Dual suspensions Recumbent with steel frame. New build and futur updates

Dear fellow ebikers.

I own a heavy steel touring bike that I electrified in 2016 with a rear hub Mac motor 8t (58V 27Ah battery from Em3ev). At that time, I was commuting 50 miles a day. I also use the ebike to do my regular shopping, visiting in-laws, etc… However, my back was suffering as well as my neck due to the tuck position and the lack of suspension. Then I discovered thanks to internet the world of recumbent bike. I tried a model in a shop and though I can learn how to ride this type of bike. I decided to join a new club: the ‘bender’ club. My wife was delighted! I purchased a fully suspended steel frame kit recumbent from a Dutch company Nazca (1800 euros in July 2017). It is a steel frame with a 24-inch suspended fork made of alloy. I then added the following components, which most of them were scavenged from my first ebike built.
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Components:
Back wheel with SKS mudguard: Mac 8t motor laced to a 26-inch Halo SAS rim 36 holes. The rim is very strong stronger than the Alex one sold by Em3ev
Back tyre: Schwalbe marathon GT365 26-inch 2 inch wide
Front wheel with SKS mudguard: 24-inch Halo rim laced to a Shimano XT hub
Front tyre: Schwalbe marathon plus 24-inch 1.75 wide
Front brake: 180 mm disk with Trp hybrid calliper. The manufacturer of the fork mentions 160 mm max but I went a little over without any issues.
Rear brake: Vbrake with Koolstop brake pad. I could not fix a disk brake as there was not enough room for the calliper. I would have to shave some metal on the mac motor or stretch the frame and add a washer.
56t - 48t chainring with a 7 speed freewheel from Em3ev (11-32) so I can peddle easily at 35 mph. the 56t is from SJS cycles UK. I never used the 48t.
Two Ebrakes from ebikes.ca
58V 27AH battery from Em3ev as well as the 12 FET controller
Cycle analyst
ABS moulded box, IP54, 126 x 65 x 40mm from RS Component
DC-DC converter, 36-72Vin, 12Vdc 4.2A from RS Component
Motorcycle Headlight Shin Yo Grooved ABS Plastic with a 12V 35/35W HS1 bulb
12V Automotive horn and side mirror
A 24-60 V rear light with turning signal plugged directly into the battery
XT90 parallel harness

After painting the ABS box in black after adding a grey primer, I drilled several holes to it and I screwed it directly to the side rack of the recumbent. This box holds the battery, the controller (screwed onto the top of the box) and the DC – DC converter screw on the bottom side. The box is well tight, and nothing has cracked or moved after 6000 miles. All the electric cables are run through a pipe to protect from dust, water projection, etc. The pipe is attached to the frame using cable ties and bent with a heat gun to follow the curve of the frame. The dropout are made of thick steel and the torque arms are just used to hold the mudguard. so far no issue with this setup and 2kW max.

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Riding the bike: the good things
It was the perfect solution to solve my health problems. I can ride 300 miles a week without any pain anywhere and feel fresh. The main issue with recumbent is starting and going uphill. Adding a motor alleviates all these issues. I feel very safe as I have the same height as a car and the view is great. It took me less than 20 min to learn how to use a recumbent and after a day I was proficient. I can cycle with 20 kg of grocery without any issues of stability thanks to a very low centre of gravity. Downhill I can reach 45 mph easily without peddling and with the throttle OFF and I feel very confident at these speeds. I am using extensively my bike and I want something very reliable.

Issues with the current setup and upgrades for 2019. I welcome your comments

The issues after 10 000km and the solutions
1) The Mac clutch failed after 6000 km. I changed it myself. Mac motor is good for 35 mph but get hot after 25 miles, close to 90 C. My job moved further, and I had to face a 100 miles daily commute – 50 the morning and 50 the evening, 2 or 3 times a week as I am working from home too. So far, I am commuting by train and bike, doing between 25 or 35 miles on bike one way and the left over by train. My goal is first to commute faster on ebike at 40-45 mph and then try to avoid taking the train and do the 50 miles one way with the recumbent at high speed~40 mph. I don’t have large hills on my commute, twice 6% for a mile and a 10% for half a mile and 90% of my ride is in the rural countryside. I can charge at work. Which hub will do the job?
SOLUTION: get a direct drive hub 3000W and go with a 72V battery (20s) or go with a dual mac 6t setup (14s).

