1000w + geared rear hub source?

Guys, can somebody give me a hand please. Trying to source a 135mm gear drive rear hub.

I have a 26" bike with an existing 1500w direct drive hub (135mm drop out). It's using a 12 fet 35 amp KT controller and LCD3 display. Though the bike is working great, I would like to try a gear drive rear hub, looking for increased hill climbing performance. Wide rear hubs not an option. With the fact the bike is used in a hilly area, and I have no use for speeds in excess of 20mph (think fat old man), thinking I would prefer a low speed wind if that's an option. Bike is used on the street, sidewalks, and paved trails. I do not want to go backwards from existing performance from a standing start, and emphasis lies with performance climbing hills found in a rolling coastal area.

I see the Mac 12t option at em3ev, but have an open mind/wondering about other options? Or is that motor the plan?

Thank You!

MAC is the way to go nowadays. I don't really see another geared motor option that is as good in terms of price, performance, reliability and information available. They've been steadily improved over the years and represent a good deal of current ebike motor technology. And EM3EV has always supported us well.

8Fun seem to be on many a store floor.

Can also look at BMS Battery but beware, their s/h prices are high to compensate for their great motor prices. In the end it evens out.

I do agree, if I were to buy a geared, it would be the MAC with a Sinewave or FOC controller.

What is your climate? In my desert climate, Id quickly kill a mac or other 500w rated geared motor on long hills, or long slogs through sand. How do I know? by killing motors. 1500w is considered the max safe wattage for motors like this, but others have gotten away with more simply by how they ride, and climate.

You may like a geared motor. I do for some kinds of ride. But the kind of ride I mean is I pedal a LOT. Enough to keep my rpm up on the motor, and not melt it down. I give it 1200w max, but try like hell not to give it that for more than a few seconds. Mostly, I pull sub 600w. In summer, once I heat up a geared motor, its not cooling off for a long time. Dry air, and the way a geared motor is made, keeps it from cooling back down. So the name of the game is don't get it hot too quick. Any more than 1500w, and there is not enough copper in there to handle it efficiently, and it just heats up faster.


Other bikes I ride different, but they can have a big strong heavy ass DD motor with all the watts I need. On my geared motor bike, the emphasis is on light motor, light battery, and max range by barely using the motor.

Thanks for the info so far guys. If it will help, some detail about where and how I ride.

I AM a peddler, peddling nearly the whole time I'm riding. Now generally riding with PAS set to 1-3 and 8-15mph. This to economize on battery life. PAS 3 used on hills and "difficult" terrain, like grass. Otherwise it's not used often. Bike has 2.3" tires, so sand and loose surfaces generally avoided. At some point a "fatty" may be considered, but nothing in the near future.

Battery is a 48v 13.5ah. Target range of 25 miles is generally used. My butt is only good for 20 or so, so logic would indicate range beyond 25 miles difficult to justify from a cost and weight viewpoint. Unless on a longer ride, I generally watch my charge voltage and charge as necessary (50-60% or so). With the current 1500w DD hub, I generally keep it on a diet of 1200w or so max (due to battery limitations mostly), and it will see that only on hills. Less than 1200w available may leave me walking on some hills, but thankfully there aren't many of those around. I'm hoping this gear drive will allow me to power up those without worry. Duration of climb rarely more than a couple of minutes. These are sometimes large rolling hills, not mountains.

Though I do ride in some pretty warm temps, it's pretty much the opposite kind of warm found in the desert areas. We're riding along the Gulf coast in winters, and SE Michigan in the summer. So it can be warm, but not like a desert climate.

My primary reason for going gear drive is to check them out. I now know about what to expect with a large DD. Have an open mind on the subject, and the curiosity to see which will do the job at hand better! -Al

Geared is a good way to go. I like getting the good coasting back, on a light bike. But on a heavy bike, that really does require 2000w to get up a mountain, its back to a 25 pound DD motor. No way an 8 pound geared motor has enough copper or magnets to handle 2000w continuous, for a half hour or more. The DD soaks it up.

