EbikeE and BMC for Comfort and Range

[Alan B]

Tightening the Headset

I removed the stem/steering column by loosening the clamping screw and slid it off. Underneath there is a split tube spacer from the steerer tube cap to the upper headset. There is a hex bolt holding the cap down, and it was loose. I snugged it down and the headset free play was gone, and the headset turned freely. So I reinstalled the stem and went for a test drive.

The feeling of looseness in the steering is gone, so it is definitely an improvement. It still steers quickly but feels more confident.

[pdf]

Looked up the similar test run made with the 9C 9x7 on the Mountain bike, and it used 26 watt hours per mile.

This compares to 17 watt hours per mile with the BMC V4C on the 'bent.

Amazing.

I suspect my average speed with the mountain bike was higher than the ebikeE, but the efficiency difference is too large to be accounted for by minor speed difference.

This geared hubmotor on this bike is quite efficient!

I am using a 9c 2810 at 18s LiPO on a mtn bike. Even going slightly uphill (There are some pretty significant climbs but also some valleys. The net result is slightly uphill), I use about 18 Wh/mi. The 9x7 would probably be less efficient on the hills if not kept up to speed but 26 Whr/mi seems much higher than any other numbers I've seen quoted. We built a 450 lb (including driver) electric "car" (actually a BugE, which is a 3 wheel tadpole motorcycle) with a brushed motor and if you keep your foot out of it, you can do 40-50 Whr/mi routinely, even with a modest grade. Does anyone else have some numbers for reference?

[Alan B]

Interesting. I have a couple other sets of numbers. The 9C 2807 has been on two mountain bikes, the 2810 took its place on the newer bike. Rider is about 200 pounds in one case, 150 in the other.

My work commute of 13 miles with 9C 2810 at 18S on a mountain bike uses about 35 watt hours per mile on the inbound, and about 25 watt hours per mile on the homebound trip with light pedaling. There are a lot of hills including some 10% on this route (and I pedal hard on the steep stuff and lightly at most other times). Well over 1,000 feet of vertical on this trip and some of that done twice. My experience is that anything under 20 watt hours per mile is very efficient, or it is flat and/or slow.

My son with 9C 2807 gets about 25 watt hours per mile on the test route (plus a bit further) where he was commuting for weeks when he was doing seasonal work at the shopping center. There are a couple hundred feet of vertical done twice over during each direction, so this is not flat but it is not steep, perhaps 5% at worst, but very little of it is level.

You are doing well to get below 20 watt hours per mile with the 9C. Good job! Do you pedal a lot? What is your average and peak powered speed?

My son doesn't pedal much, so his numbers are fully electric, mostly full throttle with the CA set for 20mph max. Some traffic, a few stop signs and lights and narrow littered bike lanes to navigate. He gets 30 miles range on a 10S 20AH Lipo pack which I think is fairly typical for 20 mph on a mountain bike (and is 25 watt hours per mile).

[pdf]

Interesting. I have a couple other sets of numbers. The 9C 2807 has been on two mountain bikes, the 2810 took its place on the newer bike. Rider is about 200 pounds in one case, 150 in the other

Weird. Not sure what the difference it. I can do a 14 mile round trip on a 5 Ahr 18s LiPO on that bike. When I charge it, it looks like I am putting about 4 Amp-hr back in it. Will pay more attention next time and be sure. Also, will look at watt-hr instead of current-hr on the charger if that is an option (I don't think it is though). Anyway, this is with essentially no pedaling, some short 15-20% grades, some (maybe half a mile) 5-10% grade. I do a round trip so I get the benefit of going downhill one way and up the other, so the net elevation change is 0.

