Bicycle pics - post them up

[freebeard]

This thing is going to accelerate like a car, be able to reach highway speeds, and...

Bicycle highway speeds or automobile highway speeds?

[Bicycle Bob]

One of the guys who came to volunteer on my velomobile project said he'd first been impressed when I passed him on the highway. Later, I noticed that he didn't ride a bike - he'd been in slow traffic, and I'd been on the shoulder. This was not a Nevada highway or an Autobahn, though.

[The Toecutter]

Originally Posted by freebeard

What speed are the tires rated for?

Originally Posted by arcosine

Bicycle tires are not speed rated.

The manufacturer rates the Schwalbe Marathon Plus tires at 50 km/h continuous.

https://www.schwalbe.com/en/tour-reader/marathon-plus

I currently have Schwalbe Marathon Greenguards installed that are rated for 25 km/h, but they are due for replacement and I will be using the Marathon Plus.

Originally Posted by freebeard

Bicycle highway speeds or automobile highway speeds?

I'll be able to top out around 60 mph, but I won't be doing it very often, given the risks associated with pushing to the limits a vehicle whose parts are not DOT rated. Most of my use case will be around 30 mph, with a bit of 40-45 mph cruising on occasion.

The idea I have in mind is a vehicle that can perform like a pedal-powered velomobile with the motor completely disabled. I'm hoping I get the aerodynamics good enough that under pedal-only, I can reach 40 mph on flat ground. With the motor enabled, the long term goal is to perform like a sports car, while getting the equivalent of thousands of miles per gallon. My current KMX frame will get me part of the way there, but not entirely. With the parts I have and parts I plan to get, it will perform like a slow to normal car from 0-30 mph. It has served well as a learning experience and is soon to be a functional proof of concept. It will be very usable at city traffic speeds and over long distances on back roads and bike trails.

In the long run, I will be building another vehicle capable of holding highway speeds with stability and with components rated for it. Perhaps go with 16" light-duty moped rims all around with some Mitas MC2 low rolling resistance tires rated for 100 km/h. But I'm going to need a custom frame for that, with stronger wheel hubs, thicker axles, stronger spindles, longer wheelbase, hydraulic brakes, roll cage, ect. I'm confident I can keep such a vehicle under 100 lbs, but it will take careful attention to detail, and I need to learn how to weld titanium. At its core, it will still be a bicycle, albeit a heavy one, and I want it to be ridable like a velomobile(faster than a normal bicycle) with the motor disabled. This vehicle may end up capable of reaching triple digit speeds and doing 0-60 mph in like 4 seconds using the electric drive system(possibly 2 motors in a FWD config or even 3 motors in an AWD config), at least that's the theory. Got to build this first prototype first!

[freebeard]

I'm confident I can keep such a vehicle under 100 lbs, but it will take careful attention to detail, and I need to learn how to weld titanium.

Welding titanium does not sound trivial.

Good that you know the tires limits.

[Bicycle Bob]

The car magazines that used to run tests using a bicycle 5th wheel for accurate recording got poor tread mileage but no other problems were noted.
Re: welding titanium. Only 30% of homebuilt aircraft that are begun are completed, 10% by the first builder, 10% by the second, and 10% by the third. One key to getting them done is choosing a material that you just enjoy working in. Competitive lightweight structures can be built in a wide range of materials. The stiffness per pound is almost the same for steel, titanium, aluminum, and wood, and toughness is often more important than strength. J.E. Gordon's books sort this all out with peerless prose.

[freebeard]

The stiffness per pound is almost the same for steel, titanium, aluminum, and wood, and toughness is often more important than strength.

I'm curious how basalt fiber composite would fair in a stiff/tough comparison. And how finicky lay-up is compared to glass or carbon fiber. If you coat the fabric before embedding it in the matrix it retains it's color. Else it turn a purple-black color.

I see you can get basalt coated with aluminum

https://basaltfiberworld.blogspot.com/

At its stand 4/E27 Incotelogy Ltd shows a new generation of the coated basalt fiber fabrics. The selection of possible coating materials is rather large from aluminum (Al), chromium (Cr) or copper (Cu) to silver (Ag).

