Surley Big Dummy Build

[trevor]

Hey Guys,

I know this is a fairly loaded post for my first one, but here goes nothing.

FRAME
I am really interested in doing a Surly Big Dummy build. There are a few reasons why I chose this frame. I test road the UTE and it was a lot of fun and from what I have read, the BD should be that much better. This would really be a forever frame for me. It fits a segment that really can’t be much improved upon. I can load it up with a good grocery run, put my daughter on the back, or the whole family can even hop on if need be. I can even give a buddy a ride home from the watering hole down the street. The utility is endless and that is what I really need right now. I really respect the Xtracycle platform and I can see it being very viable for a long time. I’m sure that more and more manufacturers will jump on the platform and produce more add-ons for it as people gravitate to this as a more popular form of transportation.

NEEDS
Here’s where things get a little bit tricky. 75% of the time, I see myself riding on a 10-15 mile or less round trip, running errands, myself and maybe 50 lbs. of cargo, just cruising along. 12.5% myself on long trips alone that would be 20-25 miles one way with a few hour stop, then return. The other 12.5% would be me and another adult riding for a 10 mile round trip.

The terrain is fairly flat. There are a few hills here in Phoenix that can be a total nightmare, but they are not frequent routes. One very frequent route is only about 6 mi roundtrip with a pretty consistent 15% grade all the way there. Most of the time it is 5 miles out with a slight 3-5% grade home.

I would like this to be the cleanest build ever seen. The BD has that entire area behind the seat post and rear axle that is perfect for an ebike build. Because of my desire to build a stealth ebike, I would like a rear hub system that would be covered by Xtracycle bags. This keeps me away form the Stokemonkey type of chain drive builds that add another component to an indiscrete part of the frame. I want to keep the battery and controller out of the useful area of the Xtracycle system and keep it contained to that extended frame area or under the main triangle of the frame.

MY DILEMMA
I want to keep this bike for a long time. I want to use it for both exercising and cruising as an SUV. I want it to be half utility bike and half hot rod. I know what fast is (side note – my current bike is a FS Ti Titus 29er that I am going to sell for lack of use because of kid.) Because of the length of time that I would like to keep it, I would like it to be flexible as far as setup is concerned. The whole ebike/motor/battery industry is changing so quickly as technology progresses. Some components will become more efficient and cheaper due to advances in technology while others could become more expensive due inflation of material costs.

Here’s where the dilemma comes in. I really appreciate the cohesiveness of the 48V PL350 Bionx special edition system that is coming out. It seems like the easiest solution for my build. I don’t know what the range will be and I am concerned about the amount of torque that the system would provide for a heavy loaded scenario. I appreciate the fact that it is a canned solution that would fit neatly on the BD frame in the extended area in front of the rear tire. I really don’t like the fact that it is speed limited to 20 MPH, not because I would regularly go beyond that number, but because I don’t have the option to if I want it.

The Crystalite builds scare me because they seem as if they are expert systems. From what I have read (remember – not an expert here – just an impression) is that they are a good way to economically get a lot of performance out of a custom setup. Find a good controller and battery and you could tinker for the rest of your life.

I can’t find a lot of information about the ezee system. I have found references that say it can accommodate a high speed 48V system that is not top speed regulated but haven’t found much about it. I have also read that it is a high torque system that could help with the heavy loads and the hills that I am concerned with.

THE BUILD
I know that this is going to be an expensive project. I have identified and expensive bike and my requirements are diverse. It’s easier to cut costs when you want a bike that does one simple thing and does it well. This project is more complicated because I want a utility bike that can handle a huge load, but also be a little speedster when I want it to be. I am not concerned about local laws because I expect to build the bike in a covert way that will not divulge the fact that it is electric. I am willing to pay a premium for all of this diversity in performance in light of the fact that I will keep this bike for a long time.

OPTIONS
Talk to www.electriccyclery.com about building me a BD as they do already with the new Bionx 48V PL350 that comes out in February. It seems like an easy, but expensive option. I would also be top speed limited, but I’m sure that it would be a very clean build. I would be willing to incur the expense if this was the cleanest, best performing option that would satisfy me for years to come. I’m sure that I could find a way to overcome the speed limiting eventually.

In the same light, I could order the same Bionx kit and do a more custom build. This would give me a little more flexibility over other options but I would end up with about the same bike with a little more headache.