Only difference I can see would be maybe my CA is not calibrated correctly for the controller I am using (it is a DP CA with a Lyen controller). I wrote Lyen to ask about what to use for the resistor calibration and used whatever he suggested (don't remember what it was though). I should point out that the rider weight in these cases is 165 lbs and that I usually ride on a Greenway for half the trip where 20 mph is the top speed most of the time. The Whr/mi is pretty sensitive to speed on hills so that is probably the biggest difference. Even off the Greenway, I usually stick to a top speed of around 20 mph to stay "legal". I am pedaling all the time but I know I am not contributing much because if I look at the current/power while pedaling and then stop, it changes very little.

[Alan B]

My experience has been that calibration is required to get accurate numbers.

[Alan B]

I've been looking at packing the batteries into the Searhorse case shown above. My earlier plan of using PowerPole 75's with #6 AWG pins to crimp quad #12 wires may be difficult to fit in the limited space of the Seahorse case. So this weekend I'm going to look for some #6 butt crimp tubes that could perform that role in less space.

I should check the CA calibration, the bike shop indicated they calibrated it but I don't know to what accuracy.

[Alan B]

Have to work on plumbing today..

Any suggestions for upgrading the brakes on this bike? V brakes, no mounts for disc. Are the stock ones decent or should I look for something better? At least for the front??

[StudEbiker]

There's this: http://www.ebay.com/itm/BIKE-E-FORK-gre ... 1c2207efc9

Or this: http://www.cycleclubsports.com/p-36942- ... b-36h.aspx

Someday I plan to upgrade to the front hub brake.

[StudEbiker]

Another option is Magura hydraulic rim brakes. If I could find a set at a good price, that would be my first choice, but with the odd geometry of the Bike E front fork I would like to know if they will work for sure before I bought a set.

[Alan B]

Finally got the plumbing done.

I take it by these suggestions that the stock brakes are a bit weak. That's my impression so far, but I haven't done any big descents yet with mine. Are they up to it? Or do I need to upgrade first??

The bikeE steerer tube may be 1-1/4", isn't it?

How do the drums compare to disc?

Since it is a steel fork I suppose a disc mount could be welded on.

The Shimano XTR V Brakes I put on my Mountain bike are pretty nice. Not sure if they would fit on the bikeE, but they might.

[StudEbiker]

Finally got the plumbing done.

I take it by these suggestions that the stock brakes are a bit weak. That's my impression so far, but I haven't done any big descents yet with mine. Are they up to it? Or do I need to upgrade first??

The bikeE steerer tube may be 1-1/4", isn't it?

How do the drums compare to disc?

Since it is a steel fork I suppose a disc mount could be welded on.

The Shimano XTR V Brakes I put on my Mountain bike are pretty nice. Not sure if they would fit on the bikeE, but they might.

The drum brakes are allegedly very close in braking power to discs, especially those 90mm S-A hubs. Also, they are all weather and basically maintenance free for about 10k miles.

I tried an XTR V brake on the front and had clearance issues.

I have used the brakes coming down steep descents, they do okay, but they don't inspire confidence!

One of the issues though is you don't want too much braking up front on one of these because of how the weight is distributed. Very light in the front, so too much brake and you can lock up the front. I think a big disc up front is probably overkill. I would really love to try the hydro rim brakes. I've been keeping an eye out for a used set for cheap, but no luck yet.

[Alan B]

Battery Wiring Harness



Today I made a battery wiring harness (started, not finished). Based on the earlier design but using crimp sleeve connectors. These are designed to hold up to 5 #12 wires, but in my design I have four #12 and one #10 so these sleeves are REALLY FULL. I crimped them with a 6 gauge die in my old West Mountain Radio PowerPole Crimper.

The wire is difficult to get into the sleeve, and once crimped it is locked in. I will insulate the sleeves with thick wall heatshrink later on.

This harness is set up for #12 current path of equal resistance to each of 12S3P Zippy batteries, #10 main current path, and #12 charge connectors on each of the two battery banks.

It is very compact to fit in the tight battery case here:



Above shows the bottom layer of batteries, one parallel bank, and the balance wiring and Methods HVC/LVC board.