At Ebikekit.com, Jason settled on a 22 amps controller, and telling people they could not get a warranty if the bike, battery, them, and cargo weighed over 300 pounds. We melted motors easily on hills at 400 pounds.

Bottom line really, is if you can climb a hill at 15 mph, you have not overloaded at 1200w, (52v and 22 amps) that's easy to get to that speed on a 6% grade. But at 400 pounds, best we could do up hills was about 8 mph.


On the other hand, feed that light motor more current that its even remotely designed for, and you just make heat with the watts over 1500. Its just not enough copper for the big current. Lots of people do feed a Mac 30 amps of 48v. But its about the upper practical limit for that motor.

Geared motors make noise so people hear you coming up from behind them.
Direct Drive is more reliable, and people can't hear anything when using a sinewave controller. Not sure how the noise is reduced with geared + sinewave.

I have some MACs, 2, 7turn, 5, 8turn and a 12turn. Love em! Yes they do whine a little and I don't care that they hear me and like it at times. They do climb hills well. 12turn is run 66v nominal and 44v when I deplete the 66v pack. 66v gives me right around 30mph with big tires and like 24 on 44v. In your case a 12turn would be my choice. I have had other geared and DDs, I now have all MACs. You would love the bottom end torque. My favorite is the 8turn. I now live in the heat and so far it has been great. I don't push them long, maybe 3 miles WOT and they are still cool enough to put my hand on the hub or the axle which is the cooling path. 90deg days and I ride 40 to 50 miles a day. Longest ride so far is 67miles with abut 10+ miles left in the battery.

Dan

dogman dan said:

Geared is a good way to go. I like getting the good coasting back, on a light bike. But on a heavy bike, that really does require 2000w to get up a mountain, its back to a 25 pound DD motor. No way an 8 pound geared motor has enough copper or magnets to handle 2000w continuous, for a half hour or more. The DD soaks it up.

At Ebikekit.com, Jason settled on a 22 amps controller, and telling people they could not get a warranty if the bike, battery, them, and cargo weighed over 300 pounds. We melted motors easily on hills at 400 pounds.

Bottom line really, is if you can climb a hill at 15 mph, you have not overloaded at 1200w, (52v and 22 amps) that's easy to get to that speed on a 6% grade. But at 400 pounds, best we could do up hills was about 8 mph.


On the other hand, feed that light motor more current that its even remotely designed for, and you just make heat with the watts over 1500. Its just not enough copper for the big current. Lots of people do feed a Mac 30 amps of 48v. But its about the upper practical limit for that motor.

Click to expand...

Dan,
Interesting data/thoughts for sure. I suppose I should have already mentioned I'm a BIG guy (6'2" and 315). So with a bike in the 60-65lb range, things will be closer to the 400lb side of things for my purposes. For that reason, and the fact Jason's site really isn't set up for a 400lb gear driven rig (1 year warranty requires weight of less than 300lbs), or the fact I'm looking for just a motor and wheel, I pretty much moved on from a purchase there.

It would be interesting to know more about the motors you melted at 400lbs (brand? wind? other details?) so I could avoid them and know more about features/setups to avoid that situation. At this stage of my lifetime, I absolutely HATE learning things the hard way, especially when info to avoid that is available somewhere.

Thanks! -Al

Those melted motors are basically similar to all the other larger geared motors. All 500w rated motors. Can push them to 1500w, particularly if you don't try to kill them climbing mountains, as I set out to do. they do fine though, on flatter terrain at 400 pounds. The warranty is based on the idea that some of the customers live in west virginia, west Pennsylvania, or the rockies. He can't just replace a ton of motors because people live in the hills. Hence the 300 pound limit warrantee.

So the Mac is not your solution, no any other geared motors I have heard of, if you want 2000w. Or want to climb mountains heavy. I wish they did make a 1000w rated geared motor, but it would not fit in a 135 mm dropout if they did. Make the magnets 10 mm wider, there would be no room for the gear and clutch assembly inside 135 mm.


