EbikeE and BMC for Comfort and Range

[Alan B]

Just noticed it looks like you have chrome front forks. Those are pretty rare and are a desirable option for a Bike E. I like what you have done with the battery carrier. Have you checked the wheel base on your Bike E? 52"=standard Bike E, 56"=Ex. long. The long frames are nice to have even if you aren't too tall.

Thanks for the info. I haven't measured the wheelbase. I'll have to measure it. I think it is too long for my bike rack, but haven't tried that yet. The longer frame would be better for carrying batteries. I wish it was easier to get inside the main beam. There's room in there for a modest battery pack but the riveted rear fork setup takes a lot of internal space and isn't easily removable. I'm tempted to remove the rivets and make a slide in tray that bolts the rear forks on. The tray could carry the batteries forward and controller to the rear and make a very tidy package.

Interesting about the front fork. What is different about it from the non chrome units?

I have noticed a little play in the Aheadset. I'm not sure how to adjust that. it doesn't seem to be a problem, it is only noticeable when taking the weight off the front and wiggling the handlebars forward and back.

[StudEbiker]

Most of the front forks are painted gray. Putting the batteries in the frame is something that I think everyone that thinks about doing a Bike E thinks about, but in the end I just don't think it is very practical. As you have already noted, the space is pretty small, there's rivets for the rear fork, and the cables run through the frame. It's really nice to be able to run the cables through the frame put many batteries in there and then you have to run your cables on the outside. The longer wheelbase is not just good for carrying more batteries, it is also better for weight distribution (especially if you're not too tall) and allows for a bit softer ride as the frame will flex a little more.

[Alan B]

Another bit of progress - picked up the motorized wheel. It is a BMC with 7 speed 11-30 freewheel and Schwalbe big apple from ebikessf.com. Ilia was very helpful in getting things ready in time and everything is pre-tested so we should be good to go in that department.

[Alan B]

The wheel fits. With the Big Apple 2.35 it just barely clears things. Had to remove the brakes to get it in. They will fit, but it was easier to have them out of the way. Deflating the tire should work also.

So what's the deal on the dropouts? 11mm wide?? Very shallow, too. Steel. Not terribly thick.

Probably need torque arms both sides at least. No regen on this gearmotor with freewheel. That's a bummer because the hall connector won't fit through the arm.

I'll reserve judgment until I can get better light on the project. It was late and the light isn't good where I had room to work on it.

[StudEbiker]

The wheel fits. With the Big Apple 2.35 it just barely clears things. Had to remove the brakes to get it in. They will fit, but it was easier to have them out of the way. Deflating the tire should work also.

So what's the deal on the dropouts? 11mm wide?? Very shallow, too. Steel. Not terribly thick.

Probably need torque arms both sides at least. No regen on this gearmotor with freewheel. That's a bummer because the hall connector won't fit through the arm.

I'll reserve judgment until I can get better light on the project. It was late and the light isn't good where I had room to work on it.

Yeah, deflating the tire is usually easier than taking the brakes off if there is clearance issues.

Steel doesn't need to be as thick as aluminum to have the same or better strength, so the dropouts are plenty adequate. I don't know how many watts you are planning to put through the hub, but I would think one torque arm would be okay for up to 48v. Popping the connector off the hall wires to pass through the torque arm and putting them back on is not complicated or difficult.

[Alan B]

I measured the distance between the axles a couple days ago and it fell between the short and long wheelbase numbers. Not sure if that was the correct way to measure it.

Well my batteries arrived yesterday so last evening I started charging batteries one by one on the Cellpro charger. However the evening's activities were interrupted when I found out my wife had a call from Microsoft yesterday and they spent an hour or more "cleaning up" her computer. Obviously a scam. So we were busy cancelling credit cards and scrubbing her computer. Maybe her next computer should be a Mac. She's used PCs for years and normally would not fall for a call like that but she was having some problems and it came at the right moment.

So the schedule (to make the ride) is very tight now, maybe not even practical. I'm going to forge ahead, but the bike may not be ready in time for Saturday's ride.

I have decided to go with 12S Lipo for now. It makes things easier and quicker and reduces some potential problems. I still need to make the wiring harness. It is about 20% complete now. Torque arms to do as well, NordLock washers to install, mounting the controller and throttle and routing wires, connect the batteries and strap them down. Finish charging the batteries individually. Make female-female JST cables 2 each. Test and program the controller and cycle analyst. Mount a mirror. Collect tools and clothing for the ride. Mount a water bottle cage. And a few more things I'm not recalling now.

[Alan B]

Charging the last new battery now.

My other batteries are very close to full charge, may top them up but probably not needed.

However the torque arms are a problem. The holes are undersize. Hard work gently enlarging them. 1 hole of 4 done.

Also it appears there is not enough room for the standard torque strut. So I will have to make custom ones.

[StudEbiker]

What is a torque strut?