The thing that concerns me most about this setup is that it is a proprietary system that is not very flexible. It seems as if I would be tied to Bionx (which is a Canadian company that is far more regulated by the laws in Canada and seems more interested in keeping with the law than providing really high performance systems) and not getting the performance to dollar benefit that I could with a homebrew system.

The other option that I have is to have you guys point me in the right direction. From the examples that I have given you, you know that I am willing to pay for a dream machine that will give me enjoyment for years to come. I would appreciate the option to tinker with it and continually make it a better bike, but if the prospects of that are slim considering the speed at which technology is advancing and my aesthetic and performance requirements, I may be better off going with the canned system.

I am really interested to hear what all of your input is and appreciate your thoughts.

Thanks,

Trevor

 

[amberwolf]

Regarding premade systems in general: If you want something simple to install with a company that can be there for support, these are probably your best bet. However, they will cost a lot for what you get, and you're limited in the results you get from them; harder to customize to your specific desires or needs. Not a problem if those systems already do what you want, but like you say about the Bionx 20MPH limit, sometimes you might want something more, and wouldnt' have that available.


Personally, given the requirements of that 15% hill (and any others you will regularly be on), I think a thru-the-gears setup is your best bet for efficiency. It can also be more efficient when hauling heavy cargo, yet can also go very fast because you can just shift up to faster gears when desired.

Disadvantages of this setup are that it can be (but doens't have to be) louder than a direct-drive hubmotor, and that being more mechanically complex could have more potential failures. As long as it is designed and setup right, those won't happen with regular maintenance on the drivetrain just like you would do on a pedal-only bike anyway.

My CrazyBike2 currently uses a hubmotor, but once I work out my drivetrain issues I want to put it back to thru-the-gears (mid-drive, BB-drive). It's not really any noisier one way than the other when the chainline was setup right.


Since the Big Dummy frame is Xtracycle-based, the Stokemonkey system is essentially a turnkey system you could just drop right in on it to do this, but you can also roll your own version of such a thing, if you want more power or different configuration than it offers, and it should be possible to build one that is stealthy and hidden from view (depending on how you setup the panniers or other coverings in the rear).


That said, a hubmotor will work too, but in the summer heat you might end up having to have ventilated covers for it so you don't damage it on the hills. I've not tested this myself yet, but Dogman in a similar climate in Las Cruces has, and melted a few motors that way (I have a couple of them here and they're kinda toasty looking). A temperature sensor inside it would not be a bad idea (this is planned for mine, but haven't done it yet).


If you can find someone willing to part with it, a 9C 2806 rear would do what you want and stay cool doing it, and might not require ventilation in summer (that will depend on the load you put on it and how long it has to deal with that load). I use a 2807, which is a faster motor but also gets hotter under loads a 2806 probably wouldn't. So far never hot enough to be a problem, but I haven't challenged a hill with it on anythign other than my very light Velcro Eclipse bike.


For batteries, there are a lot of options, but it depends on your level of patience and willingness to do manual work and maintenance on them, or budget for monitoring systems, as to which ones would be better suited for you.

RC Lipo packs are probably gonna be the cheapest for the amount of power you can get out of them, and the lightest, but the really cheap ones do appear to have a certain amount of variation in them, and some simply show up defective (and might not be worth money for shipping for warranty replacement, depending on where they come from). Some of the cost savings is offset by whatever level of automatic charge/discharge management system you need/want.

Ping batteries are a more expensive way of getting a pre-built battery pack with management built in, but are backed by his (from what I've read) good support. Catch is that suport is in China, so costs and time delays for shipping stuff exist.

Other solutions for making your own packs or for buying premade packs exist, too, both for LIthium in various flavors, and for the older Lead-Acid (SLA), NiCd, and NiMH technologies. So far I'd give Lithium the hands-down winner in my experience, and I'd only use SLA if I either had no budget for anything better or if I had a need for the ballast weight for some reason.



Regarding being able to tinker with the system to improve it piece by piece, if you get a complete integrated system that's going to be tougher, as you may have to reverse-engineer what some of it does in order to replace it with soemthing else, or else live with the limitations of that part if it can't be replaced without sacrificing other needed functionality.

