how about a combo PWC & motorcycle?

The Honda Trail bikes are great for trails (which is why they no longer make them), but their power-to-weight ratio is woefully inadequate for what you have in mind. Yes, their one saving grace is the hi/lo transmission, but that is not enough to overcome the weight penalty for floating it. I know, I spent many years on a Trail 90, then a Trail 110.

 

A practicle problem would be how do you come ashore with your amphibian ? Im presently anchored off a yacht " favorite port" ...good holding, protected, great supermarket ashore, hardware store, fun cafes....but...the harbour walls are 1.5 meters high and the surrounding beach geography is rocky, rocky and more rocky with the nearest road set back one kilometer behind a pine forest. Its gonna be tough going

 

I think most harbour do have a ramp for trailerable boats. But it may be not free.

 

Ramp ? Yes and no...none in this harbour. About 2 miles south is a ramp for hauling fishing boats . Remember, when sailing around many of the prime spots are islands. Not many cars

 

Village_Idiot, are you worried about weight/low performace on land or water?

Understand I'm willing to accept almost any Performance Penalty on either land or water, and I'd take what I can get.

Honda 110 is still made in Oz and NZ according to wiki, and its wet weight is just over 200lbs, which includes lots of 1960 era steel body work, and generally burly construction. So I'm guessing the motor/trans/exhaust is around 100lbs of that. Also says "7hp" which seems high and probably "at the brochure" as opposed to "at the rear wheel".

As long as a massively down geared motor/trans can haul the craft(300lbs craft, 200lbs rider for total of 500lbs) up a standard launch ramp fast enough to maintain two-wheel balance I'd be more than happy, and if it can do that it will have plenty of power for flatter water or land.

I do remember seeing a fat man(300+) on a Trail 90 chugging up a steep hill in San Fran, so I figure it is doable once down-geared.

7hp, even via non-optimized water-jet should be plenty for an over-sized stout kayak, and should also be good for "faster than you want" on a recumbent bike/kayak on roads. If the Honda 110 does around 60mph, chop the gearing in half and 30mph is still more than enough.

Having a kayak based(single reasonably narrow) design with two inline wheels might allow for most operators to "walk it" dismounted up steep ramps with motor assist if the motor can't haul the craft and one or two fat riders, I think it should be able to haul a single 200lb rider up 90% of launch ramps.

I think corrosion is a bigger problem, especially when trying to keep costs reasonable. Stainless custom exhaust ain't cheap, but do to the on-going miracle of CAD/CAM things like this are getting cheaper fast.

Cooling is another problem if using an existing air-cooled motor(for cost and simplicity) on a heavier, slower, more shrouded(figure the motor will be 'sunk' into the hull even if exposed to air) application. I like the Vespa Ciao moped with its integrated fan/shroud. I think all old Vespa scooters also have forced fan. I've always wanted a rider operated small electric fan on a aircooled motorcycle, so I don't sweat about cooking engine oil when stuck in traffic.


Another tough problem is suspension, or lack thereof, in a recumbent/kayak hybrid. But since I'd like the wheels to fold into the hull, I guess I'd bite the bullet and add some suspension to take advantage of that Range of Travel. I believe recumbent bikes without rear suspension have seats with quite a bit of suspension, but I'd want my butt at the lowest possible point for stability in water. Maybe a sling across the seat which would be dropped for water-mode. You need something to prevent lower back damage(which often shows up years later-see "Hard tail chopper").

 

Mike, that "about 2 miles" sounds like exactly what I'm talking about!

"Ramp ? Yes and no...none in this harbour. About 2 miles south is a ramp for hauling fishing boats . Remember, when sailing around many of the prime spots are islands. Not many cars"


So I figure if you don't have a berth along that wall you mentioned in a prior thread, or if they want a king's ransom, you anchor out, then you launch your Hybrid Motor-Recumbent-Kayak and motor over to the ramp at about 8 knots and ride up the ramp.

Even if you don't want to or aren't allowed, to cruise around on the roads, at least you can quickly and easily get a couple blocks past the actual ramp/marina area and park and lock your Hybrid around some tree or telephone pole.


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Quote:
Originally Posted by michael pierzga View Post
A practicle problem would be how do you come ashore with your amphibian ?
I think most harbour do have a ramp for trailerable boats. ((((((((((But it may be not free.)))))))))

correct, but at least in USA, they are free for just about anything except backing down a trailer and generally tying up the ramp for a few minutes. In other words they are free for all "hand launch" kayaks, canoes, wind-surfers, etc., even if "hand wheeled" on little dollies. So even though it has a motor, the Hybrid should be able to use ramps for free. The "To pay or not to pay" seems to be based on if what you are doing means someone else, with a tow vehicle and trailer, would need to wait while you are in the way.

 

I thought of something similar but using a mountain bike for muscle power.

The best idea I think is two narrow catamaran hulls with the bike/scooter mounted on a frame at the center line, the rear wheel drives a roller that powers a prop. On shore you remove the cat hulls that then it forms a bike trailer that you pull behind the bike/scooter. A couple of light weight wheels built into the hulls or on the collapsible frame (that hang down below the hulls) become the trailer wheels.

