Time to upgrade EVERYTHING, need advice again!

[wallypedal]

I've asked for and received great advice on here concerning the e-bike front end attachment for my son's outdoor wheelchair. It has been an on-again, off-again process of lots of frustration and learning, with intermittent short term successes. This started over 7 years ago!

The original configuration was with a no name gear motor, 36 volt, who knows the wattage setup, with a cheap battery and controller, also no-name. We have since purchased two different LiFePo4 batteries, two controllers, and a 500 watt brushless motor. They were simply not up to the conditions and needs, and we have determined that we like the basic concept, but need to replace all the componentry. That is what we are asking for advice and suggestions on now, in terms of equipment and suppliers.

The basic configuration wish list:

20" wheel set up for disc brakes, and the disc brake itself.
Although we have been running 36V to date, we aren't insisting on that. Ideally though, the battery needs to fit and be easily removed from the space between the front of the handle bars and tube down over the front tire. The present aluminum case one fits on a rack there. The battery weight on the front helps traction.
The BEST motor for high torque and reliable cool running at very low speed, but high load as on steep grades with rocks, ruts, and rolling resistance. That means from creep speed without overheating or dropping out due to amp or voltage limits up to a couple mph on very steep upgrades. Top end is not important. We know that almost anything will get up to 15 mph or so. That's plenty. It appears BMC may be higher quality and better supported than Mac, but that is only based on web info. I cannot tell from motor specs what the true comparison and capability is for these motors. "High torque" doesn't compare to "20T" very well. What is the mechanical gear ratio and the recommended motor r.p.m. for continual operation? Again, I can't tell from the web site specs.
MATCHED controller (Infineon programmable?) with Cycle Analyst.
Reversing is nice, but it looks like no gear motor setup will do that. I keep saying gear motor, because am not aware of any DD motors that will perform in these conditions. There may be some we haven't discovered.
The BEST battery/BMS setup matched to the motor and controller chosen.
A charger also set up to match up with that battery/bms.
A matching steel shock fork that will fit our present frame, with appropriate dropouts and strength for the motor. We would like to have options on rake angle.

Ideally, we would like to have all these components as a package from one vendor. They should be warranted if at all possible. The vendor should be ready to support the owner(my son) quickly and thoroughly if ANY problems arise. He doesn't want to rely on ol' Dad to be his mechanic and electrician, and I don't want to be either. Our time together outdoors is much too valuable to be spent maintaining garbage equipment.

If this isn't the appropriate sub forum for this topic, we'll be glad to move it or have it moved. You guys have been the best in helping us so far. Thanks!
Wallypedal

 

[amberwolf]

Regarding the reversing, you can defeat the clutch/freewheel mechanisms in geared hubs, and then they will reverse (and regen brake).

Some, like one of the older Fusin 36V hubs I have here, could come with a non-freewheeling planetary set. I don't know if any newer or bigger ones do or can, though you could certainly have one made for whatever motor you get.



Another option might be a "middrive", used on the fork/bars and driving a normal front wheel thru a chain. If your fork is steel with wide enough dropouts, then you could use a narrow BMX or single-speed (or beach cruiser) bike rear wheel.

That wheel would have it's own freewheel either built-in or threaded on. With some of the cruiser wheels having IGH's in them, you could also then be able to shift gears for creeping along when needed, for high torque at low speed.



There are some pretty heavy-duty DD hubs that could take the abuse you're after, I think, but AFAICR they're all meant as rear wheels, so you would have to make new wider forks for them to go on this. (you'd probably want to do that anyway, as they'd be torque monsters as well, and would easily destroy a typical fork's dropouts, possibly even with average torque arms).

Hubmonster, Cromotor, some of the old Crystalyte X5 series, etc.

You'd want to put them in as small a wheel as you could, to reduce the speed they'd get up to while increasing their torque and ability to handle hills/etc.


You might want to play with the http://ebikes.ca/simulator with various motors to see what they could do for you in the conditions you're expecting.

