog it hard once he got the feel of it :wink: ) each ride worried the heck out of me.

As I remember you looked kinda grey and shaky as you handed me the bike for that ride, but I appreciate the vote of confidence.

ps: when are you planning on the Raleigh 20 build? I'm about to order a motor for the swift and maybe we could share shipping? It would be kinda interesting to get one Bafang SWXU and one Q100 and then we could switch wheels and really compare.

 

[footloose]

...kinda grey and shaky as you handed me the bike for that ride...

Grey and shaky? I need to cut back on the coffee and get out in the sun a bit more :wink:

Re the SWXU-Q100 comparison project... sounds pretty interesting.
Who are you thinking of ordering from?
I can definitely see a place for Raleigh 20 with one of these motors.
The Commuter Booster setup is sweet, but belongs mainly on the flat-lands.
The MAC setup is also pretty fine, but may be overkill in a lot of situations.
It's pretty clear that I really *need* something sort of in between...

 

[-dg]

Re the SWXU-Q100 comparison project... sounds pretty interesting.
Who are you thinking of ordering from?
I can definitely see a place for Raleigh 20 with one of these motors.
...
It's pretty clear that I really *need* something sort of in between...

I have not picked a vendor. It kind of depends on what else I'm ordering along with it and what the shipping charges are. Also, I'd like to get a sensorless one with the Bafang 3 pin "waterproof" connector as it is nice and tidy, but I don't know which one has it. I've dealt with greenbikekit who have been fine so far, but don't have it sensorless, and elifebike who were also ok, but don't have the SWXU. Bmsbattery has it, and has the torque arms I want, but I don't know if it is sensorless. Batterybikekit apparently let you specify all the motor options, and have some other parts I want that I did not find elsewhere, but charge more for shipping. I guess I'll dither until sometime next week and then place the order. If you want to add the Q100 the order, it would probably save on the shipping.

My plan is to get a front motor, "201" rpm, ie slow wind, and then run it on 14s lipo. On the swift I can fit an 8 and a 6 cell 5Ah lipo just in front of the rear wheel wheel. This should give a comfortable 18+ mph on the flat and have more reserve for hills than the fast wind. These are very small motors compared to the MAC or even my wife's SWXK, but I think the small wheel and slow wind should give it enough leverage to be useful. My goal for the build is to keep it as light as possible so it can be carried up BART stairs easily. Hence the 5Ah of battery and the tiny motor. Keeping the speed down helps the range a lot with the small battery. I'm hoping for 15 miles and planning to have an extra plug in the harness so I can parallel another pack onto it if I know I will need more range. Overall, I think I can keep the added weight under 10 lbs.

 

[Supertux1]

I have a bit of a beefier version of this setup. (See the build post in my signature.)
Basically the same but with 18.5Ah NCM, 12 FET and a CA v3.

I use the CAv3 in 'fly by wire' mode where it is the only device that talks to the controller and my throttle controls how much Power (Watts) is to be used.

I use the aux input of the CAv3 with a 3 position switch to set limits for the Power. Power limits are selectable between thirds of the maximum Power limit which I set to be 1500W, so 500W, 1000W and 1500W limits respectively. I also use the CAv3 auto-cruise feature.

When I am commuting and want to blend in with other bike traffic or conserve power, I auto-cruise at about half throttle on the first switch setting, so about 250W. Since it is a power output feedback loop, naturally it slows down going up hills and speeds up going down hills.

When I am passing someone, or trying to get up a hill quickly, I will flip the limit switch to 1000W or 1500W briefly and then back down again.
If nearing the end of my commute and depending on how much juice I have left, I will sometimes cruise balls to the wall WOT @ 1500W.

I pedal to help get the bike moving from a dead stop (reduces motor complaining) but that's about all I add.

I pedal backwards when moving at high speeds just to see if anyone notices.

