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The "Frankenfork" Linkage-type fork

Honus

Honus

Monkey
Jun 6, 2006
177
0
Boulder, CO
dw said:
I've had a soft spot in my heart for that Tyrell since I was a little kid. Is that weird? Probably.. But nonetheless.
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Nah, it's not weird at all- a lot of those cars built in the 70's were super cool and very inventive, especially the CanAm cars. Some of my personal favorites were the Shadow CanAm cars designed by Trevor Harris (same guy that did the RockShox LTD bike, all conquering Nissan GTP cars and multiple Baja race trucks), the Lotus 56 turbine F1 car, Brabham BT46 F1 fan car and the Chaparral cars. There was a lot of creative thinking going at that time that resulted in some very unusual and sometimes quite successful designs.

 
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Wilhelm

Wilhelm

Monkey
Aug 10, 2003
444
19
Honus said:
Found a couple more pics of the Ribi fork I had saved-
The RC250MT has kind of a hybrid of the earlier steel fork and the later version monoshock Aluminum fork
This is probably one of the best pics of the monoshock version
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Honus,
Awesome pics. Indeed, this



is one of the very best pics of the later HONDA RIBI-type fork monoshock version. Do you remember the web links where you found this pic as well as this



one? By now I was on hunting for Valentino RIBI-style fork pictures as much I could get.

A newer HONDA US patent (7,896,379) from March 1, 2011 of a linkage fork, unfortunately suited for street bikes only: "Motorcycles having upper and lower arms coupled with fork and frame".

*.pdf download
 

Attachments

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Buckethead

Chimp
Jul 14, 2011
2
0
Hi, back on page 5 you had a photo of a Confederate Fighter disassembled. May I please have the link to the site where you found it? Thank you, I only ask because I am student trying to create a 3d "model"(virtual) of said bike.

Thank you,

Cozmo
 
Wilhelm

Wilhelm

Monkey
Aug 10, 2003
444
19
Buckethead said:
Hi, back on page 5 you had a photo of a Confederate Fighter disassembled. May I please have the link to the site where you found it? Thank you, I only ask because I am student trying to create a 3d "model"(virtual) of said bike.

Thank you,

Cozmo
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Unfortunately I did not save the website where I found the pic separately, you can only right-click the pic and look for the URL where it is stored (http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc6/222624_209907995710173_104633106237663_671851_127037_n.jpg). Alternatively I can only recommend a web search by Google.

Regards,
Wilhelm

 
N

NWS

Chimp
Sep 19, 2010
66
0
I'm pretty sure that fbcdn.net is Facebook's content distribution network. So, if Confederate has a Facebook page, there's a good chance those pictures came from their Facebook photo album.
 
tacubaya

tacubaya

Monkey
Dec 19, 2009
720
89
Mexico City
B

Buckethead

Chimp
Jul 14, 2011
2
0
Thanks guys! Sorry it took me so long to reply, forgot to check back. Please don't think that I don't appreciate the help; this is awesome. Thank you again!

Cozmo
 
Wilhelm

Wilhelm

Monkey
Aug 10, 2003
444
19
The Austrian SCURRA Trelever[SUP]®[/SUP] integrated enduro fork (180mm) by Martin TREBICHAVSKY looks like an obscure mixture of Valentino RIBI´s quadrilateral MX fork/Ê-FØHRK and the SAXON/MotoDD/BMW Telelever design:


Courtesy of PinkBike.com, 2013 InterBike


Courtesy of VitalMtB.com, 2013 InterBike
 
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S

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
Rip said:
Now with twice as many pivots to service....
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Yeah but let's not kid ourselves on the service intervals of a telescopic fork as compared to a frame's linkage.

That Scurra thing looks like a geometric nightmare as far as steering and handling go!
 
Jm_

Jm_

sled dog's bollocks
Jan 14, 2002
20,062
10,626
AK
Wilhelm said:
The Austrian Scurra Hard integrated enduro fork (180mm) looks like an obscure mixture of Valentino RIBI´s quadrilateral MX fork/Ê-FØHRK and the SAXON/MotoDD/BMW Telelever design:
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Just go ahead and repost it in the old and obscure bikes thread.
 
F

FarkinRyan

Monkey
Dec 15, 2003
611
193
Pemberton, BC
Wow. It's like one of those things you'd see in Popular Mechanics or New Scientist that are all "LOL, here's what people in 1993 thought bikes 20 years in the future would look like!"
 
Wilhelm

Wilhelm

Monkey
Aug 10, 2003
444
19
The British COFA Engineering recently made an obscure adjustable light-weight 230 mm travel fork. That gadget looks somewhat similar to the SAXON/MotoDD/BMW Telelever design. The 26" wheeled NOAH rig was unveiled at 2014 Bespoked UK Handbuilt Bike Show (UKHBS), London.


Courtesy of Pinkbike.com


NOAH bike showcases outside-of-the-box suspension

By Ben Coxworth
April 21, 2014

One of the great facts about bicycle design is that there are at least two or three intriguing alternatives for every established way of doing things ... and suspension is certainly one of those established "things." In the past couple of years alone, we've seen leaf shocks, looped wheels and parallelogram seat posts offered up as replacements to the standard shock absorber. UK-based COFA Engineering recently showcased its own unique take on bicycle suspension, known as the NOAH system.

