$1500 Bike conversion for Dr. Sweet Meat

[sflorlando]

Hello All,

So this is how the electric revolution happens, not with a bang or some new miracle product but by word of mouth. After all isnt that new miracle product just months away from its new international release!

Empty promises made by "Millionaires and Billionaires republicans" while the Democratics sit on their hands waiting for someone to come up with solar panels made out of bamboo. Thats right...I insulted both parties equally.

Well after showing a friend my pieced together bike, he wants one.

So here is how we start:

My dentist friend "Dr. Sweet Meat" would like to have a nice dependable ebike that is capable of 30+ mph with a range of 20 miles. With a budget of $1500 I have selected the following components:

1. Crystalyte hs3540
2. Cycle Analyst
3. Throttle
4. 72V 40 amp controller
5. bike bag to fit in frame
6. Torque arms

So the question remains: which battery to buy and will his bike work well with this setup? Is there any commercial products that currently fit this requirement?

I would love to be able to recommend a plug and play setup that has been correctly engineered. After all he is a Dr and not of the DoctorBass variety!

Thanks and appreciate all your advice!

Ken

 

[StudEbiker]

Couple of things. I think you may mean 72V controller.

And I think you may mean, "Dr. Sweet Meat" :wink: but maybe not.

 

[sflorlando]

Yep you are right on both accounts!

The Dr Sweat meat sounds disgusting.

Ken

 

[john7700]

Sounds like a perfect candidate for a 48v15ah A123. A little expensive but good performance. Going lipo with a non-technical noob could be a recipe for disaster. Plug and play Lifepo would be my suggestion. That bike doesn't belong going much faster than 30 MPH and it should be close to the 20 mile range with maybe a little peddling. I would just rear rack mount it with that bike at that performance level. The fifteen or so pounds of battery on a good rack with that hardtail will perform just fine. Spend a little money on a nice trunk and rack system. Also, budget for some swable big apples or equal fat tires.

 

[neptronix]

I also vote for a123. Long life, good discharge, safe, and a decent price. Good pack for someone who could give less of a damn about all the nerdy stuff we spend hours babbling on about.

cell_man is the only guy i know of who is making these tho.. he's on vacation until early December according to his site
Maybe another builder exists.

If an A123 battery can be fit into the center triangle with a falconEV bag, that would be so ideal for good bike-like handling.
( that bike has loads of triangle space. )

For 30mph speed, you don't even need the crystalyte. A cheapo MXUS/9C/Golden Motor/Conhismotor/whatever flavor of the day cheapo DD motor would work just fine. That will shave $ off your build cost as well.
The crystalyte HS/HT are good motors, but are not known for their reliability actually. They seem to have some machining and design issues with the axle still.

 

[Farfle]

9c for sure, plenty of power and much better QC than a crystalyte.

 

[The Mighty Volt]

9c for sure, plenty of power and much better QC than a crystalyte.

for real???

 

[neptronix]

9c for sure, plenty of power and much better QC than a crystalyte.

for real???

Unfortunately he is not kidding. There are many kinks to be worked out with the new Crystalyte HS/HT motors. If not for design issues, manufacturing seems to be a little janky too.

It's pretty effed up considering the price of the motors.
I'm holding out on those until they're fixed. Until then, any cheap POS DD motor would honestly be better if you're gonna run ~30mph.

 

[The Mighty Volt]

9c for sure, plenty of power and much better QC than a crystalyte.

for real???

Unfortunately he is not kidding. There are many kinks to be worked out with the new Crystalyte HS/HT motors. If not for design issues, manufacturing seems to be a little janky too.

It's pretty effed up considering the price of the motors.
I'm holding out on those until they're fixed. Until then, any cheap POS DD motor would honestly be better if you're gonna run ~30mph.

Ah the new stuff, yes, I read those stories too, but the old X5 is mustard still.

 

[dogman dan]

Though I've never seen one in real life, the NEW INPROVED clyte hype beats me. Just about thread one was all about how to not cut the wiring doing a simple install by doing a modification. Oh, I see they kept the worst part of the old design. 8)

Obviously I like the 9c good enough, I must, I have about 8 of em laying around in three different windings.

 

[Farfle]

Even the old x5s, which sadly are no longer made had poor manufacturing tolerances. Still doesnt make them any less badass tho .

 

[Lenk42602]

Even the old x5s, which sadly are no longer made had poor manufacturing tolerances. Still doesnt make them any less badass tho .

..... is that why you scoop up all the old ones in the "for sale" sections?!

 

[NeezyDeezy]

I'd definitely go:

9x7 9C motor
60V, 15 AH battery (ping or cell_man)
Method's 60V 25A controller

This will be lighter and cheaper than what you proposed, and still have all the performance he needs. The battery won't fit in any standard in-frame bag. It would be better to make something custom anyway, that way you could incorporate the controller and maybe a locking mechanism.

 

[Hillhater]

Better ask if "Dr Sweet Meat" wants to be able to ride the bike without Elec assist at any time ?
If so a geared hub ( MAC or BMC) may need consideration.

 

[neptronix]

I'd definitely go:

9x7 9C motor
60V, 15 AH battery (ping or cell_man)
Method's 60V 25A controller

Some problems with this config.
+ That 9x7 on 60v nominal could overheat on hills or just during normal. It also needs 30A or more to maintain it's most efficient speed on the flats, and much more to maintain good speed on hills. I think i actually melted one of my magnets off my 9x7 running 57v nominal / 55a on flat ground!! It also will want to go about 35mph on a 26" wheel. I would not hand this motor at that voltage to a newbie.
+ That 25a controller is not going to put out enough amps to get a DD like that into it's efficiency zone. It would constantly waste power when not being pedaled furiously. It would do even worse on hills.
+ A 60v 15ah ping is not going to put out the current needed ( >30a ) for the 9x7 at that winding and voltage. An A123 would work.

