Bonanza "Bulldozer" Dual PhaseRunner AWD

[GCinDC]

drawing 55A max on my ebike (70lbs), i (175lbs) pull two kids (45lbs + 35lbs) in a trailer (25lbs?) up this 11% grade. i go 21 mph no problem...

classic case of hubris. no sooner do i say this than i get almost to the top of that hill today (thankfully) and the motor starts groaning, refusing to budge when i throttled. quick check. kids patient. nothing obvious. i had to walk the bike and trailer the rest of the way up the hill, and then drop my front gear down to the middle front... i mention it to illustrate the challenges of ebiking, particularly at high voltage.

what went wrong? don't know! better fix it tonight tho or else i'm taking the subway... i noticed that when i started going downhill, with system still on, i got the same groaning when regen was activated. i'm gonna guess it's melted phase wires. i HOPE that's it... off to the garage...

Ooops: I meant to quote this post, NOT edit it...

 

[Alan B]

...

Also, some other misc points:
- the 11T cog on the freewheel does a lot to compensate for the gearing adjustment w/ a motor, and is much easier than dealing w/ changing the front chainring
- easy to get good torque arms for a front motor install, but not for rear. and if you're going to use regen with any power, you might need 4 custom jobs. but these will compensate for having aluminum dropouts. (i MUCH prefer rear motor to front). ps. does ampedbikes have universals which work well w/ rears?
- other points i forgot :lol:

let's have a photo of your bike! i'm wondering if you'll put the battery in the frame or on a rack...

Thanks for the great comments, I'll have to spend some time on the simulator.

It is hard to believe the 11T is that much different than a 12T, but that certainly has been mentioned. Unfortunately it seems to be a problem. The 7 gear clusters are reportedly too big to fit, but perhaps that one mentioned above does fit. I suppose the clusters cannot be taken apart and leave out a gear, I've never messed with one.

On rear torque arms I wonder what can be fabricated easily. Seems like a custom made part would not be hard here. I might be willing to make some parts for this project.

I do need to take some photos of the bike. It is a large tube aluminum hard tail frame mountain bike with front suspension. It was about $600 from REI, this was perhaps 7 years ago. Taiwan made. SRAM 5.0 setup, V brakes. Alex rims. Lots lighter than my previous steel MTB which was triple butted cro-moly lugged.

Battery placement might be both sides low rear. I'm considering making a pair of 8S 25V 16AH packs with the big cylindrical Headway cells. A series parallel switch would be interesting with that setup. Then if someone wants to "try" the bike I can lock it into 25V mode by removing a jumper plug so they can't get in as much trouble.

Edit - for newcomers, the 8S nomenclature refers to 8 cells in series (and the "P" designation is for how many cells in parallel). So the battery voltage is 8 times the single cell voltage. With two 8S packs they can be wired in series for 16S1P for high voltage, or in parallel for 8S2P and double the amp hour current capacity.

 

[Alan B]

I had one other thought on the batteries. I like 12V modules, so I may be building my packs from those 16AH 4S cylindrical units. Four 12V modules would be handy to work with. Perhaps get six modules to have a couple of spares, and if up to three could mount low on each side of the rear wheel you could then configure for 24/36/48V 16AH, or 24/36V 32AH or 24V 48AH.

Or even 72V 16AH

My normal configuration would probably be 48V 16AH. If a cell or module had a problem it could be quickly reconfigured for 36V 16AH and still ride home.

The blocks of four 16AH cells look interesting due to the easy serviceability of any cell. They are not as dense as the prismatic but they may be more practical.

12V packs can be used for other applications besides the bike, such as Ham Radio. I have lots of 12V compatible gear and high current power supplies.

Note that also anything over 50V legally requires different work practices such as certified and tested voltage rated gloves, as well as additional training and authorization (see NFPA 70E), and at my workplace that is an issue. I could not work on my own bike on the premises if the voltage is over 50V (and a fully charged 48V pack is over 50V, as is the charging system). By reconfiguring to lower voltage I can work on it, and the voltages over 50V are constrained to the battery combiner and controller when they are present, so they can be more readily insulated and shielded.

