www.recumbents.com - Streamliner Fairing Construction and Design
www.recumbents.com
www.recumbents.com
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
 All Forums
 www.recumbents.com
 Technical / Bike Building
 Streamliner Fairing Construction and Design
 New Topic  Reply to Topic
 Printer Friendly
Previous Page | Next Page
Author Previous Topic Topic Next Topic
Page: of 4

Speedy
recumbent guru

USA
882 Posts

Posted - 10/10/2017 :  19:46:26  Show Profile  Reply with Quote
Glowing discs are why cables are better then hydraulic.
Dog Boy's accident was caused by the glowing discs syndrome which melted the hydraulic hose and then there was no brakes.
Note that brakes on Sven's bike are Magura hydraulic rim. They would not stop the bike in the wet and were known to heat burst tires for more then one owner.

Pretty much stopped building or pedaling bikes. Still on two wheels though. The commute to work makes motorcycles the best choice. Bought my first motorcycle at 13 and figure I've owned around 50 since then. Still comfortable at speed but not doing the same things I did as kid.
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/11/2017 :  06:58:36  Show Profile  Visit alevand's Homepage  Reply with Quote
He's lucky that the hydraulic oil dint leak onto the red hot disk and ignite, leaving a chard resemblance of a bike. I stopped riding motorcycles in 1983 after a fall, been pedaling since. I built my first recumbent that year.

I calculated it takes 34 KJ to get a 160 mm disk read hot (650C). That's a 37 m hill (120 feet) so for two brakes that would be a 240 ft hill, neglecting aerodynamic drag for a 200 lb bike and rider.

And 12 KJ to raise the pressure in my 700C tire by 1.16, 100 to 116 psi, neglecting cooling (13C average temperature rise), a 72 ft hill, negating aerodynamic drag and cooling. So Id be safer by not using the max tire pressure and having a higher rated tire..

Does the tire pop or come off the rim?

Does the disk warp after being red hot?

C:
Tony Levand

Edited by - alevand on 10/11/2017 07:23:40
Go to Top of Page

Speedy
recumbent guru

USA
882 Posts

Posted - 10/11/2017 :  09:08:31  Show Profile  Reply with Quote
Does the tire pop or come off the rim? ... Seen it both ways

Does the disk warp after being red hot? ... Not always, but once a piece of metal changes color it has gone thru a phase change and should be assumed to be damaged.
Most standard off the shelf discs for bicycles have some chromium to prevent rust which is not ideal for friction or heat dissipation.
Cold rolled steel actually works better if you can make them.

Edited by - Speedy on 10/11/2017 11:55:44
Go to Top of Page

purplepeopledesign
recumbent guru

Canada
680 Posts

Posted - 10/11/2017 :  13:00:34  Show Profile  Reply with Quote
Any idea the energy difference switching to 203mm rotors for a 20" wheel?

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/11/2017 :  14:36:19  Show Profile  Visit alevand's Homepage  Reply with Quote
203/160 = 27% more.



C:
Tony Levand
Go to Top of Page

purplepeopledesign
recumbent guru

Canada
680 Posts

Posted - 10/11/2017 :  20:39:49  Show Profile  Reply with Quote
So 25kJ or a 47m hill. That's not insignificant.

Hydraulic brakes have that much better modulation, I wonder if there is a way to keep them while still having some other kind of drag brake for mountain descending?

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
Go to Top of Page

Joel DIckman
recumbent enthusiast

USA
129 Posts

Posted - 10/12/2017 :  10:28:03  Show Profile  Visit Joel DIckman's Homepage  Reply with Quote
quote:
Originally posted by purplepeopledesign

...Hydraulic brakes have that much better modulation, I wonder if there is a way to keep them while still having some other kind of drag brake for mountain descending...


Upright tandem riders have been using Arai drum brakes during long mountain descents for many years. They seem to prefer this to disc brakes. Don't have any personal experience with them myself though.