48v would be a hell of a lot more suitable. But the 25A controller may have heat problems as it'd want to push, i'd estimate, 20-25A constant on the flats to maintain 30mph on that motor. You would need a 9FET doin' 30A to keep that motor happy.

 

[NeezyDeezy]

I'd trust Neptronix on that. I have ridden my 9x7 at those specs without any problems, but I'm not as experienced as others on the board. I'm surprised it would need a lot more amps at 60v, especially if he'd be willing to pedal. And safety/speed doesn't seem that far off considering he's asking for at least 30+ mph, but again, there very well may be better options.

 

[dogman dan]

I can't comment on the 60v (nominal) battery. You can heat up a 9c pretty good just running full speed on flat ground on 72v though. I've seen that. I believe it has to do with increased wind resistance requiring more watts continuous, plus the efficiency issues discussed above. At some point, a line gets crossed and the motor will heat to a point of equilibrium that is too high for long term reliable use. If the ride is short, then you get away with it. If long, you melt a motor. Depends on weather too. Winter you get away with more.

Give him the 48v 15 ah ping, and the 20-25 amp controller, and he'll not have problems overheating till the grades are more than 7% for more than 3 miles. That I've tested and passed at 110F ambient temp. He'll only get 27 mph. If he must have 30, and the hills are easy, then put him on a 2806 motor. BTW, at just about 30 mph, you start to really have problems doing any pedaling along with the motor if the bike has 48-14 gearing. So you open a can of whoop ass on yourself trying to find the right crank to have a 52 tooth sprocket if you don't have one already. Few road cranks fit an mtb, or in this case, a comfort bike.

Another good option for 30 mph is the faster version of the Mac.

 

[sflorlando]

thanks guys for the input.

I think were gonna look for a 48Volt 15 amp Ping Battery along with a 9C. Curious to see the difference.

Which 9C should we go with from ebikes.ca?

Im kinda of afraid of him burning up the controller so id like to overbuild this. Should we upgrade to the 40 amp controller but limit it to 30 amps on the CA?

Can the ping battery handle continuous 2 c discharge?

thanks!

 

[dogman dan]

That ping cannot do the 40 amp controller. I tend to say 25 amps max continous. Some have gotten away with bigger, but a lot depends on if steep hills are ridden, and if any weak cells happen to be in the battery. The bigger the amps, the faster any weak cell goes bad. Used conservatively, even a marginal cell could last years. But go bad right away if hammered with 2c enough. Aim for 1.5c discharge max. At 25 mph, you sholdn't be pulling much more than 12 amps on flat ground.

You aren't going to burn up a controller that easy. I've melted several motors, but rarely had any problem with a controller on stock settings. I did fry one I soldered the shunt on. Just mount the controller where wind can get at it.

2807 would be my recomendation. 27 mph top speed, which can still be pedaled if you have at least a 48 tooth crank. A 2806 would have a faster top speed, but not climb hills as well. At top speed, you need big gears to keep pedaling along. Sit on a bike long enough no pedaling, and your ass suffers.

 

[john7700]

Sit on a bike long enough no pedaling, and your ass suffers.

Sit on a bike seat long enough pedaling and your ass suffers :lol:

 

[Pure]

I know hills are not much of an issue down there. There are are a few large ones but they are not a common sight in the Central Florida area. But having said that, with what your Doc freind is wanting, a 15 amp ping is going to be pretty much maxed out almost all the time. A 20 amp Ping would give you a lil more wiggle room but not much. Personally if I were you I would go with a headway pack, either a custom job or one offa the shelf. EV assemble seems to have gotten their crap together with their QC on their headway packs and their prices are competitive with Ping's. Even still the QC issues are not a big deal. Go over the pack and make sure the bolts on the end caps of the bats are tight and that's should be about it. This 16Ah pack should have no problems pulling 80 amps http://www.evassemble.com/index.php?main_page=product_info&cPath=1&products_id=59 and is plug and play.

As far as his choice for a bike to convert goes, that bike should b=make for a pretty good conversion as long as he isn't looking to go much faster than 30 mph. The bike's geometry is setup to be a cruiser so higher speeds wouldn't be very safe. But it has plenty of room for a frame bag and with big enough tires the ride should be pretty comfy. He can also add a shock seat post to help smooth out the bumps.

edit: Oh yeah, how bout some pics of your finished build. *poke poke*

 

[999zip999]

Go with a cellman triangle battery in his triangle bag 51v a123 with his mac motor and the controller has a plug for a c.a. Or look at Justin's or Ilia at ebikessf.com. Save money by spending more now and get something good and you will save money and headach's and not waiting for repairs remenber some of these places have NO customer service ( ebay ) ect.

 

[sflorlando]

Yes I need to put a post with my finished bike. I recently went up to 42 mph on it over a slightly sloped downhill run. If I had a decent straight road I'm assuming I could get close to that since it is quite easy to get 35+ mph. Pics to follow!

 

[dogman dan]

Duhh, Florida. Forgot where you are. In that case, choose the 9c motor based on what top speed you want, 27 mph, or closer to actual 30 mph. 25 amp controller, 48v 15 ah ping. Even at 30 mph, most of the time you'll be drawing much less than 15 amps, so no prob for a 15 ah ping. A 20 ah 48v ping is a sonofabitch to carry on a bike. 48v 15 ah fits on a rear rack, and can be tolerated. On that bike, it should fit in the triangle.

 

[Pure]

Next time you take your bike out set your CA to a 30amp limit. That will be the performance MAX for the 15 amp Ping. Then ask yourself if that will be enough for the Doc. It might be, but try it first. I bet you will find it to be a lil boring.