[todayican]

Ok, this idea got its start over at ES but I wanted to post it here as well to get ideas / feedback.

The idea is to build a mostly enclosed recumbent motorcycle capable of highway speeds (70 to 80mph)

Something with a lightweight steel frame, purpose built, room for lots of batteries for a long range version with the "main pack" being carried low in the frame.

The way I have it drawn now it will have room for 172 headways with room for another 172 in an upper compartment.

The plan is to use one of marks motors running at 96 to 108 volts.

Please take a look at my absurdly bad pencil drawing and let me know what you think, with any luck we can get some guys together and build an "open source" solution to going far and fast (and in comfort) on 2 wheels :-)

p.s. photoshop enhancements would be most welcomed :-)

[todayican]

Got the frame started :-)
tshtrikes.com

[john818]

Love your projects! I've been thinking about recumbent motorcycles myself lately. Can't wait to see how this turns out.

One thing I wonder about with your frame is that there seems to be no triangulation under the seat. Is the tube stiff enough? Won't it flex a lot? I don't know. I'm just asking.

[Woodsmith]

Reminds me of the Quasar from the 1970's. I really fancied one of them.

[todayican]

Ill do some triangulated cross members under the seat and forward frame.

Curious, if this bike were sitting on the pavement today, and had a top speed of 100mph with a 200 mile range, what would it fetch?

[kek_63]

Well, I know, It would fetch a couple of big speeding tickets for me

[sunworksco]

Originally Posted by todayican

Ok, this idea got its start over at ES but I wanted to post it here as well to get ideas / feedback.

The idea is to build a mostly enclosed recumbent motorcycle capable of highway speeds (70 to 80mph)

Something with a lightweight steel frame, purpose built, room for lots of batteries for a long range version with the "main pack" being carried low in the frame.

The way I have it drawn now it will have room for 172 headways with room for another 172 in an upper compartment.

The plan is to use one of marks motors running at 96 to 108 volts.

Please take a look at my absurdly bad pencil drawing and let me know what you think, with any luck we can get some guys together and build an "open source" solution to going far and fast (and in comfort) on 2 wheels :-)

p.s. photoshop enhancements would be most welcomed :-)

Here u go.

[samborambo]

Originally Posted by todayican

Ok, this idea got its start over at ES but I wanted to post it here as well to get ideas / feedback.

The idea is to build a mostly enclosed recumbent motorcycle capable of highway speeds (70 to 80mph)

Something with a lightweight steel frame, purpose built, room for lots of batteries for a long range version with the "main pack" being carried low in the frame.

The way I have it drawn now it will have room for 172 headways with room for another 172 in an upper compartment.

The plan is to use one of marks motors running at 96 to 108 volts.

Please take a look at my absurdly bad pencil drawing and let me know what you think, with any luck we can get some guys together and build an "open source" solution to going far and fast (and in comfort) on 2 wheels :-)

p.s. photoshop enhancements would be most welcomed :-)

Motorcycles generally have a pitiful drag coefficient. Your recumbent idea and the extra cowling do help mitigate the frontal area and aspect ratio of the bike by putting the rider "in" the frame. However, that cowling creates a serious problem in strong cross winds. It'll turn the bike into a kite! I discovered this when researching an electric motorcycle conversion a while back and trying to mitigate drag.

eg: Have you ever seen the movie "World's Fastest Indian"? That bike's cowling was perfect for straight line time trials/top speed on a calm day but if it hit a strong cross wind it would topple immediately.

Sam.

[sunworksco]

A bike that has a low center center of gravity with the weight of the components and driver low will not be affected by wind.The "The Fastest Indian" was a little top heavy.

[TomA]

I like the bike, its a great effort.

Your biggest problem is going to be the practical issue of what you do when you stop. Craig Vetter's enclosed Helix has doors where he can stick out his feet to hold the bike up. If you put the rider's feet inside the body work, you'll either have to do that or make an outrigger setup that can be deployed at stoplights, etc.

Additionally, this bike doesn't seem to have a very low cg, and with all that battery mass up front and high, the steering may be very dicey. My experience is limited to bicycle frames, but you should look carefully at the rake and trail you really want before you mount the new Honda head tube. You could also see how much of the battery weight you can get *under* the lower frame tubes to lower the cg. I disagree that just because your cg is low, crosswinds won't affect you, but yours isn't going to be low anyway, so unwanted aero forces are likely to be substantial.

There is indeed a structural weakness problem with the upper shock unit pickup creating a bending force likely to crack the seat back bottom welds, or otherwise cause trouble, as John818 pointed out. This area is going to be difficult to triangulate, or even gusset, but you need something there unless you go to a monoshock swing arm that loads the frame directly and not the seat back.

Lastly, and I'm no Joan Claybrook, but I have to say this one kind of scares me. It looks like it will have squirrely handling. More than that, if you lay it down, a major leg crush injury is going to be all-too-easy to sustain. I would think about adding some tube structure outboard of the lower frame rail so that the rider's legs won't be between the frame and the ground if it were to topple. I know, we don't build them to crash them, but as it is, a simple driveway tipover could lead to a big-time injury. I'm also a little spooked about the rider's relationship and proximity to the vertical battery framing, (what is going to bang into what?) but a seat belt and helmet would likely solve that. Don't get me wrong, I love this thing, but the older I get the more conservatively I look at safety and failure modes...

Having said all that, man, its cool. I'm anxious to see it running with Mark's motor, because I think this bike will be a little over his recommended 400lb weight rating. Since I'm bouncing around the same weight with my trike, your experience will really help me with getting operational data points at this weight. This bike will be a great test bed for the EnerTrac hub motor. Great job so far!

TomA