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Re: Cromotor vs 54xx - Fight!

Posted: Jan 20 2012 5:14pm
by waynebergman
Thanks Oatnet...........that frame could make a nice Boardtrack style bike with a springer style set of forks, drop down handle bars and a retro saddle. Maybe a nice motor battery combo like on Juicer 2's rig.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 20 2012 9:20pm
by Gordo
oatnet wrote:The improvement in handling will surprise you. :D

You don't like the looks? After a lot of positive feedback, -JD

Image
That rig is so ugly the only hope is to paint the entire bike PINK with some daisy's on the box. :!: :mrgreen:

Re: Cromotor vs 54xx - Fight!

Posted: Jan 20 2012 10:15pm
by oatnet
Gordo wrote:
oatnet wrote:The improvement in handling will surprise you. :D
You don't like the looks?
That rig is so ugly the only hope is to paint the entire bike PINK with some daisy's on the box. :!: :mrgreen:
Always a kind word, that Gordo. :lol:

-JD

Re: Cromotor vs 54xx - Fight!

Posted: Jan 20 2012 11:07pm
by hillzofvalp
Yeah.. If it floats your boat great.. Bt I couldn't do the front pack.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 12:06am
by Gordo
hillzofvalp wrote:Yeah.. If it floats your boat great.. Bt I couldn't do the front pack.
Well I certainly intend to try it for 2 reasons. I know for a fact that the 2 POS I have constructed have far too excessive weight on the rear rack, WHICH IS WRONG :!: If it was not for the fact that a guy with a lot more experience has done the front pack many times and assures us it works in a balanced fashion, I would not believe it. My only solution is a TIMMA type frame to get the weight as far forward as possible without going to the forks. The cost of a full custom frame vs the pack on the forks, is a no brainer. I simply must try it. The off the shelf type of clamps are a fair method of attachment for people with limited machinery. Me thinks there is a far more elegant way to mount a box than those great ugly clamps with nuts inside, which you then have to pad and protect the cells from. I do have the experience of having owned a 1200 Goldwing motorcycle which had a huge weight factory mounted in the exact same spot. I did not notice the different handling from many other wings I have ridden. I didn't know it was there until I changed the headlight from 40W to 100W one day.
Make no mistake, I believe in this :!:

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 2:00am
by Alan B
hillzofvalp wrote:Yeah.. If it floats your boat great.. Bt I couldn't do the front pack.
Before you say that you should either try it or do the research on it.

Read the bicycle dynamics thread. Some surprises in there.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 11:14am
by oatnet
Alan B wrote:
hillzofvalp wrote:Yeah.. If it floats your boat great.. Bt I couldn't do the front pack.
Before you say that you should either try it or do the research on it.

Read the bicycle dynamics thread. Some surprises in there.
:shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock:

Interesting read, but you forgot the link to your thread:
http://www.endless-sphere.com/forums/vi ... =7&t=35909

And here is the wiki article you link to in that thread.
http://en.wikipedia.org/wiki/Bicycle_an ... e_dynamics
Center of mass location

The farther forward (closer to front wheel) the center of mass of the combined bike and rider, the less the front wheel has to move laterally in order to maintain balance. Conversely, the further back (closer to the rear wheel) the center of mass is located, the more front wheel lateral movement or bike forward motion will be required to regain balance. This can be noticeable on long-wheelbase recumbents and choppers. It can also be an issue for touring bikes with a heavy load of gear over or even behind the rear wheel.[19] Mass over the rear wheel can be more easily controlled if it is lower than mass over the front wheel.[10]

A bike is also an example of an inverted pendulum. Just as a broomstick is easier to balance than a pencil, a tall bike (with a high center of mass) can be easier to balance when ridden than a low one because its lean rate will be slower.[20] However, a rider can have the opposite impression of a bike when it is stationary. A top-heavy bike can require more effort to keep upright, when stopped in traffic for example, than a bike which is just as tall but with a lower center of mass.
This explains a lot of what I am seeing and trying to describe with indequate vocabulary. Wild that I stumbled into this phenomena just by feel. Alan, thanks so much for posting that! :D