When you drive the contraption up onto a beach or ramp you can easily put your foot down to on the ground between the hull the side of the bike/scooter. With a collapsible frame it would make the whole thing easier to stow on the boat. If you use two plastic kayaks as your cat hulls, than you can also use them as a tender or for local day paddles, with coming covers you use the kayaks as the bike trailer to stow supplies you buy in town. Larger purchases can be strapped to the top of the assembly in trailer mode.

This will allow you use the bike or scooter alone, the kayaks hulls alone, or as an amphibian bike/scooter/trailer, and it can be dismantled and stowed in pieces if need be. You can buy a standard scooter, some cheap plastic kayaks (make sure the displacement is large enough for two people and the scooter and gear), and use some lightweight aluminum square tube to make the frame. the only special item to fabricate is the drive device, and a bit of snooping around will likely find the parts you need to make one up.

 

I like Petros' idea, except I would add the ability to adjust the beam on the cat hulls so you can adjust for stability vs. towing ease, etc.

Squidly, I just think the Trail 110 is woefully underpowered compared to other bikes/powertrains available today. Interesting to know that they still make/sell them in other parts of the world, as old used ones around here will command good prices (sometimes more than they cost new) when in good condition. I think China has made a lot of clone parts for these bikes, including the engine.

 

Dont you think trailering 2 kayaks (even on a light trailer) will severely kill the usability of a bike/scooter in town :?:

 

Squidley, sounds like you are pretty sold on your idea. Here are some issues I have bumped into along the same lines:

1. Vehicle Inspection/Registration, in all major countries you'll need to conform to regulations, they may or may not allow one off or home built vehicles;

2. Insurance will generally be required to operate any motor vehicle on public roads. What insurance company will insure a home built vehicle that appears to be a kayak with wheels?

3. If you stay under say, 49 cc as the drive engine to stay under the issues above, you absolutley will not have enough power to climb any significant grade pulling two people and the contraption with a banana from the store. A 500 cc strugles enough pulling two up on a bike, depending on the weight. That's why I went with a 650cc and it can also pull a small trailer that could also be the frame for the inflatable pontoon system, a 1000 cc would be even better.

4. IMO, due to the restrictions of 1 and 2 above, the way of least resistance is to keep the floation device as a home made water craft that is easily described and conforms to reality along with a motorized vehicle that will pass as a road worthy vehicle.

You could put a kayak on a go-kart, but you'll never use it on any street in the states or europe, you'd have a better chance with floats on an electric wheel chair.

As mentioned above adding a salt water environment in the equation is a real problem, I don't want my Transalp rusting away. I thought using a water proof bag system that would cover the bike might work, but I don't know about condensation issues but it would keep salt out.

I'm not sure if the bars on the big rukus fold in and down,but some bars do. That rukus could easily fo in a bag. If that is your cat you posted, a boom could set the small bike off the boat on a dock.

A 650 dirt bike will climb out of most anything, but not bolders along a rocky shore or quicksand mud or deep sand, just can't put off in such areas. The smaller the engine the more difficult such terrain will be, fat tires or not.

Having skids instead of wheels will effect the approach and departure angle of your machine going over rough terrain or cresting over dips in a roadway, like approaching some RR crossings, depends on how long your outriggers are.

Using that electric bike posted above sounds like a great idea!

Keeping within a realistic budget, the least expensive way to go is a trailer that can be pulled by your land vehicle that is also the frame for inflatable pontoons or boat that your land vehicle can be carried on. Such a contraption would be pretty limited to calm seas, lakes and riverways. When you get ashore, if you don't want to lock your rig to a tree, pack it up and pull the trailer with you. A motorcycle would work well for this arrangement and it could all be registered and insured for each element, for what they are.

If I had the cat pictured above and that Big Rukus, I'd bag it and be on my way, set it off on the dock and wheel it away.

My "thing" was to do the Great Loop and have transportation along the way, giving me the menas to take side trips of hundreds of miles, legally.

 

If the dinghy had an electric motor and the bike had one too, a single battery and controller could be shared to save weight. The battery and controller would then be unplugged from one to be used for the other. The bike could then weigh maybe 50 lbs for easy loading.
A solar panel on the dinghy could assist charging.
I can't see how any other configuration would be practical. At least this way, nothing extraneous would be needed for either boat or bike--- they could each be built for a single purpose at the same cost (except for a few connectors and a small water resistant carry case which would likely be needed to seal the dignhy's electrics anyway.

 

Too late guys ....

http://www.shuttlebike.com/

 

Yet another
http://www.akwakat.co.nz/

 

Agree with Doug...these high level requirements sound like a winner. I would add the following:

-Scooter engine box would need to be water resistant, with exhaust mounted up high so a splash from a wave doesn't gag the intake/exhaust.

-Scooter motor/transmission & fuel mounted as low as possible to keep CG low (better stability & control of water craft).

It will be interesting to see if anyone tries it. The concept would be great for exploring river/lakes & trails. So much for taking the ferry . I don't think such a craft would be rugged enough to take big ocean waves though, unless the scooter/hull mounting & other critical components were corrosion resistant & ready to take a real beating.

 

Forget the scooter, I'm more interested in that gal on the bike