They don't show you much in the high-speed twistees for a reason. That backend breaks out too easy. Without leaning, the front has to much grip for the rearend.
I'm just guessing, of coarse.
I'm sure it's a great fun ride, just not the "cornering racecar" they are portraying.
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04:15 AM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
OK. So I've found the platform and have the idea in my head for modification.
The basic design will be lifted from a "SportCycle" seen below but honestly, the awkward looking body on these things just ruins it for me:
but if we take a look at one without its "skin", you can see the potential. Hell, I think this one looks flat-out SEXY just like that, (kinda reminds me of the Ariel Atom) why ruin it with a stupid looking body? But hey, that's just me...
ANYWAY, You can see at this incomplete stage its RIPE for the modifications I have in mind:
- don't bother with a floorboard - create a mount for a chopper-style saddle (obviously higher off the ground then where the Sportcycle designer intended, probably about as high as where the higher square tubing sits in the above pic) - Raise the steering column height, axe the steering wheel and fit with handle bars - don't bother with an automotive 3-pedal system, keep the bike controls
[This message has been edited by OKflyboy (edited 03-21-2008).]
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11:05 PM
lurker Member
Posts: 12353 From: salisbury nc usa Registered: Feb 2002
what are the respective merits of the two wheels in front vs in back? i have a little project in mind for 3-4-5 years down the line, and it may move in the trike direction for simplicity's and lightness' sake, but not if it means sacrificing stability or control.
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11:43 PM
Mar 21st, 2008
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
what are the respective merits of the two wheels in front vs in back? i have a little project in mind for 3-4-5 years down the line, and it may move in the trike direction for simplicity's and lightness' sake, but not if it means sacrificing stability or control.
If you've got some time to read, here's a great article about 3-wheeled vehicle handling characteristics:
I still dont see why people build the reverse trikes... they are kind of cool, but I would think 4 wheels would be better for handling... unless it is still like a bike and you can still lean in turns...
I'd rather build something with 4 wheels and a cage myself, kind of how they build a dune buggy... but for on-road instead (go-kart on steriods)
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09:31 AM
PFF
System Bot
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
I still dont see why people build the reverse trikes... they are kind of cool, but I would think 4 wheels would be better for handling... unless it is still like a bike and you can still lean in turns...
I'd rather build something with 4 wheels and a cage myself, kind of how they build a dune buggy... but for on-road instead (go-kart on steriods)
There's several reasons to build a RT vs. a four wheeled car.
1) A properly designed Reverse Trike will OUTHANDLE just about anything on the road.
Read the link I provided lurker about 3-wheeled handling.
2) Most RTs keeps the motorcycle almost intact. This means you have the motor, transmission, fuel tank, all electronics (blinkers, etc), drivewheel, all ready in a neat little package.
3) A RT can keep the motorcycle registration. SCV (Specially Constructed Vehicle) tags are a b?tch to get, and the vehicles themselves are a b?tch to insure once you get the tag.
4) They're a relatively small investment. Most of the RTs I've seen and wanted were built with less than $10K
5) They're just plain radical looking, and many people (myself included) like the weird looking stuff.
[This message has been edited by OKflyboy (edited 03-21-2008).]
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10:44 AM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
The T42 turbo trike design. It is a trike based on a suzuki GSX-R 1000 -01 motorcycle that I have built a turbokit to. The engine power is 280hp, and it weighs 460kg = 600hp/tone!! Type of vehicle: Threewheeled motorcycle with body. Engine: Suzuki GSX-R 1000 -01 TURBO. Dimentions: Total length: 445cm. Weight: 460kg with fuel and no driver. Total width: 217cm. Wheelbase: 312cm. Hight: 110cm. Engine power: 280bhp, ~190nm. Front Suspension: Öhlins shockabsorbers, Pushrod. RC: at 100mm. = 25% antiroll. Rear Suspension: Rebuilt Suzuki absorber. Turnradius: 13,7m. Steering: 1,9 turns (side-side). Maximal lateral acc: 1,55G (before tipping over). Passengers: 2. Performance: 25km/h - 200km/h= 9sek.(driver + passenger and wheelspin to 180km/h ). Topspeed: 300km/h. Seats: TILLETT racing T250 seats. Airodynamics: AirForce racing rear wing- Gives upto 186kg DF (down force) at 300km/h.
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01:08 PM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
2003 Car and Driver article about the Sportcycle (back when they were selling kits, and calling it the Indycycle. Now they sell plans and a few parts, but no longer kits.)
If you really want the ability to turn fast, You'd get more bracing with the sit in kind vs the bike type. You would have to do alot of counterbalancing to physically turn the Trirod, especially thru multiple twisties, at over 1g.
