Comparisons? WattHrs/mi/lb. @ speed

EbikeMaui said:

Lowell said:

knoxie said:

Yes I agree

I sometimes rise as well but I also try not to and try and be smart and bite my lip, the times I dont are normally when I have had a few beers and I get pissed! quite literally!

Its tough to do but Yes the best thing is to ignore anyone who makes inflammatory remarks, being ignored is much more annoying for people that are trying to provoke a reaction, if everybody ignored people who troll then they do eventually go away, have you noticed how this years power assist posts compare to last year? I can think of 2 people that used to post on there that now dont, it kind of proves my point.

I promise I wont rise again

Knoxie

Click to expand...

Arguing with certain people is like racing Lycras on a 5000 watt ebike. It's fun for a while, but gets boring because you already know the outcome.

Click to expand...

Yep. Lycra Racer after you run out of battery power shortly.

Click to expand...

To quote something I vaguely remember from an old Disney movie about a Morgan racehorse:

The horseshoes only have to last the duration of the race

I think Stu Whitman was the star of that movie.

Finally met my goal of a >60km/h average on my work commute. 60.7km/h to be exact including traffic and stop'n go. 32.3Wh/km. Tucked in I can get as low as 26-2700W input power to go 80km/h on the flats, and I'm only using 55-60% of the battery which should give the packs a long life.

Next goal will be a little aero tweaking to try and reach 60km/h average with 30Wh/km consumption.

EbikeMaui said:

GREAT! Thats not a legal ebike. And how much does the total ebike with the batteries weigh ? :lol: You have a heavy flatland motorcycle racer with pedals is all.You still cant get all the components you need in one package without modfication.
The brushless Etek just needs a motor mount and sprocket and do better with the same batteries. For those constant speeds you certainly do not need pedals.But there is that option.

Click to expand...

All this applies to your heavy non-legal pedaless ebike that has to be modified with mounts & sprockets that you can't get in one package just to end up with a slow, heavy, uphill-tugboat is all.

So what's your point, zero-point?

The shortcomings you level at Lowell's ebike are appropriately aimed at a mirror. A faster ebike always has the option to run at a slower speed to increase range. Unfortunately the option to run at Lowell-speed doesn't exist on a randybike.

It will be a long time b4 any ebike manufacturer will ever cater to your niche requirement. The bright side is we can all look forward to a very long period of your railing against how nobody builds an ebike that is useful to a fraction of a percent of the market that needs volcano climbing capability.

The flatland racer is a more saleable product because it is useable to the far greater majority of people. Most people don't give a rats a$$ about the motor's efficiency at slow speeds (if at all) because they want to spend as little time as possible going slow. One more doubling in the specific energy of battery capacity will render the motor efficiency argument dead anyway.

Toorbough ULL-Zeveigh said:

EbikeMaui said:

GREAT! Thats not a legal ebike. And how much does the total ebike with the batteries weigh ? :lol: You have a heavy flatland motorcycle racer with pedals is all.You still cant get all the components you need in one package without modfication.
The brushless Etek just needs a motor mount and sprocket and do better with the same batteries. For those constant speeds you certainly do not need pedals.But there is that option.

Click to expand...

All this applies to your heavy non-legal pedaless ebike that has to be modified with mounts & sprockets that you can't get in one package just to end up with a slow, heavy, uphill-tugboat is all.

So what's your point, zero-point?

The shortcomings you level at Lowell's ebike are appropriately aimed at a mirror. A faster ebike always has the option to run at a slower speed to increase range. Unfortunately the option to run at Lowell-speed doesn't exist on a randybike.

It will be a long time b4 any ebike manufacturer will ever cater to your niche requirement. The bright side is we can all look forward to a very long period of your railing against how nobody builds an ebike that is useful to a fraction of a percent of the market that needs volcano climbing capability.

The flatland racer is a more saleable product because it is useable to the far greater majority of people. Most people don't give a rats a$$ about the motor's efficiency at slow speeds (if at all) because they want to spend as little time as possible going slow. One more doubling in the specific energy of battery capacity will render the motor efficiency argument dead anyway.

Click to expand...