Anyone who has a setup that exceeds 50V could find themselves in a situation where they would not legally be able to work on it at their place of business. Depending on the policies of your workplace even working on systems under 50V may require training and authorization. Being able to readily convert it to 24V can help in these situations.

 

[GCinDC]

My normal configuration would probably be 48V 16AH. If a cell or module had a problem it could be quickly reconfigured for 36V 16AH and still ride home.

I think most controllers have LVC settings. My '72V' controller won't operate below 60V...

....anything over 50V legally requires different work practices such as certified and tested voltage rated gloves...a setup that exceeds 50V could find themselves in a situation where they would not legally be able to work on it at their place of business.

then how would you get KFF? :lol:

legality is another matter. i think for most states 500W, 20mph are the maxes.... so even 36V would put you out of legal limits...

 

[dogman dan]

Is ok. They won't let me get paid to work on my bike anyway. But yeah, in a workplace that knows about such stuff, you might be wanting a 36v bike, so they let you bring the charger onto the premisis.

Or you could stick 36v labels on everything Just claim it's 12s. Or build a 36v bike, and carry a 12v battery on the side. Then as soon as you are out the gate, plug in the spare 12v. Or build as a split pack, and charge each side at 24v. Lots of ways to skin that cat.

One thing I like about my 6x10 commuter, is it rides at a nice legal 20 mph, but climbs with 1000 watts. Not legal wattage, but it sure gets up the hills better than a "legal" 20 mph 400 watt gearmotor. Who knows what your watts are anyway, all anybody can really check is your speed.

The trigger shifters built into the brake levers, and a half throttle is what I have now, and it works fine. If you look into retro stuff, you can find em from when 7 speeds was the norm. Lots of it on ebay.

 

[chroot]

My ebike running 74v nominal and i commuter to my work UPS. They never ask me how much volt batteries. The UPS is very strict business and Just don't do ego or stupid that might lead you into trouble by violate business's policy. Just keep your mouth shut if your are going bring ebike to the business premise.

Even tho I am using LiPo dangerous batteries on my work premise. I usually charge 4.16v and full WOT 3 miles to my work so by time I arrive there. The batteries start drop under 3.9v or so will be ok as long as you are near the storage level 3.8v each cells. It should be ok!

-edited - I read your info using LiFePo4 battery. It should be ok to bring your ebike to your job place. LiFePo4 is more safer
than the LiPo battery. I am sure there a way put safe zone for your ebike parking somehow as long as your work permit you to park your ebike or storage the battery on their property.

 

[Alan B]

The issue I am referring to is not regarding battery chemistries or e-bike rules, but safe electrical work rules. Many workplaces won't be sensitive to that but anywhere in the US that electrical work is conducted they must legally comply with NFPA 70-E rules that require NO body contact with voltages exceeding 50 volts, so additional protections must be added whenever covers are removed.

Having 24 or 36 volt batteries is fine, as long as the parts that exceed 50 volts are all covered/insulated and not worked on except when positively de-energized. But if you need to probe and make some measurements then rules apply as to protective measures that must be taken. Also, anyone working on electrical equipment needs to be authorized by the "authority having jurisdiction" for the business. Usually this is the engineering or maintenance organization within the business that is responsible for all things electrical (including the accident report if you hurt yourself on the premises).

Being able to take it down to 24 or 36 volts, and using those voltages for charging makes it easier. The low voltage cutoff should be part of the battery pack rather than the controller, in my view. This will then not interfere with shifting the voltage.

I'm not talking about working on it during work hours, but that adjustment you make just before you leave for home. If you never need to work on it at all, great! Just make sure all the conductors are insulated/covered!

Anyway let's not get stuck on this sub-topic here.

Back to shifters, batteries and other good e-bike design.

 

[Alan B]

...

The trigger shifters built into the brake levers, and a half throttle is what I have now, and it works fine. If you look into retro stuff, you can find em from when 7 speeds was the norm. Lots of it on ebay.

So will any 7 speed shifter work with any derailleur, or do they need to be matched?

And any 7 speed gear cluster will match up?

Or are certain combinations required??