NOAH stands for Normally Operated Articulated Hybrid suspension system, and it was publicly displayed for the first time earlier this month at the Bespoked UK Handmade Bicycle Show in London.

It's a full-suspension system, but instead of incorporating the usual rear shock and front suspension fork, it utilizes two midships-mounted rear shocks. A linkage consisting of two A-arms runs from the telescopic fork to one of those shocks, allowing it to soak up the hits taken by the front wheel. You can see it demonstrated in the video below.


So, what's the point? According to COFA, there are several.

First of all, because the fork legs are supported closer to the wheel, they flex less. Additionally, the fork is lighter, as it doesn't contain any springs, dampers or other shock-absorbing hardware. The weight is instead moved toward the middle of the bike, thus reducing unsprung weight and improving the handling.

It's similar in principle to the single-arm telelever system, used in bikes such as the Scurra Hard Enduro. COFA, however, wanted to boost the amount of travel possible with that setup, while also improving the steering.

"The rear pivot point of the top A-arm is adjustable, allowing the path of the lower yoke to be altered for different riding conditions," COFA's Robyn Taylor explained to us. "For example ? the steering angle when not compressed can be set steeper than usual, resulting in a quick-steering bike on the flat. However, when the forks compress the steering angle can be relaxed, aiding handling over rough terrain."



Additionally, the rear suspension layout allows for the use of a Nuvinci N360 continuously-variable hub transmission, eliminating the need for a rear derailleur ? although slightly increasing the unsprung weight in the back.

In its current form, the NOAH concept bike has a whopping 230 mm of front travel, although it also tips the scales at 40 lb (18 kg). For that reason, its designers are looking into the use of lighter building materials for subsequent versions.

"The end goal is to produce a limited number," said Taylor. "We had a good response at the London show, but we do accept it's not to everyone's taste!".


In its current form, the NOAH concept bike has a whopping 230 mm of travel in front, although it also tips the scales at 40 lb (18 kg).


The rear pivot point of the top A-arm is adjustable, allowing the path of the lower yoke to be altered for different riding conditions.


The fork is lighter than a regular suspension fork, as it doesn't contain any springs, dampers or other shock-absorbing hardware.


The rear suspension layout allows for the use of a Nuvinci N360 continuously-variable hub transmission.


The one-of-a-kind NOAH bike.

Source: COFA Engineering via Bike Radar
 
Wilhelm

Wilhelm

Monkey
Aug 10, 2003
444
19
Wilhelm said:
Another interesting concept bike with a linkage fork and many more funny approaches was designed by Adrian GRIFFITHS at TopTrail Ltd. (CEng MIMechE), a professional engineer with over 25 years experience in automotive chassis engineering, and built by Dave WRATH-SHARMAN of Highpath Engineering as a functional prototype: The "Interconnected Suspension Bicycle Project", an all terrain concept bike.

Technical paper

Pics:










Videos technology:

Videos performance:
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Sometime ago I posted Adrian GRIFFITHS´ The TopTrail Interconnected Suspension Bicycle Project. Recently I found an article "Suspension invention: the promising TopTrail linked suspension technology" about this project and perspectives at VeloVision #41, 06-2011, 46-48, VeloVisionMag.co.uk (e-paper unfortunately not for free). However, a free German translation "Praxistaugliche Verbundfederung" w/ hi-res pics has been published at FahrradZukunft #15, 04-2013, 17-21, FahrradZukunft.de.


Adrian GRIFFITHS, CEng MIMechE.










Early prototype.
 
Tantrum Cycles

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
Honus said:
Nah, it's not weird at all- a lot of those cars built in the 70's were super cool and very inventive, especially the CanAm cars. Some of my personal favorites were the Shadow CanAm cars designed by Trevor Harris (same guy that did the RockShox LTD bike, all conquering Nissan GTP cars and multiple Baja race trucks), the Lotus 56 turbine F1 car, Brabham BT46 F1 fan car and the Chaparral cars. There was a lot of creative thinking going at that time that resulted in some very unusual and sometimes quite successful designs.

Click to expand...
Damn. I click on this thread and there he is, front and center. My fuckin hero, best friend and best man at my wedding.

Trevor is the most prolific and successful designer of wheeled (mostly competition) vehicles in history.

I will be staying with him next week after my trip to taiwan. We'll talk about linkages and women. Free body diagrams, no software.

He taught me not to be so smart.

Not the right thread, maybe, but....
 
Tantrum Cycles

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
This is Trevor's bike. Killed for political power play type reasons.

These frames and my first hand made Patronis proto were actually made be the same artist/SoCal fabricator, Derek Collins, who briefly had his own brand called Rigid.

Below in trevor's yard, he got to keep one, shown with my proto.

Note the brake therapy on the frame.....


Bike-ad-Giant-Tomac-1995.jpeg
trevors bike too.jpg
 
dump

dump

Turbo Monkey
Oct 12, 2001
8,451
5,067
@Tantrum Cycles I remember seeing that Tomac ad in the magazines back then and expecting to see that frame soon... never happened and I recall being slightly disappointed. Seemed pretty cool at the time.
 
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