NAHBS 2014 mid-drive build

PaulD

1 kW
Joined
Aug 28, 2008
Messages
361
Location
Ashland, OR, USA
Hey ES,
I thought I'd post some build pics of the ebike that I took to the North American Handmade Bike Show in Charlotte, NC last week. I had the opportunity to work with a super talented industrial designer and go from concept to prototype over a 6 month period.
As many of you know, NAHBS is typically not the kind of show where ebikes are welcomed, but fortunately Gates wanted to display a few ebikes utilizing their belt drive, which opened the door to allow me to bring an ebike. Paul Brodie had brought an ebike to NAHBS in 2013, but the organizers were hesitant to allow them this year. Good thing a big company like Gates believes in the electric revolution!
Anyways, other than gates, I had the only ebike, so I got a lot of attention. I had the pleasure of meeting Snath (Larry) who traveled from Atlanta. It was great to meet an ES member there, and Larry showed me some of the cool battery stuff he is working on and some of his builds.
Anyways, here are some pics of the build process. Things were rushed (understatement) leading up to the show, so it's amazing that everything came together in time!
1174715_304821049671254_226928841_n.jpg

1511236_304821373004555_1152471944_n.jpg

10155289_304821489671210_1639220816_n.jpg

1926828_304822129671146_537205733_n.jpg

1888751_304822329671126_2145458727_n.jpg

10012535_304823043004388_7283364_n.jpg

10155765_304823509671008_1348510494_n.jpg

1148945_304823673004325_2135313330_n.jpg

1503828_304826133004079_423895476_n.jpg

1901250_304826343004058_2075349356_n.jpg

1908259_304826693004023_1925732156_n.jpg

1011597_304826439670715_1713475458_n.jpg

1660882_304823713004321_79705148_n.jpg

10014930_304844693002223_1697613075_n.jpg
 
Paul's craftsmanship and attention to detail was equal to any that I saw at the show. Not to mention, of course, that his was a way cool ebike!

It was really neat to meet up with a noted ESer.
 
Mind if I write an article about this bike? Thanks for posting this, either way.

If it's any consideration...I have it on good authority that Vladimir Putin does not want you to allow me to write about this, and I think you should stand up to assert your rights as an independent E-biker, if only as a symbol of hope and freedom for E-bikers everywhere.

edit: as much as I am hesitant to critique what is clearly a work of art and the organic display of an untamable genius...it could use a billet coffee cup holder and a suspension seat-post?
 
Thanks for the comments, all.
Ron, no problem on writing an article on the bike, I'd appreciate it! Let me know if you have any questions.
K-Ray, total weigh is about 38lbs. The goal was to keep the weight down and as close to the bottom bracket as possible. This will hopefully make it feel as agile and bike-like as possible.
 
Paul! Raising the bar my friend! Outstanding!

You are an artist! I'm blown away!

Next race we are gonna do, you gotta let me ride it!
 
Thanks guys. The true artist is the industrial designer, Michael Hritz. You can see some of his other work here: https://www.facebook.com/michaelhritzart
I just took his art and made it into an ebike.
Oh and that is my girlfriends dog, Molly. She's a sweet dog, and is far more photogenic than me.

Luke, at 750 Watts, it's no race bike, but you'll definitely have to take it for a spin when. I see ya next!
 
Warren said:
Paul,

An absolutely gorgeous bike. I saw the show when it was in Richmond, Virginia in 2010. Handbuilt craftmanship to make you cry. Glad to see more e-assist entries.

Is 38 pounds with the battery pack installed? If so, how many Wh is the pack?

Thanks Warren. There were some amazing bikes at the show. The craftsmanship and detail is crazy on some show bikes. I shudder at the amount of time put into finish work and small details.
The 38lbs is with a 470wh pack. I am working on some changes that may result in a slightly heavier pack, but I think some weight can be taken out of the frame and drive system...
 
Wow!! That's such a light bike for having a very useful amount of battery on board! Fantastic job as usual my friend!

I love the picture of your Dog with the brazed frame, something is very artistic about it. You and your lady and dog are always welcome to visit again anytime you like. :)
 
liveforphysics said:
Wow!! That's such a light bike for having a very useful amount of battery on board! Fantastic job as usual my friend!

I love the picture of your Dog with the brazed frame, something is very artistic about it. You and your lady and dog are always welcome to visit again anytime you like. :)

Thanks buddy. Very few ebikes have the insane level of weight saving efforts found on modern road bikes. I think there is a lot of room for improvement on high end ebikes. And, you and your wife are always welcome here if happen to be passing through Ashland.
 
Paul,

"The 38lbs is with a 470wh pack.

Yeah. I realized, after I wrote to you, that I could figure it pretty close from your photo of the naked pack...10s4p?...that it was around that size.

"Very few ebikes have the insane level of weight saving efforts found on modern road bikes."

For a steel bike, with a reasonable amount of battery, you are doing great.

There is this, but the drive and battery is tiny. Drives like this can work, but only for an avid cyclist.

http://www.electricbike.com/lightest-bike/
 
This transmagnetics 4-inch diameter motor is VERY similar to the GNG motor, but smaller. It has a low pole-count, but...it also has the desirable thin 0.35mm laminations. Between the two, this motor should be able to be run very happily in the 72V range (if you want).

By the way, I added the details provided by Paul, so the article is 99% done now. After staring at the frame for a while, I noticed a few other things about it, this is a more sophisticated design than what I had at first thought. Paul states he was inspired by the Green Pea Bikes concept design, put together by Michael Hritz.
 
s. Later, the brass welds can be sanded perfectly smooth for an incredibly beautiful finish.

Hi Ron, Great article on this nice bike. One correction however, brazing (despite the name) uses BRONZE rod, not brass, as the filler material. Bronze is stronger and more corrosion resistant than brass.
Many bronzes are significantly stronger than mild steel.
I used to modify motorcycle frames quite a lot, and always brazed them rather than welded. Brazing has several advantages over any form of fusion welding:
-The parent metal is not melted during the operation, so does not tend to become brittle along the edge of the weld;
-The bronze (when brazed by a skilled operator) tapers nicely from its maximum thickness in the middle of the joint down to the surface of the parent metal. This feeds the stress from the joint smoothly into the parent metal. Some welds change cross section rapidly at their edge, producing a "stress-raising" sudden change in area.
-Both of these factors mean that a brazed joint can be significantly less affected by fatigue than a weld.
And, as you say, can look nice as well

For these reasons, the tubular chassis of the Arial Atom sports car is brazed, not welded. They had to go round the old folk's homes to find retired craftsmen who were skilled in brazing, because it is pretty much a "lost art"! The retirees taught a new generation the methods.. and a few frame builders are keeping it alive too.
Regards,
Dave
 
Warren said:
I am confused...no news there...how do you wire up 40 cells to get a "48" volt system?

https://scontent-b-sea.xx.fbcdn.net/hphotos-ash3/l/t1.0-9/1148945_304823673004325_2135313330_n.jpg

Good eye, Warren. That is the first prototype pack when I was running at 36V. I was so rushed I didn't take pictures of the current pack.
 
Back
Top