Contemplating Mid-Drive build

[Lupulin]

Hi everyone, sorry for the long first post. Long story short, I'm looking for some help choosing a hub motor but first here is where I am coming from and what I'm trying to accomplish:

I have been looking for an ebike for a while but can't quite find what I'm looking for. I have ridden an el Mundo fairly often and like it, but I would rather have a Mid-drive for hill climbing/battery life reasons (plus I just like the idea of using the gears better than a hub motor). That and its just too big for my storage situation. I have ridden a few other ebikes: Juiced riders ODK 2, eZee expedir and xtracycle edgerunner (non powered). FYI my normal ride is a Surly LHT 26" with drop bars and 90% of the time I am on the hoods.

Juiced Riders: I have ridden this bike twice. I would like to say that I had really high hopes for this bike.

I like the wheelbase, the dual 20" wheels, the stout frame, stout kick stand, powerful disc brakes (again 20"??), huge battery and the placement. The price is pretty good too for what you are getting. The rack could be a little lower, but certainly not a deal breaker for me. The first time I rode the bike the motor really stood out to me, and not in a good way. I will say it was quite powerful and I was surprised how much I liked the cruise control, nice feature IMHO. But the motor was loud and there was a lot of resistance to the point that I felt I needed to use the motor, making it seem more like a human assisted electric bike vs. an electric assisted bicycle. The second time (a few months later) I will say this seems to have improved (geared motor getting broken in??). But the worst part, for me, was the riding position. It was too upright for me and I didn't feel like I could get much power thru the cranks. I hated the seat (easy fix), and the bars were terrible, completely wrong angle for my hands. I understand they come long so you can cut them back but I don't think that would change anything. I also don't particularly care for the step thru frame. With the smaller wheels I feel like I could easily swing my leg over and would prefer a more traditional frame.
I like what Tora has done and if I could get this with a freewheeling mid drive I probably would try to fix the riding position with different stem/bars/seat post. I have read the reviews on here and online and am glad there are so many people happy with their bikes, but as it currently is, it just isn't the bike for me but I'm looking forward to seeing what comes out of this company in the future.

eZee Expedir

This was closer, but I still wasn't wild about the seating position and I really didn't like the Pedal Assist. It seemed like when I stopped pedaling for safety reasons (stop light/sign or car/pedestrian) the PA would keep powering the bike for another whole second. To me, very unnerving and somewhat dangerous. I might be able to get used to it, but I really didn't like it. I want a throttle bike. I know this has a throttle (and I saw 22ish MPH) I just don't think I want the PA.

Xtracycle Edgerunner

This was my favorite! Riding position was pretty much spot on, I think they nailed it. I don't like the two different size wheels! I don't get why they did that? If the realize the advantages of the 20" wheel in back, and this is a cargo bike, why not have a 20" front with a nice low frame mounted rack?? Back to the bike, the reviews I have read online seemed to say that it was responsive, sprightly, impressively light weight feel. I didn't get that feeling, it felt heavy (it is, but hey, its a cargo bike) and slow but STOUT. Man that bike is built like a brick ****house. I bet it comes into its own when heavily loaded down like it is meant to be! The tires could have something to do with that (Fat Franks I think?).

So I'm leaning toward having a friend of mine who builds frames make me a custom frame! I'm leaning toward something like an edgerunner with dual 20"s and a hub motor mid-drive with a lighter tube set (I don't think I will need a bike THAT stout). I'm not sure of if I should make it xtracycle compatible or not, again for length reasons. With the mid drive I'm thinking it will be between and Edgerunner and the ODK (this seems like a nice practical size for me) in length. I had been leaning toward modeling the drivetrain on a da Vinci tandem until I saw the Stokemonkey equipped Edgerunner from Grin Technologies. I'm still leaning toward the tandem design b/c I don't think I like chain line but keeping an open mind (KISS).

A couple other designs I like:
Bridgestone Josis wagon (pretty good)
EBS Work (Really like this bike and they actually make a few really cool bikes)
Xtravois 2.0 but with a traditional double diamond frame and free wheeling mid-drive

Pretty much a mini velo Yuba Mundo with a frame that incorporates an Urban Commuter Mid-drive.

So I'm starting with looking for motors and it has me wondering why the Stokemonkey was originally (and will continue?) to use a 500W motor? I'm not a speed freak, but I was thinking 1000W 48V system. I'm still researching batteries so I don't know what xSyP yet, but I figure I'll get to that after the motor dimentions. Any help with the motor would be much appreciated. One of the nice parts of the original motor (crystalyte 407 I believe) is that it is QUIET and this is more important to me that all out speed or being able to haul 600 lbs up 25% grade. I'm a 40yo 6'0" 175 lb male that is in fair shape that will be using this for transportation and running around town/grocery store.

Anyway I'm looking forward to this project and sharing it with all of you. I'm sure I'm going to learn a lot and try to minimize my mistakes. After having several hobbies, I've learned to invest more in the beginning that tip toe into it and have a bunch of useless equipment by the time I finally decide to get what I want.

Thanks for reading and I'm looking forward to hearing what everyone has to say.

 

[Warren]

Lupolin,

You can buy the new Stokemonkey motor, controller, CA, etc. from Grin Cycle.

http://ebikes.ca/store/store_motors.php

Making a mount is not very difficult. Since the motor has a standard 100 mm/4 inch axle length, a short piece of 4 inch aluminum channel and two plates works fine as a mount, and is about as simple as it gets.

http://endless-sphere.com/forums/download/file.php?id=76962

You could mount it with various U bolts or strap clamps.