But the larger DD motors will eat that shit up, which is why my big longtail cruiser has a 25 pound hub motor on it, not a 9 pound geared. Refering back to your original post, wanting more hill performance, you won't see it till you go into 2000 or 3000w. More power will get you more performance, and the geared motors are too small to do this for you. Tiny magnets compared to your DD.


A mac 12 t will do something though, it can be a more efficient way to get up hills. It will be way slower, but able to run that slow without melting as fast. The motor I melted was a 10t, and melted down when the load slowed it to 5 mph on the big long hill. A mac 12t would likely be ok down to 10 mph up hills, but since its a slow winding, you'd get less power out of it rather than more. So you'd have to pedal like hell to keep it up to 10 mph when the hill gets steep. Not what you are looking for I thought. No geared motor will be, unless you can lighten the load.


But, there is a way to dramatically improve your current motors hill performance without adding more watts. Lace it into a 20 inch wheel. This actually puts the motor in a lower gear, physically. Your motor in 20 inch wheel will definitely climb like a goat. This does of course, mean a bike change, or a big modification.


That is exactly what I was after, when I built this bike. Ability to climb those same big ass mountains at 20 mph top speed, using only 1000w. The small wheel meant that the motor could climb more loaded down, without going below minimum rpm, than a 26" wheel. It could climb those mountains at 10 mph without overheating, while the big cruiser needed double the watts, to maintain its minimum uphill speed of 15 mph.

Dan,
Without investing a lot more than I want, this bike I have is not capable of 2000 watts, other than possibly a short burst (like accelerating quickly to speed for instance, or crossing a busy road in a big hurry). That might be fun, but hardly a priority.

Target are hills, not mountains, and 8 to 15mph cruise speed. I'm an old man riding for pure pleasure. I have no need to be in a hurry. 20mph is something I do only once in a while (like riding DOWN some of these big hills!). I got the need for speed out of my system a long time ago. Yes, I was truly nuts at one point, but that's a different topic. I'm WAY more laid back and patient any more, thus the focus on lower speeds.

Your focus seems to be much more aggressive riding than what I am interested in, so to draw on your experience, do you think I'm nuts for considering the MAC 12t for the more sedate riding I'm planning on, with the occasional big hill to be conquered? Is there potential for a performance gain (more usable torque) at lower (8-10mph) speeds with a gear drive like this?

Thanks for your time and patience here! -Al

Whether we are talking DD or geared, hills certianly are the challenge for hub motors. The problem with these discussions about proposed hills to be tackled is quantifying them. How steep is steep? Is it steep and long? Rather than getting the protractor out, maybe duration is not a bad way to think about it.
Momentum goes a long way and with my, weaker than a MAC hubbies, being to hit the bottom at full tilt will carry me a long way up on a 2 minute climb. It would have to be a steep hill indeed for me not to be able to crest it.
The thing to always keep in mind is The First Law of Hub Motors, which states; Never allow the climbing speed to fall below 1/2 of the top speed, at which point the motor is generating more heat than forward momentum. One quickly learns to anticipate the rare occasion when it's time to jump off and push. One senses the bike is going to stall if you keep pushing it and the idea is to Never, Never let a hub motor stall out.
I have never damaged a geared hub motor, or for that matter, had it get too hot(again, how hot is too hot?). But I have melted the connectors on my phase wires, and after they were elimitnated, melted the phase wires themselves. I've done this on long dirt road climbs where wash-outs or ditches forced me to come to almost a complete stop halfway up and I've done it in the flat running high speed-range motors. When the motor struggles to reach it's theoretical top speed (No-load speed?), the controller tries to supply everything (Amps) it's worth and that's when the melting occurs.
But this is where the "Catch 22" of climbing with hub motors come into play. Although it may seem counter-intuitive, in an effort to carry that momentum as far as possible, one wants to start with as much power as is safe(How safe is safe?)for the motor, but to be ready in mind and body, to shut it down quickly when it become apparent that an unintended stop is in the near future.