Hill climb

[Lowell]

Actually I don't think the Crystalyte motors are that excellent, however they get the job done for a reasonable price. More importantly they have been on the market for a while, and have very good availability. I don't want something experimental on my commuter bike, where if I need a replacement I'll be waiting more than 1 day.

Tell me about your ebike again?

 

[eP]

Actually I don't think the Crystalyte motors are that excellent, however they get the job done for a reasonable price. More importantly they have been on the market for a while, and have very good availability. I don't want something experimental on my commuter bike, where if I need a replacement I'll be waiting more than 1 day.

Tell me about your ebike again?

I do understand you. I have quite different goal.
I can't tell you about my ebike 'coz i haven't one yet.
So i can only tell you about my goals (which i would like to achive) for now.

In my country hub motors are very rare and awfully expensive. So i'm looking for people they would like to achive similar goals to mine.
After long net searching i see the hub distributors are not interested in distribution efficient hubs at wide speed and torgue range.
They can earn more money by selling efficiency limited products than selling some more efficient and more universal models.
This is them right marketing/selling strategy so i'm not surprised they do it this way.

The similar situation was a few years ago at RC hobby market. Distributors and producers wanted selling brushed motors as long as possible 'coz brushed one have much shorter life.
So hobbyists started to use rebuilded CD motors for greater fun, (it is not very complicated task ) and now we have much better brushless motors availability then few years ago.

I don't want wait few years as some smart guys do less limited hubs then X-lyte and cheaper also, or X-lyte motors will halfed at price.
But i also dont want do all alone and losing my time for advertise that my experimental motors are better choice.
So i'm looking for guys which are interested at building some experimental motors for fun and possible future gains.

Maybe i'm wrong but i strongly suppose now you could achive better results for less time and money if you try to build experimental hub ( with stron and cheap Neo magnets) then try to rebuild your vehicle for lower air drag.

Even if you succesfully rebuild it, it will still power hungry at even light slope (at high speed) or at high slope at any speed for the sake of low efficiency. And this way you dont solve the problem of excessive heat. ( Even if your batts and controller allow pump huge power to motor you will cannot do it if the high temperature dont allow (the high temperature can burn your motor and destroy motor's magnets).

So if you want get reliable vehicle at such extreme conditions ( very high speed or high speed climbing ) it is much better way to rebuild the motor or build experimental one - in my opinion ( but i could be biased of course - for the sake of my goals ).
So i'm looking for guys which want discuss and argue if i'm wrong.

Regards

 

[EbikeMaui]

Actually I don't think the Crystalyte motors are that excellent, however they get the job done for a reasonable price. More importantly they have been on the market for a while, and have very good availability. I don't want something experimental on my commuter bike, where if I need a replacement I'll be waiting more than 1 day.

Tell me about your ebike again?

I do understand you. I have quite different goal.
I can't tell you about my ebike 'coz i haven't one yet.
So i can only tell you about my goals (which i would like to achive) for now.

In my country hub motors are very rare and awfully expensive. So i'm looking for people they would like to achive similar goals to mine.
After long net searching i see the hub distributors are not interested in distribution efficient hubs at wide speed and torgue range.
They can earn more money by selling efficiency limited products than selling some more efficient and more universal models.
This is them right marketing/selling strategy so i'm not surprised they do it this way.

The similar situation was a few years ago at RC hobby market. Distributors and producers wanted selling brushed motors as long as possible 'coz brushed one have much shorter life.
So hobbyists started to use rebuilded CD motors for greater fun, (it is not very complicated task ) and now we have much better brushless motors availability then few years ago.

I don't want wait few years as some smart guys do less limited hubs then X-lyte and cheaper also, or X-lyte motors will halfed at price.
But i also dont want do all alone and losing my time for advertise that my experimental motors are better choice.
So i'm looking for guys which are interested at building some experimental motors for fun and possible future gains.

Maybe i'm wrong but i strongly suppose now you could achive better results for less time and money if you try to build experimental hub ( with stron and cheap Neo magnets) then try to rebuild your vehicle for lower air drag.