 

[John in CR]

The only answer for low speed high loads is to take the motor out of the wheel and gear it lower. While there are some hubmotors for wheelchairs that are wound for low speed use, they're for use on relative flat terrain and will overheat in the conditions you demand. I believe a hubmotor is still what you want, but get it geared down to a granny gear, so the motor is untaxed yet spins itself up well to produce reasonable power and can cool itself well while maintaining quiet operation.

 

[d8veh]

The Xiongda 2-speed motor could be a good solution. It can change to a lower internal ratio, which gives it very low speed and very high torque. It will give a maximum of about 9 mph in a 20" wheel in low gearand about 15 mph in high gear. It has enough torque to drag 135kg up a 15% hill without pedalling in a 26" wheel, so you should be able to manage about 20% with a 20" one. You can buy the Xiongda kit directly from Xiongda. It's doesn't cost much - something like $260 for everything including shipping, which is an absolute steal.

http://xiongdamotor.en.alibaba.com/custom_page_1/New_Double_speed_Motor.html

http://endless-sphere.com/forums/viewtopic.php?f=3&t=58490

You can use any 48v battery you want because it only draws about 15A. I like these ones because they're very light for their capacity. I've had three of them, which are still going well after nearly three years:
http://www.bmsbattery.com/48v/248-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

 

[wallypedal]

Great responses all, please keep them coming!

Reliability and adequate torque at very low speed is key. Traction and reverse are secondary. Freewheel reverse is required minimally. He can back up to turn around using normal arm action on the wheelchair wheels. We can deal with the traction issues by using add-on chains which we developed and have proven out.

If there is a way of attaching mid-drive to the fork, along with internal or external gearing, that looks pretty interesting. The additional fork weight would assist traction as well. For independent use by him, we'd want to have the battery easily detachable. He needs to be able to continue to handle the front end separate from the chair by himself - load/unload, etc. The mid-drive weight plus battery might prove awkward otherwise.

He lives in Colorado Springs, and so making up a mid-drive shock fork, disc brake setup should be possible by one of the many Colorado fabricators. That's an assumption, and we don't have anyone in mind. Any suggestions?

The dual power motor setup is intriguing. Support appears to be iffy. Also not sure if their "27 degree" reference is in fact that according to engineering definition, vs. "27%" or something else.

I am confused John, where you say the only answer is to get the motor out of the wheel, yet later say we need a hub motor and mention wheelchair motors. We do not want the bulk, weight, or connectivity issues associated with any attachments to the chair itself. The chair when detached functions as an everyday chair used by him independently. He throws the front end in the back of his vehicle, rolls up to the driver door, hops into the driver seat, detaches the wheels, yanks the Velcro cushion off, stows those, folds the seat back down and puts the chair frame on the passenger seat. Takes about 10 seconds and he does it without assistance.
Thanks again!
Wallypedal

 

[amberwolf]

Pretty sure John in CR is meaning doing the same middrive-on-the-fork I'm talking about, just using a hubmotor (out of the wheel) for it's drive source.


He's mentioning wheelchair motors, but as undesirable alternatives you'd want to avoid for your situation, rather than as something to use.


FWIW, there *are* larger heavier-duty wheelchair motors (I have one here) that could actually make a middrive easier to mount, but cost (new, anyway) is prohibitive because of their specialized use/source vs what amounts to the same motor as a higher-end ebike hubmotor that's common and relatively cheap.


Just remember that a middrive does make things more complicated, but it would certainly let you set up any gearing ratio you'd like, or even enable multiple ratios for different circumstances. Chain guards could easily be put on there to keep it looking nice and fingers off the potentially-dirty chain when he's putting the drive system on the chair or taking it off, and in all likelihood if made right keep most of the dirt out of the chain in the first place, extending it's life (and that of the sprockets).

