Warren's 350 MAC mid-drive (finally) recumbent

I love your build, simple, well designed, minimalist. How much pedaling do you do? What power are you running?

Your wh/mile are great.
 
Veloman,

"How much pedaling do you do? What power are you running?'

I deliberately did not include a freewheel between the cranks and motor. We are inherently slothful. Other than when I am coasting above 27 mph, I am always pedaling. Above 27 mph, downhill, the watts quickly drop to ~50, which is the motor at no load, so no point in wasting juice. I always start off pedaling in 1st to ~7 mph, then to ~10 mph in 2nd, at which point I give it full throttle. This pops it to ~250 watts. If I am starting out uphill I may give it a little throttle, maybe 50-100 watts to get rolling until I get clipped in. I keep shifting until I get to 20-22 mph. On levelish ground I am in 5th or 6th mostly, somewhere between 250 and 390 watts. I have tried various strategies. Trying to always stay at 350 watts, meant shifting constantly. For averaging 20 mph, with lower Wh/mi, I pedal unassisted if I am over 20 mph, and the watts are falling (down a grade and/or strong tailwind). Up hill, below 20 mph, I will let the watts climb into the 400's, and as high as 500 for a few seconds. The reason is that on these 8-18% grades I get almost linear speed gain for extra watts. Downhill, above 20 mph, the actual speed gain from adding motor watts is exponentially smaller...that aero drag thing. I run 1/3C to 1/2C on my 30 amp pack. Riding this way, my voltage, under load, starts at ~39.5V dropping to ~38.0v by 80% DOD. If I am going on a short ride, like the one in the gale the other day, I will keep it WOT, even downhill. It bumps the Wh/mi up 10-20%, but it is fun, and I have lots to spare. The Cycle Analyst gives the max amps, and min voltage for each ride. It is safe to assume these are simultaneous, and indicate my highest instantaneous watts. The product of these two is always 1000-1200 watts.

The motor and planetary gears, should hold up much better, running through the gears, in the mild manner I use.

Warren
 
Thanks again Warren, I hadn't realised that the BMS motor doesn't freewheel. I think there will be quite a few people who will want to follow what you've done.
 
The weather has been pretty nice the last month, if a bit wet.

I've made a few small changes. I made a new bottom for my battery rack. The old one was 2" wide stainless channel, like the two vertical members, so the battery hung at an angle, resting on one edge. Also the rack had no front-to-back bracing. This allowed the battery and rack to move front-to-back slightly with each pedal stroke. Naturally, the rack bottom fatigued, and started to crack at the ends. I fab'ed up a new bottom from 1/8" aluminum (printer plate from a job 35 years ago), 4" wide this time, with 1" edges bent up to hold the battery in, level and secure. No need for toe straps to keep it in place now. Also, to make the rack stable front-to-back, I pop riveted a back wall to the rack, made from thin stainless steel (from our dead toaster oven.) The battery rack mods, minus the toe straps, added about 4 ounces.

I also swapped out the 53 tooth chainring for an old 52 tooth, Sugino Cycloid, elliptical chainring, I had once run on a fixie. This is a true elliptical ring, set up and run like a Q ring.

http://www.rotorbikeusa.com/pdf/Q-Ring%20Recumbent%20instructions.pdf

Feels good, so I'll stick with it.

Also added a bungee to stop the fork from flopping at rest. A hand on the bar would prevent it..unless you were reading a map with both hands, and it flopped around, and you fell on your arse...hypothetical, of course. :)

Did 102.8 miles yesterday, 20.8 mph average, 9.1 Wh/mile. Used 23.99 amp hours from my 30 amp hour pack. All on smooth, straight, rolling, state and county roads. Sunny, breezy, high of 90 F.
[edit: 6575 foot climbing, mostly single digit grades]

I was taking it easy, because of the heat, so was adding about 100 watts average. This would come to 13.9 Wh/mile for non-pedalers, and would reduce range by at least a third.

replaced tires at 3367 mi.
replaced chain at 3444 mi.
4064 miles, 11.04 Wh/mi average
 

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Just for fun, yesterday evening, I did my 7.2 mile loop, from our front door. I have done this ride since 1979. In 1994, I started timing and logging it. At least once a year I would manage to do it at 20 mph. My best was in 2001 at 20.7 mph. Last night, on the electric, I averaged 25.2 mph, probably faster than I could have done it at any point in my youth. I know that most bicyclists would consider this cheating, and why bother, but it still felt damn good. :)

The motor was putting out 310 watts average, and I was putting out about 200 watts, about 2/3 of what I used to be able to put out at 20 mph on my road bike.

