Joe Perez

iTrader: (8)

I haven't really kept informed of the latest offerings in motors for such an application, but having built two e-bicycles, 48v sounds low to me. My last bike ran 52v at full charge, and topped out around 25 MPH unassisted on level ground. Granted, this was due in large part to the gearing of the motor; I had it set up with a very high ratio to maximize hill-climbing power, as at the time I lived in a very mountainous area. I'd think that with a different motor and gearing, it'd have probably been good for maybe 40 MPH (with no ***** on the steep inclines), but that's still on the extreme low end of motorcycle performance.


Most of the seriously insane e-bikers seem to be leaning towards 72 - 96 volt systems these days.



Edit:

Here's a rule-of-thumb guide I found in a writeup from the folks at Electricbike.com, based on the Cromotor V2, which is a non-geared hub motor intended for light motorcycles.

50V
75V
100V
125V

EO2K

iTrader: (37)

Oo, nice table! Thank you much! Many props!

Well. 72-96v, eh? That changes costs for a few things, other than just batteries obviously. 48v seems to be the break point for this type of hardware when it goes from expensive to painfully expensive. I may have to rescale my budget a skidge.

Joe Perez

iTrader: (8)

That's obviously just one table for one motor, but it's in the ballpark. Be aware that for any given motor, they're typically offered in several different winding configurations, which you'll see referred to in shorthand as figures like 5T, 7T, etc. These are windings ratios, and in general, a lower T ratio yields a higher Kv factor (where one Kv = one RPM per volt when unloaded) at the expense of a lower current-handling capacity and thus lower torque. On my last eBike, I used a 10T motor (the highest T-ratio available) and then further ran it through a planetary gear. As a result, it'd do the same 25 MPH up a 10% grade that it would on level ground (albeit pulling insane amounts of current to do so), but it would go no faster. It would still provide some assist, if I pedaled hard enough, to just break 32 MPH or so, but it (and I) were screaming to get there. Also, 32 MPH on a mountain-bike frame does not feel safe.

Every motor will have a datasheet which lists the various Kv factors for different windings, and based upon that and the outer diameter of the tire you can estimate no-load MPH for a given voltage. (Sadly, I haven't found a convenient formula for estimating required current for a given combination of speed / weight / grade / etc).



Also, bicycle tires and wheels apparently don't like turning at 70 MPH for an extended duration, just FYI.

fooger03

iTrader: (2)

I had issues that started slowly at first, and were most noticeable when I was lifting. Some days were "good" days, when I knew I could make a bit of progress, and some days were "bad" days, when it was all I could do to lift a pair of 25lb plates. At first, I couldn't figure out an explanation for it other than my shoulder just really hurt through a significant range of motion; better some days than others. The issue persisted for about 3 years without ever getting better - it was incredibly frustrating - and I never did see a doctor about it.

I decided one evening while laying in bed with that arm over my head that "gee, that doesn't seem like a very natural position for my shoulder to be in..." I intentionally laid it by my side that night. The next day when I lifted, I had a "good day" - there was still pain, but it was a 2 instead of a 6 or an 8. After just a single week, my shoulder pain went away completely and permanently.

It's been about 2 years since, and I still have to occasionally force myself to not put my arm over my head, but no pain and no issues. The occasional "arm-up" night doesn't cause an issue; it's the repetitive process of night after night that slowly degrades it. Apparently the body is pretty good at healing itself, you just have to make sure you don't leave it in a damaging position for 30% of your life.

EO2K

iTrader: (37)

That last part us why this is a motorcycle, and not a bicycle

Oh yeah, I understand where you are coming from. That is why I'm trying to find real use cases with real data. I astounds me that people just seem to slap these things together with no idea how much the end product weights or how much amperage they are using. Or maybe they just don't want to share data. /boggle

This will def not be a hub motor setup. Most likely this will end up being a chain drive setup so I can use standard motorcycle tires and rims, and more importantly, sprockets.