Keep in mind if you do a suspension fork, all of the mounts for the motor/middrive have to be on the wheel side of the fork, not the handlebar side. Otherwise at every bump/dip your chain "length" changes and stuff can derail, or you end up needing extra tensioners and whatnot to keep that from happening.



The Xiongda motor sounds like another possible alternative, and that would probalby not require any fabrication to install, just mount in the existing forks and go. Might need a really good torque arm for that low gear though.

 

[wallypedal]

Amberwolf, thanks! It's obvious you have pondered our questions, explanations, etc. and are coming back with appropriate info. I've been looking at some of the "side mount" stuff too. It looks similar to what you're suggesting with a hub or mid drive on the frame, with an outside possibility the motor could be mounted on the fork with an extra support. When I look at some of the side mounts on regular bike drive wheels they are mounted right next to the hub with a little short chain. Interesting anyway. That would in theory still allow for a shock fork and remove the chain tension issues. Have also read that the Nexus 3 speed IGH is pretty tough and has been used in e-bike apps successfully. I need to go do the calcs on sprocket size, wheel/tire size and motor rpm's to help determine what the true sprocket and gearing needs are. It is still difficult to tell from the various specs out there what a motor is capable of in terms of torque at rpm's lower than the rated value for a given motor, and the potential heat problems too. The guys with real world experience become more important in that regard. Torque at the fork is also hard to estimate, but something has to give or want to give up in these high load situations.
The recommended two speed motor along with the best controller to go with it is the easiest and close to lowest cost possibility. Guess we could buy a couple of 'em with one as a backup. Wonder if there is an Infineon controller to match, and if a Cycle Analyst would work with it.

I'll be running these ideas by the owner in the next couple days. He's still up in the hills, powering on the level and easy upgrades, and hand pushing up when it gets nasty. He is strong, and it's quite a sight with the chained-up front wheel churning occasionally, right hand working the throttle, and left arm turning the wheelchair wheel on that side. Until he finally asks someone to push or go get the truck. That is really what we're trying to resolve.
Wallypedal

 

[amberwolf]

CA works with anything DC; just get the "SA" model so you have a shunt to plug the battery into (controller plugs into the other side). And whichever version includes the external speed sensor, so you don't have to connect to a hall in the motor.

 

[John in CR]

Pretty sure John in CR is meaning doing the same middrive-on-the-fork I'm talking about, just using a hubmotor (out of the wheel) for it's drive source.

I'd never do a mid-drive on the fork. I'd drive the rear with it, either as a separate drive line in the case of a high power motor or if you want regen and don't have a freewheeling axle, or add freewheeling cranks and put it in the pedal line and take advantage of the variable gearing with a moderate to low power motor ala Stoke Monkey that the guys in SF with steep hills swear by.

 

[John in CR]

Wally,

Wally, yes a hubmotor as the motor, but not in a wheel. They're capable of much more low rpm torque than a similar size shaft output motor that you can use relatively small gear reductions to achieve the low speed and hill climbing desired. That makes the chain drive nearly silent when properly aligned and an idler used to eliminate the chain slack on the lower half. It also means you can use larger sprockets, which also keeps the chain quiet, but also because the chain stress is lower you can use bicycle chain and sprockets, which enables easy and cheap changes to get exactly the results desired as a single speed.

 

[amberwolf]

I'd never do a mid-drive on the fork. I'd drive the rear with it, either as a separate drive line in the case of a high power motor or if you want regen and don't have a freewheeling axle, or add freewheeling cranks and put it in the pedal line and take advantage of the variable gearing with a moderate to low power motor ala Stoke Monkey that the guys in SF with steep hills swear by.

Remember: this is not a bike or a normal trike; it's a regular hand-operated wheelchair with a clamp-on quick-release "bike"-like front end to turn it into a kind of powerchair when needed.

But for this user, it has to remain just a regular lightweight wheelchair when it is not connected to that front end unit, and it has to quckly and easily come apart for him to (by himself) separate them and put them away in his bigger vehicle.

