FJ1300RT Reverse Trike Concept

noland said:

nofreeride,

I like your second CAD version better. Have you calculated the weight distribution F/R, and weight as taken at each wheel? I wonder if nitrotate has done this as well? In his video, the wheel spin is crazy! (Granted - no CT yet and he does have a wing). You mention power to weight ratio. In the car world, the Ariel Atom has been the recognized standard in this type. (They have a spec page that tracks power to weight and performance). I guess what I'm getting at is that has anyone considered how to best lay that power down? IDK. Thoughts?

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Thanks for the comments.

I am going off of the last design shown in the post, the blue and silver car. It has and will change slightly as the build progresses (I have already added 6" of legroom to the cockpit over what the design had). I am updating my drawings as I go so as to hopefully have an accurate set of plans when I am done.

I do not know what the final weight distribution will be, nor do I know exactly how much it will weigh. I designed it with the weight as far forward as possible, within the constraints I had to work with (side by side seating, legroom, firewall behind the suspension).

For a reverse trike, stability is achieved through a wide front track, low cg, and long wheelbase, along with forward weight distribution. Without fancy interference measures (like the CanAm) sliding before rolling over needs to be part of the design.

Performance is secondary for me. If I wanted to compete with the Ariel Atom, I would have made it with 4 wheels, a shorter wheelbase, and a rear-mounted FWD drivetrain. That said, I don't expect it to be a slouch!

Less weight on the rear and a single, narrow rear tire is admittedly not optimal. For max performance in a reverse trike, we would probably be looking at driving the front wheels instead.

GalaxyBlue said:

Would be interesting to see this in reality.

I would think a Busa would make a better platform for this though.

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The FJR does have an advantage as a platform, what with shaft drive.

I remember way back in the day, when I used to hang out on some hot-rod forums, a guy was thinking of making a standard-layout trike, and was wondering what motors, other than goldwings, he could get with shaft drive...

The main thing I can think of, with the reverse trike layout, is that the shaft drive should be capable of handling the higher power requirements of the heavier vehicle with less wear. Now, I'm sure someone is going to read that and say, "but the Busa makes 1.21 gigawatts, and its chain doesn't break". Well, the busa does make a lot of power, (though the torque is basically the same, FJR and Busa both produce right around 100 ft lbs) but the tire limits how much you can get to the ground. I mean, think of it like this: if you rev the busa up to peak torque, then let the clutch out with any sort of rapidity, what happens? Either a burnout or a wheelie.

If you put a car tire on, that has 5x as much contact patch, on a reverse trike, I would expect a burnout, but you'll be overcoming a lot more grip (and thus putting a lot more load) on that chain before you do.

I believe that the T-rex has a very heavy duty chain, and (from what I've read on the tubes) even then it wears out chains and sprockets faster than a normal bike.

I'm certainly interested in this. If I saw a sweat deal on a front-wrecked FJR, I'd give serious thought to it (and then the reality that I haven't the time or money to invest in it would reign me in).

I've been following this project with interest! I think the FJR - esp an AE version - makes a good base for this for many reasons.

I have a Q tho; I looked and don't see it, but maybe the answer is obvious. In your mockup pic, you show the basic from platform/suspension/seat, and the FJR sans frontend on a little dolly behind. Are you going to keep the FJR in that configuration and just figure a way to attach it? Maybe by anchoring through the neck and another couple of points to secure it?

That would make sense really as you keep the packaging, wiring, systems etc all intact in the original frame. What about airflow the the radiator?

Cool project, I gotta say! You got me thinking.............

fljab said:

Are you going to keep the FJR in that configuration and just figure a way to attach it? Maybe by anchoring through the neck and another couple of points to secure it? ... What about airflow the the radiator?

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Yes, the plan is to attach the motorcycle to the frame in several places. Stay tuned to see exactly how that goes. Air flow will be ducted to the radiator from below the floorpan.

nofreeride said:

fljab said:

Are you going to keep the FJR in that configuration and just figure a way to attach it? Maybe by anchoring through the neck and another couple of points to secure it? ... What about airflow the the radiator?

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Yes, the plan is to attach the motorcycle to the frame in several places. Stay tuned to see exactly how that goes. Air flow will be ducted to the radiator from below the floorpan.

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Staying tuned Aye............

Sweet man I just saw this so you got started huh? Congrats! Did you notice in my thread that I did finally measure my wheelbase and weight it etc. etc.?

We talked a week or two ago about ideas for reverse... I finally finished up my first prototype and tried it out and I don't think it's going to work...

We need to talk again so maybe I can help you avoid wasting time on the same idea I just tried (of course unless I do find a way to get it to work...still trying.).

Tate

Nitrotate said:

Sweet man I just saw this so you got started huh? Congrats! Did you notice in my thread that I did finally measure my wheelbase and weight it etc. etc.?

We talked a week or two ago about ideas for reverse... I finally finished up my first prototype and tried it out and I don't think it's going to work...

We need to talk again so maybe I can help you avoid wasting time on the same idea I just tried (of course unless I do find a way to get it to work...still trying.).

Tate

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Yep, got the roll bar and several other tubes tacked in, including the front fork tube mount. Will take pictures and post as soon as I have it mounted and free-standing.

I'm a long way from working on the reverse so I'll let you figure it out first .

