Component choices for recumbent bike...

Discussion in 'Motorized Recumbents' started by nomorefours, Sep 26, 2007.

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  1. nomorefours

    nomorefours Guest

    Hi, All

    Have not actually started my project yet, still doing research.

    I already drive a 100% electric truck (converted Chevy S10).

    My sunny day commuter has been a Ducati motorcycle, but now I am planning to build a high powered electric 'assisted' recumbent bicycle for that purpose.

    I love electric vehicles, I love tinkering, I love two wheels, and the cheapskate in me can't resist a no insurance, no gas, inexpensive and fun commuting option!

    I am very lucky in that my commute (roughly 25 miles round trip) is almost entirely on a bike path, where the traffic is extremly light - not even many other bikes.

    I haven't bought the bike or the drive components yet, and I am looking forward to any help this forum can provide to make sure I buy the right parts for my project.

    I did test ride a number of recumbent bikes last weekend (without any power assist), and I really like the recumbent thing...very comfy, aerodynamic, it just makes sense to me.

    I am looking to accomplish the following:

    1. - I am looking for a range of ~ 40 to 50 miles. From driving my electric truck, I totally understand the equation between speed / acceleration and range. I don't mind slowing down (and pedalling) to get more range, that's fine...but I want to get at least 20 miles of range while riding fairly aggressively (minimal pedalling), with the ability to push that out to 60 miles or more by pedalling and cruising closer to 20 to 25 mph...

    2. - I would like to be able to cruise at ~ 45 mph on smooth pavement (I plan to install a full lexan windshield / fairing), although much of my commute will be on a bike path at lower speeds.

    - I weigh 260 lbs.

    3. - The steepest, longest hill I will encounter is heading up to my house - roughly a 15% grade, for about 2/3 of a mile. I need to be able to do this at the end of my ride.

    I have narrowed down my vehicle and components of choice, and I am interested to see what all of you think.

    I want my final result to look very similar to the photos you can see at the following link:

    As you can see, the bike is a front wheel drive bicycle, leaving the rear wheel completely unencumbered to install a hub motor with disk brake. This is attractive, plus the fact that the bike has two 26" standard mountain bike wheels - very unusual for a recumbent.

    I am thinking abut a 5302 or 5303 Crystalite hub motor running at 72 volts, from (2) 20 Ah 36V lithium batteries and 2 chargers (one for work, one for home).

    I would like to use a programmable controller, such as the Alltrax 7234, or at least be able to limit the maximum current. I realize what I am planning will stress every component on this bike, and I know I will end up breaking parts...I want to be able to fine-tune the power between reliability and fun / performance. Also, this controller has a high enough rating to use a more powerful motor (like the ETek) in the future if I choose to...possibly for a different project.

    Any thoughts or comments on this plan? Are the motor and controller a good match? Will I regret the weight of the 5XXX series motor in a suspended rear triangle?

    Any other thoughts...?



  2. billvon

    billvon Guest

    I think you might have trouble finding a hub motor that will take a disk brake. The Crystalytes generally won't.

    That is very similar to the setup I have, but with a standard upright bike. I have blown one controller so far trying to run at 72 volts, but it works great at 36 volts and 48 volts. I am doing the big "FET swap" to try to get the controller to work better at the higher voltage.

    The Alltrax is for brushed motors only I believe, and the higher power Crystalytes (X5304 and equiv) are brushless. I would recommend a rebuilt Crystalyte 72v 35a controller with upgraded FETs combined with a CycleAnalyst monitor/controller to limit current/speed.

    Well, you're not going to be able to get away from unsprung weight with a hub motor. At higher speeds it might be an issue.
  3. billvon

    billvon Guest

    BTW your link doesn't work!
  4. nomorefours

    nomorefours Guest

    Electric recumbent


    Thanks very much for your responses.

    Sorry about the link...try this:

    The more I think about it, the more I am thinking about mounting an ETek beneath the frame behind the front wheel.

    The installation will be vastly more complicated, but the end result will be significantly better in many ways...

    Benefits of the ETek would be:

    - Ability to fine tune the gearing
    - Very low center of gravity
    - No excessive unsprung weight
    - Almost perfect weight distribution
    - Ability to use gears (would help with climbing the hills on a weak when almost home) - possibly an internal rear hub gear system instead of a derailleur?
    - Tons of torque and (with gearing) speed...without going to extreme voltages and possibly frying components
    - Comparable weight to a powerful hub motor (eg Crystalite 53xx series)
    - A properly engineered installation will spread the torque through the strongest part of the frame
    - Chain drive to the rear (vs. a hub motor) will not cause the rear suspension to extend fully on acceleration

    Drawbacks of ETek:

    - Vastly more complicated simple bolt-on affair here...
    - More expensive and heavier controller required, although this would offer the benefit of being programmable
    - may be a little harder on battery life / range (less efficient?)
    - No possibility of regen (I don't really care that much)
    - Potentially more expensive since everything will need to be sturdier to handle the power...wheels, wiring, controls, etc, etc
    - Weight (compared to a smaller hub motor with smaller batteries, anyhow)
    - Additional maintenance / complexity
    - Not nearly as 'stealth'

    If I do end up going with the Etek, I would likely just buy the Alltrax 4834 / Etek drive system package from these foilks for $1114, batteries and charger extra:

    It may be slightly more expensive, but all I need to do is fry one controller and I will have spent about as much with the Crystalyte setup...

    What do you guys think?


  5. nomorefours

    nomorefours Guest

    Link again

    Something about this link keeps getting autopmatically edited...aaargh!

    Try this:



    I guess it looks like an email address. so it is editing it...


  6. gone_fishin

    gone_fishin Guest

    the previous link (post #4) works fine for me...if all good, i can delete this and post #5

    the "editing" i think you think you're seeing is only the auto-wrap...shortened for display.
  7. bucvoss

    bucvoss Member

    I just built a 48 volt etec trike. i love the thing. I have 4 -75 amp hour battery's on it and a 400 amp altrax programable controller. I custom built 90% of the bike. pulls like a tractor and will out accelerate most cars up to 10-45 mph. I have the pedals and all so i can have it look somewhat legal.:rolleyes:
  8. ozzyu812

    ozzyu812 Member


    Are you looked into the Cyclone kits?
    scroll down to this:
    1000W " Kit" speed up to 70 km/h ( only for expert)
    Then the battery:
    10Ah48V LiFePo4 batteries pack in bag+BMS+3A charger for 1000W kit ( 3.5 hours)
    It was way out of budget or that what I would have gotten.