Hillzofvalp's 29er Thread... now with custom 63T (cromotor)

My bike probably has less drag than most ebikes on ES because of the slim enclosure, big wheels, and big apples.

I still am not getting full on from the controller like Ithought I was with the 115% setting. I'm looking into that currently

Edit: I'm about to shoot myself in the face at how low my iterm max is.

Update.. Iterm as was at 3.04.. Close to where I had for my previous controller. Get this: it is now 3.32 with my 18Fet. I swear to god it must have risen.

Shove it up my ass:
53.9/60*5280*12*25.4/2284/68.2=9.28RPM/volt

I should see a performance increase and a huge decrease in heat..... Lol
 
hillzofvalp said:
Shove it up my ass:
53.9/60*5280*12*25.4/2284/68.2=9.28RPM/volt

I should see a performance increase and a huge decrease in heat..... Lol
Click to expand...

Looks like you are good to go :mrgreen:

Now monitor the temp and if you want more go to a smaller wheel and up the voltage. Just don't let it stay very hot. I generally try back off if my windings get close to 100c which is usually Around the point you start feeling the power fall off a bit, but it doesn't fall off anything like a 9c or smaller motor will so pay close attention.
 
Alan B said:
Did you mean to build a motorcycle? Are your brakes, tires, suspension, handling and personal safety equipment safe for 40+? Do cars know to expect your bicycle at 40+?
Click to expand...

No, yes, yes, yes, yes no and no. More yes than no! I am taking suggestions for a helmet.. I tried a full motorcycle helmet and it was a bitch (lost sensation for speed and can't hear). I look around and I see people all the time on mopeds with no helmet or leather, and mopeds are arguably more dangerous than ebikes because, if built right, the ebike is much more maneuverable.

40 mph is usually when no cars are around or I'm being an ass hole.

Bike is probably one of the strongest hard tail 29er if not 26er you will encounter on this forum. I really need to get a thud buster to protect my crotch. Mst place I ride, the front suspension, huge tire volume, huge wheel, and huge steel frame absorb almost all shock. Most roads I know where the hazards are and I protect the crotch. I really want a brooks saddle with springs.
 
hillzofvalp said:
.................... I look around and I see people all the time on mopeds with no helmet or leather, and mopeds are arguably more dangerous than ebikes because, if built right, the ebike is much more maneuverable...
Click to expand...
thats gotta be the best argument against helmets etc. that I've ever heard... :roll:

seriously dude. suit up. Ive crashed at ~20km'h (15mph) and cut up my hands so badly that I couldn't ride for nearly a month (wasn't wearing gloves). I still have the scars now, where small stones embedded themselves under my skin. Had I not been wearing a helmet, I'd at the very least have similar scars on the side of my head. And bare in mind... I know how to try and crash without hurting yourself, ive done it enough times on bikes, and thousands of times on boards (one reason I prefer boarding, snow's softer). Had I not it'd have been much worse. A crash at 40 without gear, short of low siding it in a wet grassy field you're gonna get hurt. anything between bad gravel rash to death, where gear might have meant a bruise or two.

Good to hear the motors fine. but quit trying to test stuff at >100%. It achieves nothing. as others have said it gives you a boost in rpm and high end torque, and loweres efficiency as a result, but does nothing to assist you in troubleshooting your motor.

Nice build too, those huge frames let you pack a heap in! and it actually makes a cro look small :shock: .
 
hillzofvalp said:
I wear a bicycle helmet.. I want to get a better helmet with my ears more open to the air. I normally wear long pants and mountain shoes for joy rides.

I am wondering if motorcycle course would be remotely useful.
Click to expand...

I found the moto courses I took in the past year while getting my riders licence to be helpful for any 2 wheeled riding. You'll learn various strategies to try to stay alive at high speed, traffic, poor weather etc.

My lightweight low power learner-legal motorcycle which I was licensed to ride after taking an easy 2 day course was still 25kW and 150kg, far beyond the power and weight of most ebikes. They're quite different to ride then something 5kW, 35kg with thin tires but the experience is still useful.
 
I just crashed at 30km/h and got some nasty road rash. I really like my DH helmet, it gives full face protection and is lighter then a DOT helmet, but It offers more protection then a normal bike helmet.

And if I didn't have gloves on my hands, they would have taken it hard!
 
gensem said:
sometimes John tone looks a little harsh but he is really a nice person.
Click to expand...

I think so too. And my above comment wasn't meant to piss John off. In fact I totally agree with his point. In my fumbling way I was just trying to smooth things over, but as usual, just made things worse. :oops:
 
hillzofvalp said:
I wear a bicycle helmet.. I want to get a better helmet with my ears more open to the air. I normally wear long pants and mountain shoes for joy rides.

I am wondering if motorcycle course would be remotely useful.
Click to expand...

how bout this?
http://www.chainreactioncycles.com/Models.aspx?ModelID=45391



hillzofvalp said:
Cool.


What oyoh guys think about brazing small copper tubing to the steel parts of the stator... Then running a pump from the inside of the motor to a smallish unobtrusive heatsink out the axle?
Click to expand...

a small heatsink probably wont make much difference. the whole idea of pumping fluid through your motor is you can capture heat with the fluid, and then transport that heat to a point with a large surface area (ideally far larger than your motor's). if its a small heatsink then its not going to be able to achieve much. check out what doc's and keyne's bikes... they're good examples of liquid cooling. you could attach a small radiator like keyne's in your rear triangle, perpendicular to the motor. that would probably still work well.
 
I like that idea a lot.. Since it has way more potential AND I can CNC stuff. Docs design might be less effective with cromotor stator since its coated with some type of paint.. I'm also not sure if water would leak through the little gap between the two halves.