You know it's funny but for the past year during my entire build project I've managed to overcome any challenges and brain teasers on my trike except for how to do "reverse"!! :blink:

Reverse has had me completely stumped! Finally I came up with an idea and it was actually looking really cool but then the motor just couldn't cut it so I'm back to the drawing board...

Either way I'll be sure to keep you updated on what I come up with so you'll have a good valid option when you get to that point.

Don't give up on your project! Keep it up an when you are done we'll meet up and ride someday! We're only 3 states away... :lol:

Nitrotate said:

...I've managed to overcome any challenges and brain teasers on my trike except for how to do "reverse"!! :blink:

Reverse has had me completely stumped! Finally I came up with an idea and it was actually looking really cool but then the motor just couldn't cut it so I'm back to the drawing board...

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I dunno why this came to mind right away for reverse:



Sorry, not much help :lol:

LOL, not with 1200 pounds uphill...!

Sure! You can clearly see that they both have their feet out helping. That ought to be enough!

Yes, a trap door in the floorboards would work for smooth level surfaces. Actually, I was thinking along the lines of a winch motor engaging the rear wheel or the ground for reverse. Any other ideas?

nofreeride said:

Yes, a trap door in the floorboards would work for smooth level surfaces. Actually, I was thinking along the lines of a winch motor engaging the rear wheel or the ground for reverse. Any other ideas?

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That is what I tried a couple days ago and it was a no-go. I'll get some pictures and post it so you can see. Backing it up on a flat level surface is not my worry, my trike actually rolls really easy and I could just push it back no problem but the minute you try to push it up any kind of incline (ie. angled parking downtown) you're screwed.

I used a cheapo electric winch motor from Harbor Freight and took the guts out and set it up so that the actual gear teeth drop down on the back wheel and roll it. It worked on level ground but would bog down and stop when I tried to go up my driveway slope. I'll set it back up again tonight and do it again on video and show you...

Nitrotate said:

I used a cheapo electric winch motor from Harbor Freight and took the guts out and set it up so that the actual gear teeth drop down on the back wheel and roll it. It worked on level ground but would bog down and stop when I tried to go up my driveway slope. I'll set it back up again tonight and do it again on video and show you...

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Looking forward to it. No way to add lower gearing? I guess if you're using the teeth of the winch on the rear tire that's the most gearing you'll get without adding complexity.

nofreeride said:

Nitrotate said:

I used a cheapo electric winch motor from Harbor Freight and took the guts out and set it up so that the actual gear teeth drop down on the back wheel and roll it. It worked on level ground but would bog down and stop when I tried to go up my driveway slope. I'll set it back up again tonight and do it again on video and show you...

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Looking forward to it. No way to add lower gearing? I guess if you're using the teeth of the winch on the rear tire that's the most gearing you'll get without adding complexity.

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Correct, because I have to tuck that whole assembly up under the tail, I had to cut through the plastic to be able to raise it up high enough. It actually looks and operates up and down really cool but just doesn't move the bike strong enough.

Nitrotate said:

Reverse has had me completely stumped! <snip>

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Two things you might want to look at for ideas; both use electric motors I believe.

> Sidecars will use electric motors the sidecar wheel for reverse. I remember seeing it as an option in the HD catalog some time back.

> Gold Wings offer reverse; don't they use an electric motor as well? Might be worth seeing how they do it.

Either way, I think the idea is to use electric on either the driven wheel if you can figure out how to do it. or one of the fronts ala the side car idea...

Just a thought!

Yeah I have seen those but not sure they'll work. I'll keep playing around and see what I can come up with either on the front or rear. Hope we're not jackin' your thread much nofreeride...

Nitrotate said:

Yeah I have seen those but not sure they'll work. I'll keep playing around and see what I can come up with either on the front or rear. Hope we're not jackin' your thread much nofreeride...

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It very much applies to my project. If anything, I'm hijacking yours, no?

Would a high torque starter motor do the job? I'm not sure of the specs of the winch motor, but it seems like a starter turns a heavy motor via small teeth on a large flywheel, so it could be made to work?

Yeah I imagine so. I also have the ability to get a motor from my work. I work for a large GPS company and we produce equipment for construction vehicles so I'm going to talk to my buddy who's an engineer upstairs and see if he has an old one, maybe that will work.

Reverse gear on a shaft drive bike is especially problematic, as you'se guys are finding out. Chain drive bikes offer the option of driving the chain with a third gear that is engaged only for reverse. The OldWing had the advantage of the designing engineers being able to design it into the starter gear assembly, internal to the engine.

I'll add some words, you guys will have to see if they contain any fragments of an idea.

Your challenge in using a small motor like a starter motor will be to find gear multiplication between the motor and wheel, either a gear interface to a wheel or very good friction drive to the ground or tire plus, perhaps motor speed control.

Late model cars, especially the Corvette have very strong starter motors. I keep thinking about the ABS tooth gear on the rear wheel. Dunno if you could access that directly for a starter motor, add a small belt drive or as a place where you could install your own gear interface in place of the ABS tooth ring.

You may want to swing by McMaster-Carr, Graingers or MFC and look up conveyor rollers, drive rollers, friction wheels, etc and do a little imagineering. You may see something that will turn on the light.