Safe riding,
Joel Dickman
http://lightningriders.com

These three prevent most accidents: seeing, being seen, & (usually) common sense.
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/12/2017 :  11:00:36  Show Profile  Visit alevand's Homepage  Reply with Quote
http://santanatandems.com/Techno/DiscBrakeTech.html

10 inch disk (254 mm):

http://santanatandems.com/Techno/UnderstandingBraking.html


C:
Tony Levand

Edited by - alevand on 10/12/2017 13:44:56
Go to Top of Page

Speedy
recumbent guru

USA
882 Posts

Posted - 10/12/2017 :  14:00:46  Show Profile  Reply with Quote
Even if the feed line does not melt off hydraulic fluid can boil which can render them useless.
Mechanical is the safest choice.
Santana surely have done their homework but ... the weight reduction holes in the disc look too large for my taste. The aluminum cooling fin is a nice touch.


Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/12/2017 :  14:53:53  Show Profile  Visit alevand's Homepage  Reply with Quote
You'd probably want cross 4 lacing with that disk. I agree on the holes. I like how it floats. I am going to experiment with aero braking before going to disks.

C:
Tony Levand
Go to Top of Page

Speedbiker
human power expert

USA
3744 Posts

Posted - 10/13/2017 :  22:46:59  Show Profile  Reply with Quote
Before you elite hpv designers start suggesting Matthew use big rig air brakes, take a moment to remember this bike is being designed to haul a high schooler to school.
Go to Top of Page

carolina
recumbent guru

USA
566 Posts

Posted - 10/13/2017 :  23:33:20  Show Profile  Visit carolina's Homepage  Reply with Quote
Now , hold on just a minute.

velosRus.com
Go to Top of Page

Jerry
recumbent guru

USA
967 Posts

Posted - 10/14/2017 :  08:08:18  Show Profile  Reply with Quote
I still think he should start with coroplast. It is cheaper and easier to re-design and change things until you get it where you want it. Also lighter and you don't need a mold or plug to build it. When you build a fiberglass or CF shell it is hard to change the fit and size of the shell. Coroplast is easy to change and at around $20 a sheet, you can afford a lot of mistakes and changes. Once you get it right, it is weather proof, quieter, and pretty darn fast. And if/when you crash, it is easier to repair. OK, I like coroplast!

With Matthews design skills it would look professional too.

Edited by - Jerry on 10/14/2017 08:09:55
Go to Top of Page

Speedbiker
human power expert

USA
3744 Posts

Posted - 10/14/2017 :  08:16:21  Show Profile  Reply with Quote
Jerry, I believe Matthew is more ambitious than that, and is wanting the challenge of a more complex build. Remember, he doesn't have a job and family. Am am encouraged that a young person is so motivated, rather than throwing a bunch of time and money into gaming, partying, or buying a car he doesn't need. Future great engineer in the making!
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/14/2017 :  12:37:24  Show Profile  Visit alevand's Homepage  Reply with Quote
Mathew is planning on using v-brakes, if you read the post about him being a Florida flat lander. . We are just discussing brakes in general, maybe hijacking the tread..

C:
Tony Levand

Edited by - alevand on 10/14/2017 12:38:50
Go to Top of Page

Jerry
recumbent guru

USA
967 Posts

Posted - 10/14/2017 :  14:54:55  Show Profile  Reply with Quote
I agree Thom, but Matthew did say he wanted the shell to fit different size people. That would be a lot easier with coro. You can actually expand coro very easily. Glass, kevlar, and CF, not so easy. Get your feet wet before you try swimming the ocean. Plus, I have seen a few coro built velomobiles and one streamliner look just as good as OEM built ones. Whatever he decides, I hope him the best.
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/14/2017 :  17:21:59  Show Profile  Visit alevand's Homepage  Reply with Quote
They have a 3d printer at work that prints using plaster, after it dries they infuse it with superglue. Its strong enough to machine afterward. They use it in mocking up nuclear reactor components. It can print table size parts.

