Design Space - Specialty E-bike frames

[John in CR]

All marketing. The engineering is smoke and mirrors, so the buyers can have their bike price dick measuring contests. No woman would pay $3000 for a 15lb chunk of aluminum.

 

[Willow]

again, agreed.

 

[John in CR]

Marvn, Sorry I'm a bit jaded today for some reason.

BTW, did you ever get the performance cranked up on your leaning trike? With dual X5's and such small wheels it should be a wheelie machine and eat almost anything's lunch from a stoplight up well past 40mph with a good voltage. I realize that's not the target performance for posties, but I guarantee an immediate market for that level of performance, especially in a stable through curves trike which are all but non-existent.

 

[Willow]

...didn't take offence to anything. I reckon your on the money.

trike has 5302's and been running at 48V (52V)...Thunderskys. Voltage sag is a more than I'd hoped. Bike is pretty heavy too, so motors are being pushed to their limits - taking as much current as the batteries can give them. Have been having issues with one of them getting much hotter than the other - I suspect they are wound differently (one might be a 5303) - still havn't got to the bottom of that one. Top speed so far was 80km/h, and will cruise at 55km/h - no wheeleis, there just aint enough torque in the 5302's.... but will powerslide ok in the dirt. Super stable at speed - could do 120km/h without issue.

Have bought more batteries and will now be running at 66V - which is all the room I have in the body for... unless I change to A123's or the like. Charger was on-board, but space now occupied by batteries. Have batteries and electronics on the workbench at the moment. Need to do some fabrication on the battery boxes and install some torque plates in the drop-outs. Upgrade to motors and batteries sometime in the future.

Going to America in two weeks, so will have to get it back on the road when I return, and hopefully can afford to do the work. I will get it road registered when it's up and running again.

As for getting the project any further than a one off - thats a hard thing. A lot of money, and quite risky. Looking for funding or partners to move forward from this point.

 

[John in CR]

5302's need current to shine, and no way TS's could deliver performance to one, much less two. As I said in your old thread, I believe the Xlytes are meant for one direction forward due to the splayed stator. I seem to recall Justin mentioning they are less efficient in reverse, and one of yours is definitely running in reverse. Ypedal said the opposite though, and while that's hard experience to dispute, I'd try flipping the wire out of the right one to be sure.

Another possibility might be the batteries. With two high current demand motors each asking for more than the batts can deliver, maybe one is hogging the current available and doing all the work. Keep in mind that the controller is asking for current in pulses, and no telling what happens as those pulses overlap.

Figuring out if the motors are different windings is easy enough. Just lift one rear off the ground (other off) and find out the no load speed at that voltage. Then check the no load speed of the other.

Your plan is definitely sound, ie 2 high speed wind power hubbies in small wheels driving the trike. Work out the issue and it becomes a screemer, and you can tell the prospective money guys that it's simple to turn down the performance level to whatever they desire. Eye-popping is what you want them to test ride though. Just be sure to turn it down a bit for soft start, because people don't need the jerkiness of the hard start like LFP had dialed in for his hill climbing monster bike. FWIW, I believe your trike has the potential for fairly close to that same level of performance.

I'm putting together an X5 bike right now. If you really need me to test the motor both directions I will.

 

[Willow]

I'd love to have it super hot... I'm very much new to this, and although I did vast amounts of research, my product selection has let me down a little... but I'm not too disapointed. Time and money, two things I could do with a hell of a lot more of.

Strangely enough, the hot motor is the one that is running in the forward direction... but it is powered by the controller that is first in the chain. Controller gets real hot too. I might try and swap the leads to the two motors and see what happens.... and play with the settings in the controllers.

 

[MadRhino]

...A dedicated e-bike frame is in a category of it's own.

Of course, but it will have a real plus-value if it can ride smooth and corner hard like one of those top end frames. I can imagine an exoframe that would have the same geometry and suspension equilibrium, like splitting one of those in halfes and reassemble them 4in apart.

As for building on a good MTB frame, battery placement and weight distribution are always a problem, but not impossible to solve. Nevertheless, aesthethics would require a specific frame, and if it handle as nicely as one of those it will be a success.

Top end suspension frames are expansive, but not so much because of marketting IMO. They are developped with years of supporting a racing team, try and error and redesign, putting together a new manufacturing process every year... Most of all, quality check scrap nearly half of them before they ride, and 10 to 15% will be replaced on garantee within 2 years of use. A friend of mine working at Guru cycle, work one full week on a carbon fibre frame, and often to see it crushed in the chipper because it failed the radiography inspection or torsion test.

 

[Hillhater]

... Most of all, quality check scrap nearly half of them before they ride,

.. If true, ..thats just plain poor manufacturing procedures.