 

[amberwolf]

This is a bit hard to follow completely

That's probably not unusual for stuff I post. :lol:

(haven't looked at a bar-end yet),

I mounted my thumb throttle on the bar end for The Velcro Eclipse,
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=20595&start=0
as I had nowhere else to easily put it right then. I haven't changed it because it works as-is pretty well, though for a long trip it'd be annoying. Would need to be an inch or more closer to the main bars for comfy use.

If I go for combo shifters / brakes I lose the switches (unless they can be retro-fitted), but that's probably okay.

There are a number of threads around here demonstrating mounting DIY switches to your own brake levers, at least one and probably two relatively recent ones are specifically for the combo units. Some use reed switches, some use halls, others use physical switches. Some mount to the brake lever/barmount, and some mount to the brake line itself, like my first iteration:

http://www.endless-sphere.com/forums/viewtopic.php?p=277113#p277113

Actually a trigger or thumb on the left side would control regen. Proportional control of regen would be great.

Depending on the controller you have this might be possible, but most only have on/off braking/regen. There are also discussions and threads about that, too, including an idea I have yet to test about PWMing the brake input based on a hall throttle or similar. Might require physical modification of the controller to change or remove any "ramping" the electronics do to the brake input signal. If it's not done in the hardware you probably can't do it, as there's no way I'm aware of to get the source code for the MCU to reprogram that (it's not one of the programmable parameters on any of the common ebike controllers).

Certain versions of some controllers have a mode where once regen is engaged it is controlled via the throttle for intensity. Not sure if anyone still sells these.

 

[amberwolf]

The 7 gear clusters are reportedly too big to fit, but perhaps that one mentioned above does fit. I suppose the clusters cannot be taken apart and leave out a gear, I've never messed with one.

You can, but since the width is of the underlying core freewheel assembly, it won't help the problem of fitting it in between the dropouts.

The 9-speed cassettes typically pack the sprockets in closer to each other, requiring a narrower chain than a 7-speed, etc. But they are still wider than the 7-speed, so wont' fit where the 7 would. The wheels 9-speeds go on may have greater dishing and/or a narrower hub.

 

[Alan B]

So can we disassemble a couple of gear clusters and put the 11T on a narrower cluster?

I wonder what CPU they use in the controller. Might be fun to reprogram it. Variable regen is not a high priority.

I ordered a 4S / 12V set of Headway 16AH cells to experiment with. Might be the first quarter of the battery pack. May have to design a little BMS for it.

Checked my bike. 11T on the cluster, 44T on the chainring as expected. Put some air in the tires, they were flat from sitting.

So what is that roughly pedal speed wise. Assuming 100 rpm on the pedals, that would be 400 rpm on the rear wheel. The circumference is about 80 inches. That makes 32,000 inches per minute. Or about 2700 feet per minute. Which is a bit over half a mile per minute, or a bit over 30 mph, roughly. I probably cannot spin that fast, however.

I also noticed that the shifters are SRAM 7.0 while the derailleurs are 5.0. Guess they are compatible.

 

[dogman dan]

What I've seen in screw on clusters, which are used on hubmotors, is that they are not able to be dissasembled. In 8-9 speed, I've seen cassete type freewheels where the first 7 speeds are fixed, and the last one or two can be taken off easily and swapped. On the 7 speeds, 14 tooth is commonly the smallest size you get. Generally though, a 48 tooth front ring and 14 tooth rear gives you a bike that pedals Ok at 25 mph, and can be pedaled up to 30. Fast enough for most. I find at really high speeds, like 40, the pedaling causes unwanted wobbles.

5,6,and 7 speed freewheels all take the same wider chain, and shifters index the same. So a 7 speed shifter works fine for a 5 speed derailur. It just works for the frist 5 speeds and then hits the stop on the derailur. But a 7 speed cluster with a 9 speed shifter willl index wrong, because from 8 speed up, the chains get narrower and the gears closer together to fit more in the same space.

So if you want to go to 5 speed or 7 speed, you can mix and match shifters and derailurs to some extent. Except for the chain width, the derailur is not something that has to match perfectly.