The wheelbase is measured between the contact points of the front and rear wheel.

[Alan B]

I remeasured the axle to axle length and it is 52". So it is the short wheelbase, unfortunately.

So I spend the rest of the evening filing torque arms. Now all four holes fit. Whew.

The torque strut is the piece that goes from the end of the torque arm to the frame. It is in tension or compression. On my mountain bike I went through the calculations and discovered that at the force level it operates it could be 6061 Aluminum so they are not hard to fabricate. I do not like the slotted ones that are supplied as the slot makes it easy to adjust but allows the parts to slide at some unknown force far below the material strength, so I make a strut the right length and drill precise holes to fit the bike. In addition I thread the strut on one end because on my mountain bike there was insufficient space for the supplied nut to clamp the arm to the strut. The same appears to be true with this recumbent.

I also drill the clearance hole at the other end undersize and ream it to fit so there is very little play in my torque strut.

So, to complete the rear wheel installation I need to take the hall plug apart and thread the nut and extra washers off, thread torque arm and washers back on, put it all together, make the torque struts, and reassemble the hall connector. I might have to take the phase connectors off as well and replace them after.

Some folks have indicated that the torque arms might not be needed with the steel dropouts, but given they are 12mm wide and the axle flats are 10mm or a bit less I think the torque arms are probably required.

[Alan B]

The bad news is that I didn't finish in time for the Mega Monster Enduro ride today. In fact, I'm not quite done yet, though as you can see in the snapshot above the torque arm and torque strut are in place. I've added a bunch of photos to the album here:

https://picasaweb.google.com/1158081452 ... directlink

The good news is at this point the motorized wheel is mounted. I took it out for a pedal test after dark when I finished installing the #10-32 socket head screws into the frame. They are not the standard metric threads on the rear dropout that most bikes have. So I had to make a hardware store run to get them. Interestingly enough, the water bottle mounts are metric standard. So the bike is a mix.

Anyway, it pedals and glides fine. So that is good. It's a roller again. Seems to have good pedal speed with the 11 tooth cog on the 7 speed freewheel.

The Nordlocks and other spacer washers are installed, and the motor power cable routed. The controller is temporarily installed. The rear brakes were reinstalled.

The motor cable connectors need to be reinstalled as they had to be removed for passage of the parts. Still have lots of wiring and detail work to do, but it is close to an electric test!

[Alan B]

One other comment is that the torque arms are pointing to the rear, so the reaction force is upward into the dropout. This is especially important since the shallow dropout is not a tight fit being 12mm wide where the axle flats are only 10mm. So all forces on the dropouts are either up or to the rear.

[Alan B]

I updated the photo in post #1 of this thread, the "before" picture.

Today I have been doing all the little stuff. I installed the thumb throttle, cycle analyst, speed sensor, made a battery cable adapter, and put a pair of 6S 5AH turnigy Lipos on the top of the main beam. Most everything is held on with tie wraps and/or vet wrap. So there is only one significant task left to go, and that is repairing the motor cable that was cut off earlier to facilitate installation. That and calibrate the wheel diameter for the speed sensor. After lunch I'll see if I can get that done before the weather turns. It has been nice, but overcast is moving in and it may rain later.

[Alan B]

She's electric!

12S 5AH 50V (full charge)
BMC V4C rear hubmotor (speed winding)
20" Schwalbe Big Apple rear, 16" gumwall front
Lyen 12FET Controller
Cycle Analyst Large Screen direct plug w speed sensor
2 ebikes.ca torque arms with homemade torque struts

Top speed approx 25 mph, still accelerating a little, calibrated the wheel from measured diameter.
Power 1000w noticed so far when climbing

Climbing 10% did okay, not super fast, will have to measure better later.

Was reminded that I need a rearview mirror, forgot to install that.

Slight surging noticed if the load is very light, will have to try adjusting parameters or try an Xlyte analog controller.

I like the motor on the recumbent. It is really nice gliding along, and getting launched up to speed. There is a little gear noise, not loud but noticeable. It glides very nicely when the power is off. Can pedal to about 25 mph, so well matched.

The brakes seem decent. Coming down the 10% warmed the front rim and I could smell the pad rubber slightly since it is so far in front of me. The rear rim is painted and that brake works well but screeches a bit under some conditions.

There is a little play in the headset bearing. Need to figure out how to tighten this Aheadset.

Need to start thinking about a more permanent battery. Perhaps four 6S 8AH zippys in 12S 16AH?

[StudEbiker]

Here is a link to the owners manual, but it doesn't cover headset adjustment.

http://www.bicycleman.com/recumbents/bi ... Manual.PDF

I was looking at your newer pictures on Picasa and noticed that you have the throttle to the left of the brake lever. I think the throttle would be much easier to reach if you put it in between the grip and the brake lever. 25MPH on 12s LiPo with a gear motor in a 20" wheel is quite impressive! I look forward to some long term test reports.