2) The rear tyre was totally worn at 5500 km and then at 9300 km. The 2-inch Schwalbe Marathon GT365 was superior to the Marathon Supreme for wet surface but it gets worn very quickly due to a softer rubber. A month ago, I had an accident at 30 mph and slide on a mud with leaves on the road for 20 meters: it was painful, bruises, scratches all along my leg and elbow and finger broken.
SOLUTION: upgrade to motorbike/rim tires for safety at high speed and for better longevity: both front and back 19inch rim with Heidenau K34 3-inch-wide tyre. I am not doing any off road. I want the best tyre – longevity and adherence- for wet and dry asphalt. I found a good candidate: the MXUS 4t laced to a 19” motorbike rim. I will purchase it from an Austrian company which claims it has a 135 mm dropout. https://www.ebikeparts.at/catalogue/mxus-3k-turbo-motor-and-front-wheel-set_135/ I will have to swap my 24” fork with a 26 single crown one able to accommodate a 20 mm hub.

3) Front brake pad gets worn after 5000 km.
SOLUTION: use a direct drive motor Mxus which offers the possibility of regen. I will need a new 12F controller, maybe the new Russian one from nuculear or one from powervelocity. I will also install front and back Magura MT5e brake which can triggered a brake light (useful for registration as a moped).

4) The 7 speed freewheel DNP from Em3ev failed at 6000 km and another one at 9300 km. I am pushing hard on it with the 56t ring and 11 sprockets.
SOLUTION: get a good Shimano one with 14t cog and purchase a front ring with 70t or even higher in order to be able to peddle at 40 mph. https://www.dutchbikebits.com/alligt-chainrings

5) the HS1 bulb is not so great to illuminate the road at 35-40 mph. I changed it to a H4 55W bulb, but now it struggles to light up! I guess my DC-DC converter is only 12V * 4.2A = 50 W which explains the issue.
SOLUTION: get a 100W DC-DC converter with input between 90-60V and output of 12V.

6) My 58V 27Ah from Em3ev is good for 35 miles at 35 mph. So, I will require a giant battery – in fact two batteries: 20s so 84V fully charged, 10p times 2. Capacity: 50h? Which cell will be the best for my task?
SOLUTION: Let s work on the assumption that at a speed of 45mph my ‘fuel efficiency’ will be 50Wh/miles. (I am not a big guy, only 145 pounds for 6 feet) Then it will require 50*50/84~30Ah to cover 50 miles. However, in order to lengthen the lifetime of the battery, I will have to use only 60% of its capacity and therefore get a 50Ah battery or even higher. The 84V 50Ah battery will be split into two boxes, one in each side of the bike rack: 84V 25Ah each with their own BMS and they will be paralleled. I guess to reach 45 mph on a recumbent will require at least ~3000W with 3” wide motorbike tyre. With 72V for a 20s battery, I need to pull 42A or 21A per battery. With a 10p battery I will pull a little more than 2 A per cell so less than 1C for a Panasonic 3A cell. With the Mxus I can pull even up to 6000W without destroying the motor if I add some ferrofluid and hubsink, which translates by a little more than 1.2C per cell.

Which cell will be the best for my task? PANASONIC NCR 18650PF 2900mAh/10A vs SONY NC1 2900mAh/10A vs LG MG1 2850mAh/10A vs Sanyo NCR 18650GA 3450mAh/10A. I will order them from Tumich on endless sphere. I am planning to order the NESE modules from Lithuania and try to build the battery. I can replace the cells easily if one(s) is (are) gone in the future whereas with a soldering pack I will face a big issue. I will first build one 20s10p battery and check how far I can go with one while still using the train.

Btw, my employer subsides my commute. So, the more I cycle the more I save and make money vs using my car. So, the money I spend on the ebike is more an investment. I enjoy also cycling as it is the only sport I practice which is good for my health and mental (less stress than driving).

Many thanks in advance for your comments,

Kind regards,

Pierre

Sounds like you came to a lot of the same conclusions i did after just 20 miles of riding my first semi recumbent, and your application is the same as mine.. high speed.. long range..

