Hub "Mid Drive" Build

[LI-ghtcycle]

No freaking way O_O...

In a way, it makes sense that your efficiency is higher.
Hub motors do have an efficiency range, and if you keep them at peak efficiency, you can really go far on less amp hours.

By the way, do you cycle in the crouched position the entire time, or upright? i hear that makes a big difference.

My riding position is the same as it has always been, slightly forward, I make no attempt what so ever to crouch, the fairing does all the work, however, once I get the helmet I want, I imagine I will have less drag, as a MX helmet with the large visor on the top must cause a good deal of drag.

I think the real difference the fairing makes is in that the slightly forward angle of one's chest when riding makes a rather large "pocket" much like if you had a piece of cardboard about the same width facing the wind, this makes a very high drag "sail".

The fairing eliminates this largest section of drag from the equation, and all the rest is really insignificant by comparison, so that is why I notice a big gain (this is just my thoughts, not anything specifically told me by Karl at Zzip Designs).

[Gordo]

If you happen to find that the ABS wears quickly, try finding an old kitchen cutting board made of the white slippery type of plastic.

Its polyethylene AW....

KiM

AW, Kim;
We have found that the 55US GAL plastic food grade barrels are made of the same stuff (HDPE) and are almost indestructible. The food industry can only use them once so they sell for $5-$10 from yogurt or jam makers. We used it for ski-skins on snow machines to slides on lumber chains. The links of a lumber chain are 1.5" X 4", run 24 hrs per day carrying lumber in a mill. A strip of barrel last @ 10 years.

[LI-ghtcycle]

If you happen to find that the ABS wears quickly, try finding an old kitchen cutting board made of the white slippery type of plastic.

Its polyethylene AW....

KiM

AW, Kim;
We have found that the 55US GAL plastic food grade barrels are made of the same stuff (HDPE) and are almost indestructible. The food industry can only use them once so they sell for $5-$10 from yogurt or jam makers. We used it for ski-skins on snow machines to slides on lumber chains. The links of a lumber chain are 1.5" X 4", run 24 hrs per day carrying lumber in a mill. A strip of barrel last @ 10 years.

Perfect!! Thanks for the tip!!

I just happen to have a black 55 GAL drum of that stuff! Good thing I didn't find a cutting board at goodwill!

[AussieJester]

If you happen to find that the ABS wears quickly, try finding an old kitchen cutting board made of the white slippery type of plastic.

Its polyethylene AW....

KiM

AW, Kim;
We have found that the 55US GAL plastic food grade barrels are made of the same stuff (HDPE) and are almost indestructible. The food industry can only use them once so they sell for $5-$10 from yogurt or jam makers. We used it for ski-skins on snow machines to slides on lumber chains. The links of a lumber chain are 1.5" X 4", run 24 hrs per day carrying lumber in a mill. A strip of barrel last @ 10 years.

I actually have a couple of meter square 10mm thick sheets of polythene i bought it for my DiY CNC build
I think i sent a couple of strips of it to AW in a package too IIRC? Slippery stuff and wears well is good for chain guides for sure. Don't know of the drums you speak of though Gordo don't think we get them like that in OZ.

KiM

[amberwolf]

I actually have a couple of meter square 10mm thick sheets of polythene i bought it for my DiY CNC build
I think i sent a couple of strips of it to AW in a package too IIRC?

Yep; if I hadn't already had the cutting board pieces in place, I'd've used some of what you sent for that. However, since it's still intact I can use it for other guides on whatever middrive I come up with for CB2 or it's descendant.

[Gordo]

I actually have a couple of meter square 10mm thick sheets of polythene i bought it for my DiY CNC build
I think i sent a couple of strips of it to AW in a package too IIRC? Slippery stuff and wears well is good for chain guides for sure. Don't know of the drums you speak of though Gordo don't think we get them like that in OZ.
KiM

The other source of HDPE I just recalled was natural gas line. Comes in many sizes and colors. Very thick wall. I have pushed a piece of AL pipe inside the HDPE and then a bearing in the pipe. With a grove in the plastic you have a good guide roller.

[LI-ghtcycle]

I'm really glad that I have this recorded in the "Efficiency" thread, so that I can be sure that I'm not just excited and exaggerating!

http://endless-sphere.com/forums/viewtopic.php?f=3&t=6615&start=60

Here is the trip I took to Portland to have the Nuvinci built, using the Amped 9 x 7 rear hub motor while it was still in the rear wheel, and the efficiency was about 13 Wh/Mile, and now with the mid drive, 7 Wh/Mile!

I did want to correct something however, I confused myself thinking that at one point I had a 30A controller with 9 x 7, I think this is because I tested a different kit recently that does indeed have a 30A controller, so some of my conclusions were incorrect based on that, however, I am still using a watt meter, and that will keep track of the watts properly no matter what the controller's amps.

I have switched from getting a disc front brake hub to a Sturmey Archer 90mm Drum Brake hub for the longevity of the brake shoes more than anything, but being sealed from the weather, I think this will be a huge asset as well, since not even freezing rain would prevent normal operation of the the front brake, not to mention I won't need adjusting/servicing for many thousands of miles!

Don't get me wrong, I have nothing against disc brakes, but for the lack of maintenance and still have comparable stopping power to good front V-Brakes (when they are in ideal weather/operating conditions) and a proven track record being used on heavy cargo bikes, AND allows me to avoid the whole QR skewer dilemma since it has a solid axle, it's a perfect choice for me.