Recent content by lazarus2405

If pedaling loosens it, you've probably got it installed backwards. The drive side (right side) of the BB should be reverse threaded and tighten counter-clockwise, otherwise precession will work it loose. From your build pics I can't tell what sort of BB you're running. Tell us (show us?)...

Federal law does not allow for the riding of ebikes on public roads. States and their respective DMVs make those regulations. All that federal law allows for is the regulation around consumer protection with respect to importing and selling ebikes; it has nothing to do with the legality of...

To hold 60mph on an upright, unfaired bike you need about 7kw at the wheel, which, yes, will be about 9kw at the battery. Any hub motor setup with an intelligent choice of voltage/gearing/winding for that speed will probably be slightly over 80% efficient. Extremely poor aerodynamics is the...

I have to wonder, what on earth sort of controllers are you folks using to push >100a at >100v? :shock: I'm at the limit of what my Kelly can provide at 90v absolute maximum, and I'd like to get educated on the next steps. 20kw... *whistles*

Math to the rescue! Let's say we're pretty conservative and say you want your wire radius r to equal skin depth δ, so that current density in the very center of your wire is still ~.37 (1/e) what it is on the outside of the wire. It's more or less an approximation for at what point skin effect...

. The answer is pretty much yes, sort of - it's complicated, but it could certainly help significantly. If you could magically increase surface area without increasing length, then yes, it would be exactly linear. The rate of heat transfer depends on the delta-t, area, and the coefficient of...

I'm afraid if you really want a motor in the front, you'll need a different fork. If you swap to something with 10mm QR ("normal" dropouts), sure you can put a motor up there, but keep the power down. More than 1kw and you're risking a destroyed fork and a loose wheel. If you're getting a full...

Do you have any numbers for side cover temperatures with and without oil cooling? Perhaps with an infrared thermometer, or holding a probe to it at the top of your big hill. If we know exactly how much hotter the side covers are, we could calculate how much extra oil cooling gives you. Without...

I've been commuting in traffic at 35mph six days a week for two weeks on 16s 10ah of 20C Turnigy. For me that's about 40a continuous, 4C, and dissipating ~100w of heat (total battery IR 0.055ohm) between 8 of those 4s hardcases. At the end of my five mile commute, my batteries will be slightly...

That's something I've been thinking about for a little bit. You really don't want to switch under load, so there isn't an arc to have to quench, so the voltage rating of the contacts shouldn't matter. Finding DT relays rated for that sort of current is a pain, though, so I wonder if you could...

Consider drilling (or having someone else drill) holes in the side covers of your hub motor. Accept the fact that water will get in and give it a much better chance to get out. You don't want water trapped inside where it can't escape, it'll just rust your motor. Look into some kind of covering...

Sorry, let me give some background. I'm an LBS mechanic. When you bring in your flat to be repaired, I'm the person who gets to do it (well, not *you*, but the type of person who can't change their own flats and goes to the bike shop every time :roll: ). The number one most frequent cause of...

You can convert most rims and most (non-"tubeless") tires to tubeless with Stan's sealant plus yellow tape and/or rim strips. "UST" tires don't need sealant, but you won't get puncture protection benefits without it. I run Stans tubeless on my (human-powered) mountain bike, and I love it for...

Back to my charger, it's set to run at 5.5a up to 4.15v/cell and terminate when that current drops off to 0.5a. If I wanted to accomplish what you're suggesting, I would use that third pot in my charger to raise the cut off, maybe to 2.0a, or 3a or something higher. In my case I would do that...

Those foldable footrests look like just the trick. They don't have to support any real weight, correct? They're just a place to rest a foot. A nitpick, those BMX pegs are not intended to be footrests. They're for performing tricks. A real BMX setup might have two pegs, one on the front wheel...