If you piece the system together first, then you can change pieces out later, too, as you decide you want something better. Typically I've found that the battery has been my most limiting factor in my experiments, rather than the motors or controllers, especially in the brushless hub motor stuff. Many of the motors can take a lot more than they're spec'd for in short doses, if the controller and batteries can supply the power to do it. Controllers can often also take short overloads if they can then cool off, but batteries can only supply what they are made to, and if you abuse that you can permanently damage them or shorten their useful life significantly. Much more so than motors or controllers.


Any pieced together system could be made to look almost any way you want, as could probably many of the pre-built systems. Just depends on what you want to spend on fabricating housings, covers, or other things like that, which are part of what increases the cost of those pre-built systems in some cases.

 

[joe tomten]

I'm picking up a townie 21 and extracycle setup today, and have a couple of 9C motors sitting ready to apply to the rear hub. One is a 2807 like the one I run on my heavy tandem cruiser, and the other is a 2805 that I got for my bmx.

I'm considering actually putting the 2805 on a 24" rear, so that I can have plenty of speed, but better torque than otherwise provided by the 2800 series in a 26" wheel.

I really like the big dummy too, but I need to start with something a bit more affordable. I like the fact that I can scoop up the occasional deal offered here on the E-S by various vendors (these past 2 rear hubs were $60/ea) because I'm not locked into an expensive and proprietary format. Allows much more experimentation, and I learn a lot more (though with some cost in frustration) in doing so.

 

[joe tomten]

Interesting,

I just picked up the bike. And the guy I got it from said that he had a crystalyte 5 series motor that he had mounted to the front (susp) fork - and said that it did just fine.

He had the 48v 16ah nicad battery in the back on the snap deck - and further said that he really liked the distribution of balance front to back. Even further said that when he carried much of any weight on the back that the heavy xlyte5 was a very nice counter balance.

I may just give the front 2807 a try on the front with the 48v 14ah ping behind and see if i like how it rides.

First time that i've ridden a townie. Am really liking the the crank-forwardly aspect the ride.

 

[Mundo]

I got an e-mail today from Yuba Mundo, they have a great sale right now....Mine has been really super, it's kinda like having a mini-van.

http://yubaride.com/yubashop/product.php?id_product=62

 

[amberwolf]

Have you come to any conclusions yet, Trevor, or are you still pondering what questions to ask?

 

[trevor]

I have been reading and researching a lot more and have come to a few conclusions. I hope to start ordering parts tomorrow. I got a lot of good information from Justin and Grin in BC and I think I am going to order a kit from them. I'm planning on putting together a 48V 10ah kit from them with a 40A controller that I will current limit with their computer. I really like how easy all of there stuff goes together and and the comprehensive dedication to a wide range pf products.

Really the only thing that has held me back is choice of motor. I looked at eZee but I think I would like to go with something gearless. That led me to 9C 2807 and the Clyte 5304. I'm concerned that the 5304 may be overkill and that the 9C may not be enough. For the price difference though, I can probably get a 9C and if it doesn't work, sell it and get the 5304.

The idea behind the other parts of the system is that they probably wouldn't need replacing and I could always change motors or battery systems when I wanted to.

Please let me know what you think and thank you for asking.

 

[pdf]

Trevor,

I have an Xtracycle with the Stokemonkey. I have put more groceries on that bike than I'd ever have thought possible. Brought home three full reusable bags plus a gallon of milk, bottle of wine, six pack (Harpoon Winter Lager), and large box of laundry detergent. It never ceases to amaze me in that way. And the motor makes it that much sweeter, because coming up a hill with 50 lbs of cargo is not much fun. Didn't even breathe hard or really even raise my heart rate. My ideal bike would be a BigDummy with perhaps an internal 7 speed rear hub and a Stokemonkey. Disk brakes would be sweet also (think the Big Dummy can be built up with disk brakes, if not mistaken).

If one of your frequent route is truly a 15% grade, that is (in my experience) a pretty substantial grade for a ebike. If you have any chance to test what you are proposing, I'd recommend it. Although I don't have the system you are proposing, I think a 10 Ahr battery will be taxed to get you up a 15% grade with any motor while loaded. Just 20 amps will be 2C and you will need considerably more than that to get up a 15% grade with a hub motor, even humping it on the pedals. I don't know what battery you are looking at however.

I can't say enough good things about the Stokemonkey for climbing a hill, but everyone has their preferred system and the hub motor folks sing their praises also.