That's why the fork is the only place he's got for putting a middrive. (unless you can think of a good way to get drive power from the "downtube" to the front wheel without interfering with steering/etc).


I suppose a clamp-on drive of some sort to a wheelchair wheel on one side (or both) woudl also work, but the only quick release way I can imagine at the moment is to use an Eboost or Commuterbooster type friction drive. Probably isn't going to be able to transfer the power needed that way.

 

[John in CR]

Oh shoot, I really pulled a brain cramp on that one. It was in the first line of the top post. A big heavy high power hubbie in as small a wheel as possible and run at low voltage is what's called for in this case. I think I still have a slow wind Xlyte 54xx with a built on 10" scooter rim that might fit the bill perfectly just sitting in Baton Rouge collecting dust. Run it a low voltage and it would be a real creeper. I'll check with my son to see if we still have it. Team Hybrid is expensive, but they have exactly that kind of wheelchair setup http://teamhybrid.co.uk/shop/product.php?s=viper-power-cycle. Maybe they can sell just the viper motor, which looks like a big one.

OTOH, I'd want to look at doing something completely different that's a lot more fun to ride. Does he really have to stay sitting in the same chair, or could he pull a lightweight wheelchair in back, or even carry a folding chair? If he can transfer himself from a trike to a chair, then I'd want to go with something with a much lower center of gravity so he can have reasonable performance with greater safety. Trikes are inherently unstable, and with such a high center of gravity it wouldn't take much to go over. I've seen some cool off-road trikes the past couple of years, and electric would make them over the top.

If the wheelchair has to be used, what about 2 wheels in front with a hubmotor in each? I'm sure there's a design in that direction that could add good stability and allow more than just creeping along performance. Plus more traction and double the torque and double the cooling comes along with that solution too.

 

[dogman dan]

Tiny wheel might be the key. I've seen hubmotors designed for wheel barrows. High weight, low speed application.

Not sure where to get one, but smallest wheel possible will definitely help.

The geared motors such as a Mac or BMC are able to lace into a 16" rim, and are a bit lighter than a dd hubmotor.

The 10" scooter hub sounds like a good idea, but that is a powerful and heavy motor. On the other hand, they are known to soak up heat a long time before they overheat. It's just a matter of will a heavier hub motor be a problem for him to detach and toss in the back of the car.

I'd take that offer, and try it. If that doesn't work for you, you can resell the motor here I'm sure.

 

[wallypedal]

Wow, you guys are really helping our process along. John in CR, we're interested in that old slow creeper. Perhaps PM is in order. We know all about Team Hybrid. Essentially the same device we have, after the original UK designer/marketer went belly up. Same frame, different components for sure, not designed for slow speed rough ground unfortunately. No USA distributors, we have communicated via their FB page. Wish we knew if the BMC or Mac setups would handle it. They have to be better than than the DD motor we have now, and there are a couple USA vendors. Need that true ratio/rpm/torque information on those two side by side still.
We have been considering alternative detachable designs - like the rear end off one of these smaller wheel electric dirt bikes, complete with suspension and attached to the back wheelie bar sockets. Still use the front for steering, easy rolling and braking with a plain hub on it. ?? Maybe. Or a differential live axle with cogs on it in back, cogs pressing down on wheelchair wheels. Weight, detachability, etc. are still issues.

He is tremendously upper body strong, don't think any detachable front is a problem in that regard in terms of weight.

Thanks again guys!
Wallypedal

 

[wineboyrider]

Conhis makes these small diameter hub motors not geared that might fit what Dogman is talking about?http://www.conhismotor.com/ProductShow.asp?id=85

 

[amberwolf]

Wish we knew if the BMC or Mac setups would handle it. They have to be better than than the DD motor we have now, and there are a couple USA vendors. Need that true ratio/rpm/torque information on those two side by side still.

Have you tried using the simulator at http://ebikes.ca/simulator? it takes some reading of the instructions below it, and then some playing around with it to understand how to use it for your application, but it might help you pick a system.