Of course if you are looking at the flea market for 7 speed stuff, you find it on an old steel MTB...... and there you go. Easiest thing might be to hunt for a cheap used bike. Something that was quality 10 years ago. Save the nice bike for the next time, and do an easy one to start out with.

Even easier is a beach cruiser with a rear derailur. Often sporting 48 tooth front chainring, they have sturdy steel for front or rear motors, and often are 5 speeds. You'll only need the top 2-3 gears.

The work thing is easy, just label stuff 36v and forget about it. You can't fix stuff in the field, but if you did happen to need to open the battery box, just roll it out the gate first.

 

[Alan B]

What I've seen in screw on clusters, which are used on hubmotors, is that they are not able to be dissasembled. In 8-9 speed, I've seen cassete type freewheels where the first 7 speeds are fixed, and the last one or two can be taken off easily and swapped. On the 7 speeds, 14 tooth is commonly the smallest size you get. Generally though, a 48 tooth front ring and 14 tooth rear gives you a bike that pedals Ok at 25 mph, and can be pedaled up to 30. Fast enough for most. I find at really high speeds, like 40, the pedaling causes unwanted wobbles.

5,6,and 7 speed freewheels all take the same wider chain, and shifters index the same. So a 7 speed shifter works fine for a 5 speed derailur. It just works for the frist 5 speeds and then hits the stop on the derailur. But a 7 speed cluster with a 9 speed shifter willl index wrong, because from 8 speed up, the chains get narrower and the gears closer together to fit more in the same space.

So if you want to go to 5 speed or 7 speed, you can mix and match shifters and derailurs to some extent. Except for the chain width, the derailur is not something that has to match perfectly.

Of course if you are looking at the flea market for 7 speed stuff, you find it on an old steel MTB...... and there you go. Easiest thing might be to hunt for a cheap used bike. Something that was quality 10 years ago. Save the nice bike for the next time, and do an easy one to start out with.

Even easier is a beach cruiser with a rear derailur. Often sporting 48 tooth front chainring, they have sturdy steel for front or rear motors, and often are 5 speeds. You'll only need the top 2-3 gears.

Great info, thanks! 25mph is fine for pedalling. This is not a racing machine.

Does a narrow rear derailleur, such as the 9 speed one I have, work with the 5/6/7 speed "standard" chain?

So if I want to use a "standard" six speed cluster I need a "standard" chain and indexing in the shifter to match, but any brand 6/7 speed shifter should be ok.

So the existing 9 speed forward derailleur and chainrings are compatible with the wider "standard" chain?

The forward shifter on my set has multiple "clicks" per gear, so it is not exactly indexed. I think there are about three clicks per gear change. So that may work with most anything, it does not seem to be critical.

 

[GCinDC]

just a note: i'm no expert, but i've learned from the bike shops that on the back, there are freewheels and cassettes. the 9c and GM motors use freewheels NOT cassettes! bear it in mind before you go shopping...

and to summarize, you've got a nice light aluminum bike that you want to convert to commute at 25mph over a very hilly 13 miles (one way) with light pedaling. am i right?

if you had to make a decision right away, you can't go much wrong with the 48V version of this: http://www.e-bikekit.com/shop/index.php?p=product&id=26&parent=4 you'll probably find that it's a lot cheaper than geared models. who knows. i don't... could never bear the thought of noisy gears, not that the 9c is perfectly silent, but....

if you ever feel you need more speed, you can just swap out the controller with a 72V one for ~$100 and add more battery up to 100V. the same motor can scale that much. (which to me also means that it's overbuilt for 48V, and consequently more heavy, but nevermind that. most of us here will assume you'll be upping the voltage once you get hooked.)

i'd also suggest getting the 11t freewheel. i'd be surprised if it didn't fit, and in all likelihood, you may not even have to adjust the gears. you will now have a full or half throttle, in the place of your grip shift, so you can either do what i did for a year and just push the grip shifter further up the handlebar until you get a clue how you really want it to be. wasn't pretty but it worked fine for changing gears as much as i did. or, once you get the throttle, go looking for an older model shifter to mount on the handlebar - but be aware that the throttle housing is a bit big and will likely get in the way of the action of most shifters...