Here is one installed on a Surly LHT.

http://mrbill.homeip.net/albums/stokemonkey_and_ping_battery/pages/page_1.html

 

[Lupulin]

Hey Warren, thanks for your reply.

Cool! I had never seen a LHT set up with a StokeMonkey, thanks for the link. However I think I would rather keep my LHT as a regular pedal bike for touring and build the mini cargo ebike as my cross town and errand bike for getting stuff done without arriving all red and sweaty. I am planning on buying, if not all, at least a good portion of the equipment from Grin as Justin was instrumental in keeping the board alive and I believe he has earned some of my business as well as my Local Ebike Shop.

I'm curious why CleverCycles/Chimp and Justin (who I understand isn't a stickler for obeying the ebike power limits) chose to use a 500W motor thru the gears vs +1000W? There must be a reason as Naked Bicycles also used this same motor for its Big Bum. Is it a size limit? Was it done this way because its a quiet motor? Durability? Are they running it over 500W?

I would rather get ~ 1000W on 48V but I would like it to be QUIET and will sacrifice power for silence and stealth. Anyway, if I don't get much in the way of suggestions I probably will go the Crystalyte 40x route from Grin. Does anyone know the critical dimentions I will need to put the motor between the chain stays on an extra pair of dropouts ala Xtravois 2.0 so I can start drawing up more detailed plans and get them to the framebuilder??

 

[turbo1889]

As to frame ideas, since you mentioned a double F&R 20" wheel bike with cargo racks both F&R with a short wheel-base that isn't too long, thought I should provide you with this link (click on the picture) to add to your ideas list for your custom frame. It's not electric, but an electric mid-drive version or something similar could certainly be built.

 

[Warren]

Lupulin,

"I'm curious why CleverCycles/Chimp and Justin (who I understand isn't a stickler for obeying the ebike power limits) chose to use a 500W motor thru the gears vs +1000W? There must be a reason as Naked Bicycles also used this same motor for its Big Bum. Is it a size limit? Was it done this way because its a quiet motor? Durability? Are they running it over 500W?"

I assume the reason is size, weight, and price. Most of the time, running through the gears, you won't need over 500 watts at bicycle speeds. You would only need more if you want to go really fast. That is fine too. But to do it for any distance will take a huge battery. The controller determines how many watts the motor will put out. The motor determines for how long.

Check out the simulator over on Justin's site.

http://www.ebikes.ca/simulator/

The Stokemonkey is on there, in two different winds, as are lots of others. You can simulate the effect of running through the gears by changing wheel size in the calculator. Do you know about gear inches? Basically change your bike's virtual wheel size by multiplying by your gear ratio.

http://www.sheldonbrown.com/gears/

If you have the room, and the money, you could make an incredible cargo bike with a 25 pound Crystalyte motor, a 72 volt, 40 amp controller, and 4 kWh battery pack, running almost 2 horsepower through the gears, for 3 hours, and nothing getting too warm. But do you really need that?

 

[urbancommuterstore.com]

Here is my Edgrunner with a mid-drive kit. The front cranks freewheel. Im currently using a Crystalite motor. I cruise around 30mph on the road whenever possible just to get home quick from work at night.

http://youtu.be/ldKLiiz4Oj4 short video clip

 

[TroySmith80]

I've been thinking along very similar lines. Long bikes take up too much space in my garage, hard to transport by car and i rarely need the full capacity. I think with 20" front and rear, and carefully designed cargo space, you can carry nearly as much in a far smaller package. The ODK is really really close, but it's just too nerdy looking. Sorry, i guess i'm vain.

I've been working on a design of my own. Slightly long chainstays so there's room for Donkeyboxx or similar saddlebags without my heels hitting them in the back part of the pedal stroke, easy step through (this is really fantastic in a town bike), large and strong front rack, moderate geometry and body position, etc.

Some variations of the design:

I've been trying to decide if i have the talent, time and determination to make the thing a reality, or if i can just find something close enough that is for sale.

I don't know if i'd bother with the complication of a crank drive, now that the Bafang BBS01 / BBS02 are out. pretty much all of the advantages, but extremely simple.


Have you seen the EBS Leaf Long?

the NOiS cargo?

Lorri

Donkeybike

Demonchaux

The trouble is most of them are either ugly IMHO or are not available in the USA


See also: http://www.bikeforums.net/folding-bikes/813498-20-wheels-cargo-bike-2.html

 

[Lupulin]

Hi Troy,

I have seen the Leaf before and really like that bike. The same Japanese builder also has a long tail cargo bike that is pretty cool.

I hadn't seen the NOiS before, thanks for sharing that. I like it too, but I don't see myself using the bike w/o the rear rack, so I'd rather just have it welded on and be part of the frame.

I must say my favorite bike in your post was the last one you drew up. I have been trying to design a bike like that in bikeCAD.ca, but just couldn't figure it out!! I'm also with you re:bafang BBS02 drives. Since I have seen these, my requirements have shifters a bit. I think that drive system could be pretty cool. Would love to try one.

Jeff

 

[Bikengineer]

I love a good 'cycle truck'. Although it may look nerdy those bikes with a straight steel bar forming main frame, front rack and back rack would be very strong.