[Alan B]

Sure would be nice to have a little more room in this nice SeaHorse case. The harness I made is taking more space than is available. May have to make another one more carefully designed for the space. May need longer wires just to get to the space available for connections.

[Alan B]

The hydraulic crimper arrived. Looks nice. No testing yet.

Took a run to the hardware store tonite.

Picked up some really thick heatshrink, some of the small copper crimp sleeves, and a ten foot section of "vinyl downspout". This stuff looks quite useful for batteries. It is 2" by 3" so the Turnigy fits with 1" to spare, but the Zippy 6S 5AH packs fill the tube nicely, leaving room for some wires to pass by. It is thin and light and somewhat flexible, not brittle like PVC. The inside size is just under 2-1/4 by 3". The Zippy packs are under 7" long so six of them is 42" plus some space for connections and balance boards, easily under 50".

Taking a tape measure to the bikeE we find:

Above the top of the frame beam is about 20-24", depending on where the seat is positioned. With my long legs there is about 24" available.

Under the frame beam is 30 inches to where the cables come out.

Six Zippys 6S8AH are about 1KWH and takes a bit more than 42" of this rectangular vinyl pipe. Could split the battery into the two halves of three Zippys in parallel each and get 12S 24AH in a pair of 24" long pipe batteries. These could go above and below the beam, or on either side of the beam under the seat but spaced out a bit to miss the forks. The motor controller could go right at the aft end of the tube under the beam.

This is very tempting. Anyone else done this? Others have used this vinyl downspout pipe on some builds, but not a recumbent that I recall.

So should I make a vinyl tube battery for the bikeE?

[Alan B]

Took a closer look at the battery situation today. I'm going to try a vinyl downspout tube battery. Three Zippy 6S 8AH in parallel in each 24" tube. One above the frame, another below.

[docnjoj]

I have a E-Bikee with a rack just under the seat. It could house your batteries easily and these racks are still sold. Might be an option?
otherDoc

[Alan B]

I'll have to look for those. Didn't know they were still available.

[Alan B]

Not easy to find, BikeE underseat racks.

[docnjoj]

Here is one that could work. Not cheep though. It seems that Bike-e parts are getting more difficult to find.

http://www.calhouncycle.com/productcart ... roduct=118
otherDoc

[Alan B]

Here is one that could work. Not cheep though. It seems that Bike-e parts are getting more difficult to find.

http://www.calhouncycle.com/productcart ... roduct=118
otherDoc

Thanks for the link. Looks like a good rack. Not sure if it will fit the square beam of the BikeE...

[Alan B]

Installed the Big Apple tire and thornproof tube on the front wheel, and moved the thumb throttle to the right between the brake and shifter. Had to leave a gap so the throttle didn't hang up on a protrusion from the shifter. Adjusted and tested the mirror. Removed the temporary batteries so now it is pedal powered. Started making the new battery setup with 2x3 vinyl downspout. Ordered more vet-wrap.

Next need to make a new wiring harness for the batteries in the square tubes configuration.

Nice weather here today, over 70F, and going to be warmer tomorrow.

I need to break out the hydraulic crimper and get busy...

[Alan B]

Bad News

The zippy batteries fit nicely in the 2x3 vinyl downspout pipe... right up to the wiring pcboard where they get a little taller and wedge.

Back to the drawing board...

[ddk]

Bad News

The zippy batteries fit nicely in the 2x3 vinyl downspout pipe... right up to the wiring pcboard where they get a little taller and wedge.

Back to the drawing board...

were you using the small tubing or the large?
just wondering... it seems a clever solution for packaging LiPo sticks.

*edit* I see you were using the smaller down tube.
It's also available in a larger size of about 3x5

[Alan B]

They only had one size at Home Depot. It is 2" by 3". What is the other size??

[ddk]

HD would have to special order it but ~3x5
I know it's available
used it on my house in 2003