Search found 7729 matches

by Chalo
Apr 29 2021 11:36am
Forum: EBike General Discussion
Topic: 27.5” front 26” rear - Wheelbuilding
Replies: 111
Views: 3159

Re: 27.5” front 26” rear - Wheelbuilding

markz wrote:
Apr 28 2021 1:44pm
Super cheap, I should buy a laser rpm counter
https://www.ebay.com/itm/402559151095?h ... SwVTVfnaFx
Do you need special reflective tape or anything will do
That's about the same as the one I have.

Any reflective tape, or even a white mark on a dark background, will do.
by Chalo
Apr 29 2021 11:00am
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 777

Re: My model of spoke breakage.

Thing is, thin spokes don't experience the same depth of stress cycles as thick ones. Under the same load, a 12ga spoke can be cycling between (say) 1200 N and zero every time the wheel goes around, where a 14-15ga spoke fluctuates between the same 1200N and maybe 800N. The number of stress cycles i...
by Chalo
Apr 29 2021 12:21am
Forum: Battery Technology
Topic: is there a prob in this battery diy plan with prebuid case?
Replies: 41
Views: 1701

Re: is there a prob in this battery diy plan with prebuid case?

So why are you planning to use vape pen cells instead of cells that match the application? https://ae01.alicdn.com/kf/HTB1ddVZXdfvK1RjSspfq6zzXFXat/20pcs-3-7v-15Ah-Lithium-lipo-polymer-cell-1174170-3-7v-16Ah-17ah-for-diy-battery.jpg chalo you are recommanding me rectangular cell instead of vtc4 son...
by Chalo
Apr 28 2021 9:20pm
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

Umm, no. The person/company/country that does that, goes broke first. I guess so! After all, both Tesla and SpaceX went broke trying to be the first company in new fields. And Qualcomm is now out of business after trying to bring digital communications to the world. Like one of my buddies during th...
by Chalo
Apr 28 2021 9:03pm
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 777

Re: My model of spoke breakage.

Also interested in why a thicker and so stronger spoke would be more likely to break Chalo I don't understand why, if the rim and hub are matched, a thicker spoke is not stronger and more long lasting. Sure, you need to stretch it the same amound and to do so you need stronger hub and rim I think y...
by Chalo
Apr 28 2021 4:57pm
Forum: EBike General Discussion
Topic: Converting a Bakfiets cargo bike
Replies: 50
Views: 4798

Re: Converting a Bakfiets cargo bike

LewTwo wrote:
Apr 28 2021 4:07pm
Have you considered something like this ?

https://nl.aliexpress.com/item/1899546461.html
Image
Ewwww don't do that. It isn't strong enough, it won't stay aligned, and it's skankier than (the rhetorical) your mom.
by Chalo
Apr 28 2021 4:54pm
Forum: Battery Technology
Topic: Ebike Battery stored for a long time
Replies: 23
Views: 652

Re: Ebike Battery stored for a long tome

Batteries can sit for years and still be usable, as long as they were disconnected from any load. The main risk with bike battery packs as we know them is that the BMS can completely drain one or more cell groups (to run the basic functions of the BMS) if left unattended for a long time. It would be...
by Chalo
Apr 28 2021 2:02pm
Forum: Bike Mechanical & Structural
Topic: My model of spoke breakage.
Replies: 19
Views: 777

Re: My model of spoke breakage.

Your model doesn't account for enough variables. I have had wheels that accumulated more than 20k miles without spoke breakage. I have had others that began breaking spokes within a couple thousand miles, despite being carefully built from top quality components. A properly stress-relieved wheel doe...
by Chalo
Apr 28 2021 1:35pm
Forum: EBike General Discussion
Topic: 27.5” front 26” rear - Wheelbuilding
Replies: 111
Views: 3159

Re: 27.5” front 26” rear - Wheelbuilding

markz wrote:
Apr 28 2021 1:19pm
Yes, that is the only super easy way to know.
Maybe the independent re-seller might know what the default wind count is for the motors they sell.
Ultimately, it isn't turn count, but kV that matters. That's much easier to determine without disassembling anything.
by Chalo
Apr 28 2021 1:26pm
Forum: EBike Non-hub Motor Drives
Topic: New "TSDZ2 Torque Sensor Central Motor"
Replies: 8605
Views: 946149

Re: New "TSDZ2 Torque Sensor Central Motor"

Based on the picture of UK bracket spindles from the 1970s... This looks far from good material composition. Look at the cracks and metal flakes inside the casting! :roll: That's a surface characteristic of rapid fracture. It's not a reflection of the steel's quality (though cruddy steel is more vu...
by Chalo
Apr 28 2021 11:44am
Forum: EBike Non-hub Motor Drives
Topic: New "TSDZ2 Torque Sensor Central Motor"
Replies: 8605
Views: 946149

Re: New "TSDZ2 Torque Sensor Central Motor"

A normal square taper crank [spindle] is 17mm. People break those also. Tsdz2 is 15mm, and the 68-73 version is 14mm in the lock ring groove. The 100mm version is 13.4mm. As for the butter comment, try to put one in a lathe, you will agree. That, plus the underdimensioned shaft is not a great desig...
by Chalo
Apr 28 2021 10:55am
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