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04:07 AM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
THIS is more along the lines of what I would like, different engine and more open bodywork though:
http://www.blackjackzero.com/mainindex.htm Light, compact and reduced to essentials the Zero evokes the purposefulness of a big bike, a fighter plane or sports racing car. Its character and individuality leave in no doubt that its form has been dictated by function.
Its HAMMERHEAD layout puts the drive, the power, a large proportion of the weight and roll stiffness at the front where it belongs. Single rear wheel drive trikes too often display alarming characteristics where the rear threatens and can overwhelm in a variety of ways.
With the Zero, the planted bit of the car does the work, the rear trails obediently and faithfully contributing the least possible weight and an absolute minimum of roll effect and weight transference from the rear. Result; an ultra compact car that is instantly responsive, lightly loaded and tremendously quick as it unlocks the maximum potential of its comparatively modest powerplant.
[This message has been edited by Gokart Mozart (edited 03-22-2008).]
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04:32 AM
craigsfiero2007 Member
Posts: 3979 From: Livermore, ME Registered: Aug 2007
I think I'd have to drive one before I believed the handling.... just doesnt seem like it would handle that well having all the support up front for turning.. now if it were to lean into the turn that would be different.
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08:35 AM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
If you really want the ability to turn fast, You'd get more bracing with the sit in kind vs the bike type. You would have to do alot of counterbalancing to physically turn the Trirod, especially thru multiple twisties, at over 1g.
That's very true, and something I had been pondering myself. I'm thinking with a Chopper-modified Sportcycle high-G cornering wouldn't be as much of a concern. Granted I would still want something that's not going to tip over at the drop of the hat... Another thing I've learned after studying the Sportcycle over the past couple of days is that the Sportcycle is a very well thought out vehicle. The designer, Jim Musser, didn't just weld some stuff together and call it a trike. I'm wondering about the viability of modifying this design to suit my purposes after all. What I've found is that I really like my design idea but I also really like the Sportcycle. I''m going to go forward but if in my calculations I cannot make the Chopper-mods the way I had intended I will probably just go ahead and make a Sportcycle (minus the stupid looking body...)
[This message has been edited by OKflyboy (edited 03-22-2008).]
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09:21 AM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
The Zero is a fine machine. I've developed a real fascination with all RTs over the past few years. However, it's just not what I want to build. I'm trying to stick with a design that keeps the motorcycle chassis more or less intact. I don't mind welding a bit here or there, but I'm really hoping to keep the mechanical fabrication to a minimum.
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09:24 AM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
I think I'd have to drive one before I believed the handling.... just doesnt seem like it would handle that well having all the support up front for turning.. now if it were to lean into the turn that would be different.
I understand you skepticism. Trikes have a real nasty reputation, some of it deserved. But most of those that deserved it were also very poorly designed.
To quote Robert Q. Riley:
quote
A conventional, non-tilting three wheel car can equal the rollover resistance of a four wheel car, provided the location of the center-of-gravity (cg) is low and near the side-by-side wheels. Like a four wheel vehicle, a three-wheeler's margin of safety against rollover is determined by its L/H ratio, or the half-tread (L) in relation to the cg height (H). Unlike a four-wheeler, however, a three-wheeler's half-tread is determined by the relationship between the actual tread (distance between the side-by-side wheels) and the longitudinal location of the cg, which translates into an "effective" half-tread. The effective half-tread can be increased by placing the side-by-side wheels farther apart, by locating the cg closer to the side-by-side wheels, and to a lesser degree by increasing the wheelbase. Rollover resistance increases when the effective half-tread is increased and when the cg lowered, both of which increase the L/H ratio.
So there's more to it then putting a couple of wheels in front of a motorcycle, or putting a "trike kit" (turns the single rear wheel into two) on a Goldwing and expecting it to react the same is if it was still a motorcycle. There's a lot of planning that goes into properly designing a RT.
[This message has been edited by OKflyboy (edited 03-22-2008).]
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09:30 AM
PFF
System Bot
avengador1 Member
Posts: 35468 From: Orlando, Florida Registered: Oct 2001
A T-Rex started it all for me. Saw a T-Rex once a few years back, said "What the hell was THAT?" Went home, googled, found out about RTs, and have been hooked since.
[This message has been edited by OKflyboy (edited 03-22-2008).]
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02:21 PM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
If you didn't live in the middle of OK I'd say go for a test ride on a Can Am Spyder but the closest dealer is in CO. Do you plan on coming to the 25th show?
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02:32 PM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
If you didn't live in the middle of OK I'd say go for a test ride on a Can Am Spyder but the closest dealer is in CO. Do you plan on coming to the 25th show?
Unfortunately no on the 25th. I love the Spyder too, but again, not what I want (sensing a theme? LOL)
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02:34 PM
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
So there's more to it then putting a couple of wheels in front of a motorcycle, or putting a "trike kit" (turns the single rear wheel into two) on a Goldwing and expecting it to react the same is if it was still a motorcycle. There's a lot of planning that goes into properly designing a RT.