The only part I'm a bit nervous on is not putting the motor on the swing arm and thus screwing up the chain drive. I have seen where people have adapted to a shaft drive bike, and while it will be quieter and less maintenance, its a mechanical hurdle I would have to overcome, and then the motor will be mounted off the centerline of the bike, and things will get complicated. I'm trying not to over-complicate things as much as possible

I need to make a decision as to if I plan on going with AC induction or permanent magnet brushless. The elmoto crowd really seem to like the AC motors but its probably another $500-$750 that will need to be added to my budget. Maybe I'll sell one of my ARs or something.

Also, srs question: what is wrong with Leaf cells? They appear to be lighter and have a higher discharge rate, density and cycle count than LiFePO4. y u no leik?

Joe Perez

iTrader: (8)

Well, don't totally discount hub motors. There are some serious ones out there, and people have lately been lacing them into moped and light motorcycle wheels, which gives you durability and good tire selection. While they aren't the #1 choice for maximum HP, and require a bit of care with regard to cooling (filling them with ATF is a popular option among the high-power crowd), there's something to be said for the simplicity of not needing a chain and sprockets.


Nothing at all wrong with either Leaf or PHEV Prius cells if you can find 'em. You just offered me the opportunity for an easy joke.

Monk

iTrader: (3)

There's a wrecked prius in the junkyard right now.
I don't have any idea what I'm doing, but I can take the sawzall to it if you want.

aidandj

iTrader: (5)

Do it!

But don't kill yourself.

EO2K

iTrader: (37)

You should check of the $$ on salvaged cells Lithium Batteries and Packs

Joe Perez

iTrader: (8)

Just FYI, the majority of Prii use NiMh batteries, which is not what EO2K wants. NiMh are a good choice for hybrids, as they accept very high charge currents and are thus great for regenerative braking. But their power density (watt-hours per kg) is low as compared to the various lithium-based batteries.

So far as I know, only the most recent-gen plugin Prii used lithium chemistry batteries.

EO2K

iTrader: (37)

^^ What Joe said.

The difference is I had to look it up and apparently he just knows these things

rleete

iTrader: (21)

The older you are, the more funny it is:

You are in the middle of some home projects:
putting in a new fence, painting the porch, planting some flowers and fixing a broken door lock, working in your garage.
You are hot and sweaty, covered with dirt, lawn clippings and paint. You
have your old work clothes on. You know the outfit -- shorts with a hole in
the crotch, an old T-shirt with a stain from who-knows-what, and an old pair of tennis shoes.

Right in the middle of these tasks you realize that you need to run to Home Depot for supplies. Depending on your age you might do the following:

In your 20s:
Stop what you are doing. Shave, take a shower, blow dry your hair, brush your teeth, floss and put on clean clothes. Check yourself in the mirror and flex. Add a dab of your favorite cologne because, you never know, you just might meet some hot chick while standing in the checkout line. And yes, you went to school with the pretty girl running the register.

In your 30s:
Stop what you are doing, put on clean shorts and shirt. Change your shoes. You married the hot chick so no need for much else. Wash your hands and comb your hair. Check yourself in the mirror. Still got it! Add a shot of your favorite cologne to cover the smell. The cute girl running the register is the kid sister of someone you went to school with.

In your 40s:
Stop what you are doing. Put on a sweatshirt that is long enough to cover the hole in the crotch of your shorts. Put on different shoes and a hat. Wash your hands. Your bottle of Brut is almost empty, so don't waste any of it on a trip to Home Depot. Check yourself in the mirror and do more sucking in than flexing. The hot young thing running the register is your daughter's age and you feel weird about thinking she's spicy.