4083 miles
 
Warren said:
Don't know why jpgs are coming out like this. :-(
If you are using something like MSPaint to resize them, then there are two ways to do it.

One of them (Ctrl-W) shrinks the whole thing which is what you want, and the other (grabbing a corner and resizing from there) has two options, one of which (selecting all and then grabbing/resizing) resizes the image on the background, which is not what you want, and the other of which (selecting none and then grabbing resizing) does the same as Ctrl-W, which is what you want.

But CtrlW is easier. :)


EDIT: if you select anything before doing the resizing, no matter which way you do it, it does what you already see--so you have to be sure to select none first.
 
It has been hot here for a week, as in 99-102 F every day. Fortunately, I was back at work Monday through Friday, covering for my friend who wanted a week off. Since I had been retired for a month already, I was feeling generous. :)

Working in a poorly air conditioned shop all day gave me an excuse to lay back when I got home. But the day before, and today, I got myself out to ride in 100 degree temps. Since I am only pulling 1/3 to 1/2 C out of my 30 amp hour pack, the pack isn't getting any warmer than the surroundings. But I do notice that the controller, and motor are getting a little warmer, though still not uncomfortable to hold a hand on. I suspect I will have lots more opportunities to ride in 100 degree heat this summer.

4282 miles so far

Went for a ride in my neighbor's Leaf again today. Definitely cooler in there than on the bike.
 
Damned chip seal! Having grown up in Wisconsin, where the glaciers dropped mounds (moraines) of smooth rounded gravel, I never minded when the road crews would redo the roads. Sure there was a little sticky tar to deal with for awhile, but the tiny, round stones never created a problem. Here in Virginia we didn't get glaciers, so they blast rock, and crush it in huge mills. The tiny rocks used to resurface roads here, are like millions of flint arrowheads!

Two days ago, the county chip sealed our roads again. It takes months of driving, for the stones to wear smooth. Yesterday evening I went for a 40 mile ride. Not only do you get tar thrown all over your back, and have to slow down in the curves, but the tiny flint arrowheads stick through your tires. About two hours after getting home, I noticed the rear tire was flat. First flat in 4809 miles! :-(
 
Whatever they use when the redo roads here, it's so hot most of the time that the tar stays sticky for a long time (even at night) and you can actually turn *harder* than usual, as your tires will grip *really well*. Doesnt' cut into tires, either.

Unfortunately because of the heat, the weight of cars braking for corners or accelerating from a stop at intersections causes "waves" of asphalt to build up and dips on one side or the other of the waves. Some of them can get several inches high, especially at the asphalt/concrete join line near the curbs. :(
 
"Unfortunately because of the heat, the weight of cars braking for corners or accelerating from a stop at intersections causes "waves" of asphalt to build up and dips on one side or the other of the waves.

Gad! We call that "washboard", but it only happens on dirt roads. Well, except for this July, with the highest temperatures ever recorded, we had airplanes stuck in the runways. And every day this month has had a higher than average high. May you live in interesting times.
 
I used to see it on the dirt roads in Texas, but it was usually caused by the graders going over and over an area that had large rocks under it; the rocks wouuld lift the grader up and it'd drop right back down past them, so you end up with the washboard problem for hundreds of feet sometimes in those areas (sometimes only a car length or less).

Here in Pheonix on the asphalt, it's not really a washboard effect, as there's only one hump/dip in any one place...but they are at practically every corner, intersection, parking lot driveway exit/entrance, etc. :( It did not used to be quite as much of a problem, but nowadays hardly anyone spends money on fixing the roads or maintaining them unless they become dangerous or impassable, and almost no one fixes parking lots, other than to sometimes repaint the lines once they have worn completely away (like Goodwill's center finally did over on 35th ave and Peoria, within the last week--but they didnt' touch any of the huge potholes and whatnot in the pavement, and now that they've painted on it they certainly aren't going to).

The road edge on the northeast curve of Metro Parkway at metrocenter has had chunks out of the pavement, leaving holes several inches deep, for months in one section and perhaps a couple of years or more in another, whcih has one hole at least the diameter of a truck tire, and is probably at least 3" deep with one spot that is much deeper but has filled with debris so it isn't obvious. Someone once put a traffic cone in it, but that didn't last long as cars just drove over teh traffic cone (why they AIM for them I don't know, but it appears to be a common game to try to run as many of them over in a row as possible).

