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-   -   designing a safer cycle/tricycle (https://www.bikeforums.net/advocacy-safety/486659-designing-safer-cycle-tricycle.html)

Charles Brown 11-15-08 12:49 PM

designing a safer cycle/tricycle
 
I've been thinking for some time of building a bicycle or tricycle where the rider would be surrounded by a roll cage. This cage would be triangulated for strength, stiffness, and light weight, and would double as the frame-wheels, pedals, the seat, etc., would bolt right to it. For weather protection and/or aerodynamics it would be easy to add a cover. Is anyone else thinking this way, and if so, can I pick your brains for some good ideas for the design? Thank you, Charles Brown 1875 Sunset Point #206, Clearwater, FL 33765

AndrewP 11-15-08 01:26 PM

It wouldnt do much for safety, since it wouldnt stop the rider from striking a hard object when they fall or are hit. However a device to hold an umbrella over the rider might attract some users

gcottay 11-15-08 01:30 PM

A velomobile with an exoskeleton might be interesting if you were able to keep the weight down.

trekker pete 11-15-08 02:07 PM

Seems like weight is the major concern.

I think the idea has merit.....in florida or some other flat as a board place, but, even moderate hills would kill you.

I think a better idea might be some sort of airbag system that would deploy behind you. It might even be carried in a backpack. Such a system might help you against being hit from behind, which, imo is the one type of accident we have little control over. Side or frontal impacts, I think are best avoided by staying awake and riding defensively.

Flying Merkel 11-15-08 07:54 PM

Sounds like you'd end up with a device no one would want to ride. One of the great joys of bicycles is the minimalism.

There's a big difference between 20 lbs & 30 lbs.

There is a guy around here with a motor scooter with a roll cage. It looks like it gives the illusion of safety without signifcantly increasing safety. More weight far away from the center of balance will make evasive manuvers harder. Trikes are already suffering from weight problems.

Interesting thought, but historically a blind alley.

mondaycurse 11-15-08 07:56 PM

Add an automatic gun turret that destroys cars that get within 5 feet of the bike.

zonatandem 11-15-08 08:01 PM

Many inventors have had similar ideas; there is no market for something like that.
If you want to build one for yourself, then fine.

Carusoswi 11-16-08 02:03 AM


Originally Posted by Charles Brown (Post 7856776)
I've been thinking for some time of building a bicycle or tricycle where the rider would be surrounded by a roll cage. This cage would be triangulated for strength, stiffness, and light weight, and would double as the frame-wheels, pedals, the seat, etc., would bolt right to it. For weather protection and/or aerodynamics it would be easy to add a cover. Is anyone else thinking this way, and if so, can I pick your brains for some good ideas for the design? Thank you, Charles Brown 1875 Sunset Point #206, Clearwater, FL 33765

I saw on the news a suit (probably intended for motorcycle use) that had built in air bags that were activated by a sort of dead man tether that would deploy CO2 to inflate airbags built into the suit if the rider becomes separated from the bike for any reason. It looked like an ok idea, but the implementation seemed slow compared to my experience (or sorry the day(s)) with auto airbags.

You'd be injured and dying before the suit fully inflated.

. . . but the idea seems interesting. Whether or not it could be practically developed for bicycle use remains to be seen, and I'm still not certain I'd want to wear such a suit.

My thinking is with others, here, that to build a cage around a bike tends to defeat the purpose of cycling. You really couldn't go anywhere. Might just as well use a trainer indoors, surrounded by the walls of your home.

. . . but I don't mean to knock your idea. Worse vision has resulted in useful inventions.

Caruso

hotbike 11-16-08 11:30 AM

You mean like this?
http://i134.photobucket.com/albums/q...Velomobile.jpg
This is only a Polaroid, let me show you a better picture:
http://i134.photobucket.com/albums/q...mobile1990.jpg

Well, it definitely can be built. This one used Kevlar though, which is a bit pricey. The pictures show the Type 6 in 1989 and 1990. There are aluminum tubes in the canopy, but they are molded into the Kevlar, not welded to the bike frame.

I started by attaching two six-foot long aluminum tube to the top-tube, using ten stainless steel hose clamps. The hose clamps are the kind used for automotive radiator hoses, two inch diameter.

I plan to build a new velomobile, but next time I will make the seat lower, and further back Lowrider style, and I will make the fairing wider. This fairing was only twenty inches wide. Next one will be at least twenty four, maybe twenty six inches wide. And wider at the rear too, the bike in the picture has a rear fairing only fourteen inches wide. The front and rear fairings should be the same width.

It worked for me, good luck!

Flying Merkel 11-16-08 11:39 AM


Originally Posted by hotbike (Post 7860977)
You mean like this?
!