Anyone can buy a 90% efficient 5 KW motor that can provide 1 to 90 ft lbs of torque to the wheel at any RPM.But yea Lowells hub motor may be $200. cheaper and he has to make a controller, torque arm, and hopes his front forks and wheel spokes dont break or the controller blows.. It's not if... it is when! Not to metion abusing batteries.

Yea my heavy huffy that is a total of 64 lbs can go 40 miles at 25 mph without having to pedal.But I think pedals were still there on the bike last time I looked.And it goes a lot faster than I drive it which is still too dam fast.
http://video.google.com/videoplay?docid=1363294199598759645&q=ecyclemaui

Sorry for thinking that randybike didn't come with working pedals. Your other copyright@ prior art picture shows no chain or chainring to the pedals & you always brag how you never pedal. (Didn't want to attach the pic here for fear of eliciting everyone's ire; moreso than usual anyway.)

sOKAY, your bike has pedals & is totally illegal. Then why for are you bustin Lowell chops over it, trying to make it seem like your shit smells sweeter somehow? At least his can be made legal in the time it takes to pull off a couple of battery packs.

I guess you must think that something less than Lowell's 50mph cruising speed is too dam fast to enjoy the scenery. :lol:



P.S.
Here's a tip for you Randall.
I you have such a stiffie for posting the above copyright @2003 pic all over the place, then just make it your avatar already & earn everyone's gratitude in the process.
Ask the mods for help if you don no how.

Ok, I've cleaned some of the trash from this topic. PM me if:
-you'd like one of your own posts nuked
-you feel I deleted your post unfairly
-you have other posts in mind you'd like to see gone

I'm still not sure how to measure an ebike's effectiveness/performance, but efficiency alone seems rather a poor way to go about it. It's kinda like measuring penis size to determine how good someone is in bed.


For example, in my neck of the woods what happens is you'll be on your own past, at most, 32km/h. So from that point on the only specs that matter on your electrical system becomes weight/rolling resistance. I had to seriously drop the hammer, and for a long time on 42kg bike de merde in order to accelerate from 32 to 40. I could describe it's acceleration as being "eventual". But 32-40 ish happens rather quickly on my 15kg DH bike, and next to that one a 10 kg road bike feels like it has a motor. So, even let alone not being able to put a 50Kg bike on a bike rack, repair stand, or hauling it up stairs, weight is certainly very significant.

Also average trip speed & watt consumption over 20min rides, and pedal only top speed should tell a lot about about how well a bike is suited to it's environment, how well it works out IRL.

Wh/Km @ speed also sounds pretty good, the goal here would be to get a fair guesstimate of the electric system's eff. Obviously, bad eff means more batteries per distance, so this is linked with weight. Trouble with it is that not all ebikes reach the maximum allowed cutoff speed, and this legal limit changes a little depending where in the world you are. However, nearly all electric bikes seem capable of reaching 25km/h on their own. This would be a rather convenient speed since it should mostly prevent varying wind resistance from skewing this eff guesstimate.

Motor only hill climbing grade @ speed would be another significant measure to include in the motor part of the specs, crapping out on >10 % @ 4km/h is very different from crapping out on >10% @ 20km/h...

Amount of maintenance... How many times per 3 months does said bike need some type of maintenance? How much is related to the motor/electrics, and how much to the bike? What does it consist of?

Cost... Two bikes that have otherwise semi-identical specs, but one of them costs twice more... Are obviously quite different beasts.



Now how to squeeze all this in a unified ebike performance evaluation forumla is beyond me. Geography, weather conditions ect. that the bike is used in changes the relative importance of various specs, and since it varies per user, seems like it would probably be quite tedious to make this into a unified formula. Maybe some kinda online calculator where you plug in your hills, price point, or whatever could show you several bikes that come pretty close to what you're looking for...

So, even let alone not being able to put a 50Kg bike on a bike rack, repair stand, or hauling it up stairs, weight is certainly very significant.

Click to expand...

My ~45kg bike loads fine into the back of the Benz as I don't own a bike carrier. It balances just fine on my repair stand, which cosists of a 5 gallon bucket under each peg. Stairs are also not a problem, although I don't see much need to take it upstairs from the garage, or to the upper section of my shop. Of course I'd swap the heavy NiMH packs for lithium in a second if price was no object...