One thing i noticed, starting out with an eZee hub ( MAC's lighter ~750w rated brother ) is that since i have 20" wheels and lower load % than a regular bike, the drag from the motor's gears makes up a large part of the wattage to cruise at lower speeds. At 20-25mph, i'm seeing a pathetic 60-70% efficiency, although the watts per MPH is much lower than on a regular situp bike, so i can't complain too much...

Probably the same situation with your MAC. The only way to get efficiency out of it is to wail on it..
But at the same time, the bike can reach pretty fast speeds when being pedaled. I've clocked in at 21mph.. 4 mph faster than i usually pedal at on a road bike. So a smaller geared motor would be ideal if the bike doesn't need to go fast.

But according to the ebikes.ca simulator, a DD with 0.35mm lams rolls along at a pretty consistent 80-90% efficiency across the range of speeds on these aerodynamically gifted bikes.. so you're barking up the right tree.

I think you'll find that a 3000w rated motor is not necessary for a bike like this. I found that with my smaller wheel, a 3T Leafmotor 1.5kw would make it up a consistent 7% grade for up to 10 miles. Your mileage may vary with a wheel size that's close to 24". If you do not have monster hills to climb like me, a 30mm wide DD might do the trick. But play with the ebikes.ca simulator to find out.

Battery mounting will be a nightmare of course. I am in the process of learning some kind of CAD software so i can design some mounts that put the battery in an ideal place. Your SWB semi recumbent is going to make this even more difficult, but still doable. On your bike, i'd split the battery into two packs and mount them under the seat. A pair of the 14S 7P packs from em3ev is the most appealing option to me ATM since you could get 2.4kwhrs this way

I would use the ebikes.ca simulator as a guide of how much power and battery you need. My guess is that low power, high energy is the way for you. I'm thinking that Samsung 30Q is the way for me, because the bike needs to sustain 2500W so it can scale a mountain. Your power requirements are going to be a lot lower than you think.

PS, if this frame doesn't work too well for mounting batteries, check out the Maxarya Ray 2.

http://maxarya.com/ray-1/

Beefy dropouts.. better ability to mount batteries under the seat once you take that plastic cover off. Standard shock fitment. 3 inches of rear clearance for a moped/scooter tire. Smaller rear wheel is an advantage for power density on a DD hub.. and it's around $1000 for the whole bike.

The no front suspension is kind of a fail, but you don't need it so much because of the bike's weight distribution. The front fork interface looks like a standard 1 1/8, so you could throw a chromoly fork or 20" suspension fork on there and get a cheap ride quality improvement out of it.

I picked a cannondale easy rider as my frame of choice because of the stupid long wheelbase and supreme ride quality, but you only see a few of those pop up on eBay per year. The Ray 2 would be my second choice.

Nice! Mine is suspended only on the rear wheel, which is fine for me but I don't try to ride at 40mph. I envy your fancy cantilevered rear rack; all I have for now is the mid racks. I would like to move my handlebars to below the seat, once I figure out some way to install a pivot down there, if only because the over-seat bars interfere with my knees.

I'm not going to comment on your recumbent motorcycle build ideas, except - surely you will install torque arms?

Wow, 50 miles from work! You understand that you get to choose where you live and where you work, right?

Consider getting an H4 LED lamp to replace your H4 Halogen. Not necessarily this particular one, but something like it.
Then you can keep your converter and pull fewer amps from your battery. It might even be brighter. It's a win-win.

https://www.amazon.com/Headlight-Motorcycle-Version-Bright-1400LM/dp/B07FGDT6Q4/ref=pd_lpo_vtph_263_lp_t_3?_encoding=UTF8&psc=1&refRID=F8QA7XH77NRFRQY2WEAW

I also don't think you need a 3kw motor to hit 40 mph. A smaller (than a 3 kw motor) and lighter direct drive hub motor of the correct (fast) winding could probably get you to 40 mph even with a 48v battery . With a full recumbent, you can get up to 40 mph with around 1250 watts. Most of the "1000 watt" direct drives can handle 2000 watts pretty easily and more so with some StatorAde added. Of course, 40 mph is well above the limit of 15.5 mph electric assist that is allowed in the UK. But I'll leave that between you and the local constabulary to deal with. Maybe you could buy some of those fake muscle pads and wear them under cycling tights so that it looks like you got the leg power to do 40 mph on yer own. :^)