Hub "Mid Drive" Build

[amberwolf]

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. It may be cast from teflon; I used pieces from one as chain guides on CrazyBike2's powerchair drive, and they worked wonders without catching the chain, and didnt' show any signs of wear when I eventually removed all taht and went to the hub drive back in October.

[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. It may be cast from teflon; I used pieces from one as chain guides on CrazyBike2's powerchair drive, and they worked wonders without catching the chain, and didnt' show any signs of wear when I eventually removed all taht and went to the hub drive back in October.

Great idea! I'll keep an eye out for some at the local goodwill, need to get a new fanny pack anyway. Hopefully the pipe won't show any wear to speak of.

I'm going to start cutting up old frames soon as I can and build a rack that allows the motor to be in a better position.

Really don't like having the high center of gravity, makes the bike far too tippy! Might get started on my front racks first if I can cobble something together until next week when my neighbor can do some more welding for me.

[neptronix]

Ahh yes.. maybe a smaller motor like a bafang or mxus geared hub would do better for weight balance. i think you can get them as light as 7lb. Half the weight, and you can bring it down closer to the wheel..

Of course they can't kick out the same amount of power tho :/

[John in CR]

Okay LI-ghtcycle, now it's time for the biggie now that you have the gearing dialed in. What kind of mileage are you getting with no pedaling? wh/mile on the flats at say 20mph. Did you run the motor before in-wheel for some directly comparable data?

[LI-ghtcycle]

Okay LI-ghtcycle, now it's time for the biggie now that you have the gearing dialed in. What kind of mileage are you getting with no pedaling? wh/mile on the flats at say 20mph. Did you run the motor before in-wheel for some directly comparable data?

Yep, I'll have to look back at my post in the efficiency post to get specifics, but honestly, I have to do some more riding to make sure the gearing is dialed in, yesterday I was so beat after trying to make a tensioner, that I only road across the street in the neighbors extended driveway back and forth, and with some wind skewing things.

[John in CR]

Even just a preview would be nice with existing gearing, you can always change the Nuvinci setting to get what looks the lowest current for that speed. In real world use we wouldn't be continuously adjusting the Nuvinci, would we? I'm just interested in whether it seems like you're taking a notable efficiency hit from the Nuvinci, or does it pretty much pay for itself for overall efficiency by allowing higher rpms, especially at the lower speeds. It would be great if the extra hill climbing ability comes with an overall gain, but it would be worth it to me even if it cost 5-10% overall.

Maybe you mentioned it before and I missed it, but how is the chain sound?

[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

[LI-ghtcycle]

Even just a preview would be nice with existing gearing, you can always change the Nuvinci setting to get what looks the lowest current for that speed. In real world use we wouldn't be continuously adjusting the Nuvinci, would we? I'm just interested in whether it seems like you're taking a notable efficiency hit from the Nuvinci, or does it pretty much pay for itself for overall efficiency by allowing higher rpms, especially at the lower speeds. It would be great if the extra hill climbing ability comes with an overall gain, but it would be worth it to me even if it cost 5-10% overall.

Maybe you mentioned it before and I missed it, but how is the chain sound?

Well, first off, I don't have a wind tunnel or any other real impirical way to give anything more than my anecdotal experience, that being said, from the get go, I have noticed a slight decrease in efficiency in the form of a slightly slower top end, say 2-3 MPH less on my top end, however, it has been more than off-set by ability to gain efficiency on the low end.

I'm not sure what you mean by not wanting to adjust the Nuvinci continuously? I love the fact that I can dial it in to the exact gearing ratio that is most comfortable/efficient for both my legs and motor and I can do it with out having to think about it, it's one of the main reasons to get a Nuvinci IMO, because you have nearly infinite "gears" with-in the range that it spans.

I have definitely noticed already a pretty big gain in the hill climbing efficiency, I would say it's about 20-30% more efficient with the amount of watts needed in the past with-out it using the same hub motor in the wheel.

Now it's even more efficient since I can gear it down so low, but until I get some weight on it, I won't really know the full extent of it's increased efficiency, the best base-line I can say now is once I have my cargo pod/panniers built and loaded with the same amount of weight I had when I went to get the Nuvinci wheel built, and see how many watts it takes to take it on a day that isn't so windy (14 MPH steady just when I pulled up 20 mins or so ago, and we have gusts up to 40MPH!).

As far as chain noise, what noise! It really isn't noticeable, no louder than any other bicycle chain, even with the 13T. Chain wear might be a different story, it seems to have stretched considerably today, but that could just be because I have 4-6 links from an ancient exercise bike, that reminds me, I better go buy another chain so I can have all new links, I think the old stuff is starting to stretch.