Personal preferences aside, Wh/km seems to be a universal benchmark of efficiency, along with maximum speed on various percentage grades to measure hillclimb ability. Individual users can decide for themselves on specific requirements such as bike carriers, stairways and whatever else. My own bike needs to fit into standard common public bike racks which is why I only have an upper windscreen/fairing.

Rider weight and hight should not be overlooked either. Two of my customers are BIG guys, and weigh around the same as my bike with me on it. (275-280lbs) Besides the obvious disadvantage on hills, they will have a lot more drag at speed than a 180lbs 5'9" rider.

Also average trip speed & watt consumption over 20min rides, and pedal only top speed should tell a lot about about how well a bike is suited to it's environment, how well it works out IRL.

Click to expand...

Problem is that some assist systems are poorly suited to 'no pedal' operation, and the people that use those almost always pedal to some degree. If you test those systems without pedaling, the numbers aren't that great. My comfortable pedal only speed of 25km/h is largely irrelevent since I have no intentions of ever pedaling unless the electrics can't propel the bike.

Lowell said:

.

Click to expand...

Problem is that some assist systems are poorly suited to 'no pedal' operation, and the people that use those almost always pedal to some degree. If you test those systems without pedaling, the numbers aren't that great. My comfortable pedal only speed of 25km/h is largely irrelevent since I have no intentions of ever pedaling unless the electrics can't propel the bike.

Click to expand...

What does that say for any hill or adverse wind conditions when 750 watts of efficient power is required to go 10 mph on a 100 lb ebike.. Since many members do not have a hill climbing testing ground they may at least find a route with a 1000 ft rise on a 3 mile trip up hill.A one way trip up hill will pretty much give your round trip figure in watt hours per mile since you can coast back on a ride that was paid for. There is no way to compare anything in ebike tests while pedaling unless you want to factor in a average of 75 to 100 watt hours on 3 hour or longer trips with a heavy (100 lb or over) ebike in which you can get a long term average.For fast short trips with a lightweight ebike you may have 3/4 of your power comming from pedaling which does NOT say ANYTHING about motor performance.

Well I don't like wh/km alone because that's just fuel consumption, and the same bike will get different consumption at different speeds, so I figured the optimal speed to test a steady state consumption would be 25km/h given the belief that pretty much any bike can reach it. So that's why I figured wh/km @ 25km/h was a better idea then just wh/km.


The above, plus max no pedal hillclimbing grade @ whatever speed, is meant to measure the electric motor's performance, but the idea behind the 20 minute/km/ or something test was to get a good idea of how the bike works out IRL, that is to say the run was intended to be done however the said bike is normally used. That is to say: With or without pedaling, on the flats with no stops, throwing it around hills, urban warrior, etc... So that checking specs and stuff of several bikes should end up giving a good idea how well a given setup would work out in the kinda use a person intends for it.

For example Bike de merde worked out pretty well for me, but make it 1/2 the weight, say with battery capacity adjusted for equal range, then top speed would have been similar with a somewhat better average speed. Now if you put a fat dude who don't pedal on same bike, I surmise he would have thought the bike was blowfull, wh/km shooting through the roof & speed would have been a good deal slower. In the same line of thought, I only twice went through the battery in summer, when I first assembled it the batteries were at 12.4v but of course I went to ride it anyways... The other time what I did is checked no-pedaling range before it was modified, and it gave me 50kms with a top speed slightly faster then 25km/h. Once modified for more amps, it would (pretty quickly) reach a high value of 32 and really rip up hills, but then peukert kicked me in the balls. Once in it's intended element, with very fat and aggressive studded tires, then it would give me about 15-20 kms range at full throttle, & that's with a good pedal to it.


And yeah, rider's specs are of course important, I didn't specify it because it seemed obvious, but I surely would expect people to have at least a pretty good description of their bikes, like the type of motor, maybe top speed, bike's weight & other stuff along those lines, and something similar for the rider, what kinda riding they do, did they just get back into cycling or have they been at it for years? And where do they ride, etc...