Took my bike out today for a long hard ride with various hills. This was at 4.3kW, 77A/145A. Got 42.7Wh/mile..624Wh total (remember big wheels plus 25-40mph riding) Winding temp was 107C after the ride. Question: what do you use as medium between thermistor and winding? Right now it's just jammed in one of the winding loops (pinched in small gap but touching at least one winding wire). Is this sufficient? I suppose the ambient air is very close to the winding temp after a long ride anyways?

Also, do you worry about the hot thermistor wire significantly affecting the measured resistance, or is it too localized to matter? This would make my temperature appear lower than it should be.
 
hillzofvalp said:
I like that idea a lot.. Since it has way more potential AND I can CNC stuff. Docs design might be less effective with cromotor stator since its coated with some type of paint.. I'm also not sure if water would leak through the little gap between the two halves.


Took my bike out today for a long hard ride with various hills. This was at 4.3kW, 77A/145A. Got 42.7Wh/mile..624Wh total (remember big wheels plus 25-40mph riding) Winding temp was 107C after the ride. Question: what do you use as medium between thermistor and winding? Right now it's just jammed in one of the winding loops (pinched in small gap but touching at least one winding wire). Is this sufficient? I suppose the ambient air is very close to the winding temp after a long ride anyways?

Also, do you worry about the hot thermistor wire significantly affecting the measured resistance, or is it too localized to matter? This would make my temperature appear lower than it should be.
Click to expand...

the wire to the resistor is going to be in the order of a few mohms or so, vs a few kohms for the resistor. to put it simply, the wire temp is going to make jack all difference, unless you need temps accurate to the thenth or hundredth of a degree .

Get yourself some thermal cement. the stuff sets quite hard, and will help the resistor stay in place + provide a better thermal path.
 
Good to read your cromotor is healthy!
Did you find that your phase and hall wire colours lined up between your lyen controller and motor?
 
Yeah they do. The issue I think had more to do with a weird throttle issue.. I ended up having to adjust the ca throttle output to get full power at all speeds. The whining sound seems less pronounced or even gone.. It was probably a bearing seating issue or something wacky with the covers not seating right

I need to make a more appropriate video but this gives you an idea of hill climbing power in such a big wheel

[youtube]IllYFsVci4U[/youtube]
 
Well hillzofvalp, how would rank the motors torque? You sure do seem to have your bicycle hauling ass with that 29" wheel. I must say I'm surprised by how fast it accelerates. Looks like it works out great in the 29" wheel. Now that you have a temp probe you have can choose to just enjoy it as is or start experimenting a bit and up the power a little (with caution). I need to get some more video of my own bike when I get another powerful controller built, 20" wheels are really too small for this motor in my opinion, it just makes so much torque on my bike at my power level.
 
I don't really think its enough for unintendedd wheelies at 15 mph or more. But there has been numerous occasions under 15mph where I've felt the front wheel lift and even drag at an angle ( :shock: )

I'm around 200lbs.. Total system weight is 275lbs. I will get video of my passing cars up a longer steep grade
 
Today went ona long ride with my multimeter connected to the thermistor. I found that it was only when I rally hammerd th throttle under 20mph that brought the motor temperature up. Most of the time I stayed in 90-100C range. Today was hot though, and by the end of the ride I got it up to 121C. This is an average ride that I do.

The hill that I thought I killed the motor actually didn't really raise motor temps much at all (35mph+ over 1/4 mile 2-4% grade).

once over 100C I do notice less performance. I'm beginning to think howi can water cool this motor cheaply.. And I'm looking into cutting down 6-8" cpvc (~200F rated) couplers.. Gluing them in as well as an easily fabricted lid with dp420 in a similar design keyne displays with his carbon fiber 9c.

Thoughts?
 
DP420 does not work under hi temps...
I know because i use hot air gun to remove DP from my dropouts a couple times already.
 
I know, i set my gun for 200C...
Just be aware that I think it would be wise to test DP420 at 100C instead of just using it, im guessing it ll lose strengh compared to ambient temp operation.
 
I just want to say how happy I am with my cromotor and ebike in general. Thank you endless-sphere

Shortly I will be posting cad of my proposed 26s6p swappable downtube packs. I'm hoping they will make a Jim johns delivery job more practical... And give med the 0-25mph in 2.5seconds that I yearn for
 
Not having a mechanical engineering background, I didn't realize just how easily one could plug in the chain and sprocket specs in into a huge set of equations to find all the geometry for the sprocket. This document will save me a lot of frustration, and my 63T gear could be of the utmost quality.

http://www.robo-works.net/Mechanics/week%203/day%201/draw_sprocket.pdf

Does anyone know the exact specifications for bicycle chains? I know they're 1" pitch and accomodate 1/8" and 3/32" thick gears. What I only know within .001" is that the rollers are are around .300". Does that sound right?
 
hillzofvalp said:
Does anyone know the exact specifications for bicycle chains? I know they're 1" pitch and accomodate 1/8" and 3/32" thick gears. What I only know within .001" is that the rollers are are around .300". Does that sound right?
Click to expand...

They're 1/2" pitch.

It's been a while since I reverse engineered a sprocket, so I had to look up the roller diameter I measured-- it was 7.65mm or about .301" as measured. I believe that's descended from a legacy dimension of 5/16" (.3125"), with more clearance designed in to improve performance. Things like customary clearances tend to change over time alongside other developments.

I know that my chain wear checker delivers very different results on new chains than on 40-year-old chains, which had smaller clearances all around. I have to take this into account when assessing wear, because old chains tended to start from less-than-zero measured elongation, whereas new chains can measure up to 0.5% elongated when brand new.

1/8" and 3/32" may describe the internal clearances of the chains thus named, but 1/8" and 3/32" sprockets tend to measure an actual .100" and .080" thick at the teeth, respectively.

Chalo
 
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