Rans Stratus Recumbent conversion -- help

[Kunk222]

Project description:

I'm a retired Mechanical Engineer living near Portland, OR. My current favorite ride is a beautiful Rans Stratus LE recumbent which I would like to convert to electric assist.

The Portland Oregon area is a beautiful place to ride and has an excellent bike culture with a well developed network of bike paths, trails and lanes. My local Beaverton area is somewhat hilly with 5 to 20% grades.

I'm about 5' 11", 220#, with two blown knees (old football and skiing injuries). So,the beautiful hills around here are a definite problem, especially on a recumbent. So I have decided to electrify my bike.

So, my basic question to you is what do you think would be the best combination of drive type, battery and controller for my needs and bike.

Here are my design goals:

- Easily handle the local hills (up to 20% grades) with moderate pedaling.
- Range of 30-40 mi with light pedaling.
- Speed of 20 to 30 mph with light to moderate pedaling.
- Safe Lithium battery technology i.e. LMO, LFP, NMC.
- High quality BLDC motor and controller.
- Must be cost effective (under $2K, system total)
- Must be reliable.
- Very clean and water resistant installation...It's Oregon. It rains...a lot.

Summary:

My intended use is a daily, local area ride on bike paths, roads and hard packed bike trails. Typical grades in this area are 10% up to 25% with a distance of 1/8 to 1/2 mile. As I said, my knees are shot so that I really need help on the hills rather than speed. Quality is also important. I have absolutely no use for low quality and unreliable equipment.

Thank you for any help, ideas and suggestions you can provide...kunk

 

[Drunkskunk]

With those kinds of hills, and given your Mech Eng background, you should look at A GNG chain drive. Unlike a hub, you can shift gears with a chain drive. That will give you all the torque you need to mount those hills, and the speed as well. the 48-60V 650W version should do well.

Gear drives are more complex and have more maintance issues than a standard hub drive, so I don't recomend them to most new users, but a Mech Engineer shouldn't have any trouble with them.

As for the battery, a LiFePO4 from EM3ev.com would be a wise choice. Typicaly, you want 35 watts of capacity for every mile you plan to go at 20mph.

 

[Warren]

kunk22,

I think the Bafang 750 would be fine at your weight.

http://em3ev.com/store/index.php?route=product/product&path=36&product_id=166

With the extra weight, and little pedaling, in big hills, I would suggest a one kWh pack for a reliable 40 mile range, and not hammering the pack with a high C rate.

http://em3ev.com/store/index.php?route=product/product&path=36&product_id=166

You may also want a tandem type rear wheel...Aerospoke carbon, or 48 spoke typically.

Warren

http://www.evalbum.com/4525

 

[Kunk222]

Thanks guys,

Very helpful information. Not very many responses overall. But you guys gave me some great fud 4 thought. I'm not sure yet, but the Bafang 750 is looking pretty good. I could always transfer it to my wife's bike if I decide to experiment further with my recumbent or nerd-mobile, as the wife calls it. Thanks again...kunk

 

[Aushiker]

If you haven't already it might be worth posting in the Bentrider forums as well. There is a sub-forum called "Power Assist."

Regards
Andrew

 

[GiantEV]

Definitely em3ev for the battery.

For the wheel I'd go direct drive since it's your first kit, and it's more reliable than a mid drive.

Check out ebikes.ca for the wheel kit:
http://www.ebikes.ca/shop/conversio...te-rear-hs-kit-advanced-pas.html?options=cart

The kit from ebikes.ca comes with everything you need besides the battery. The Cycle Analyst 3 can monitor the temperature in the motor and slow you or stop you if you are riding any hills that are taxing the motor too much. This is one of the big advantages of the Cycle Analyst 3 and a motor with a thermistor.

This should come in under your $2k budget, and will be a very reliable system.

 

[999zip999]

You may want a slower wind hub motor like a 3525 it may work better for your hills.

 

[Lebowski]

you can build something like this, build 3kW motor and use it for middrive:

 

[Kunk222]

Hello all,

Thanks for the input. I have found what I need to get started on my recumbent e-bike.

Craig's List had a new "Golden Motor" 1000W DD motor, basic controller and accessories for less than $400. The same day there was also a new 48