-JD

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 12:51pm
by Gordo
I recognize this phenomonen from changing the mast on a cranky boat.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 12:56pm
by waynebergman
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Thanks Alan and Oatnet for trying to help us understand better what is happening up high in the front of the bike when its moving. The broom stick analogy was excellent for helping me understand what is going on when the bike is moving. I am still wondering at what point or speed of movement does this change take effect of slowing down the lean. I guess what I am getting at is say you are just going super slow say 2 miles an hour trials style, is this going to make the top feel top heavy like it would when you are stopped at a traffic light. I am guessing there is a certain speed that starts to work in ones favour for the top heavy feeling to disappear. It sounds like a moot point but I am curious. By the way I am on board with this. Picture attached of my efforts for up front mount.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 12:59pm
by Alan B
Good job on adding the links and quotation and finding the phenomenon with your battery mount in the first place, Oatnet. When I read the article I knew instantly why your battery was working so well for you. I haven't tried it yet but plan to. Many things are a lot clearer now.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 1:38pm
by Gordo
waynebergman wrote: I guess what I am getting at is say you are just going super slow say 2 miles an hour trials style, is this going to make the top feel top heavy like it would when you are stopped at a traffic light. I am guessing there is a certain speed that starts to work in ones favour for the top heavy feeling to disappear. It sounds like a moot point but I am curious. By the way I am on board with this. Picture attached of my efforts for up front mount.
The precise answer depends on many factors. The weight of your wheel, tire, battery, case and mount, but also the DISTANCE from the center of the forks to the center of the weight. The further you push the center of weight forward, the more pronounced the effect on handling. It is the old "lever arm" from school physics vs gyro effect of the front wheel being dependent on rotating mass. The speed on a bicycle where the top heavy feeling goes away will be different for each setup. Heavy cruiser motor bikes take a lot more effort on the counter steer than light race bikes. Likewise the speed where the top heavy effect goes away is higher than the race bike.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 1:40pm
by neptronix
Since this has became a 'front battery mounting' thread ... ;)

I must ask.. what do you front mounters think of a solution like the surly front rack?

http://www.amazon.com/Surly-Front-Nice- ... B001GSOJTI

I'd like to do the traditional oatnet style, but i'm dealing with a bike designed for 80mm forks. Finding one of those triple crown style forks, even a non suspension one, seems quite difficult.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 21 2012 3:22pm
by Gordo
Nep,
I worry about getting the weight too far forward. Maybe a mount from 2 positions on the handlebars and 2 on the conventional forks? :mrgreen:

Re: Cromotor vs 54xx - Fight!

Posted: Jan 22 2012 9:05am
by BATFINK
Thanks for the tips Oatnet, just a few more parts to get for my bike and I should be finished within a month, why waste your time explaining time and time again how good a front mounted battery is if some people don't get it they don't get it. I've ridden a non ebike many times when I was a feeble kid with another kid sitting on my handlebars just for fun and I was able to turn no problemo :-) haven't we all done that in our lives??? If you haven't you haven't lived ;-) I like the purposeful look too. Can't wait to set it all up

Sent using Endless-Sphere Mobile app

Re: Cromotor vs 54xx - Fight!

Posted: Jan 22 2012 1:40pm
by Gordo
oatnet wrote: Mass is mass whether it is in a Pelican box or in the front end, they both rotate around the axis easily. Frankly, the gyroscopic effects are harder to overcome than the mass. People have been using front baskets for heavy loads for years, and after 5-6 front-pack builds I think rotation is a non-issue.
High COG: Take a look at these KTM gas tanks. They mount the "dead weight" at the same height as one of my front-mounted packs, as close to the fork as they can cram it. -JD
I have been re-reading this thread and would just add that the sloshing fuel is worse than dead weight, particularly until the fuel gets down to where it is isolated on both sides of the tank. And it is not a problem :!:

Re: Cromotor vs 54xx - Fight!

Posted: Jan 22 2012 7:55pm
by John in CR
Mounting a battery up high is more a problem when you are off the bike than on it, but high rear is a lot worse than high front.

Re: Cromotor vs 54xx - Fight!

Posted: Jan 24 2012 3:41pm
by nomad85
Any good ideas on how to do a front battery mount on non triple crown suspension forks that don't involve welding/machining? Big zip ties? :)
Great job on your boxes oatnet!

Re: Cromotor vs 54xx - Fight!

Posted: Jan 24 2012 3:48pm
by oatnet
nomad85 wrote:Any good ideas on how to do a front battery mount on non triple crown suspension forks that don't involve welding/machining? Big zip ties? :)
Great job on your boxes oatnet!
Thanks Nomad!

Zip tie's won't do it, you need a hard mount that won't let the load shift. I use double-crown forks so I haven't experimented with single-crown forks. I look forward to seeing what you come up with!

-JD

Re: ??????? vs x5403 - Fight!

Posted: Jan 24 2012 4:06pm
by oatnet
I'm so disappointed I renamed the thread.

Last I talked with Accountant, his order of (100) motors was going to be a mix of 9kv and 13kv so I could get a 13kv, with a 17kv for Doc. Today he reports the order will be (2) 13kv for Zombiess and Dr. Bass, and (98) more of the awkward 9kv motors. :| :? Nobody buying these 9kv motors is going to get the 13kv high-speed performance reported by the Italian guy, so I hope Accountant will be able to sell them and place a 3rd order. I am skeptical, so I put ???????? in this thread's title instead. Well, last time the 13kv motors we bought turned out to be 9kv motors, maybe we'll get lucky and this time the 9kv motors will actually turn out to be 13kv.

Anyhow, that leaves me without at hub motor that can keep up with the x5403. I'll keep searching, maybe John in CR will be able to bring his motors to market. Until then, this will be a x5403 build thread looking for another fast hubby!

-JD

Re: ??????? vs x5403 - Fight!

Posted: Jan 24 2012 5:29pm
by zombiess
oatnet wrote:I'm so disappointed I renamed the thread.