Even if you succesfully rebuild it, it will still power hungry at even light slope (at high speed) or at high slope at any speed for the sake of low efficiency. And this way you dont solve the problem of excessive heat. ( Even if your batts and controller allow pump huge power to motor you will cannot do it if the high temperature dont allow (the high temperature can burn your motor and destroy motor's magnets).

So if you want get reliable vehicle at such extreme conditions ( very high speed or high speed climbing ) it is much better way to rebuild the motor or build experimental one - in my opinion ( but i could be biased of course - for the sake of my goals ).
So i'm looking for guys which want discuss and argue if i'm wrong.

Regards

:lol: If you want performance you can add more batteries to what motors are now available and try to fix things as you go . Or make your own that will not break down if you overbuild and use parts you can always find rather easily.After ebiking over 20,000 miles on a single homade car alternator with a quality designed controller only the batteries are the weak link.But not too far off if they can last almost 1 year.If you want a ready made quality ebike with longevitity and performance that lasts longer than the manufactures your in luck with most of the available ebikes here at the moment. Just dont blink.
http://video.google.ca/videoplay?docid=1363294199598759645&q=ecyclemaui http://video.google.ca/url?docid=-1501457501981349249&esrc=sr6&ev=v&q=ecyclemaui

 

[Lowell]

I'm not really sure what I could gain by rebuilding my motor, it works fine, and looks good inside. I would much rather spend time building some A123 packs to lower the voltage sag from the NiMH cells.

As for burning the motor and destroying the magnets, doubtful that could happen as the X5 is a big motor, with similar weight as an Etek. I've also added cooling holes to the side covers which help keep temps down on the 6km stretch of highway near my house. I usually ride that at 80+km/h WOT.

 

[eP]

:lol: If you want performance you can add more batteries to what motors are now available and try to fix things as you go.

Are you kidding guy ?
Are you trying kill me by LOL ?

It is IMPOSSIBLE get the good performance if the motor is heavy, weak or inefficient.

This way you offer you can get more or less bad compromise. It is way to get fast a more or little fun if you have enough money.
But this way you cannot make any new or check new idea.

For a little fun i can ride on my old cheap bike.
I'm keen on veryfying new ideas so i'm looking guys for discuss which could check my ideas for fun and gain for them.
So i like Safe's simulations (if they are well done)
because it is a first step to get a right conclusion or check an doubtly idea.

Or make your own that will not break down if you overbuild and use parts you can always find rather easily.After ebiking over 20,000 miles on a single homade car alternator with a quality designed controller only the batteries are the weak link.But not too far off if they can last almost 1 year.If you want a ready made quality ebike with longevitity and performance that lasts longer than the manufactures your in luck with most of the available ebikes here at the moment. Just dont blink.
http://video.google.ca/videoplay?docid=1363294199598759645&q=ecyclemaui http://video.google.ca/url?docid=-1501457501981349249&esrc=sr6&ev=v&q=ecyclemaui

So tell us why you build your own motor ?
For the sake of price ?

I like to buid the motor for showing all people: do the same and gain is yours and all of us.
It is my goal. I dont need one only for riding so much, to spend so much time for research and make.
The great fun for me is from a good (new) veryfied idea.
So i don't want do the same the others done before for the lack of time or lack of better ideas/materials. I dont want repeat bad compromise.

If anybody convince me his idea is better than mine and that way we can get a better/good compromise i will try copy his idea.
So it is the reason i want to discuss also.

For now i see geared motor are much better for climb assistance ( when you have limited power budget ) than motor hub.
So for limited power vehicle my idea is to buy 2-3 5330 outrunners at Kv=200-250 and drive the rear hub by chain. Each motor is for $50USD around.
If think 70% efficiency is possible this way versus 25-50% for hub motor.

What you think about that ?

 

[eP]

I'm not really sure what I could gain by rebuilding my motor, it works fine, and looks good inside. I would much rather spend time building some A123 packs to lower the voltage sag from the NiMH cells.

You could gain lower heat loses and better heat dissipation.

As for burning the motor and destroying the magnets, doubtful that could happen as the X5 is a big motor, with similar weight as an Etek. I've also added cooling holes to the side covers which help keep temps down on the 6km stretch of highway near my house. I usually ride that at 80+km/h WOT.