 

[wallypedal]

Just spent 15 minutes with the simulator, still learning! It seems pretty useful when understood. Thanks!
Wallypedal

 

[John in CR]

Wow, you guys are really helping our process along. John in CR, we're interested in that old slow creeper. Perhaps PM is in order. We know all about Team Hybrid. Essentially the same device we have, after the original UK designer/marketer went belly up. Same frame, different components for sure, not designed for slow speed rough ground unfortunately. No USA distributors, we have communicated via their FB page. Wish we knew if the BMC or Mac setups would handle it. They have to be better than than the DD motor we have now, and there are a couple USA vendors. Need that true ratio/rpm/torque information on those two side by side still.
We have been considering alternative detachable designs - like the rear end off one of these smaller wheel electric dirt bikes, complete with suspension and attached to the back wheelie bar sockets. Still use the front for steering, easy rolling and braking with a plain hub on it. ?? Maybe. Or a differential live axle with cogs on it in back, cogs pressing down on wheelchair wheels. Weight, detachability, etc. are still issues.

He is tremendously upper body strong, don't think any detachable front is a problem in that regard in terms of weight.

Thanks again guys!
Wallypedal

Wally,

My big question is why the detachable rig, since the relatively narrow track with high and reward CG make the wheelchair the weak point of the design as a vehicle? Is it for transportation to another location where he needs the wheelchair at the other end. I'm thinking that best solution would make the trike a stand alone vehicle with a geometry that makes it far more stable even at higher performance. Then instead of creeping up a slight incline with loose rocks he's able to power up them with confidence. That brings tadpoles into the equation, or 2wd or 3wd deltas, leaners, etc. A quick search turned up Angle Tech, which has a few slick recumbent trikes that are off-road capable, and mods would be simple to remove the pedal line and secure his legs.

If a detachable wheelchair is a requirement, then approach it for a better transformation to a trike, while retaining the strong point which is the strong stub axle wheels. How about simply flipping it on it's back, so as a trike he sits on the backrest and the seat becomes the backrest? That lowers his seating position and moves it forward for much more stability along with more front wheel traction. Being lower it should make it easier to climb aboard after connecting things up or if he had a mishap while out.

Version 1.0 got him out and sold on e-power. Let's make the next one v2.0 instead of just v1.1 with a more suitable motor.

John

 

[wallypedal]

John,
Detachable may well be thinking too narrowly. The device he has was designed that way, and our v 1.0 sort of locked us into that concept. What is wanted is a unit he can load/unload and assemble with ease independently, and does the job. He does have a small pickup truck and another vehicle. His daily use chair can be part of the equation - he can still use it when he gets out of his vehicle to move around on and use as a base for unloading the v2.0, assembly, and then transfer to the v2.0 - so the chair presently used with the front is not really required. Weight, cost, ease of use and transport then - along with performance - are the truly key factors. I appreciate being spurred to re-think all this!
Ironically, the AngleTech place is about 3 blocks from his apartment in the Springs. He will be visiting them for sure.
Wallypedal

 

[wallypedal]

This looks a lot like what is possible and practical. Good on these guys for making something unique that works! http://outriderusa.com/products/horizon.
Now, do we buy one or build one???
Wallypedal

 

[crea2k]

The Infineon is old hat now, get an Max-E, no cycle analyst needed either. http://adaptto.ru/products.shtml

 

[wallypedal]

The Infineon is old hat now, get an Max-E, no cycle analyst needed either. http://adaptto.ru/products.shtml

Sure. As soon as their proponents quit hijacking threads, and they sell and distribute in the U.S. with a website in English and have proven support and a warranty.

 

[crea2k]

There are people on here that sell them to the U,S already, Allex on here sells them to the U.S and ships within a few days.

 

[d8veh]

Is there a reason you eliminated the Xiongda? As far as I can see, it does everything you want - just bolt it in and away you go. You can even use your present 36v battery.