Let us know what you go with and how it works out. Maybe someone with a similar build (longbike with hubmotor) will comment on the ability to climb a 15% grade loaded. You are going to love the BigDummy. My Xtracycle is both my daily commuter and my grocery/hardwarestore run bike.

By the way, I carry my batteries in a CLC toolbag I bought off Ebay for about $10 and bungeed in the front triangle. It is better than carrying it in the panniers I think. Leaves more space there and also a better balance. On the Xtracycle if stored in the back, it rubbed at the attachment point for the rear fender and eventually rubbed a hole through the pannier and nearly through the battery casing.

 

[trevor]

Thanks PDF. I re-evaluated the actual grade of the of the hill that I mentioned and it is really about 5-7% for about a mile. I don't know why I thought it was 15%. I had to go back and lookup the way that grade was calculated and double check my accuracy. I appologize for misleading you guys.

I also forgot to mention that I was planning on running 2 of the 48V 10ah batteries in parallel. This was a recommended by Justin at Grin. He mentioned that these fairly slim batteries fit well in the panniers of the BD and didn't mention the problems that you've had. I specifically asked him about mounting the batteries in the frame. I would really like to mount them on the water bottle mounts somehow and will look at doing that when the batteries get here. Does anybody have any idea how to do this?

 

[amberwolf]

Thanks PDF. I re-evaluated the actual grade of the of the hill that I mentioned and it is really about 5-7% for about a mile. I don't know why I thought it was 15%.

What is the actual street or path you'd be on? I (or others here) can double check this for you to be sure it's accurate, so you don't end up with any surprises.

I also forgot to mention that I was planning on running 2 of the 48V 10ah batteries in parallel.

That would help them significantly, since they'll support each other under higher loads, where each by itself might not be able to handle the loads, depending on their chemistry/design. (meaning that they might be degraded faster than normal under the high loads).

I would really like to mount them on the water bottle mounts somehow and will look at doing that when the batteries get here. Does anybody have any idea how to do this?

THere are several ways, depending on the size and shape of teh packs. I mounted a bag to hold my 36V 9Ah NiMH pack on The Velcro Eclipse's water bottle mounts like this:
http://www.endless-sphere.com/forums/viewtopic.php?p=301791#p301791
It didn't take very long, although by chance I already had something the right size with holes in the right place, etc. The only difference it has now vs what's in that thread is that the velcro straps to hold the battery secured inside the bag are completely inside the bag now, with their middle section clamped between the two plates.

Making a full box to hold them probably wouldn't take much longer, depending on what exactly you're after.

I'm concerned that the 5304 may be overkill and that the 9C may not be enough. For the price difference though, I can probably get a 9C and if it doesn't work, sell it and get the 5304.

The 9C may well work fine for you. It depends mostly on how well it works in the summer heat on that hill, really. If you could get the 2806 version, I would almost guarantee it's smooth eternal operation even with the hills and our weather, based on Dogman's tests of it. But even the 2807 will probably work. At worst you'd need ventilated covers for it (and if you need test that theory I have a pair of ventilated covers that could be put on it temporarily before you drill holes in your own, or even just trade covers if you wanted, assuming you get a front motor).

I have not yet run the 9C 2807 on CrazyBike2 or DayGlo Avenger up a hill yet, but I did run it on The Velcro Eclipse up the southern slopes of North Mountain, crossing it on some back streets to get to the other side, using just a little 6FET Lyen controller, and I didn't have any problems with it. TVE is just a regular light bike, so no real load on it other than my 150lbs, and the probably 50-ish lbs of bike, motor, and battery pack.

CB2 however has run that 9C at high speeds (25-31MPH) at full unlimited throttle on 60V of NiMH at the Undead Race for some minutes at a time, and regularly takes me to and from work (~2.5miles) at 20MPH and many stops/starts, no pedalling. It also hauls significant loads (30-80lbs+ of groceries/etc) at least once a week, sometimes several, with no sign of strain (except on the pack, which can pull ~40A). CB2 itself is 150lbs+, as am I, so at least 300lbs every workday for the commute, and 330-380lbs+ for cargo runs.

DayGlo Avenger has seen even higher loads on it, pulling the trailer. I guess DGA itself is 80lbs+, and the trailer is at least 30lbs I think, plus 200lbs+ of dog food (or dogs) have been pulled with it with no issues, although I wasn't trying to go all that fast because of the trailer's behavior and our "wonderful" roads.

