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warren
human power expert

USA
6093 Posts

Posted - 02/04/2015 :  16:18:29  Show Profile  Visit warren's Homepage  Reply with Quote
This is pretty cool: https://www.youtube.com/watch?v=HVx3aIePO00

The rear wheels are offset using bike cranks. This is a novel idea that makes it easy to create a bolt-on tilter rear end. The test trike still has no rear brakes, but its just a test mule so that's ok. It would be easy for Jim to add hub brakes to this design. Will engaging the brakes on the rear wheel "lock" the drive unit so it won't fall over when you stop? It seems like it would work that way to me. If so this solves a huge number of tilter issues.



Jim says that he and Maria will be at the Ft. Lauderdale (Pembroke Pines) HPRA races this weekend (Feb 7). It will be great to see the Parkers and how this cool bike performs!

-Warren.

Edited by - warren on 02/04/2015 17:37:11

Speedbiker
human power expert

USA
3749 Posts

Posted - 02/05/2015 :  21:54:32  Show Profile  Reply with Quote
Warren, as you know from tilters and landing gear, the faster the engagement/disengagement, the better. Best to have that separate from the braking. It sure does look simple and fun. I wonder if it will slow the bike measurably. Imagine coming into a food stop 300 miles into a 24 hour and having a bike that doesn't fall over.
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stix
recumbent enthusiast

Australia
135 Posts

Posted - 02/06/2015 :  04:23:02  Show Profile  Reply with Quote
WOW! That is an amazing video!

Stix

Peregrin on Birk (Birk Comet RT with full fairing)
Lightning F-40 (built around R-84 frame)
Soma Smoothie Upright
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alevand
human power expert

USA
2915 Posts

Posted - 02/06/2015 :  05:15:32  Show Profile  Visit alevand's Homepage  Reply with Quote
.

Edited by - alevand on 02/08/2015 11:36:40
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warren
human power expert

USA
6093 Posts

Posted - 02/06/2015 :  08:49:59  Show Profile  Visit warren's Homepage  Reply with Quote
A simple carbon leaf spring between the BB and the end of each crank would allow tilting and keep the bike from falling over, at least when there is no rider.
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Speedbiker
human power expert

USA
3749 Posts

Posted - 02/06/2015 :  18:33:13  Show Profile  Reply with Quote
Tony, almost nothing you suggest is correct.
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Larry Lem
human power expert

South Sandwich Islands
2524 Posts

Posted - 02/06/2015 :  19:19:29  Show Profile  Reply with Quote
I can't tell "how it works". Any better explanation of the design?

Larry Lem
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Kragasaur
recumbent enthusiast

259 Posts

Posted - 02/06/2015 :  19:47:50  Show Profile  Reply with Quote
quote:
Originally posted by warren

A simple carbon leaf spring between the BB and the end of each crank would allow tilting and keep the bike from falling over, at least when there is no rider.



Warren,
A spring like that could work. But do you even need it? Someone on the other forum suggested that arranging the cranks at an angle of less than 180 degrees (so that the pivot is below both axles) would provide some self-righting force. I'm still thinking that through, but I think it might be correct.
I kinda like the idea of a subtle self righting force rather than a full-on tilt lock. Of course, a spring like you suggest could be either subtle or not. It seems like tweaking the crank angle could also provide an adjustable righting force, and be even more simple/elegant.
Am I wrong about the self-righting potential of using cranks at less than 180 degrees?

Eric
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Kragasaur
recumbent enthusiast

259 Posts

Posted - 02/06/2015 :  20:36:10  Show Profile  Reply with Quote
quote:
Originally posted by Larry Lem

I can't tell "how it works". Any better explanation of the design?

Larry Lem



Larry,
I think it's as simple as this: a crank is mounted in the rear dropouts and a rear wheel is attached to the end of the crankarms where the pedals would normally go. Since the crank allows one wheel to go up and the other to go down, the bike can tilt around turns or ride upright on tilted/crowned roads.
But it still mostly escapes me as to how this is an advantage. It seems like (and appears) it handles pretty much exactly like a two wheeler. It does seem to have a kind of passive suspension, since the two rear wheels ride different tracks. It seems it would also handle speed bumps really well, since the offset rear wheels would hit the bump at different times.
But frankly I'm wondering if the greatest advantage (for Cruzbike anyway) is that perhaps if makes it easier for a beginner to handle a FWD MBB bike, which are notoriously hard to learn for some people. It would be a lot easier for Cruzbikes to sell bikes if there was a way that would make it easier for beginners to ride them.
I readily acknowledge that there could be aspects of this design that I'm missing. And that while I imagine this post could be read as being negative, I actually think the idea is kinda neat and would like to give one a try.
Eric

Edited by - Kragasaur on 02/07/2015 09:40:18
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Speedbiker
human power expert

USA
3749 Posts

Posted - 02/07/2015 :  18:36:31  Show Profile  Reply with Quote
Tony, lock up both wheels and they lose traction and you fall over. There is very little load on either wheel. Also, as those of us who have used landing gear know, to be caught upright at a stop you want something that engages quickly and holds you securely. Same with the launch. How could you take off safely? Very carefully. Most everyone one this forum who built a tilting trike found a disk brake impractice for a tilt lock. So, Tony, beyond the theoretical fact that locking both wheels would hold your position, in reality none of what you said was of use. And if you really want to screw up hold the thing handles when turning, go ahead and spring load it to center. I really want to fight a spring as I lean into a curve!
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purplepeopledesign
recumbent guru

Canada
683 Posts

Posted - 02/07/2015 :  21:55:01  Show Profile  Reply with Quote
quote:
Originally posted by Runxner

A few prior homebuilt video's here
http://recumbents.com/forums/topic.asp?TOPIC_ID=1994


Are you sure about that link?

:)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/
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Runxner
recumbent enthusiast

USA
441 Posts

Posted - 02/08/2015 :  09:25:55  Show Profile  Reply with Quote
oops this linkhttp://recumbents.com/forums/topic.asp?TOPIC_ID=5022

Team Low-Life
Lowracer Test Pilot/Evangelist
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Speedbiker
human power expert

USA
3749 Posts

Posted - 02/08/2015 :  09:45:06  Show Profile  Reply with Quote
Yes Tony, of course it still needs developing. Your point about it's usefulness with a lock is ridiculously obvious. Did you think they had no plans for a lock? Did you think that is the final product. Perhaps we should let them finish development before we tell them everything that is wrong with it. You never know, some pretty smart people might be involved.
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 02/09/2015 :  13:22:38  Show Profile  Reply with Quote
Me thinks, someone needs to eat a Snickers Bar, to reverse the moph' to Joe Pecsi/Don Rickles.
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warren
human power expert

USA
6093 Posts

Posted - 02/12/2015 :  08:51:48  Show Profile  Visit warren's Homepage  Reply with Quote
We had a good chance to check out the Cruzbike leaning trike's capabilities last weekend during the Florida HPRA races. Jim and Maria took turns racing Cruzbikes with the leaner mechanism bolted on. The trike seemed to handle both the high speed corners of the road course and the velodrome well. Their speeds with the tilter mech were slightly slower than the same bike with a single rear wheel, as expected.

Now they need to figure out how to add brakes and a tilt lock to make this a production option.

-Warren.
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purplepeopledesign
recumbent guru

Canada
683 Posts

Posted - 02/12/2015 :  10:59:33  Show Profile  Reply with Quote
So... it doesn't stay upright by itself even without the weight of a rider? And as an aside, I was under the impression that two sets of brakes are needed to be race legal.

:)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/
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Speedbiker
human power expert

USA
3749 Posts

Posted - 02/12/2015 :  11:53:27  Show Profile  Reply with Quote
Yeah, it looks like they skated around the two brake rules. But who cares? Not me.
Remember, that thing i just a prototype. If they figure out a lock and brakes, maybe they'll sell them. If not, maybe another tilt system. Or maybe nothing... It's their deal.
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purplepeopledesign
recumbent guru

Canada
683 Posts

Posted - 02/12/2015 :  18:54:29  Show Profile  Reply with Quote
All tilters are prototypes, but that doesn't mean that the last time I made the rounds that Tim, Dennis and I weren't still put up against the rulebook. Kudos to Team Parker for sneaking it past. My gripe would be with the censors. I'm sure it was unintended, but the less famous would likely prefer a little less hero worship. As a designer, it would sure make it easier if I didn't need to figure out rear brakes. On the other hand, the other pilots would probably wish that their opponents have the extra safeties in place.... you know, just in case.

