Search found 7154 matches

by Chalo
May 24 2019 2:18am
Forum: E-Bike Technical
Topic: Drivetrain reco for torque not speed
Replies: 3
Views: 97

Re: Drivetrain reco for torque not speed

Application is a loaded cargo bike in hilly areas. Also want good dragging-braking ability, ideally with strong regen. Going over 48V if needed, thinking 3 or maybe 5kW ? If you surrender your requirement for e-braking and/or regen braking, you can have a very suitable system for a cargo bike appli...
by Chalo
May 24 2019 1:14am
Forum: E-Bike Technical
Topic: Rim cracking on inside between spoke holes.
Replies: 1
Views: 45

Re: Rim cracking on inside between spoke holes.

That's too much pressure, on a too-wide tire, on a too-light, too-narrow rim.

Replace it with a BMX/freestyle/dirt jump rim. Those are designed for strength, and to be compatible with 100psi tires as wide as 2.4".

Alex DM24 is excellent and reasonably priced if you can find one.
by Chalo
May 23 2019 11:16pm
Forum: E-Bike General Discussion
Topic: Frame Hole Drilling...
Replies: 25
Views: 473

Re: Frame Hole Drilling...

If the holes are in the sides of the tubes and not the top or bottom, the stresses there will be near zero so not much chance of cracking The forward and rear ends of the top and down tubes see rather large torsional loads. I had a sturdy big-tubed aluminum bike frame that cracked at the rivet hole...
by Chalo
May 23 2019 1:55pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Cheap Sachs XR1 upgrade
Replies: 28
Views: 615

Re: Cheap Sachs XR1 upgrade

The problem with a mid drive is still the strength of the bicycle chain. I've tried to get several manufacturers to make modified rear derailleurs that can accept a BMX chain. but there is no interest. Over 1kw, drivetrain problems start to become a thing because of this. If you are okay with losin...
by Chalo
May 22 2019 1:47pm
Forum: E-Bike General Discussion
Topic: Frame Hole Drilling...
Replies: 25
Views: 473

Re: Frame Hole Drilling...

I look at some commercial ebikes and thery have drilled holes for wires right next to where the frame welds into the stem tube. Does it mean ebike makers don't know what they're doing? From what I can tell, they really don't. Consider how often they use 12ga spokes with bicycle rims, and lace the s...
by Chalo
May 22 2019 11:18am
Forum: Electric Watercraft
Topic: How can I get more speed 12v 45lb thrust
Replies: 13
Views: 320

Re: How can I get more speed 12v 45lb thrust

Water is a fluid so you have a drag is the cube of your speed problem. To beat this you either need a more efficient hull, less wetted area, or a shitload more power. Making your electric kayak fast will be expensive, but also very possible. Maybe the prop isn't that efficient, but solving that iss...
by Chalo
May 21 2019 1:51pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Greetings, care to help design a build?
Replies: 13
Views: 256

Re: Greetings, care to help design a build?

yes, carmakers (exept tesla, that has like hundreds of thousands of cars driving around the world for years now...) use pouches and they also have litteral hunderds of pounds in structural protection and compression housings with massive bolts to keep the cells from puffing up and exploding. that s...
by Chalo
May 21 2019 1:36pm
Forum: Electric Watercraft
Topic: How can I get more speed 12v 45lb thrust
Replies: 13
Views: 320

Re: How can I get more speed 12v 45lb thrust

If it's meant for a much heavier boat than the propeller likely has a low pitch (theoretical distance traveled forward for every revolution). So you are probably at max rpms for the 12V, but the motor likely has untapped torque. If you put a propeller on with a larger pitch, then I imagine you coul...
by Chalo
May 21 2019 1:34pm
Forum: E-Bike General Discussion
Topic: Trail Z front disc brake
Replies: 4
Views: 144

Re: Trail Z front disc brake

Do you mean a Currie Ezip Trailz bike? The ones I've seen don't have disc caliper tabs. But they also have cheap and horrible brakes that are easy and cheap to upgrade. If you don't have disc caliper mounts on your fork, your best option is to get a decent quality linear pull brake and fit it with g...
by Chalo
May 21 2019 12:54pm
Forum: E-Scooter and Motorcycle General Discussion
Topic: Greetings, care to help design a build?
Replies: 13
Views: 256

Re: Greetings, care to help design a build?

high capacity 18650 is your only choice if you want to do it. maximizing battery density and stability (so no pouches!) is key in making a form factor battery that fits the bikes cowling and does not explode. Lots of EVs use pouch cells-- many more than those that use cylindrical cells. You and I p...
by Chalo
May 21 2019 12:06pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1443
Views: 174826

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

A 60mph streamliner coffin might be more resource-efficient than a car, but it's almost as hostile and inconsiderate. If we can get everyone on the streets within a city moving at 20mph or less, better things will happen than only energy efficiency. Yes, it will make room for light EVs and human pow...
by Chalo
May 21 2019 12:17am
Forum: Battery Technology
Topic: Calling all battery surgeons! Have you seen this?
Replies: 21
Views: 393

Re: Calling all battery surgeons! Have you seen this?

58.8V is the final charge voltage for 14S "52V" lithium ion batteries, but it's also the final charge voltage for 16S "48V" LiFePO4 batteries.