I also stall uP fan for 4 minutes an my uP will still working well.

So check the motor current at 80km/h and tempreture and do the same for 70 km/h and 75 km/h and you can extrapolate it to 96 km/h.
But first of all check the yours magnets temperature limit to avoid destroying them.

 

[Lowell]

25-50% efficiency for a hub motor? Maybe with a passenger, trailer and going up a 10% grade. :lol:

The AXI outrunners are great motors. I have a 2208 on one of my micro helicopters and the performance is awesome, and certainly more power than my flying skills can use.

http://duzi.cz/duzi_hornet2_2004_01.wmv

Looks like the 5330 is more like $200 each. Doesn't sound very economical to use 3 of them.

http://www.hobby-lobby.com/brushless-axi5330.htm

 

[Lowell]

I'm not really sure what I could gain by rebuilding my motor, it works fine, and looks good inside. I would much rather spend time building some A123 packs to lower the voltage sag from the NiMH cells.

You could gain lower heat loses and better heat dissipation.

As for burning the motor and destroying the magnets, doubtful that could happen as the X5 is a big motor, with similar weight as an Etek. I've also added cooling holes to the side covers which help keep temps down on the 6km stretch of highway near my house. I usually ride that at 80+km/h WOT.

I also stall uP fan for 4 minutes an my uP will still working well.

So check the motor current at 80km/h and tempreture and do the same for 70 km/h and 75 km/h and you can extrapolate it to 96 km/h.
But first of all check the yours magnets temperature limit to avoid destroying them.

With better batteries, I can eliminate heat losses on the battery side. 10V sag at 60 amps = 600W used heating the battery packs. If heat ever becomes a problem in the hub, I'll address it at that time.

 

[eP]

25-50% efficiency for a hub motor? Maybe with a passenger, trailer and going up a 10% grade. :lol:

Looks like the 5330 is more like $200 each. Doesn't sound very economical to use 3 of them.

Dear Lowell could you read carefully ?

I've said:

So for limited power vehicle my idea is ...

Try to calculate your hub efficiency at 600 W power limit when you need 30Amps for the sake of torque.

When you do that you will not be so happy i'm sure.
---------------------------------------------------

At $200 it is not ecoonomical in fact.
But at $50 level is worth of considering i'm sure.

TP5330

 

[eP]

With better batteries, I can eliminate heat losses on the battery side. 10V sag at 60 amps = 600W used heating the battery packs. If heat ever becomes a problem in the hub, I'll address it at that time.

At 60A you get 24V sag inside the motor, so even you reduce battery sag from 10V to 2V you still get the 3 times more heat (than you reduced at battery side) inside the motor.
And keep in mind we taking 60 mph at flat road.
At little slope your current arise to 70A and speed must drop as you reach your huge power limit.

Keep in mind this topic name is hill climb.

 

[safe]

Try to calculate your hub efficiency at 600 W power limit when you need 30Amps for the sake of torque.

When you do that you will not be so happy i'm sure.

I've made the case that for very limited motor size that gears are the way to "save the day". If you can gear your bike really low for the hills and really high for the flats then you can achieve high efficiency everywhere. Realistically you can get 70% efficiency all day long and also avoid the dangerous effects of heat.

So for a small motored bike simply eliminate completely the idea of a hub motor... it's simply a terrible idea... a complete waste.

All the guys here that like their hub motors are running 2000 Watts or more. In the default setup a hub motor is limited to about 20 mph and mild hills. Otherwise you are expected to do most of the work with your own pedalling... so the motor becomes a kind of mild "assistance" rather than your primarly drive... which is "nice" but not in the same category as these "monster bikes" that people talk about.

 

[eP]

Try to calculate your hub efficiency at 600 W power limit when you need 30Amps for the sake of torque.

When you do that you will not be so happy i'm sure.

So for a small motored bike simply eliminate completely the idea of a hub motor... it's simply a terrible idea... a complete waste.

I see You are wrong as usual :wink:

All depend on Rmotor value.

It is very big difference if one motor have Rm=400mohm and the second one have Rm=100mohm.
I assumed they have others parameters the same.

So the second one can achive the same efficiency as the first one,but at 4 times less power and 4 times slower speed.