 

[footloose]

That's a nice bike! Super clean.
If I were starting over on this project (... hmm... sounds like an idea...) I'd do a couple things differently, more like yours.
Key things I'd do differently: a bit more suspension. Would probably use shocks on front forks, and ThudBuster on seat wouldn't hurt either.
I tried to mount electronics under back rack on mine, didn't work. Nice solution to use a rack designed for "29er" config, with a bit more clearance.
May have to try that.

CAV3... V2.3 version I have is great, but looks like V3 is way more configurable... both a plus and a minus in some ways.

Also finding that I use the '3 position' switch all the time. Just have to be careful when switching on the fly... the sudden increase in power wants some focus on part of the rider at moment of transition.

Like you, I frequently pedal backwards. Just feels right to be pedaling, and I'm convinced nobody notices the difference :wink:

Have been using bike a lot on local rides, which are 50% uphill, 50% down. Basically pour on the power uphill... 1500W... for short period. Then coast downhill. Seems to work beautifully, the power / coast cycle keeps anything from overheating, and the overall power consumption works out to surprisingly reasonable figures.

 

[Supertux1]

Nice! I should have my kit from Cell Man today. He estimates my Samsung 18.5 ah triangle pack to about 33 miles at 20 mph with little or no pedaling. Obviously there are lots of variables so it is just an estimate.

That sounds about right. I've been 30 miles on my bike and have yet to see 47v on the CA. It does slow down near the end though, and it seems like its dragging until you realize you've been doing 25 mph for the last hour.

 

[Supertux1]

That's a nice bike! Super clean.
If I were starting over on this project (... hmm... sounds like an idea...) I'd do a couple things differently, more like yours.
Key things I'd do differently: a bit more suspension. Would probably use shocks on front forks, and ThudBuster on seat wouldn't hurt either.
I tried to mount electronics under back rack on mine, didn't work. Nice solution to use a rack designed for "29er" config, with a bit more clearance.
May have to try that.

CAV3... V2.3 version I have is great, but looks like V3 is way more configurable... both a plus and a minus in some ways.

Also finding that I use the '3 position' switch all the time. Just have to be careful when switching on the fly... the sudden increase in power wants some focus on part of the rider at moment of transition.

Like you, I frequently pedal backwards. Just feels right to be pedaling, and I'm convinced nobody notices the difference :wink:

Have been using bike a lot on local rides, which are 50% uphill, 50% down. Basically pour on the power uphill... 1500W... for short period. Then coast downhill. Seems to work beautifully, the power / coast cycle keeps anything from overheating, and the overall power consumption works out to surprisingly reasonable figures.

This is the rack I have: http://www.amazon.com/Topeak-Explor...604&sr=8-4&keywords=topeak+explorer+bike+rack

The tubes on the rack are all 3/8" for which you can find rubber insulted steel p-clamps for (meant for cables) in the electrical section of most hardware stores. I got mine at Home Depot. I put two of these on each side of the rack then connected them to small flat pieces of hardwood which serve as adapter 'plates' for the controller underneath. It comes apart easily for maintenance. I mounted the radio shack junction box to the four bolts on the front of the rack that attach near the seat.

(I have a bunch of dc to dc converters for 12, 5, and 3 volts for the lights and a cigarette lighter socket up front, however I don't want to mess up the clean waterproof build with battery taps so I'm just running all those off separate rechargeable batteries for now.)

If you do it that way i have, you free up the top to use Topeak's nifty rail system which works very well for holding their bags and baskets. The controller is protected on all sides. I bungee the bags to the seat post for extra support though.

My front shocks are crappy Sun Tour brand and honestly they don't do much, because I pretty much locked them out by cranking the preload knobs as far as they go. You should also look at getting some fenders made for mountain bikes to keep water away from everything, mine are Planet Bike and I had to use zip ties for the front due tO lack of mounting holes.

 

[-dg]

You should also look at getting some fenders made for mountain bikes to keep water away from everything, mine are Planet Bike and I had to use zip ties for the front due tO lack of mounting holes.