The basalt fiber fabric is ideal for all applications where it comes to the temperature resistance, insulation, fire protection and fire-resistance: fire curtains, insulation textiles, textile heat shields, incombustible architecture textiles. Basalt fibers withstand temperatures up to 750 °C.
Such specific coating of plain or twill basalt fabrics can create for each potential application the benefit profile which allows to fully exploit the special properties of the basalt fiber fabric.

The coated with aluminum 3D Basalt fabric, which was developed specifically for design applications, can be used for example for special decorative surfaces for reception desks, kitchens or displays etc.. The objects that are enhanced with these fabrics, get a unique, three-dimensional structure.

Basalt fiber is a natural product. There aren’t any chemical changes during the manufacturing of basalt fibers. Also in the LCA assessment (LCA), basalt fibers show much better results than glass or carbon fiber.

[Bicycle Bob]

When a manufacturer brags about their physical properties, but does not present any numbers, I wait for other news.
The toughness, however, will employ the usual Cook-Gordon (yes, Gordon the author) mechanism for crack stopping, also used by wood and teeth. As a crack tries to extend itself, the tip is trying to peel up as well as apart. The "peel-up" force is only 20% as strong, but if a resin-fiber interface is weaker than that, it will pop first, and blunt the crack. Once the matrix has been widely destroyed, the toughness of the fibers themselves comes into play.

[freebeard]

https://duckduckgo.com/?q=Cook-Gordon+mechanism+for+crack+stopping

By coat the fabric I meant sizing. Don't know if the metallic coating is consider sizing or not. I couldn't find the reference at basalt.guru that talked about a nano-scale (hydrophobic?) spray-on like Nano-clear/Neverwet preserving the coloration of the raw material.

It sound like the Cook-Gordon method is a sizing or coating:


https://bruces23.files.wordpress.com...rdon-model.jpg

Anecdotally, basalt bends or deforms where carbon fiber shatters. Plus it's bulletproof.

[Bicycle Bob]

Sizing is like a wetting agent, and something to protect the fiber during processing. Glass fibers typically lose a lot of strength from mutual rubbing even with it. The sizing can vary according to the intended resin to speed up the impregnation and maximize adhesion. Metal coatings are quite rare, used to add qualities such as electrical conduction for lightning protection. The Cook-Gordon mechanism is quite automatic, provided the resin is under 20% the tensile strength of the fiber. If you use really good glue with weak fiber, it will be able to crack right through.

[freebeard]

Here's a first pass at an answer, but while it's not raining, I need to get out for a bike ride.

Aluminium - Specifications, Properties, Classifications ...
https://www.azom.com/article.aspx?ArticleID=2863
The specifications, properties, classifications and class details are provided for aluminium and aluminium alloys. ... Alloying, cold working and heat-treating can all be utilised to tailor the properties of aluminium. The tensile strength of pure aluminium is around 90 MPa but this can be increased to over 690 MPa for some heat-treatable alloys.

Basalt Rock Properties and Uses - Science Struck
https://sciencestruck.com/basalt-rock-properties-uses
The rock hardness of basalt is 6 on the Mohs scale, and can be seen through a combination of its compressive strength: 100-300 Mpa (Megapascal), its tensile strength: 10-30 Mpa, and its shear strength: 20-60 Mpa, which denotes that depending on the mineral makeup, basalt rocks fall in the strong - very strong category.

Fiber Reinforced Polymers - Characteristics and Behaviors
https://www.build-on-prince.com/fibe...-polymers.html
Basalt Fiber Reinforced Polymer (BFRP) Basalt fibers have higher tensile strength than E-glass fibers but lower than S-glass, however, its cost is near the cost of E-glass. It has much better resistance than E- and S-glass to the alkalies in concrete.

Basalt Rebar (BFRP) Manufacturer - Made In USA
[/url] https://www.fiberglassrebar.us/basalt-rebar/
KODIAK Basalt Rock Rebar has the advantage of being a little lighter than glass, a little higher tensile strength than common e-glass. Weight is less than 25% the weight of steel with more than 200% the tensile strength of steel. Basalt rock fiber will withstand higher temperatures before weakening.

It's raining again. The bill will be paid later.