So Rm i the key parameter which tell us how good (efficient ) motor could be.

I started strongly suspect that Rm which i calculated on data from crystalyte site is not the true Rm for the motor but rather Rint of battery pack which crystalyte offer.

I've come to this conclusion when i open this simulator: http://ebikes.ca/simulator/

But still i didn't find what is the accurate Rm value.

 

[Toorbough ULL-Zeveigh]

I think you know my position by now, that an electric drivetrain doesn't really need more than a 2-speed TX. What I fail to understand is why geared hub motors like the BMC/Puma or Heinzmann don't make a 2-speed.

By my limited understanding, once you have the planetary TX in place, adding more ratios adds only slightly to the complexity, weight or cost. Can anybody shed some light on what the hangup might be why no one offers a 2-speed (or more) internally geared (i.e. planetary) hub motor?

In the race between the Puma & X5, the Puma is faster off the line because of the greater torque output the gearing provides which would work to the same benefit up a slope. The X5 on the other hand has the higher top speed. Now throw in a second set of planets geared for the top end in the Puma & you have the X5 beat & wouldn't weigh a whole lot more than the 10 lbs. it does now. So what's wrong with this picture? There's gotta be a reason that something this obvious hasn't been done b4.

 

[safe]

All depend on Rmotor value.

It is very big difference if one motor have Rm=400mohm and the second one have Rm=100mohm.

I just installed a new motor that is a 1000 Watt that has a lower resistance than the previous 750 Watt motor. It revs higher, but it seems to overall put out more power across the entire spectrum. The bottom line is that less resistance means a better motor. (it's about a 5% gain across the board)

The PMG 132 ($800+) has a resistance value that is 1/10 the value of the motors that I use. It's a better motor, but you pay more for it.

So if "cost" is a factor... and "reality" means that you must use the motors that you can afford then your resistance value will be what it will be.

The only "other" way to improve things is to make sure that what you have is used well. To do that you need to use gears so that you can be sure that the rpms are always near the efficiency peak.

Hub Motors like the Crystalyte have resistance values that are good, but not in the same "league" as the PMG 132... you don't get performance like the PMG 132 with ordinary low cost hub motors or Unite chinese motors...

The Transmagnetics looks good and their prices are in the middle...

 

[safe]

By my limited understanding, once you have the planetary TX in place, adding more ratios adds only slightly to the complexity, weight or cost. Can anybody shed some light on what the hangup might be why no one offers a 2-speed (or more) internally geared (i.e. planetary) hub motor?

I agree.

By my calculations a two speed should cover most all you need to cover. The range needs to be pretty large... it needs to be a gear ratio jump of about 250% (2.5 to 1) in order to cover the top speed needs and the hill climbing needs.

It would be nice if it automatically downshifted when the rpms dropped below a certain point...

 

[fechter]

I think you know my position by now, that an electric drivetrain doesn't really need more than a 2-speed TX. What I fail to understand is why geared hub motors like the BMC/Puma or Heinzmann don't make a 2-speed.

I totally agree. If they can stuff 8 speeds into a Sram hub, making a 2 speed geared hub motor can't be that hard. Two gears is enough. Something like a two speed Puma would really kick butt. Low for hill climbing and off-road, and high for flat ground. You could get fancy and have an automatic solenoid shifter, but manual would be fine.

Looks like another "I'll have to do it myself because the manufacturers are too stupid" thing.

Honk used to have a formula for computing motor efficiency that was based on the motor resistance and the no-load current. These two things will tell you a lot.

The Unite motors still use ceramic magnets. There's not much excuse for not using rare earth magnets these days. Using stronger magnets allows you to use fewer turns of heavier wire (lower resistance), while still maintaining the rpm/volt. If the magnets are too strong, the no-load current will increase due to increased core losses. This is more than offset by improved efficiency at high load in most cases.

Better magnets will also resist demagnetization that can occur at high peak currents with ceramic magnets.

 

[TylerDurden]

How 'bout this:

External motor with retro-direct drive... toggle switch to reverse the motor direction.

http://www.basementfreaks.com/gallery/gallery.php?gal=7205f55d4003b20e1e0e07035a45dafd

 

[Lowell]

25-50% efficiency for a hub motor? Maybe with a passenger, trailer and going up a 10% grade. :lol:

Looks like the 5330 is more like $200 each. Doesn't sound very economical to use 3 of them.