Zip ties. Classy. Heh.

Although, all my fenders ended up using at least one zip tie, and a fair bit of dremel tool surgery. One good thing about zip ties is that they don't rattle.

 

[cal3thousand]

You guys wanting a more smooth ramp up of throttle input need to check out zombiess' throttle tamer. I just got one and can't wait to get my 24S bike together to play with it.

 

[footloose]

... zombiess' throttle tamer.

I'm planning to purchase one as soon as he gets the next batch built.
Sounds like a great device!

 

[oldtown169]

I (217 lbs) just completed a round trip of 27.5 km (17 miles) on my 29er using EM3ev's 18.5 ah Samsung NCM triangle battery. Most of the ride was hard pack trail. First segment of the ride was a decline from 500 ft elevation to sea level stretched over 13.25km. Return obviously was incline from sea level to 500 ft. Starting voltage was 57.2 (90% charged). Peddling just enough to put pressure on the crank. Here's what the CA showed after the ride...

 

[footloose]

Pretty amazing.
If I'm reading it right, Implies that even starting with only 90%, charge... you could have done this round-trip 3x on a single charge.
Well, actually, looks like you might run out of power a few hundred meters short of home on that third trip and have to pedal a bit more on that last uphill, but still.
Starting at 100% charge, you'd have power to spare.

 

[oldtown169]

Pretty amazing.
If I'm reading it right, Implies that even starting with only 90%, charge... you could have done this round-trip 3x on a single charge.
Well, actually, looks like you might run out of power a few hundred meters short of home on that third trip and have to pedal a bit more on that last uphill, but still.
Starting at 100% charge, you'd have power to spare.

Yup at that rate I'd have power to spare. What I also like is that I can recharge this battery in about 2 hours after using up that amount of battery.

 

[cell_man]

Nice to see some nice reviews, thanks

If the throttle response is a bit twitchy, that can be tamed down by adjusting the phase current settings in the controller. The 10T is so torquey, you do need a gentle throttle hand at low speeds, but I would say it is still progressive, just sensitive. As standard the phase current is almost 3* the rated (battery) current. If you reduce that to maybe 2* (or whatever suits you), that will give you less power (torque) at low speeds, but you'll still have the same power as speed picks up. It is not a soft start, but the feeling may be similar, as it reduces the power at low speed, but without actually slowing the response which a soft start tends to do. There are standard settings that I would have forwarded with the SW link, just reduce the phase current below standard, leave everything else as standard.

The V3 CA allows a lot of control of how the bike reacts to throttle input, it can make the Mac seem pretty tame to be honest compared to how it performs with a direct throttle connection to the controller, but it's not, it's just delivered in a different way. I now integrate the 3 speed into the V3 CA as well. There are so many adjustments, so at first it can be a bit confusing, but we set everything up to get you started, from there you can play to your hearts content as you slowly figure out the many options available.

Thanks again guys
Paul

 

[RLD70]

I too have the 10T motor but its on the rear wheel instead and its a blast @ 48v but better @ 60v and 72v as long as you have the controller that handles it. It definitely has the power to haul a fair amount of weight as Ive learned and I baby the throttle from a dead stop and its still pops a small wheelie. It is without a doubt my favorite motor hands down and I have Paul to thank for such a great hub motor plus it arrived 3 days after he shipped it out to me. I can also say that on my old and now defunct 48v 20A lifepo4 pack getting 40+ miles out of the pack was possible until I disconnected the bms from the pack the last time and over discharged the pack down to 32v which basically killed a whole cell string. The bms shut the pack off before the watt meter read an even 48v on the pack and I figured it would still get me home, which it did, but at the expense of that cell string and I even put the charger on the pack immediately after getting home but to no avail. Bottom line is that you will love this motor the more you ride it and if your controller is capable of up to 72v, youll love it even more.