In your 50s:
Stop what you are doing. Put on a hat. Wipe the dirt off your hands onto your shirt. Change shoes because you don't want to get dog crap in your new sports car. Check yourself in the mirror and swear not to wear that shirt anymore because it makes you look fat. The cutie running the register smiles when she sees you coming and you think you still have it. Then you remember -- the hat you have on is from Bubba's Bait & Beer Bar and it says, 'I Got Worms '

In your 60s:
Stop what you are doing. No need for a hat any more. Hose the dog crap off your shoes. The mirror was shattered when you were in your 50s. You hope you have underwear on so nothing hangs out the hole in your pants. The girl running the register may be cute but you don't have your glasses on, so you're not sure.

In your 70s:
Stop what you are doing. Wait to go to Home Depot until you call the drug store to have your prescriptions ready for pick too and check your grocery list for a quick stop there. Got to save trips! Don't even notice the dog crap on your shoes. The young thing at the register stares at you and you realize your ***** are hanging out the hole in your crotch… who cares.

In your 80s:
Stop what you are doing. Start again. Then stop again. Now you remember you need to go to Home Depot. You go to Wal-Mart instead. You went to school with the old lady greeter. You wander around trying to remember what you are looking for. Then you fart out loud and turn around thinking someone called your name.

In your 90s & beyond:
What's a home deep hoe? Something for my garden? Where am I? Who am I? Why am I reading this? Did I send it? Did you? Who farted?

Joe Perez

iTrader: (8)

I wish. It's merely that my Google-Fu is superior to yours.

good2go

iTrader: (2)

^^ Too god damn true!


I think it wasn't until I was in my mid forties that I consciously acknowledged to myself that most of this posturing was utterly absurd and was based on the highly improbable notion that it might ultimately lead to sex. The thing is, in spite of my age, I had long since come to the conclusion that any female that would hook up with an absolute stranger on a trip to Home Depot was completely outside what I would consider desirable, and was instead rather repulsive and disgusting. Primal instincts, go figure.

fooger03

iTrader: (2)

In my 30's;
Rinse my hands - if there's grease or oil on them, a squirt of dawn will take enough of it off to be presentable. If the hole in my shorts is big enough for anything to hang out of it, then put on the next best pair that I own. Go to Home Depot and don't give a ****.

If it's a run to NAPA, I'll wipe off most of the grease on my hands with a dry terry towel. The dudes behind the register don't care about the hole in my shorts.

Great post!

Monk

iTrader: (3)

I am positive that my guys would not even know what I had much less charge me tose prices.

So what model year should I be looking for?

EO2K

iTrader: (37)

I mean, it COULD be done with NiMh batteries. Cheapness can be a strong motivator.

As my required budget for this project swells, things like this start looking really attractive: Zero FX Electric Motorcycle || ZERO MOTORCYCLES

Pricing on that with CA state intensives for the Zero FX is $6,745. My original budget for this project was $4,000 and I pushed it to $5,000 to account for a bigger bike and more batteries to go with an AC system. Is my time (and by extension Gessos ) worth $1,750?

Bonus points: Zero is 40 minutes up Highway 1 from my house

Joe Perez

iTrader: (8)

Based on that, I turned 50 some time in my early 30s.

Feeling it to... For the past month, I've been walking to and from work every day. 2.3 miles each way via the shortest route, slightly more if I deviate.

Yesterday, on the way home, I went to the Trader Joe's on West 72nd via Central Park. Nice scenic route. So about 8.5 miles that day, with the last 2.5 carrying about 25 lbs of beer and groceries in a backpack.

Every single part of me below the naval is in pain this morning.

To those who jog / walk long distances on a daily basis, when does it stop hurting? And don't give me the cyclists maxim about how "it never gets easier, you just get faster."

Joe Perez

iTrader: (8)

This is the level of detail at which my personal knowledgebase runs out and I start relying entirely on web searches.

So far as I can tell, the 2016 "Eco" model uses Lithuim batteries, as do all of the plug-in versions. I've found no details as to the specific battery chemistry.

y8s

iTrader: (8)

do some weight lifting (squats/deadlifts) to make your core stronger. It'll keep your spine properly aligned even after many hours of standing/walking. it's YUUUUGE.