next, get or make a couple torque arms - don't make the mistake of many a guy here of testing the motor w/o one! one hard throttle and your ebike grin will disappear as the axel hops out of the dropouts and the wire wraps around it...

as for your battery, well, you seem to be on your way there, and i have nothing useful to add about headways, except perhaps that for 13 hilly miles, 20Ah might be better suited. but since you've started buying, i suggest buying the 9C kit so you've got something to play with.

so now, before you go dashing off for 13 miles tho, you'll want the Cycle Analyst, a most essential fuel gauge, with a LOT of nice features. Under 60V, you could get a turnigy watt meter, but it's nowhere near as good. It took me a year of humming and hawing before buying the CA and I'm glad i did! you can get it from lots of places, not just from ebikes.ca. cycle 9 has free shipping on big orders and it'll come a lot faster than from canada...

you will probably find that your next upgrade will have to be in the brakes department. i tried to fit a thread on disc on mine, but there was absolutely no hope at all. i fit it on, but the disc rubbed the inside of the frame, nevermind pushing it further right to seat it in the calipers... forget it. i settled with front disc brakes and get surprisingly good braking on the rear via regen (infineon controller, hardware mod + programming) and reverse torque arms.

did you mention you've already got a light? well, next up will be your dc-dc converter... hehe

of course you'll need to store the battery somewhere, so there will be plenty to do there, but until we know more, it's hard to say....

 

[Alan B]

Great Suggestions! Really like the detail!!

I'll have to weigh my "light aluminum bike". If I recall correctly it is 20 something pounds. It is aluminum but not light like a road bike. Some of the aluminum tubes are quite large in diameter. But yes, 13 miles, hilly, light pedalling. Good climbing capability (grades to 10%). Speed to 20mph (not a speed daemon). Reliable. Efficient. Regen would be handy on the twisty hills through the park since speed is not safe.

Perhaps I should edit my shopping list into post #1 for future reference. Later. It would be good to record the 'final' list as a recipe for others to learn from...

I have some experience with the torque effects of motors, reminds me of when I tested the several HP treadmill motor I adapted to my lathe... That has some torque...

my present list:

sooner
9c wheel w 6 gear cluster (7 just doesn't seem likely to fit) and half twist throttle, controller, etc
good rear tire???
cycle analyst
torque arms (make? or start with something commercial and improve..)
battery (the headway on order is only 12V, need more...)
battery mount (panniers or similar mount?)
anderson powerpoles (have 40A and 50A on hand)
various wiring, etc

next
rear brake/trigger shifter 6/7 speed
new chain
??

later
battery management (might build this, sketched out a couple of designs already, can test without it)
I don't plan to "commute" with this setup until perhaps next spring, it has to be pretty solid before I'll venture on a 13 mile hilly trip in commute traffic...
better helmet, bright vest, clothing, etc
better charger (have something slow for now)
headlight (have a taillight)
front wheel with disc brake, front caliper and cable, better front tire
suspension type seatpost?
fenders (not planning to ride in rain but need to be prepared)

Question - to start with can I just use my existing narrow chain/shifter/derailleur for testing (single speed style)? Sounds like not.

So if the chain won't fit in the 6 gear cluster and I need to change the chain, will the derailleurs work temporarily for single speed testing?

Sorry for the detailed questions, these bike mechanics are not exactly obvious in the details. When we get to the electronics and software I will skip all the easy questions and just ask the much harder ones...

Thanks in advance,

 

[amberwolf]

So can we disassemble a couple of gear clusters and put the 11T on a narrower cluster?

That depends. If you have (or make) a chainwhip (see Sheldon Brown's site for details) you can usually take apart any screw-together freewheel cassette.

But...not all of them are the same diameter at the outer (right) end. So you may not be able to thread the 11T onto other ones you already have (or get).

If it is not a screw-together cassette, then it is probably pinned together (though some of those still use a screw-on smallest sprocket or two, like my Suntour). If it's like that, you still might be able to do it as long as the cassettes you're swapping between are the same brand and model year, because it seems that bike parts companies like to switch things up periodically to force-obsolete various parts.