C:
Tony Levand
Go to Top of Page

Speedy
recumbent guru

USA
882 Posts

Posted - 10/14/2017 :  23:45:40  Show Profile  Reply with Quote
BTW ... The Bengal caliper shown in the Santana picture can be found on ebay for under $30 and comes with a 160mm disk. Cheap safety.

I managed a 3D print shop at Autodesk for 18 months where we purchased gallons of superglue to cover prints. Finding gallon quantity's took a bit of searching and was expensive. $600 I recall.

The CAD model Matthew created looks like is was made with Autodesk Fusion 360. That software has an awesome slicer option (Available as an add-in from the app store) where it outputs cut files ready for router or laser.
i.e. a stack of foam board ready for sanding.
The original version of the slicer could do skin loft cut files. Useful for a coroplast body design.

Coroplast makes a terrific, low cost, light weight, safe streamliner body.
Lots of examples to study http://pedalprix.com.au/ (pedalprix is a Australian high school competition)
http://www.instructables.com/id/Facet-V1-Velomobile/







Edited by - Speedy on 10/14/2017 23:50:33
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/15/2017 :  07:21:34  Show Profile  Visit alevand's Homepage  Reply with Quote
That Facet is awful, coroplast can be bent. Two high school students from the Chicago area built two corovelos and they rode them to Colorado a few years ago. I rode my Carp coroliner bike over to his house to meet him one Saturday.

http://triketrek11.blogspot.com/

https://www.facebook.com/triketrek11

C:
Tony Levand

Edited by - alevand on 10/15/2017 07:43:01
Go to Top of Page

Speedy
recumbent guru

USA
882 Posts

Posted - 10/15/2017 :  10:11:05  Show Profile  Reply with Quote
Beauty ... is in the eye of the beholder.
The information is presented for study examples which does include a link to a Facebook corovelo group.


Edited by - Speedy on 10/15/2017 10:11:22
Go to Top of Page

alevand
human power expert

USA
2908 Posts

Posted - 10/15/2017 :  16:05:50  Show Profile  Visit alevand's Homepage  Reply with Quote
Aerodynamics is only skin deep. Yes I am a member of that group as well as the home-built recumbent group. My brother is a member of the Adventure Motorcycle club, he use to ride through the mountains in Mexico's Copper Canyon on his BMW, until he went off a cliff.

C:
Tony Levand
Go to Top of Page

purplepeopledesign
recumbent guru

Canada
680 Posts

Posted - 10/15/2017 :  19:22:12  Show Profile  Reply with Quote
Off a cliff!! Sorry to hear that.

And Speedy... saw on a different forum that you might be affected by the Santa Rosa fire... hopefully not too badly.

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
Go to Top of Page

Speedy
recumbent guru

USA
882 Posts

Posted - 10/16/2017 :  11:07:38  Show Profile  Reply with Quote
Definition of "Facet" ... a polygonal form.
The art and word play is obvious to me.

Adventure bikes ... my current addiction is the KTM 990 version. Got two ... one's not enough.
Last time I fell on a motorcycle was December 2010 climbing out of the Manu rain forest in Peru. Rainy, muddy road. Very minor.
Time before that was in 1979 which was a pretty nasty concussion. Those days I was doing a lot of jumping and wheelies everywhere.
Found the safety of recumbents a few years later and started to mellow a bit.

Jensen ... first day of the fire missed us by half a block. Been on pins and needles ever since.
Go to Top of Page

Speedbiker
human power expert

USA
3744 Posts

Posted - 10/16/2017 :  17:06:01  Show Profile  Reply with Quote
I'm still thinking about the havoc you could wreak with a gallon of superglue.
Go to Top of Page

Jerry
recumbent guru

USA
967 Posts

Posted - 10/17/2017 :  06:07:37  Show Profile  Reply with Quote
Hey Matthew, are you still here? Us old fossils tend to hi-jack threads! Come on back. We need input and interest from young people.
Go to Top of Page
Page: of 4 Previous Topic Topic Next Topic  
Previous Page | Next Page
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
www.recumbents.com © 2017 www.recumbents.com Go To Top Of Page
Snitz Forums 2000