...and 10 to 15% will be replaced on garantee within 2 years of use.

..and that is just poor original design (or sloppy QC checks !)

Neither of those are justifications for increasing the prices,..but they are good reasons to keep well clear of buying those brands.
No commercial manufacturer can support that level of QC rejects or customer returns.

 

[John in CR]

I'd love to have it super hot... I'm very much new to this, and although I did vast amounts of research, my product selection has let me down a little... but I'm not too disapointed. Time and money, two things I could do with a hell of a lot more of.

Strangely enough, the hot motor is the one that is running in the forward direction... but it is powered by the controller that is first in the chain. Controller gets real hot too. I might try and swap the leads to the two motors and see what happens.... and play with the settings in the controllers.

I appreciate the frustration, and from the looks I've seen and reports seeing it go in person I believe you nailed your part. ie All of the mechanical. There's definitely an issue on the electrical side, but what exactly that is can only be guesswork from this end. You suspect differently wound motors, which is easy enough to test by verifying the no load speed of each with the other off.

That wouldn't be definitive though, because if the reversed motor is slower, you'd want to try it also with the other rotation direction.

The X5302's are pretty comparable to the motors I use, so one running hot if the other isn't dialed in doesn't surprise me. The controller getting hot is also a symptom, because high speed wind hubmotors spend most of the time in current limiting mode, and that works controllers extra hard. That means the hot motor and controller doesn't necessarily indicate a problem with that side. Instead it may just be doing most of the work.

Before pointing fingers blindly or spending money trying to fix an unknown problem, I'd suggest getting the no load speed of both motors running singly along with the no load current. That can be done quite simply, and at almost no cost.

Keep in mind that the X5302 is actually capable of the same torque and the X5305 that DrBass used to tow a bus, so with a pair of them and your quite upright setup, the trike really is capable of wheelie type performance. The issue could be something very simple, and if you want some troubleshooting assistance just shoot me a PM.

 

[MadRhino]

... Most of all, quality check scrap nearly half of them before they ride,

.. If true, ..thats just plain poor manufacturing procedures.

...and 10 to 15% will be replaced on garantee within 2 years of use.

..and that is just poor original design (or sloppy QC checks !)

Neither of those are justifications for increasing the prices,..but they are good reasons to keep well clear of buying those brands.
No commercial manufacturer can support that level of QC rejects or customer returns.

It's just that at that level of performance expectation, and manufacturing that involves so much artisans handcrafting, only strict technical quality control can assure a consistant finished product. Then, some 10 to 15% of those who buy those frames are bound to brake any frame with their extreme riding style. As a manufacturer of high end performance, one can't lose them elite clients whom preferences are for a big part in the brand reputation, and has to give unconditionnal garantee.

Those high end frames are not made to stand the abuse of throwing them in bumps and drops at 50 Mph, this design philosophy is long gone and the real meaningfull objective is: They are made to win races. 85% of those who buy a pro racing frame will never race, they're just willing to pay for exceptional lightweight and precision handling, or as John said: want to flash their new toy. Nevertheless, they are for a big part of the income that is necessary to pursue tech development. Most of big brands don't make money with MTB racing frames, they accept a financial loss to development, and their profit comes from large scale production of leisure bicycles that they sell 3 times their value with their prestige name on.

Those MTB racing frames are not easy to build an E-bike on, their lightweight and slick design need alot of imagination and work to make them suitable for motorization. But for performance E-bike builders they are the best, for they handle so nicely at high speed that they compare advantageously with motorcycles, only with a fraction of the weight.

 

[MadRhino]

...No woman would pay $3000 for a 15lb chunk of aluminum.

Mine paid that for 2lb of leather and shiny hardware called: Hermes handbag. :lol:

 

[full-throttle]

...No woman would pay $3000 for a 15lb chunk of aluminum.

Mine paid that for 2lb of leather and shiny hardware called: Hermes handbag. :lol:

Gold! :lol:

 

[Willow]

Keep in mind that the X5302 is actually capable of the same torque and the X5305 that DrBass used to tow a bus, so with a pair of them and your quite upright setup, the trike really is capable of wheelie type performance. The issue could be something very simple, and if you want some troubleshooting assistance just shoot me a PM.

Thanks kindly John.... will take you up on your offer when the time comes.

 

[sk8norcal]

I was driving home today on a 45mph 3 lane expressway and in the fast lane was a guy on a Honda Monkey with a loud pipe.

anyways, reminded me of the e-motoped thread,
came across this searching Honda Monkey bikes,

OverRacing frames
http://www.cmsnl.com/over-racing-monkey-frame-kits_model14840/

 

[sk8norcal]

one more,

Chinese,

http://www.alibaba.com/product-gs/322966895/CNC_bigmini_1_KLX_shape_cradle.html