[...]that is a big rear trunk, how is that attached to the rack? https://www.jbi.bike/site/product_details.php?part_number=95715 It comes with some little steel bars that bind the bottom of the case against the rack top. I already have a smaller rack trunk on order for this bike, because this one h...
by Chalo
Apr 27 2021 11:58pm
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

The person/company who starts colonies on other planets, and/or starts mining other planets and asteroids, will win the game no matter what other countries do. Indeed, such an effort will render terrestrial countries somewhat irrelevant. Umm, no. The person/company/country that does that, goes brok...
by Chalo
Apr 27 2021 10:41pm
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

markz wrote:
Apr 27 2021 10:32pm
The Townie Electra 21D's are a nice bike, I keep my eyes out for a good priced used one.
Why did you route the cable to the inside of the fork and the inside of the front rack?
I wanted to minimize the chance of snagging on stuff.
by Chalo
Apr 27 2021 12:59pm
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

I see you have a v-brake on the uber wheel, so we can use a v-brake on these wheels? wow, this opens up a lot of options in bike choices, The rim says don't do it, and setting up the pad angle is tricky. But I couldn't figure out a reason not to try it with good soft pads. Since the bike is for a c...
by Chalo
Apr 27 2021 11:36am
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

I set up another one yesterday, this time with 48V for an unloaded speed of 32 mph. IMG_20210427_112934.jpg Two tabbed washers in forged CrMo fork tips for now, but Grin TAs are on the way. Hopefully there's enough room for one, because those axle studs are really short. I'll probably need to delete...
by Chalo
Apr 27 2021 11:25am
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

GDP includes things like banking and the stock market and I'm not sure how selling futures helps us build rockets Meaning the real productive economy has even less juice to squeeze out for resource sinks like space travel, and each kg in low orbit actually represents more than an average man-year o...
by Chalo
Apr 27 2021 10:06am
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

And yes it is ungodly expensive still.. but like you mentioned, prices are dropping on space propulsion, just as they will for nearly any advanced technology that sees increasing adoption rates. Tech gets cheaper (and defense industry graft can get squeezed out), but these days energy does not beco...
by Chalo
Apr 27 2021 2:34am
Forum: General Discussion
Topic: Lightweighting and aerodynamic optimization of a subcompact car.
Replies: 80
Views: 1757

Re: Lightweighting and aerodynamic optimization of a subcompact car.

Something i never thought about is the weight of the lead acid battery. Mine's the size of something that would be in a V8/V6 car and weighs 35lbs. I have no clue as to why this car has such a large battery. Perhaps an oversized parasitic drain. Braille makes low internal resistance AGM batteries f...
by Chalo
Apr 27 2021 1:59am
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

Here's an interesting little datum for y'all. Over the last 20 years or so, the median cost of launching a kilogram of mass to low earth orbit has dropped from very approximately $20k to very approximately $10k. Per kilogram. Another: In the same period, the global GDP per capita has increased to ab...
by Chalo
Apr 26 2021 10:11am
Forum: General Discussion
Topic: 2 thumbs up for mankind
Replies: 46
Views: 992

Re: 2 thumbs up for mankind

Speaking as someone who used to work for the spacefaring business: Manned space flight is a boondoggle. Unless/until there's unlimited free energy, we have to throw so many resources at it that it can't possibly pay off in any practical way. It is, and will remain, a dick measuring activity for impe...
by Chalo
Apr 25 2021 8:44pm
Forum: EBike Technical
Topic: BBS02 Improving Heat Dissipation
Replies: 10
Views: 349

Re: BBS02 Improving Heat Dissipation

The BBS02 motors are not any where as tough as a BBSHD. But hey, what do I know after supporting BBSxx customers for more than six years. Mine (now entrusted to other hands) has been fine except for the wheel speed sensor and the pedal sensor. I think it's worth it for better Q factor, chainline, a...
by Chalo
Apr 25 2021 8:33pm
Forum: Bike Mechanical & Structural
Topic: Aluminium Triangle Case build, minimal tools?
Replies: 14
Views: 473

Re: Aluminium Triangle Case build, minimal tools?

Making a sheet metal battery case is not really a "minimal tools" kind of project. I'd want access to a step shear, finger brake, large format printer, TIG welder, grinder with wire wheel, drills, files, and pop riveter. You could get away with less tooling, but you'd be paying the differe...
by Chalo
Apr 25 2021 8:21pm
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

Throw those cast things away and use a torque arm on each side. This is a BIG, powerful motor! Tabbed washers were considered adequate for fleet use. I don't know what the maximum phase amps were for the 250W controllers in Jump bikes, but I assume they were lower than that of the 20-25A controller...
by Chalo
Apr 25 2021 10:32am
Forum: EBike General Discussion
Topic: Bafang front wheel Uber motors - which controller
Replies: 84
Views: 2267

Re: Bafang front wheel Uber motors - which controller

docw009 wrote:
Apr 24 2021 9:45pm
Here's nut, c-washer and an inner washer.
The tabbed washer doesn't help if you lift it out of the fork tip slot that way. Put it on the inside of the fork tip, with the C-washer on the outside.