Last I talked with Accountant, his order of (100) motors was going to be a mix of 9kv and 13kv so I could get a 13kv, with a 17kv for Doc. Today he reports the order will be (2) 13kv for Zombiess and Dr. Bass, and (98) more of the awkward 9kv motors. :| :? Nobody buying these 9kv motors is going to get the 13kv high-speed performance reported by the Italian guy, so I hope Accountant will be able to sell them and place a 3rd order. I am skeptical, so I put ???????? in this thread's title instead. Well, last time the 13kv motors we bought turned out to be 9kv motors, maybe we'll get lucky and this time the 9kv motors will actually turn out to be 13kv.

Anyhow, that leaves me without at hub motor that can keep up with the x5403. I'll keep searching, maybe John in CR will be able to bring his motors to market. Until then, this will be a x5403 build thread looking for another fast hubby!

-JD
I'm not so sure most people want to go the speeds he went, but I can probably get Accountant to order a few 13KV in the next batch for those interested. I'm using mine for stress testing MOSFET power stages. Biggest problem is feeding it the current it's going to need, even in a small wheel. Based on my best guess simulation from dealing with my 9.x kv motor a 13 KV motor in my 21ish" tire at just 24S LiPo we are talking +105A to get to 60mph and +150A @ 30S to go 74mph. Jump up to a 24" diameter and now we are talking +185A @ 30S LiPo with a top speed of 79mph. Sit up just a little and watch the amps jump to 200A.

In a 26" wheel we are now talking about +210A@30S LiPo to go 81mph producing 4.2KW waste heat in the motor. These numbers are all modeled around my bike and observation but should be a rough estimate. As you can see it would take a heck of a controller.

I still need to make sure my shunt measurement is dialed in perfect (it's close) and really look at the cycle analyst carefully when at speed, but I think when I'm pulling 85A battery it ends up dropping down into the mid to high 75-80 amp area when I'm topped out on my current motor @ 125V 30S LiPo.

I'm actually glad my motor isn't 12KV due to the controller stress. Accountant was after something that can be driven by controllers most people already own or are easily available. No good if we end up in a Colossus situation where we have an awesome motor without an affordable controller to drive it.

Don't get me wrong, I'm not really defending the accident that happened with bad info being posted because I admit I was a little tweaked myself until I started playing guesstimate the amps with the simulator. If my simulation holds true, going to a 26" wheel on my motor and feeding it +110A @ 30S would get me 68mph. Even on a 10% grade in a 26" the amps only jump to +136 and the speed drops to 64mph. Whether or not that holds true is yet to be seen.

I can't wait to see your 5403 build, hope you like going fast. I almost bought a 5404 myself.

BTW, didn't I meet you at the Grange race? I remember a bike there with a top mounted battery like yours. Sig is funny too, I didn't even need to use a translator to guess what it said because I knew the first character. I was right LOL

Re: Cromotor vs 54xx - Fight!

Posted: Jan 24 2012 8:16pm
by Beachcruzer
nomad85 wrote:Any good ideas on how to do a front battery mount on non triple crown suspension forks that don't involve welding/machining? Big zip ties? :)
Great job on your boxes oatnet!
Yeah, zip ties. What else? Here's my 'power basket' with 12s3p lipo and three zip-tie attachment points, two on the handlebars and one on the down tube. It's hard to see in the pics, but there's an L-shaped substrate in there, made from 1/4" plywood and a pair of L brackets. The horizontal part of that substrate--let's call it the backboard--is secured to the handlebars and head tube with zip ties and also the leather straps that came with the basket. The pack is secured to the backboard using a quick-release camstrap. The basket doesn't support any battery weight. The controller is screwed through the bottom of the basket to the baseboard. It gets good airflow and is basically invisible from a standing position. The gray bit between the basket and head tube is closed-cell foam wrapped in duct tap. It serves as a shock damper for the whole system. I ride this on the beach, unpaved trails and roads with no problems. Handling is pretty good.

Not sure how many dudes on this site would want to copy the basket look (unless for their girlfriend's bike) but I like my ride and am secure in my masculinity.

Re: ??????? vs x5403 - Fight!

Posted: Jan 24 2012 9:25pm
by neptronix
Lol..

Re: ??????? vs x5403 - Fight!

Posted: Jan 24 2012 10:44pm
by dbaker
Is it 18s2p?

Re: ??????? vs x5403 - Fight!

Posted: Jan 25 2012 2:26am
by Beachcruzer
12s3p in the photo. Its a modular pack that I can run at 5, 10, or 15ah depending on how much range I want. Harness is by Icecube.

Re: ??????? vs x5403 - Fight!

Posted: Jan 25 2012 7:38am
by dogman dan
Thank god we at least see some foam around those packs.

I didn't like my 8 pound nicad on the front forks mount a few years back. I realize now, the probelm was that I set it too far forward of the handlebars. I'm definitely starting to think about rebuilding my battery setup. Maybe 4 packs on the bars, and the other four on the top tube or bottom tube in a much slimmer mount.

Likely only to get done if I start fresh with a new bike though. :roll: