LWB recumbent for long trips.

[BalorNG]

Rear disk wheel on a reclined lowracer *already* serve as a kind of rear fairing (splitter plate), and you'll need a VERY effective design to top it.

Here is a project for a reclined lowracer:

http://www.recumbents.com/wisil/misc/nocom/tb/default.htm

Notice how it turned out 'not worth it' in the end. OTOH, it did *work* (just not enough to warrant using it), and can be a good *cargo* box for a touring setup.

And btw, on a less extreme (titanium, very flexy too) lowracer I've managed to cruise at 40kmh quite easily on about 230 or so watts. They are VERY aero, but it comes with a price of low vision/visibility.

 

[ZeroEm]

That's good news about the tail. 45 kph is the goal on open roads so just a rear wheel disc would do. Would like a low racer, just not practical for me.

Not trying to get record low watts. Just want something that rides well, can carry a large battery. Don't want to peddle like Tour de France. Like the long recumbents but want to lay back more, without my head over the back axel and feet behind the front wheel 26"-29".

I know this will put me up like a high racer. Want to try bigger wheels and no suspension. Think the roads are not to bad here.

 

[Warren]

Check out this neat LWB lowracer.

https://g4bikes.com/

 

[BalorNG]

Check out this neat LWB lowracer.

https://g4bikes.com/

I'm familliar with the concept
It's a solid 'midracer' though - seat at the level of axles. Yea, I want something like this.
Problem is, his idea of a good handling does not mesh well with my experience - 60deg steering angle with zero offset means a ton of flop, and I hate floppy geometries.
While I like this idea, I think his implementation is build around a concept that is overrated (boom swinging adding arm power) and constrained by what is *patentable*, not truly optimal regarding handling given prior art in public access.
Of course, you can learn to ride pretty much anything given time and effort, but I'd much prefer steep angles myself, and 10 year old work regarding coaxial MBBs (steering angle of about 65 deg, considerable positive offset) strikes me as a much better implementation - but, of course, cannot be 'patented' because it's already public...

 

[ZeroEm]

I like anything that gets away from 20" wheels. Looks like a road bike and not a Baha off road model. No room for gear. At least it is a little different.

 

[The Toecutter]

Check out this neat LWB lowracer.

https://g4bikes.com/

Neat. It could use suspension though...

 

[BalorNG]

Check out this neat LWB lowracer.

https://g4bikes.com/

Neat. It could use suspension though...

Yea, certainly rear suspension at least. I think my Dreadnought is one of the very rare FWD-MBB fully suspended bikes .

 

[Warren]

I think my Dreadnought is one of the very rare FWD-MBB fully suspended bikes .

That is very nice! I love vertical, or even negative rake bikes. Built a few. Even a rowing bike.





Love Frank Bokhorst's bikes from years ago.

http://tilting.org.za/bok/fwd.html

http://tilting.org.za/bok/pedelec.html

http://tilting.org.za/bok/hpv.html

 

[BalorNG]

Love Frank Bokhorst's bikes from years ago.

Yup, his site was one of my inspirations too! Turned out pretty damn well, but still don't really work for truly 'ultra' distances unfortunately...

 

[BalorNG]

More laser cut parts are in, an other 40$ sensored e-board motor installed as a crankdrive, should provide a ton of torque from a stop:

I'll replace 3d printed standoff with an aluminium one later, will provide more heat shedding capacity for the motor.
Massively stiffens thin aluminium plate as of now for little additional weight...

36x reduction compared to 9x one!
Nearly 4 times the torque in lowest gear, quite comparable to 'factory' crankdrives (nearly 100 NM peak, provided the belt does not skip)

 

[BalorNG]

An other advantage - I now have a entire 'front triangle' free to play with - one of huge bikepacking bags will be ideal.

 

[99t4]

Custom-made pedals?

 

[BalorNG]

Custom-made pedals?

Yup. I have bad feet, that gives me a choice between very stiff and quite unwalkable carbon clipless pedals, or custom pedals and walkable shoes, otherwise my feet hurt a lot. I much prefer latter.

 

[99t4]

Very good. Understand completely.

 

[BalorNG]

Shaft support. Standoffs are being 'tempered' in the oven

 

[BalorNG]

Burying the spider *inside* the pulley for no bending lever.

 

[mxlemming]

What made you decide to have such a big spider and such a thin 3D print? Surely you could save cost by just filling in the middle of the print? Probably actually get more resistance against buckling as well since it would be much wider.

This contraption is so complicated. How long did it take you to design and make this bike? How do you get the time?

 

[BalorNG]

What made you decide to have such a big spider and such a thin 3D print? Surely you could save cost by just filling in the middle of the print? Probably actually get more resistance against buckling as well since it would be much wider.

This contraption is so complicated. How long did it take you to design and make this bike? How do you get the time?