Wish I could quote your whole post. With the engine hanging in front, the wheelbase won't have to be long. Also the weight is more by the side by side wheels. When the trike has seating for 2, the width of the wheels is normally wider. FWD does have problems but with what we know about it, it might be a more understanding and forgiving powerdrive.
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02:42 PM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
Wish I could quote your whole post. With the engine hanging in front, the wheelbase won't have to be long. Also the weight is more by the side by side wheels. When the trike has seating for 2, the width of the wheels is normally wider. FWD does have problems but with what we know about it, it might be a more understanding and forgiving powerdrive.
Oh, I'm not disputing the benefits as much as the styling, superficial though it may sound, I just don't really like the way they look... That and the mechanical aspect, I like the idea of being able to leave to motorcycle chassis intact, and the extent of the fabrication being lengthening control cables and such...
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02:47 PM
Apr 13th, 2008
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
Had Jury duty last week then lost my job Thursday so things are a bit hectic 'round these parts but I'm about ready to start to collecting parts and tools.
I have officially decided to bench my design changes and build the Sportcycle as designed (minus the silly looking body). I still think my ideas have merit, but I'd rather have a successful build under my belt before I start changing things.
Tool-wise, I need to buy a welder, drill press and chop saw.
Then I'm going to buy the needed steel plus a bit extra to play with. There's no welding classes available right now, but my brother's a decent welder and has convinced me that with his guidance I could pick up MIG quickly enough on my own and probably don't need a class.
There are several expensive parts needed, the steering knuckles are about $500 for the pair, the Wilwood brakes and hubs are about another $500 and of course there's the donor bike which will be a grand minimum so there's going to be a lot of saving between buying each of the major parts.
my "motivational" poster -
[This message has been edited by OKflyboy (edited 04-13-2008).]
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08:16 PM
lurker Member
Posts: 12353 From: salisbury nc usa Registered: Feb 2002
In 2003 Car and Driver wrote a review about the Sportcycle (back when they were selling kits, and calling it the Indycycle. Now they sell plans and a few parts, but no longer kits.)
Again, my first version will be different only in that it will have the fibergalss body eliminated (simply because I think it looks stupid). The second version? Don't know yet. The changes will definitely be on paper first, but I feel I need something tangible to put my hands (and a tape measure) on first before I'm ready to start putting it on paper. Not to mention I may build the first one and love it so much that I don't want to change it...
[This message has been edited by OKflyboy (edited 04-13-2008).]
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08:40 PM
Apr 14th, 2008
Gokart Mozart Member
Posts: 12143 From: Metro Detroit Registered: Mar 2003
You can say what you like, and choose to believe whatever you like, it's your hind-end.
That kind of tail-dragger configuration is inherintly unstable.
Ahh, but I don't need to "believe what I want", I have science to back me up...
My understanding of ground loops as they pertain to aircraft (having an electronics background I immediately thought of something else) is they occur when the center of gravity is placed too high and too far aft of the forward landing gear.
As I've already stated above, the key to keeping a reverse trike stable is to place the center of gravity as low and as close to the front wheels as possible. If this were to be ignored, then I suppose a "ground loop" would be possible. But then I thought I'd already mentioned that this particular RT had been designed with its CG such to avoid that situation.
[This message has been edited by OKflyboy (edited 04-14-2008).]
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09:52 AM
OKflyboy Member
Posts: 6607 From: Not too far from Mexico Registered: Nov 2004
Actually, I've been following it for over a month, he's dropped the price 2 times now. I had planned on looking at it, till I lost my job last week. Then I read this:
I would not pay any more than $50 for this bike. I took a look at it and there is way more wrong than specified. Ignition switch broken. No key so you can't open fuel tank. Wiring hacked up. Carbs hanging off of it. Way to much work is needed on this bike. He says great compression but I can crank the engine over by hand. There is just way to much wrong with it. One carb boot is ripped and the beather box is gone. SIde covers are missing.
1986 Suzuki gsxr 750 needs work runs but has not got it started in a couple of days. Great project bike for first line of sport bikes lovers.. Yoshimira pipe, been down before. Like I said great project bike..$700.00 OBO/Will trade for a 78-80's cruiser!!
[This message has been edited by OKflyboy (edited 04-14-2008).]
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09:54 AM
Jul 21st, 2008
RACE Member
Posts: 4842 From: Des Moines IA Registered: Dec 2002
OKflyboy, are you still going to build this? Any updates?
Thanks for reminding me! The loss of my previous job then a brief unemployment spell forced my money to other priorities. Back on track job-wise though. Still hoping to build soon.
[This message has been edited by OKflyboy (edited 07-21-2008).]
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05:27 PM
nmw75 Member
Posts: 1676 From: Mc Falls, Maine Registered: Mar 2007