I have had one misbehaving battery exhibit a higher voltage on one cell, but that turned out to be caused by a broken sense lead to that cell.
by Chalo
May 20 2019 9:53pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1443
Views: 174826

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Go pick an argument somewhere else. You're the one who asserted that "bicycle hub motors" could benefit from thinner lams. I told you why that isn't the case, and then you described a speed regime that isn't part of a bicycle's job. So you might be talking about some kind of hub motor, but it sure ...
by Chalo
May 20 2019 7:50pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1443
Views: 174826

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Bicycle hub motors don't run at high enough RPM to benefit significantly from ultra thin lams. Justin has said so himself, based on empirical research. If the wheel is small enough in diameter or the road speed is high enough to make ultra thin lams beneficial, then it isn't a bicycle hub motor, is...
by Chalo
May 20 2019 7:49pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Adventures On The Cheap
Replies: 14
Views: 382

Re: Adventures On The Cheap

I have to admit that I’ve been reeeeally tempted to pull the trigger on a couple of Mongoose FS bikes nearby, but I guess the Mongoose of 2019 just isn’t the incredible brand it was when I was riding BMX. You can say that again! Mongoose used to be an entirely respectable manufacturer, responsible ...
by Chalo
May 20 2019 7:21pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1443
Views: 174826

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

It is clear that 0.27mm lams are the next evolution for bicycle hub motors. A representative for MAC told me that the cost versus 0.35mm was about $20 per motor - a small price to pay for an increase in efficiency which means you can shave some battery off a build. Bicycle hub motors don't run at h...
by Chalo
May 20 2019 4:44pm
Forum: E-Bike Technical
Topic: Ebike bike Wheel pulling to one side
Replies: 44
Views: 455

Re: Ebike bike Wheel pulling to one side

So couldn't I just ask for them to cut 14 Gauge spokes for me, or is more complicated ? Also, it turns out my Giant Bike is Single Butted. I asked my buddy, whom I wish lived much closer to me. I would get him to fix up the wheel. A few bike shops can cut spokes to custom lengths. I usually use Dan...
by Chalo
May 20 2019 4:15pm
Forum: E-Bike Technical
Topic: Ebike bike Wheel pulling to one side
Replies: 44
Views: 455

Re: Ebike bike Wheel pulling to one side

I guess I'm good then. The ones I have are single gauge spokes. I checked my high end Road Bike, and it's also a single gauge. I'm not sure, I've seen a bike other than that before. The problem with your spokes isn't that they're straight gauge. They're too thick to make a reliable wheel. They're a...
by Chalo
May 20 2019 3:06pm
Forum: E-Bike Technical
Topic: Ebike bike Wheel pulling to one side
Replies: 44
Views: 455

Re: Ebike bike Wheel pulling to one side

Seems to me to be a whole lot easier to get a spoke wrench from you LBS and center the exiting rim 1/4 turn on the spoke at a time. Thing is, that probably won't do it. At a minimum, the right side spokes need to be removed and laced on the outside of the hub flange rather than the inside. I think ...
by Chalo
May 20 2019 12:46pm
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1443
Views: 174826

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

[I'll have to settle with a Leafbike motor. It won't let a sub 100 lb electric velomobile do 0-60 mph in 3 seconds though, Tires and chassis that would allow an e-velomobile to weigh less than 100 lbs would not tolerate that kind of acceleration. You have more than a little bit of sci-fi technology...
by Chalo
May 20 2019 2:04am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Greetings, care to help design a build?
Replies: 13
Views: 256

Re: Greetings, care to help design a build?

At a guess, it's going to be 200-300Wh/mile for 80MPH on a typical unfaired motorcycle. (my SB Cruiser trike is very unaero, and only goes 20MPH, but it still takes 60Wh/mile to move it around!). 80mph takes 16x the power of 20mph. So assuming the same Cd, duty cycle, and time at speed for the 80mp...
by Chalo
May 19 2019 8:41pm
Forum: Battery Technology
Topic: Powerful inside-frame battery
Replies: 15
Views: 397

Re: Powerful inside-frame battery

1. What is this type of battery called? Trouble. 2. Are there any more powerful ones out there? I.e. at least 48v 15ah, since I plan on putting my 1,5kW motor on there if I decide to buy the bike. You're limited to something close to the number of cells that were in the frame originally. So you can...
by Chalo
May 19 2019 8:11pm
Forum: E-Bike Technical
Topic: Ebike bike Wheel pulling to one side
Replies: 44
Views: 455

Re: Ebike bike Wheel pulling to one side

I put the wheel on the wrong way, and this time it was against the frame on the same side. However, with the original wheel. Regardless of which way I put it on. The wheel stays centered. What I see in your photos is that the hub motor tire wants to rub the frame on the side opposite the freewheel....
by Chalo
May 19 2019 1:25pm
Forum: E-Bike Non-hub Motor Drives
Topic: Luna Fixed Stealth 400w torque sensing mid-drive bike
Replies: 1
Views: 155

Re: Luna Fixed Stealth 400w torque sensing mid-drive bike

It's Luna's answer to everything-tucked-away e-bikes like Van Moof etc.

They call it "fixed", but it's not a fixed gear and it's far too chunky and ugly to recall the fixed gear fashion bikes of a few years ago.

Yes, it will be a huge nuisance to work on or even do basic troubleshooting.