 

[trevor]

Thanks for the help amberwolf. The ride I'm talking about is from 44th street and Camelback up Tatum to Shea and back.

My biggest question that it's hard to find the answer to is besides the big weight difference, the main reason that I am gravitating towards the 9C seems to be what I keep reading about current draw. It seems that many people refer to it as a power sucking monster. Is that really the case vs the 9C? Maybe I don't fully understand, but isn't the motor isn't going to draw whatever I tell the computer to send it? I know that it will take a little more because of the extra weight, but it shouldn't be much right?

 

[amberwolf]

For your purposes (protecting the battery against overcurrent draws), as long as you have something in the system that limits battery current (CycleAnalyst or controller's settings), it's probably good enough.

The longer explanation, which has to do with the way the system works as a whole, is more complicated, and possibly not relevant to your situation. But just in case you want to know....

The thing is, you can certainly limit the controller's input current and the total power drawn by the system, either using a controller's own programmable limit if it has one, or an external device like the CycleAnalyst that can control the throttle based on current-sensing and a limit setting.

But becuase it is a brushless multiphase motor (rather than a brushed single-phase motor) that only controls how much battery current is drawn, and how much the total power the motor will see. It does not control the actual *motor* current directly, only the motor voltage. This is because any limiting device you use (in the case of typical ebike controllers) is just going to in effect lower the throttle input, lowering the duty cycle of the PWM that is sending voltage to the motor phases.

Doing that essentially lowers the average voltage the motor gets, which also lowers the total power. But it doesn't always prevent high-current levels from flowing thru the motor (and controller) phases, and could potentially exacerbate that problem under certain conditions.

At stall (complete stop) and low speeds, the motor is going to draw a lot more current than it would at higher speeds, for the same voltage input into the motor. So lowering the average voltage to it reduces that, but it also reduces the amount of startup torque that is available to help get everything moving faster, so it takes longer to get to a higher speed where the current flow is less. This is the effect of Back EMF or BEMF, which basically means that as the motor spins faster it begins to generate it's own voltage (from the wires spinning inside a magnetic field), and that voltage is BEMF. Eventually it gets high enough to nearly match the voltage being input into it, and then currents drop a lot, keeping up just enough to keep it going at that speed under whatever physical load it has on it.

Taking longer to reach that point may mean more stress on both the motor and controller, because of more heat being generated inside them. Depending on how much and how long, it may not matter. But too much heat for too long, and things degrade or die. That's why you read about motors and controllers cooking, although the root cause of each case is different (hills, speed, fast acceleration, etc.).

Really, none of the above probably makes any difference to your setup. But I think knowing about it is interesting, and potentially important. But I'm overly-long-winded, and like to explain things too much. :lol:

 

[amberwolf]

The ride I'm talking about is from 44th street and Camelback up Tatum to Shea and back.

That does have some hill to it. I will have to check exactly how much. For others not in Phoenix, here's the Google Map with terrain to help visualize.

 

[docnjoj]

It seems that many people refer to it as a power sucking monster. Is that really the case vs the 9C? Maybe I don't fully understand, but isn't the motor isn't going to draw whatever I tell the computer to send it? I know that it will take a little more because of the extra weight, but it shouldn't be much right

Hi Trevor. My wife and I both run 9C's on heavy trike setups, mine well over 300 lbs with me on it and it uses about 15 wh/mile. We have some 4% grades and 1 10% grade and she is using a Ping 10 ah battery close to 3 years old. We do regular 20 mile rides and rarely does her battery "cut out" from low voltage, even in the winter. 20 ah and 48 volts should be fine! We do pedal all the time for exercise.
Good luck on your project!
otherDoc

 

[joe tomten]

I can report that the 9C 2807 front hub that I moved from the inline 3 wheeler tandem(heavy)/tagalong to the xtracycle worked just fine. I'm not doing crazy loads, or big hills , and If I were I'd might not be so happy with it.

Does 27 mph on the flat just fine though. And Acceleration is just good off the line.

I'm installaing a rear hub however cause I don't like running a front hub on an aluminum suspension fork. But I did like the even weight distribution with hub in front and battery in the rear.

I may do something with a battery in front, who knows. I like how that works on my bmx.