Since the splines on various sprockets may not match between different brands, you will probably need to use the same brand anyway, but sometimes one can be used on another.

I wonder what CPU they use in the controller. Might be fun to reprogram it. Variable regen is not a high priority.

I'd love to see someone do that, but since you will have no source code (or even code read out from the MPU) then you have to start from scratch. You'll need to reverse engineer all of the hardware in your particular controller first, so that you know what he MPU needs to control, and what voltage ranges it expects and sends out, using the existing software first.

I can tell you that if you *can* do this, there are a fair number of people here on ES and probalby elsewhere that would have a list of feature requests for it longer than a DNA strand. :lol: I'm one of them!

As for which MPU, that depends on which controller--for the Infineons and some others, that information is listed in various threads about them, especially the ones that already have some programmable parameters.

What I've seen in screw on clusters, which are used on hubmotors, is that they are not able to be dissasembled.

I haven't directly seen the ones on hubmotors, but standard bike screw-on clusters, with the freewheeling core and the slide-on, pin-on, and/or screw-on sprockets, can all be disassembled if you have the right tools (or make them). Many even have inter-compatible parts, but not always.

5,6,and 7 speed freewheels all take the same wider chain, and shifters index the same. So a 7 speed shifter works fine for a 5 speed derailur. It just works for the frist 5 speeds and then hits the stop on the derailur.

Actually, that's not always true, unfortunately. I have various Shimano shifters, derailers, and cassettes/freewheels/etc. In index mode, the 7-speed Shimano levers on CrazyBike2 don't usually match up correctly with the 5- or 6-speed Shimano cassettes (of the same vintage, early 90s or so. If I stack the cassettes next to each other, I can see why, because the spacing between the sprockets is different on some. So for example, the 3rd and 4th gears have trouble shifting without grinding or failing to mesh the chain, causing it to slip over to the next sprocket instead, or keep hopping up and down between two of them depending on loading.

I've had the same thing happen with gripshifters on DayGlo Avenger. At least with the thumb lever shifters they have a non-indexed mode that I can use to smoothly shift, but of course it doesn't click into the gear automatically, I have to learn where to stop for each one.

Now, the derailers seem to work fine regardless as long as they can physically move correctly over the entire range left to right and up and down, but some that have sufficient L-R range do not shift into the correct vertical position to clear sprockets in lower gears, unless adjusted out enough to not give full wrap in higher gears (which can cause slippage if you apply too much torque in higher gears). Usually, it isn't a problem (even using different brands of derailer than shifter or cassette doesn't seem to matter that much).

Does a narrow rear derailleur, such as the 9 speed one I have, work with the 5/6/7 speed "standard" chain?

Probalby not. It's fairly likely the cage is too narrow and will rub on the chain (or even snag it) as it passes thru. You can stll try it, but it may be problematic.

So if I want to use a "standard" six speed cluster I need a "standard" chain and indexing in the shifter to match, but any brand 6/7 speed shifter should be ok.

Most likely, unless it's Campagnolo; they seem to like to do things differently out of spite. :lol: Might stil work.

So the existing 9 speed forward derailleur and chainrings are compatible with the wider "standard" chain?

Probably. It is unlikely they are close enough together to pose a problem, and the cage on the front is probably not narrow.

The forward shifter on my set has multiple "clicks" per gear, so it is not exactly indexed. I think there are about three clicks per gear change. So that may work with most anything, it does not seem to be critical.

If they are SIS (or some Shimano) gripshifters, then that appears to be normal. I think that they use some of the same parts between left and right sides, so it ends up with just as many total clicks between them but the derailer is only moved into the shifting position for a particular chainring in front by three of them.

 

[jmygann]

can you get a 11t freewheel on a hub motor ??

just a note: i'm no expert, but i've learned from the bike shops that on the back, there are freewheels and cassettes. the 9c and GM motors use freewheels NOT cassettes! bear it in mind before you go shopping...

i'd also suggest getting the 11t freewheel. i'd be surprised if it didn't fit, and in all likelihood, you may not even have to adjust the gears.