How'd it handle in a crosswind?

jgedwa 11-16-08 12:03 PM

I want cupholders

crhilton 11-16-08 06:06 PM

Good luck. People make shelled bicycles for high speed but they don't have frames (not ones that would be at all safe) and they're made to specifications that would be impossible to deal with in the real world.

The immediate trouble I see is dealing with bad terrain, especially slick areas. It'd have to be a tricycle because the shell will immobilize you too much to deal with balance on bad terrain.

I imagine it still won't be terribly safe or it'll be too heavy (even if you use all carbon fiber). Maybe it could be an electric assist machine though? You could even try some kind of high end thing where you have solar panels, pedal, and have a rechargeable battery. The pedaling and solar panel would just provide extra distance.

Most users wouldn't pedal though. Your pedaling would be similar to the solar panels on a gloomy day. But the use of bicycle parts might mean a low cost efficient machine.

Edit: Low cost if PV cells ever get down to a reasonable price ( < $.05 per kilowatt hour ).

trekker pete 11-16-08 08:33 PM


Originally Posted by hotbike (Post 7860977)
You mean like this?
http://i134.photobucket.com/albums/q...Velomobile.jpg
This is only a Polaroid, let me show you a better picture:
http://i134.photobucket.com/albums/q...mobile1990.jpg

Well, it definitely can be built. This one used Kevlar though, which is a bit pricey. The pictures show the Type 6 in 1989 and 1990. There are aluminum tubes in the canopy, but they are molded into the Kevlar, not welded to the bike frame.

I started by attaching two six-foot long aluminum tube to the top-tube, using ten stainless steel hose clamps. The hose clamps are the kind used for automotive radiator hoses, two inch diameter.

I plan to build a new velomobile, but next time I will make the seat lower, and further back Lowrider style, and I will make the fairing wider. This fairing was only twenty inches wide. Next one will be at least twenty four, maybe twenty six inches wide. And wider at the rear too, the bike in the picture has a rear fairing only fourteen inches wide. The front and rear fairings should be the same width.

It worked for me, good luck!

I'll bet that thing's fun in a 20 mph crosswind.

cyclefreaksix 11-16-08 11:10 PM

Good Gawd, that's the fugliest thing I've ever seen.

hotbike 11-17-08 08:27 AM

I had no trouble handling the velomobile in a cross-wind.
Maybe 'cause the top is rounded, where the sides meet the roof.

I even had it out on a day with 60MPH wind gusts.

I have a pilots license, so I have to say it's no different than landing a plane in a crosswind.

crhilton 11-17-08 08:29 PM


Originally Posted by hotbike (Post 7865068)
I had no trouble handling the velomobile in a cross-wind.
Maybe 'cause the top is rounded, where the sides meet the roof.

I even had it out on a day with 60MPH wind gusts.

I have a pilots license, so I have to say it's no different than landing a plane in a crosswind.

My car is difficult to handle in 60MPH gusts... I'd hate to be inside a sail on wheels like that...

Feldman 11-18-08 11:28 AM

I'll echo the sidewind concern--customers of mine who race time trials and tris mention wind pressure with deep aero rims, let alone a fairing over the bike! Enough weight to stabilize this machine in the wind will be too much for most cyclists. Even at 2000 pounds, a VW Golf on a windy bridge is plenty scary! How about just designing a bike for full coverage fenders?
Those of us who ride in wet weather know that more water gets you from below than from above.

mkael 11-18-08 02:57 PM

Reminds me of this. Op must have already found this http://en.wikipedia.org/wiki/BMW_C1

Note it was produced only from 00 to 03.
Problems with seatbelts and helmets causing stress are mentioned.
Calculating the forces a helmet might have on a neck should be easy enough if someone cares enough.
I think the style problem is far worse than the weight issue.
Balance with that thing will be interesting.
I see how that provides some added safety when falling sidewards.
Frontal impact not so much.
I would adapt the basic design of the bmw c1 here.
Would just guess adding top tubes is the same amount of weight as the frame.
Make shape just like something which could be aerodynamic.
Build and try

sauerwald 11-18-08 03:10 PM


Originally Posted by jgedwa (Post 7861085)
I want cupholders

And a heated seat

hotbike 11-19-08 09:40 AM

Here's a link to a photo of a good old Airstream trailer.

http://www.flickr.com/photos/jackjon...7602790081263/

Notice how the top and ends are rounded? Maybe that's why Airstream trailers are the only ones left after a hurricane or tornado rips through a trailer park.

And here's more about the BMW C1:

http://www.carenthusiast.co.uk/shows/bmw_3.htm


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