I only went 5 miles so far today since I realized after hitting the goodwill looking for a plastic cutting board and new fanny pack, I reached for my air horn at one point "just-in-case" and it wasn't there!

I had forgotten to re-attach it when I installed the fairing!

It worked out anyway since the chain is so stretched now it seems like I could take out a link! Hopefully that is just the old chain, not the whole chain stretching!

Anyways, I'm going to just have the lock nuts hold the chain tight long enough for a trip down to the bike shop and get a another chain, then I'll see about adapting the drop-outs from my nephew's pocket bike to my test rig so I can really tighten up the chain right. There just isn't a real good spot to put a tensioner with that I have now, no good places to attach one.

[LI-ghtcycle]

Well, all I can say is if this were the Myth Busters show on Discovery, and the question was "do upright bikes benefit from handlebar mounted fairings?" then this baby is ..........















CONFIRMED!!!!!






I just had a nice little trip nearing the end of the day starting at about 4:15 PM, and I took my usual route to the bike shop, then to the hobby shop to get my loaner charger so I can send back my Hyperion to be warrantied, and I got to test the gamut!

First, I went along with traffic after leaving my house, got up to about 20 MPH before turning into a nearby housing development, then soon down my favorite hill, and a special treat!

There just happened to be a guy in a recumbent bike in the bike path, so I thought sweet! Lets see if I can catch up to him and maybe even pass him! (he was almost a full block ahead of me, but I imagine he doesn't go for broke down this hill, most cyclists are afraid to)

And then I noticed I had a light but noticeable headwind, so I thought, oh well, at least I can see what it will do under these conditions.

To my surprise, I went down the hill with something between a 5 - 10 MPH headwind according to weather underground (we have had a pretty sporadic yet dominant SE wind most of the day, calm much of he time) I still made it up to 37 MPH going down (normally in these conditions I would be lucky to get 33 MPH) kept the cars at bay behind me, AND passes the 'bent at the point where things start to flatten out, he was really kewl, gave me a big thumbs up!

SO.... the next part of the test doesn't really come until the trip back UP that monstrous hill!

After going around down town OR City, to the hobby shop then back to the base of the elevator and chatting with Al and Steve at Classic Cycles, I headed up the elevator around 5:50 PM (I almost always take the elevator, so this is part of the normal routine, sure I would have used more energy going up the first steep part of the hill, but the elevator still doesn't spare me of the steepest part of the nearly 2 mile long hill which is 12%).

One thing that I have started to realize at this point in the ride is that the motor doesn't really pull much until I hit about 60 - 75% throttle, so it's definitely running at a efficient range with the new gearing!

I take the same path on the sidewalk up the steep part of 7th street mainly because it's the most direct route, and I don't have to take Linn (the same path I like to go down) that has a really narrow bike path along a winding narrow road with blind corners where cars usually creep into the bike path while turning, and I don't have to worry as much about stopping along the route as 7th is a main through street.

When I start to approach the DQ I know I am going to have to gear down to the smallest ring in front (22T) of my pedal chain to make this hill, and to my surprise, I really didn't have to add anything at all!

Since the motor is now running in such a efficient way, I really don't need to add any pedaling at all, and it's going 10 MPH on the steepest part, 12% with ease, at only 15AMPS!!

This is FIVE amps less than before for the same performance!!

And here is where I got really excited!

The total trip was 8 miles, I used just 1.79 AH!!!!

That makes 86 Wh's for 8 miles, so just 10.75 Wh's per mile!!!

So you want to know if the gearing is the real change worth noting or the fairing, well, to that I'd have to say both! Reason is, going down hill, with the gearing of the motor maxing at 30 MPH no-load speed, it's not adding anything going down, and it's just my pedaling adding another 7 MPH going down hill into a pretty good head wind, AND going up hill, it's probably more about the gearing on the 12%, but I'm sure that the fairing still helps!!

As far as testing with-out the fairing too, sure, I'll get around to it, but it's gonna have to be a really warm day since I'm really loving the extra protection given to my hands, and when it's 50 F , it still gets too chilly for my hands in even my favorite neoprene gloves.

To compare, this kind of a trip typically would take an average of 1 AH per mile when including that big hill climb so, in other words, normally that would have taken 8AH's, and I used less than TWO!!!

I have to say with today's results being even much much better than yesterday, as far as I am concerned, this fairing has been worth it's weight! If I wanted similar performance by just getting more battery and voltage, I would have paid more than double, and I would have added twice the battery weight as I have now, in other words, I might not need to go 14S after all, 12S might just be fine especially considering it's a very real possibility that 12 AH's can do the work of 24AH's!

[neptronix]

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.

[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.