 

[GCinDC]

i should have said 7sp 11-32T... fits perfectly on the 9C, no spacers needed. from cycle 9.

note that the visible hole is much smaller than the other side which threads on the motor...

did a quick image search: here's a pic of the other side that screws on to the motor...

 

[Alan B]

I wonder what CPU they use in the controller. Might be fun to reprogram it. Variable regen is not a high priority yet though.

I'd love to see someone do that, but since you will have no source code (or even code read out from the MPU) then you have to start from scratch. You'll need to reverse engineer all of the hardware in your particular controller first, so that you know what the MPU needs to control, and what voltage ranges it expects and sends out, using the existing software first.

I can tell you that if you *can* do this, there are a fair number of people here on ES and probably elsewhere that would have a list of feature requests for it longer than a DNA strand. :lol: I'm one of them!

I did a little reading on some of the controller threads. Is there a (reverse engineered) schematic around somewhere of one? Even a block diagram?? Have not seen that yet. Working on a controller would be a good project for me (mix of electronics and software), but I have too many now. Not having their sourcecode is almost good since working on other's software is not as much fun as working on your own, but it does put a bit more effort into the front of the project. It is always fun to work on software where mistakes can burn up FETS or worse :wink:. Perhaps someday when I have more time... :lol: For now we'll just stick to setting controller parameters and Cycle Analyst programming...

So to start with the 9c kits seem to come with 25A Infineon controllers. Any reason to change that? What will be "annoying" about that controller for my application?? Seems like the right current level for 1kw. Wonder how high in voltage that controller will go. Reason I think about that is if I need more range (was one suggestion for 20AH, most were for 15AH) I cannot easily increase amp-hours with these 16AH cells, so I might have to add another 12V module. That would be about 60V, higher on full charge, and the controller might run out of range. I see folks hacking them for higher voltage but hate to do that. Hopefully 48V 16AH will be more than adequate (for a hilly 13 mile commute), it works out to almost 820 watt-hours with 16S 3.2V 16AH cells. A little regen might help, and controlling speed.

I see that some controllers have a jack for the Cycle Analyst to plug straight into. This seems like a nice cable reduction plan. Any thoughts on that? Easy to do yourself if a controller doesn't come with??

Read a lot about torque arms last night. Here, among other places:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=14195

and more here:

http://endless-sphere.com/forums/viewtopic.php?f=1&t=11570

Is there something good available for rear wheels? Have not seen it yet. Seems to be an issue, especially with an aluminum frame, and not much available for rears... Clearly it should be anchored vertically above the rear axle (so all the net forces from torque are in line with the chainstays), but nothing there very sturdy to anchor to. So perhaps a vertical arm with a pivot and a strut going forward. Perhaps it can be worked into a support for the rack and panniers. How about dual flat or tubular torque arms going up to a sturdy rack that carries the force to the seatpost/frame/seatstays? Start out flat through the rear axle and then transition to tubular at some point as it goes up? Needs to be steel at the axle, could transition to aluminum farther away where the stress is lower. The forces are not very large when levered out beyond the rim diameter... Perhaps just stay flat from the axle all the way up to the rack for battery mount. Might be interesting to make the battery large and flat and have the panniers actually sit just outside it. Symmetrical on both sides. If the panniers are narrow the total width should be reasonable, and the batteries will be protected by the panniers without having to be inside them.

It would also seem prudent to have a little "suspension" on the batteries/panniers to reduce the vertical shock component from the rear tire. Just a little vertical travel and some elastomer or a spring.

That 7 gear cluster from cycle9 looks good. Thanks for that tip again. I will definitely look at that... Looks like it can be disassembled so the spacing could be adjusted to match the shifter if necessary.. I see from the Wikipedia entry that the spacings do differ between manufacturers, as do the motion rates on the derailleurs in some cases. I suspected that part was not going to be plug and play without some research... I guess the one remaining question is what is the width of the hub plus gear, is it too wide for the dropouts/frame?? I need to measure the space available on this frame...

