Greetings my friends. 72F and sunny here in Northern California today, sorry if you are not as comfortable where you are. I had an amazing ride today on my new Cruzbike recumbent; my second ride on it since i got the electric motor system working. Joshua of EVSolutions loaned me a unique Chinese geared hub motor called either the TARN, or NuEnergy. I am running it with the stock controller at 48v with a 15A current limit, so it draws 700W. I am not sure about the efficiency, but from the performance i would say it is pretty good. The motor is meant for the front, but it is 115 mm wide so it will not fit on any standard American forks. This makes the motor almost a tailor made match for the Cruzbike, which is front wheel drive and uses a front wheel with spacers in a 135 mm dropout rear axle. The motor only weighs 5 lbs and is less than 6" in diameter, so most people don't even notice it. I was pleasantly surprised with the motor performance and the low noise level of the plastic internal gears. The motor is extremely well made, and Joshua tells me they are not too expensive. Now the bad news; they are only available in China unless we get a bunch of Cruzbike people or folks who want to get special wider forks together to order a batch. The Chinese manufacturers are all moving away from geared hub motors and towards a motor more like the Crystalyte; bigger, heavier, narrower, and more powerful at higher speeds.
The geared motor is a great combination with the recumbent, as it provides enough power to get the bike started from a stop during the somewhat awkward takeoff period. I rode the bike for a week around my place to get used to it before mounting the power system, as i had never ridden a bent before. For those who have not seen the bike, check them out at Cruzbike.com. There are photos of mine and pictures of the battery mounts on my website at bobmcree.com. Mine is the Freerider with the swept back "easy rider" style handlebars, part of what makes it an attention getter, along with the very comfortable high backed seat. I have a bad back, and this bike is very comfortable for me to ride. The improved aerodynamics of a recumbent are immediately obvious to someone accustomed to riding an upright mtb. It easily hits 35 coasting down the 5% grade on my way home, where my mtb does about 30. I finally took a look at the manual today, which is mostly general stuff about bikes with just a bit specific to the bike. One thing i did learn from it was that i have been mounting the bike the hard way, by leaning it over and swinging my leg over the high back of the seat. I can do it, but it is a stretch. They advise that it is easier to hold the back of the seat with one hand and the near handgrip with the other and step over the saddle. I tried it and it is quite a bit easier for someone not too graceful like me.
I had some custom aluminum L brackets made, 8" square with a 4" ledge, from 1/8" 5053 alloy, at a cost of $30. The rest of the hardware all comes from the hardware store. The bracket assembly bolts together on either side of the main frame member, and requires no drilling or modification of the bike. 5 1/4-20 screws connect the two halves of the bracket together and support the battery weight. Foam stick on padding should even protect the paint. The bracket has round protruding screw heads that match with the hollow dimples in the feet on the bottom of the Pelican cases that hold the batteries, and the cases are notched into the bottom ledge and then held down securely into the brackets by the seat. The battery cases are so secure you cannot budge them, and they do not move or squeak a bit at a bumpy 35 mph.
The bike weighs 34 lbs, the motor adds another 6. The battery bracket and two Pelican cases weigh 8 lb, 20 Ah 48V of DD Nexcells weigh another 29 lbs and tested out at 19.4 Ah. Throw in a pound for the controller and a pound for the rack and another pound for my heavy dual kickstand and that makes it 80 lbs which is not too bad to pick up or ride without power. My preliminary heavy handed range testing indicates i will get 40-50 miles of range out of my 1 kWh battery pack. The bike with this motor set at a 15A current limit will cruise at 23-25 on the flats using about 400W of power with no pedaling, and draws 200W up to 28. The bike rides very comfortably at this speed. It will climb a 5% grade with slight pedaling about 16-17 and a 10% with moderate pedaling at 10 mph. It will start up a 10% hill without pedaling, and has enough torque and power at that speed to climb it at under 10 mph, something none of the non-geared hub motors i have used will do. I can stop at the store at the bottom of a hill that needed a 20 mph running start to make it up at 16 using 1400W with the Crystalyte 4011, and then climb it at about 12 with a bit of pedaling and half the power on this bike. One drawback of the FWD is that on a steep gravel road you can lose traction pedaling, so the rear motor is the perfect solution. With 10 pounds of lithium carried on the rear seat post mounted rack the weight could be reduced to 50 lbs total..
The Pelican cases are extremely durable, a consideration when hundreds of dollars worth of batteries could be destroyed in a minor accident. These you can drive a car over. This size case is about $32, they have a wide range smaller and larger. They have a purge valve which is a consideration in case batteries vent, but i had to cut a hole for the wires so they are no longer hermetically sealed. I looked at hermetic connectors, and it would have taken $200 worth to do the job, so i spent the money on a front disc brake instead
There is enough room in these cases for the batteries and a 40A controller in one and that much space for a charger or other electronics in the other. I mounted my drainbrain on the front steering tube so it is down between my knees. The brake and shifter cables loop in the air to form a frame around my view of the brain.
It is considerably more effort to ride this bike than my high powered mtb, which has in reality become an electric motorcycle. The Cruzbike requires some upper body effort to offset the pedaling, and it is taking its toll on my back. Of course when using power that is not an issue. I am hoping i can tighten up some muscles so that i build up a bit more endurance, but with 40+ miles of expected range i don't need to be frugal with power. The TARN would be enough power for 90% of ebike riders, it is enough for me most of the time. I need a bit more exercise so a little pedaling will be good if my back will hold up to it.