Dear Lowell could you read carefully ?

I've said:

So for limited power vehicle my idea is ...

Try to calculate your hub efficiency at 600 W power limit when you need 30Amps for the sake of torque.

When you do that you will not be so happy i'm sure.
---------------------------------------------------

At $200 it is not ecoonomical in fact.
But at $50 level is worth of considering i'm sure.

TP5330

You would not use an X5 hub if your goal was only 600W. At 48v and 15 amps a 5304 will put 550W to the wheel with around 85% efficiency. Not sure how you arrive at 30 amps? Perhaps you're using the 2 D cell flashlight batteries that come on EbikeMaui's $500 bike.

 

[safe]

How 'bout this:

External motor with retro-direct drive... toggle switch to reverse the motor direction.

At first I thought:

"Oh geez... a garage project... "

...but after looking at it a little it's not a bad idea.

 

[TylerDurden]

At first I thought:"Oh geez... a garage project... "

No chain slippage.

Cheap, off the shelf parts.

Using a Scooter freewheel and sprocket, very low ratios are available: 11:80, 11:65...


8)

 

[Lowell]

I think you know my position by now, that an electric drivetrain doesn't really need more than a 2-speed TX. What I fail to understand is why geared hub motors like the BMC/Puma or Heinzmann don't make a 2-speed.

By my limited understanding, once you have the planetary TX in place, adding more ratios adds only slightly to the complexity, weight or cost. Can anybody shed some light on what the hangup might be why no one offers a 2-speed (or more) internally geared (i.e. planetary) hub motor?

In the race between the Puma & X5, the Puma is faster off the line because of the greater torque output the gearing provides which would work to the same benefit up a slope. The X5 on the other hand has the higher top speed. Now throw in a second set of planets geared for the top end in the Puma & you have the X5 beat & wouldn't weigh a whole lot more than the 10 lbs. it does now. So what's wrong with this picture? There's gotta be a reason that something this obvious hasn't been done b4.

From what's been posted here, the Puma single speed design hasn't been perfected yet. It seems to still be in testing and development. To do a 2 speed, the 6:1 gear reduction would need to be reduced, and some sort of lockup/clutch added to the gears. This would kill off the Puma's low end torque unless the gears could be rewored into say a 6:1 and 3:1 instead of 2:1 and 1:1.

The other thing to consider is cost. How much does a Puma motor currently cost?

 

[safe]

A typical freewheel has a range of 14-28 teeth. That translates to a 200% range. The newer cassette style hubs can go 11-34 which is 300%. And since you already have a derailler cog (held by a spring) you might as well use a regular freewheel or cassette.

I've got over 1000 miles on my 6-speed freewheel with no problems... so I don't think that strength is a big problem.

Recently I've started "double shifting" either going up or down in the gears and that "technique" is so quick that it gets you to the gearing to want right away.

 

[Lowell]

How 'bout this:

External motor with retro-direct drive... toggle switch to reverse the motor direction.

At first I thought:

"Oh geez... a garage project... "

...but after looking at it a little it's not a bad idea.

That's actually a pretty cool idea, it just needs scaling up for durability.

 

[eP]

You would not use an X5 hub if your goal was only 600W.

The strong side of really efficient and powerfull hub is it can work at high speed as well at high torque and relatively low speed.

Lets look an example:
1) case:
600 W 30 A Rm= 400mohm => Pout=240W eff.=40%
2) case:
600W 30A Rm=100mohm => Pout=510W eff=85%

so at 2) case the similar motor can work quite efficiently.

At 48v and 15 amps a 5304 will put 550W to the wheel with around 85% efficiency. Not sure how you arrive at 30 amps?

48V 13A at batt's side could be transformed to 20V 30A at motor side
But to know the efficiency we should to know Rm value at first.

Perhaps you're using the 2 D cell flashlight batteries that come on EbikeMaui's $500 bike.

I don't use any cells as i haven't any e-bike yet.
600W was only as an example for discuss.