Do you have a way of getting a total weight of the bike?

Also, did you take any pics of the custom torque struts as you were making them. I need to put a torque arm on the Nuvinci, so I could use one of those.

[Alan B]

I don't have photos of making the struts, but it is pretty simple. I use 1/8 by 1/2 inch 6061 T6 but mild steel would be even better. I cut to length and drill two holes at precisely the right spacing. I do that by drilling and threading one hole, mounting on the bike and marking the other hole, and drilling that hole just undersized and reaming it to fit.

I did have enough room behind one of the struts to mount the nut on the backside. On the other I used some washers so the bolt would not protrude too far and touch the chain.

Thanks for the comment on the thumb throttle. I will take a close look at that arrangement. It is pretty easy to reach where it is, but the hand position ends up onto the shifter a bit.

I calibrated the speedo by measuring the front tire diameter minus a little and calculating the circumference. Hopefully that is close. At some point I should check it with GPS to see if it is accurate. The values I'm getting are consistent with the predictions from Ilia, so it is probably real.

Thanks for the manual link. I've seen adjustment instructions on the net for the Aheadset, just have to adjust them for the unusual stem setup here.

There are a bunch more pictures in the album than I've linked on this thread. Link to the album in post #1 and also a few posts ago.

Total weight is bike plus BMC wheel, controller, batteries, wire and misc minus stock wheel. Batts are four pounds (two times 2 pounds), maybe one to two more for everything else except the wheel. So 5-6 plus the wheel difference. It is very light, maybe 45 pounds. Much lighter than my mountain bike with 9C etc. I'll try to get a better weight soon.

Edit - BMC motor is about 9 pounds according to web. Probably motor alone. So weight is probably about 11 pounds plus batteries. So 15 pounds plus bike or about 45 pounds.

[Alan B]

Thinking about batteries

I ordered three of the 5S 8AH Zippy's by mistake a couple weeks ago, intending to get the 6S variety. I wonder if I should use them on this bikeE at 15S. That would give me a bit more speed, probably just at or over 30 mph. Three of them is only 440 watt hours, so perhaps get three more and have essentially 900 watt hours. 15S is not the best setup for charging, but it can be handled.

I was originally planning for 18S as it matches my other bike, but that is a bit fast for this setup at about 35. Plus those batteries are paid for, so the incremental cost is rather lower than some other approach. Except for the charger which is a longer term investment. The RC charger will work at 6S or 5S, so the only difference is that I would probably want another bulk charger, or a way to easily regulate the bulk charger to 15S and 18S. It would sure be nice to have an easily settable bulk charger. And that is certainly possible.

[Alan B]

By the way, just listening to the latest podcast, and I want to say - there is NO duct tape or electrical tape on this build!

The Vet-Wrap used to hold the batteries and wires is much nicer than duct tape, and doesn't stick to anything but itself.

[ryan]

But isn't vetwrap stretchy? I'm all for skipping duct tape, but is that really an improvement?

[Alan B]

Yes it is stretchy, but it has a "maximum stretch", so I stretch it to the max, and it holds things very snug since it doesn't want to stretch any further. After a few wraps there is no moving, almost like a plaster cast, as the force and strength compound. Since there is no adhesive, it doesn't leave a mess on anything. Since it is highly frictive, and stretched, it applies a lot more tension than duct tape. So stuff is clamped in place. It only sticks to itself, but after a few wraps it is really snug.

When using it to wrap bandages you don't wrap it this tight. It would cut off circulation.

[ryan]

Well good morning, Alan. Looks like we share early bird status as well. (Though I have a sleepless toddler as my alarm clock.)

Thanks the the vetwrap tip. I'll pick some up at Walgreens today and give it a shot.

[Alan B]

Good Morning. I often wake at 4am and get on for awhile. My toddlers are somewhat over 21 and sleep till noon these days when they can.

I didn't know Walgreens carried it. Good tip. I use the 4" width mostly, though 3" is okay too. I generally order from Amazon and it comes from a horse or pet supply type. Mostly black but is available different colors. Give it a try and let me know what you think. It is easy to remove and if careful can be used again but it is not as neat when re-used.

[ryan]

Looks like Walgreens only has the 2" version. I ordered 10 yards of black from Amazon. Is that enough to wrap up my 18S4P pack? Thanks.

[Alan B]

Probably. That's the fully stretched length they quote, as I recall. What are you going to wrap them to? You can wrap yours into pairs easily enough. If you want to unitize them you might put a thin plastic or wood piece underneath and wrap them to that? Even just wrapping into pairs makes them a little easier to handle.

[ryan]

Yup, pairs (plus nearby wires). Mostly for wire management since I have such a tight space to work with. I was going the duct route but you swayed me.

[Alan B]

I think you'll like it. Easier to unwrap and work with. A little harder to get the wrap started, but take a turn around one battery and that anchors the end, then wrap from there.