Someday i should stop and snap pics of these things while I ride; need to carry a ruler with me to stick in the holes for scale.
 
Ok, this mornting on the waiy to work I got pics of one area, and another on the way home. see this post for pics and details:

http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=12500&p=623632#p623632
 
Amberwolf,

Re: Roads. Arizona must be really broke. Some of Virginia is still living in the bubble, so our roads are well maintained. I will take your word for the improved cornering with fresh chip seal. Here they leave up to a quarter inch of loose chips on top, to be pushed into the ditch by rain, and traffic. I won't be laying it over in those turns for awhile.

Mrbill,

Re: Animals in the road. I was out the other day, and saw an amazing sight. Over the years, they have cut down many of the hills from double digit, to single digit grades. As a result, many hills have tall banks on one or both sides. Coming up to a hill, I saw three deer on the bank to my right. They were maybe ten feet back from the edge, and about twelve feet above me. As often happens, they spooked. The buck took several steps and launched right over the road. Antlers flat against his neck, hind legs straight back, forelegs folded under, he looked like Superman. He made it to the other side, and disappeared into the woods. The little one turned and ran the other way, but the female followed the buck. The bank edge broke as she launched and she landed on her forelegs, and face in the other lane. It looked really painful, as she staggered to her feet, and ran into the woods.

Re: Mileage. I see you are really an endurance guy. Your average ride is twice the distance as mine. Same for your runs. My usual is 3 miles, and 10 miles is my absolute max.

The heatwave has broken here. Enjoying the beautiful weather. 5050 miles so far.
 
Did an unintentional experiment today. Five weeks ago I had my first flat on this build. I had had Stan's latex tire sealant in the tubes for 4809 miles when I got my first flat. I had come home and parked the bike. The next day my rear tire was flat. A miniature flint arrow head was sticking out of the tire. It had made quite a hole in the tire, and yet, it took overnight for it to be noticeable. There was some latex to wipe up inside the tire, before I replaced the tube. I thought, "That is pretty inconvenient. I don't think I will use any this time." Fast forward 713 miles to today. I had just left for a planned long ride. I was four miles from home coming down the first big downhill curve. The pavement was smooth but flint chips were scattered on the curve. My CA shows I hit 34.6 when the air whistled out of my rear tire. It dropped fast enough to give me a snake bite flat, in addition to the original puncture. Fortunately, I was able to roll to a stop without cutting the sidewall of my tire or damaging my rim. It took a bit of detective work to find the original puncture, and the new hole in the casing. This hole was smaller than the first. Yet this time the air left in an instant. Needless to say, I will be putting Stan's back in this new tube. :)

5526 miles, so far
 
I added a picture of my battery all charged up, LED's blazing, last night. I took my first electric ride of 2013 today. Balmy!

http://www.evalbum.com/4525

And we just had another damned quake aftershock. They say they probably aren't caused by all the fracking on the east coast. But we didn't have any for hundreds of years...until now.
 
Yesterday was a perfect day for a 52 mile ride. It was 74 degrees, clear, dry and calm. Brings it to 9000 miles exactly. Averaged 20.6 mph, at 10.1 Wh/mile.

I haven't had much to report lately. I have changed my chainring several times since first finishing the bike. I started with a 53T, went to an elliptical 52T, and finally a 50T. Each change got me a little closer to my preferred cadence.

Over the last month, I have started to have what I think is a throttle problem. It first happened once on a ride. I had stopped for a minute, flipping off the switch for the controller. When I flipped it back on, the watts reading, on the CA, went from 0 to 2, as it always does. But when I rolled on the throttle, nothing happened. I backed off and tried again, and away it went. No recurrence for several rides. Then it happened again. Gradually, it has started doing it on every ride, usually 3-6 times in a typical 50 mile ride. Occasionally, it will cut out while riding along at full throttle. Often, just rolling off the throttle, and back on will get it working again. Sometimes I try 4-6 times before it works. At these times, it will often activate for an instant at about half throttle, and then quit as I continue advancing the throttle. At one point I thought perhaps the problem was in the e-brake lever. I only use one on the left. I disconnected it, and went for a ride....same problem. I unplugged the throttle plug, and looked at the pins, to make sure they were all fully up in the socket where they belong. I am hoping it fails completely soon, so I can figure out if the problem is a broken wire, a loose magnet, or a bad hall sensor.
 
Check the throttle connector for dust. Dielectric grease can help on a poor connection. If it happens more often on cloudy days, its likely a poor connection (more humid).
 
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