My shifters are SRAM 7.0 twist type and derailleurs are SRAM 5.0 and the front chainring is Suntour 44T max, probably 24/34/44. Rear is 9speed starting at 11T but that has to go of course. It looks like I can keep the forward shifter since it has multiple detents per gear. Not sure if there is a friction mode on these shifters, nothing obvious noted yet for that.

I will also try to get some bike pics up this weekend...

edited link in to Justin's torque arm testing

 

[Alan B]

Spent some time with Google Maps and their new bicycle routing system. It found a route that I suspected but never had worked out. Shaved 3 miles off my commute! That would make it under 10 miles!!!

Then I tried to get the vertical profile. That did not work.

Then I looked up the rules for these old roads in the park. Human powered bicycles specified. Electric bikes only for the disabled. SHUCKS!. :x

This route is really excellent. It takes 3 miles off and a lot of that is very narrow twisty 2 lane mixed with cars and makes it a pretty gradual climb. I suspect at
commute time it is pretty empty on these trails as well. But pedalling a 60 pound bike up this in the morning commute would not be practical I suspect.

In the evening going downhill it might be okay to pedal it (mostly coasting anyhow).

Of course if they don't allow an electric bike, does it matter if it is turned off?????

 

[GCinDC]

then you got two choices, go stealth and slow and pedal a lot and live in fear of getting busted. bike paths around here are the same, and a buddy of mine got nabbed by a cop who finally answered the calls of the pissed off (and deeply embarrassed?) cyclists.

or go high powered so you can take a lane, and not slow cars down (esp on uphill climbs). if the speed limit is 25mph posted, drivers here would go 35 regularly... do you drive the route now? but now you've got a technically illegal ebike so..

 

[Alan B]

Hi GCinDC. Thanks for your comments.

I've followed some of your threads in the last few days. Very exciting videos! Hope your knees are doing better! I'll actually be in DC for a meeting next week, interestingly enough. Probably no spare time though...

I drive the route now. A third is 50 mph highway with a (mostly) wide margin. The other 2/3 is mostly through a park that varies from extremely twisty and perhaps 4% grade to hilly. The part that would be cut off is about a mile of highway and all the twisty stuff. Really would be nice.

I don't know any ebike riders around here so can't say how it really works enforcement wise. I probably don't want to be constantly worried about that.

In terms of speed the park is posted 25 and folks go 35 most of the time but the twisty slows them down. The pavement is not great either and there is no shoulder on the park roads. On the downhill an ebike could stay at traffic speed. On the uphill staying at traffic speed would probably require more battery than practical for a 13 mile route. I'm planning 48V 16AH LiFePO4 at the moment. Actually 16S which is a little more than 48V.

I just spent some time with the motor simulator and bike simulator. Looks like I should go with a 40A controller rather than 25A. Lots to learn!

 

[Alan B]

I see my Headway cells are due in tuesday. Great. I'll be out of town.

This is just a "test" set of 4 cells. Any reason I should not use Headway 16AH cells for my build? If these check out good I may want to get the whole set soon to have them "match", more or less.

 

[Alan B]

I took some photos and added one to the first post of this thread, as well as a link to the picasa album of all the pictures of the bike.

I also took some measurements. The top tube is 1 1/2", the main tube is 2 1/8" the seat tube is 1 1/4" and the seat post is 27mm. Space between rear dropouts is 135mm or so, hard to measure that with wheel in.

Total weight is about 33 pounds including lock, pump, rack, seatbag, tools, and empty water bottle.

 

[Alan B]

some Simulator Data

270 pound rider + bike + gear
5% mechanical loss, 0.007 tire loss, air drag 0.004

20 mph level ground 225 watts
10 mph 10% grade 625 watts

NC 2807 motor
52V 16S battery
40A controller

20 mph level ground will require 65% throttle and operate at 82% efficiency producing 250 watts (consuming 310w, 50V 6.2A which the 16AH battery could do for 2.6 hours covering 50 miles)

10 mph on a 10% grade will require 65% throttle and operate at 50% efficiency producing 625 watts (consuming 1350w, 50V 27A which the 16AH battery could do for 0.6 hours covering 6 miles)