I have another rear wheel coming this week from Dave Stanton with LH threads on the left side to accept the later thread-on version of the Currie USPD drive, and regular threads on the right to mount a cluster if i decide to do a mid-drive later or use it on another bike. I have an 850W BMC brushless motor for it that should produce some pretty good speed, or i can use one of the surplus Kollmorgens i and many others have been using for the last year or so. One big plus with this rear wheel is that i had it made with no dish, which makes it stronger. It is also 48 spoke. The Cruzbike has no rear "chain line" so it is not necessary to dish the wheel to make room for a multispeed cluster. This will also be no problem with a mid drive since the chain line will be wherever i put it.
Enough for now, take a look at the photos if you are interested, and i will be happy to answer any questions. Another nice day expected tomorrow; i'll be out cruzin'
-bob
The geared motor is a great combination with the recumbent, as it provides enough power to get the bike started from a stop during the somewhat awkward takeoff period. I rode the bike for a week around my place to get used to it before mounting the power system, as i had never ridden a bent before. For those who have not seen the bike, check them out at Cruzbike.com. There are photos of mine and pictures of the battery mounts on my website at bobmcree.com. Mine is the Freerider with the swept back "easy rider" style handlebars, part of what makes it an attention getter, along with the very comfortable high backed seat. I have a bad back, and this bike is very comfortable for me to ride. The improved aerodynamics of a recumbent are immediately obvious to someone accustomed to riding an upright mtb. It easily hits 35 coasting down the 5% grade on my way home, where my mtb does about 30. I finally took a look at the manual today, which is mostly general stuff about bikes with just a bit specific to the bike. One thing i did learn from it was that i have been mounting the bike the hard way, by leaning it over and swinging my leg over the high back of the seat. I can do it, but it is a stretch. They advise that it is easier to hold the back of the seat with one hand and the near handgrip with the other and step over the saddle. I tried it and it is quite a bit easier for someone not too graceful like me.
I had some custom aluminum L brackets made, 8" square with a 4" ledge, from 1/8" 5053 alloy, at a cost of $30. The rest of the hardware all comes from the hardware store. The bracket assembly bolts together on either side of the main frame member, and requires no drilling or modification of the bike. 5 1/4-20 screws connect the two halves of the bracket together and support the battery weight. Foam stick on padding should even protect the paint. The bracket has round protruding screw heads that match with the hollow dimples in the feet on the bottom of the Pelican cases that hold the batteries, and the cases are notched into the bottom ledge and then held down securely into the brackets by the seat. The battery cases are so secure you cannot budge them, and they do not move or squeak a bit at a bumpy 35 mph.
The bike weighs 34 lbs, the motor adds another 6. The battery bracket and two Pelican cases weigh 8 lb, 20 Ah 48V of DD Nexcells weigh another 29 lbs and tested out at 19.4 Ah. Throw in a pound for the controller and a pound for the rack and another pound for my heavy dual kickstand and that makes it 80 lbs which is not too bad to pick up or ride without power. My preliminary heavy handed range testing indicates i will get 40-50 miles of range out of my 1 kWh battery pack. The bike with this motor set at a 15A current limit will cruise at 23-25 on the flats using about 400W of power with no pedaling, and draws 200W up to 28. The bike rides very comfortably at this speed. It will climb a 5% grade with slight pedaling about 16-17 and a 10% with moderate pedaling at 10 mph. It will start up a 10% hill without pedaling, and has enough torque and power at that speed to climb it at under 10 mph, something none of the non-geared hub motors i have used will do. I can stop at the store at the bottom of a hill that needed a 20 mph running start to make it up at 16 using 1400W with the Crystalyte 4011, and then climb it at about 12 with a bit of pedaling and half the power on this bike. One drawback of the FWD is that on a steep gravel road you can lose traction pedaling, so the rear motor is the perfect solution. With 10 pounds of lithium carried on the rear seat post mounted rack the weight could be reduced to 50 lbs total..
The Pelican cases are extremely durable, a consideration when hundreds of dollars worth of batteries could be destroyed in a minor accident. These you can drive a car over. This size case is about $32, they have a wide range smaller and larger. They have a purge valve which is a consideration in case batteries vent, but i had to cut a hole for the wires so they are no longer hermetically sealed. I looked at hermetic connectors, and it would have taken $200 worth to do the job, so i spent the money on a front disc brake instead
There is enough room in these cases for the batteries and a 40A controller in one and that much space for a charger or other electronics in the other. I mounted my drainbrain on the front steering tube so it is down between my knees. The brake and shifter cables loop in the air to form a frame around my view of the brain.It is considerably more effort to ride this bike than my high powered mtb, which has in reality become an electric motorcycle. The Cruzbike requires some upper body effort to offset the pedaling, and it is taking its toll on my back. Of course when using power that is not an issue. I am hoping i can tighten up some muscles so that i build up a bit more endurance, but with 40+ miles of expected range i don't need to be frugal with power. The TARN would be enough power for 90% of ebike riders, it is enough for me most of the time. I need a bit more exercise so a little pedaling will be good if my back will hold up to it.
I have another rear wheel coming this week from Dave Stanton with LH threads on the left side to accept the later thread-on version of the Currie USPD drive, and regular threads on the right to mount a cluster if i decide to do a mid-drive later or use it on another bike. I have an 850W BMC brushless motor for it that should produce some pretty good speed, or i can use one of the surplus Kollmorgens i and many others have been using for the last year or so. One big plus with this rear wheel is that i had it made with no dish, which makes it stronger. It is also 48 spoke. The Cruzbike has no rear "chain line" so it is not necessary to dish the wheel to make room for a multispeed cluster. This will also be no problem with a mid drive since the chain line will be wherever i put it.
Enough for now, take a look at the photos if you are interested, and i will be happy to answer any questions. Another nice day expected tomorrow; i'll be out cruzin'
-bob
