Endless Sphere

Buk___ wrote: ↑

Apr 18, 2018 9:24 pm

I don't need luck, I've got math & physics.

One day you'll learn how to use them, kid. Best of luck with that.

A direct drive motor is heavier than a gear reduced free overrunning motor, all else equal. A battery that can store regen energy on demand is necessarily bigger and heavier than a battery sized only for the drive load, all else equal. Apples to oranges. Geared hubs can have regen (leave out the fr...

https://pixl.varagesale.com/http://s3.amazonaws.com/hopshop-image-store-production/100715525/236a2f9bd647c88744d7dbc3cf9cb58b.jpg?_ver=large_uploader_thumbnail&w=640&h=640&fit=crop&s=ad564f4e0f28163427b0daae2bf06a7b Probably not the best shock design, and not the biggest triangle - but hey: this fr...

You'd be much better off with 14ga and even better with 14/15ga butted.

What you've got is going to self loosen, crack your rim, or both.

The strength of the wheel is in the rim, not the spokes.

miro13car wrote: ↑

Apr 18, 2018 7:37 am

what extra weight?

A direct drive motor is heavier than a gear reduced free overrunning motor, all else equal. A battery that can store regen energy on demand is necessarily bigger and heavier than a battery sized only for the drive load, all else equal.

A sound cost-analysis, except for just a couple of tiny details: It doesn't include: Insurance Fuel Maintenance Repairs Waste disposal Decommissioning Don't forget externalities! Accidents Persistent radioisotope contamination Cancer Facilities security Lost property value Etc. How profitable was F...

Note that the uneven fit of some calipers to their mounts and bolts can cause then to shift when tightened, flexing the rotor and negating the technique you have described. The best way to avoid this is to gently snug up the mounting bolts a little bit at a time, switching back and forth between the...

It depends. Some cordless tools require an electronic "handshake" between the battery and the device before the battery will send power. Most don't, in my experience. Does the drill (or whatever) that goes with the battery have only two contacts, or does it have more? If it does, you can bet they ar...

The torque reaction of the motor on the torque arm via the axle flats is from motor torque reaction, and will be limited to that which the motor can magnetically produce. Vehicle weight doesn't enter into it. It matters to the degree that inertia, weight, and surface adhesion are the forces that th...

After two years of driving the PluginPrius, I still giggle about every time I come to a full stop, and watch the EV range click up a couple tenths of a mile. I'm averaging high 50's mpg, without even trying hard, thanks to regen. In the meantime, even stinking two stroke gas bikers are doubling or ...

Even if raw titanium becomes cheaper, it will remain difficult and expensive to manufacture things from it. For that reason, I don't think we can look forward to cheap Ti bikes anytime soon. Sub-$1000 Ti frames, maybe. But not sub-$1000 Ti bikes anymore.

There are some pretty cheap titanium bikes around, probably from China already. For the last 20 years, budget titanium bike frames have been a mix of Chinese and Russian (or other former Eastern Bloc) production. Here, i think Ti bike frames were originally a commercial spinoff from the nuclear ind...

My first modern disc brake was a Hayes MX-1. The stock Hayes organic pads burned away to nothing in less than 20 miles of city riding (with almost 500 pound gross weight, and very steep hills). The fully metallic EBC replacement pads lasted about 10 years and thousands of miles of varied riding. Tha...

Alan B wrote: ↑

Apr 15, 2018 10:41 pm

There's not much point in arguing about it, only testing can prove anything. Build some and fail them with a torque wrench, as Justin has done so many times.

What I'm sayin'. I don't have to prove the design is bunk; he can just try it out and see for himself.

Regen is apt to tear up whatever chain tensioner you put on a single chain system. It takes a lot of structural integrity in both the idler pulley and its mount if you have an idler on the load carrying side of the chain, such as would be necessary for regen.

Bicycles that drag are a drag, is all. John rides motorcycles, and has different priorities.

If you're going to employ some kind of clutch, why the elaborate tension/jackshaft/idler system? You could just have two parallel single speeds, with the higher ratio clutched and the lower one freewheeling on overrun. Check out this cool historical two-speed gearing system-- one ratio when pedaled ...

You either fail to understand or else fail to acknowledge that in stiffening up that stressed underside arch by adding material, you cause a huge stress riser at the relief slit. That isn't guesswork; it's plain to anybody with mechanical engineering chops. The hard inside corners of the "ears" woul...

Consider the SRAM Automatix centrifugal shifting two speed hub. I like mine very much.

I would not use a BBSHD with an internal gear hub if I could use a BBS02 or TSDZ2 instead. It's all good fun until you break something expensive at an inconvenient time.

If you can't tell the functional difference between an entire loop of flat spring added as a feature, and a localized thin spot created by cutting a slit partway across a plate, I'm afraid I can't help you. Make one and test it to failure with a torque wrench. See for yourself what you can't seem to...

Flat springs are thin throughout their lengths. Your TA is "thin" (not in absolute terms, but relative to the whole) in a single spot on each side. You'll get material failure there as soon as static friction is overcome and the thing is called upon to do something. What you are suggesting is that ...

liveforphysics wrote: ↑

Apr 14, 2018 11:36 pm

Who even cares about profits?

A: Rich fux.

In the thin axis, these springs are capable of being wound tight, and stretched flat and back again many millions of times. Each infinitesimal section of metal can be flexed though 20°. 30°, 90° or 180° without harm. Flat springs are thin throughout their lengths. Your TA is "thin" (not in absolute...

Have you ever wondered how springs like these: http://www.tetsufuku.com/data/tetsufuku/product/20121111_cd9306.jpg as used in garden secateurs, and those in the pliers and scissors in swiss army knives and the like: https://productimages.knife-depot.com/98/520963.jpg Or those you find in the center...

1/8" chain runs just fine on 3/32" sprockets, as long as you're not asking it to run on a multi-speed cluster. Even so-called 1/8" sprockets are usually 1/10" in thickness You're barking up the wrong tree. Roller chains are mature technology. There aren't any major improvements to be had over the pl...