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/
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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 02/13/2015 :  04:11:58  Show Profile  Reply with Quote
Speedbiker: Yeah, it looks like they skated around the two brake rules. But who cares? Not me.

Use 2 BBs with trailing cranks/arms on the outsides, then you could use brakes on both or one wheel. Lock? Why bother, these are racer bikes masquerading as trikes.

Tom

Edited by - Tom Schneider on 02/13/2015 04:14:41
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purplepeopledesign
recumbent guru

Canada
683 Posts

Posted - 02/13/2015 :  05:14:51  Show Profile  Reply with Quote
No... this particular mechanism relies on a single pivot to keep the wheels going in opposite directions.

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/
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Runxner
recumbent enthusiast

USA
441 Posts

Posted - 02/13/2015 :  06:33:07  Show Profile  Reply with Quote
The florida btrike (the b be silent) had orphan discs on the rear wheels unlike the photo above. And an orphan rim caliper from the removed single wheel.
I think every racer would enjoy less weight complexity of leaving a 2nd brake off(until they need to stop). But if you're going to be going speeds that allows you to lap other trikes, then yeah you should think about being able to brake at least as well as them.

Team Low-Life
Lowracer Test Pilot/Evangelist
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Speedbiker
human power expert

USA
3749 Posts

Posted - 02/13/2015 :  06:35:33  Show Profile  Reply with Quote
Yeah Tom, go ahead and build that and see how it works. Lots of challenges in that design. I have some ideas I want to try, so I might build one.
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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 02/14/2015 :  04:56:31  Show Profile  Reply with Quote
I did change my original plan of 2 BBs coupled with a differential bolted to the frame acting as a rotation reverser. The 2 crank/arms could then go in the same direction, trailing.
Then brakes could be used, the height would be set and tilting would be the same as a single bb with a regular crank.
Sometimes quick overthinking doesn't work!

Tom
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warren
human power expert

USA
6093 Posts

Posted - 02/14/2015 :  05:27:58  Show Profile  Visit warren's Homepage  Reply with Quote
I'm having trouble conceptualizing that, Tom. Can you post a drawing?
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txusic
recumbent enthusiast

Spain
125 Posts

Posted - 02/14/2015 :  06:45:08  Show Profile  Reply with Quote
to me, one of the best solutions for a tilting delta was the mosquito design... though i love purple's aproach.
As the crank solution, i saw a vid a couple of years ago with some sort of cargobike delta called Ilean.
*its in utube

for a tilting tadpole i allways thought that most, normal steer + tilt were a bit overbuilded and in the heavy side or in need of a complex system to unlock the tilting, also that the only lean freewheel and alan maurer's approaches weren´t valid options for a touring or street desing, only for competition, as you are in need to turn steer from a stop.

In a tadpole, i believed one of the possible best solutions to steer+lean (tilt) passes through the posibility of a pivotal front axis that acts solely on body weight shift. An arm, from wheel to wheel, that enables the outer apex wheel to surpass or adavance the inner curve wheel.
something like dutch TRIPOD design,

The self righting (however that is called), not like the tripod, comes from the linkage. Where both ligatures/joint/conexions, are made in a particular shape that wants to recover to its natural position, 90 degrees to the main boom.
Some kind of diabolo-shaped saddle joint, that acts like a gömböc (a geometrical shape inspired from the self-righting of some asian turtles), with some sort of dampener between both pieces and a springed joint, to force them to come together.
Hence tilting the body: cranks, main boom and back stay (traction wheel), naturally towards the curve (similar to jensen's approach), probably countersteering at first like a bike on a turn, with no need of levers acting or limiting, just body weight.

but that only has worked in my head... I havent got the software nor the hardware to test it and see what happens with the handlebar.

feel free to put it to the test.

Edited by - txusic on 02/14/2015 08:36:19
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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 02/14/2015 :  09:07:29  Show Profile  Reply with Quote
https://lh5.googleusercontent.com/-NHC2XtDPP-I/VN9_Wr7a-qI/AAAAAAAAABk/uMRM32P4O1Y/s219-p/Tilt%2Btrike%2B001.jpg
A quick drawing.

Tom
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