Well, my buddy does some for me at a considerable discount, so I though I'd better not waste good filament... likely an overkill, right.
It does take considerable time and effort (it is almost 2 years now actually, doing it 'on and off' of course).
But well, I have other bikes and unfortunately I no longer find 'just riding' them particularly enjoyable - unlike building stuff and solving optimisation puzzles. Not my choice, but I didn't get any unfortunately... motorcycles do not entice me either, at least for now.

Of course you can always do just 'freaky stuff' like a lot of people do, but I find poking around in Escherian corners of design space for *practical* solutions particularly rewarding. I'm a software, not a mechanical engineer, so this is strictly a hobby for me though.

 

[mxlemming]

Filament is cheap. About 25$ a kilo. Buy your buddy some rolls and save the steel 8)

It's strange how we gravitate towards the bits we don't do for a job. I'm a mechanical engineer and spend most of my days chasing a mouse around solidworks, so when I made my bike it was literally the bare minimum possible to get a motor to power the rear wheel... The rest of the countless hours I've spent designing a controller and programming it.

I cackled away when I saw you'd used stems to connect your tubes. It's like "from AliExpress import stem as joint"

 

[BalorNG]

Filament is cheap. About 25$ a kilo. Buy your buddy some rolls and save the steel 8)

It's strange how we gravitate towards the bits we don't do for a job. I'm a mechanical engineer and spend most of my days chasing a mouse around solidworks, so when I made my bike it was literally the bare minimum possible to get a motor to power the rear wheel... The rest of the countless hours I've spent designing a controller and programming it.

I cackled away when I saw you'd used stems to connect your tubes. It's like "from AliExpress import stem as joint"

It's aluminium...
And yea, one needs some variety in one's life or you go crazy(er).
Using stems (because they are dirt cheap 4-5$ a piece) as 'lugs' makes a lot of sense for a no-weld bike, they are heavy but quite strong enough.
If you think that my 'contraption' is complex, see this:

https://www.youtube.com/watch?v=6XMgaXtYjJ0

 

[ZeroEm]

I'm one that is glad you are experimenting and sharing. Like to build myself but like riding more. Nothing they sell fits my needs, they are close but built to serve the masses, not the people that are on the edges. Build on! 8)

 

[BalorNG]

I'm one that is glad you are experimenting and sharing. Like to build myself but like riding more. Nothing they sell fits my needs, they are close but built to serve the masses, not the people that are on the edges. Build on! 8)

Yea, my case is pretty 'edgy' to say the least
An obese ultracyclist, ehehe. After many years of cycling just 'riding around' is just plain not interesting, but I desperately need the exercise AND I like going to far places still.
Hence the recumbents and now e-assist. I have hopes of losing weight and going 'pure human' again, but that's a different sort of challenge.

 

[ZeroEm]

I can not stand or sit for too long. Lower back issues. Spend most of my time in bed, hence why i'm on here so much. Riding is healthy, tried traditional biking but limited to just a couple of miles so went recumbent. Then the next issue is how much pressure can put on my back by peddling. Flat ground 15mph is ok, hills and higher speed causes pain. Just riding and moderate pressure on the peddles for hours burns a lot of energy and is doable.

Same old trails do get boring that is why my trike is set up to go as far as my body can stay on the trike. This is one reason peddle by wire is enticing to me. Could limit how much pressure on the peddles could be applied and I could peddle away and not worry about it. Could just turn down the resistance if it causes pain later.

So carry on, you have a fan. Prototypes are test beds.

by BalorNG » Oct 01 2021 5:50am

wrote: ↑Sep 30 2021 3:36pm
I'm one that is glad you are experimenting and sharing. Like to build myself but like riding more. Nothing they sell fits my needs, they are close but built to serve the masses, not the people that are on the edges. Build on! 8)

Yea, my case is pretty 'edgy' to say the least
An obese ultracyclist, ehehe. After many years of cycling just 'riding around' is just plain not interesting, but I desperately need the exercise AND I like going to far places still.
Hence the recumbents and now e-assist. I have hopes of losing weight and going 'pure human' again, but that's a different sort of challenge.

 

[BalorNG]

I can not stand or sit for too long. Lower back issues. Spend most of my time in bed, hence why i'm on here so much. Riding is healthy, tried traditional biking but limited to just a couple of miles so went recumbent. Then the next issue is how much pressure can put on my back by peddling. Flat ground 15mph is ok, hills and higher speed causes pain. Just riding and moderate pressure on the peddles for hours burns a lot of energy and is doable.

Indeed, in this case electric transmission is perfect. You can tune maximum controller resistance so you do not 'overdo' it.
And you have a sympathizer as well, because I currently damaged my back again working on the bike - funny enough not by lifting it, I'm careful about it, but by somehow twisting in an awkward position It is also my problem spot that prevented me from riding typical road bikes for long even when I was reasonably fit.

 

[BalorNG]

Chain routing is a bit complex...