Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Show off your Ebike creation here.
User avatar
thundercamel   1 kW

1 kW
Posts: 470
Joined: Jul 23 2018 2:58pm
Location: Round Lake, Illinois

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by thundercamel » Feb 28 2021 11:45pm

Sorry man, I don't mean to keep correcting you. Think about the tire/rim linear speed at 35mph on a 26" wheel vs. 20" wheel :wink: You're correct for disc brakes of course.
My Ebike builds - Existing bikes, affordable motor kits, self built 14s6p batteries - Now with more recumbent!

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 01 2021 4:47pm

It's okay, i'd rather be correct. I have a horrible combination of mild dyslexia and a large number of people who find my information is trustworthy and useful. I can't always spot my own mistakes. :thumb:
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Bullfrog   1 kW

1 kW
Posts: 431
Joined: Apr 08 2017 10:37am

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by Bullfrog » Mar 01 2021 5:04pm

OK enough about stopping, who needs to stop anyway :lol: .

Lets get back to the good stuff...motors and going fast :bigthumb: .

Just kidding of course...it is just as important to be able to stop as it is to go :wink: .

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 02 2021 2:07pm

Well, getting the bike to be a perfect balance of all characteristics, as you'd do in a luxury car design, is the end goal, just like it was with the super hiryuu. Except this time, we have vastly better aerodynamics and tires that can handle my speeds and road conditions much, much better.

I don't like the caliper brakes at all but they should be fine until the aerodynamic aids are built.

The "lightest bike" 1000w mid drive has been ordered. No idea on the ETA. Will use the eZee 350rpm rear motor in the meantime to get the bike rolling.

I didn't want to use a drive unit this expensive. I would have liked to build a small BB mounted geared hub motor holder and made my ultimate recipe for this bike cheap to replicate.
But i get more power, more efficiency, and less weight this way. I also get better stealthiness and more room for battery. The 'lightest bike' mid drive is about as small as it comes.

Getting the drive ratios correct between the pedal power and the motor power should be a fun challenge. :lol:

More updates later.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Bullfrog   1 kW

1 kW
Posts: 431
Joined: Apr 08 2017 10:37am

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by Bullfrog » Mar 02 2021 2:32pm

No telling whether this bill will ever pass or not but there is a proposal to offer up to $1,500 on the purchase of a new ebike.

Covers 30% of the cost of the electric bicycle, up to a $1,500 credit.

Applies to new electric bicycles that cost less than $8,000.

Here is more info:

https://panetta.house.gov/media/press-r ... cycles-and

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 02 2021 2:56pm

Nice, but doesn't apply to my state, and i'm building something far greater than what's on the semi recumbent market.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Bullfrog   1 kW

1 kW
Posts: 431
Joined: Apr 08 2017 10:37am

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by Bullfrog » Mar 02 2021 3:30pm

It will apply to all states if it passes...i.e. federal legislation and the credit will be on your federal taxes.

What I want to know is will the rebate be effective for an ebike I build or do I have to purchase a pre assembled complete bike.

Still a lot of unknowns and who knows if it will ever pass...just something to keep an eye on.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 07 2021 8:02pm

Doesn't apply to building your own from what i hear.. and i live in Utah, yanno.


Anyway i have a small update.

Finally got those 2 chromoly prototype forks from maxarya.
The suspension fork is a spring that is set WAY too stiff to be even remotely useful.. the only good thing about it is that it would clear the cranks, but no thanks..

The yellow prototype chromoly fork is a perfect color fit for the Cannondale, so it will have a use there.


I was wrong about the reverse components headset spacer compatibility. The two bearings on the bike look identical but one has a larger groove. It can be used, and therefore i can solve the front fork height issue with the extra 10mm rise.
Once i get that crown on the fork, i'll figure out what desperate measures are needed to get the cranks to clear.


I took off the rear shock. Apparently the pivot would allow me to add another 75mm if i wanted. I can afford to lose a tiny bit of wheelbase and ditch the 150mm DNM shock ( garbage ) for a 160mm Fox or something of much higher quality to provide the cadillac grade ride quality i want.

Realistically speaking, the ideal wheel/tire combo is probably my hutchinson spherus 16 x 2.25" (motorcycle dimensions) in the rear and either a 18 x 2.0 schwalbe big apple with slime in it or a 14 x 2.25 IRC or vee rubber tire up front.

The suspension fork is off to the bike shop to have the crown fitted and better rear shock specced out and ordered.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Bullfrog   1 kW

1 kW
Posts: 431
Joined: Apr 08 2017 10:37am

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by Bullfrog » Mar 08 2021 10:05am

Yes, I agree on the E-Bike bill/rebate going to be interesting to see how it is worded and if there is any possibility to get a credit for a "build" as opposed to a retail purchase of a completed bike. Of course it hasn't passed yet so I am not counting "any" chickens before they hatch :lol: .

Update sounds good...moving forward is always a good sign :D .

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 08 2021 4:45pm

Back from the bike shop. Crown race is installed. Wait time on a 165mm length rockshox Monarch R ( same shock maxarya uses ) is out until June so i've taken a chance on an eBay seller.

More next week!
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

User avatar
tigcross   100 W

100 W
Posts: 152
Joined: Oct 18 2015 10:47pm
Location: Victoria BC
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by tigcross » Mar 09 2021 2:39am

Hey Neptronix, Great build. As a fellow recumbent devotee I know what an uphill battle it is to modify one, nothing standard and the usual rules do not apply. :)

A couple of things I would like to lay on you, and I realize that some of these observations are too late. You've bought the bike and the project is underway, but they might give you some food for thought.

Frame Size and rear-wheel trail.
You're a big guy and as a result you'll need to run the seat all the way back. One of the things I have learned along the way is that the closer the rear wheel is to the rider, the worse the ride. There are two issue at play here:
1. The ideal location for a rider's weight is balanced evenly between the front and back wheel. As the weight distribution moves toward the back of the bike it puts too much weight on the rear and and it start to slew (not sure if there is a better term), meaning there is too much load on the rear shock and wheel and too little on the front end, which causes the bike to squat and slide easily. Unfortunately most recumbent bikes suffer from this situation because very few manufacturers want to try to convince the buying public that an 8 foot long bike is reasonable.
2. Head whip. The closer the rear wheel is to the rider, the more the bumps encountered create a whiplash situation were the riders head is being whipped forward and back on each bump. I have an old neck injury that makes me particularity aware of this phenomena.
There is no easy solution to the length of the bike, but if you wanted to go crazy you could cut the frame and add an extra foot. (just kidding don't do that).

The other item to bring up is crank length. I know you've mentioned that you have some issues with your legs and prefer longer cranks, but I wanted to let you know about why shorter cranks are standard on the better recumbent bike.
It has to do with inertia: on an upright bike, the inertia from the rider's legs pumping up and down is 100% directed into the bottom bracket and the ground. On a recumbent the inertia is split, because the rider is horizontal, some of the inertia from the legs is going forward into the BB, but some of it is going up and down, this causes a bounce in the bike as the legs bounce up and down on each pedal stroke. It is for this reason that many recumbent have shorter cranks, because it makes for less up and down movement of the legs and less bounce.
Most conventional bikes need longer cranks because they need enough leverage to allow the rider to pedal hard and stay in the saddle. A recumbent does not have this problem because the rider has a back-rest to push against. The downside is that recumbent riders often injure their knees because they can put to much pressure through them because of the back-rest to push against (this is what led me to develop the GCD for the Electrom).
In your case shorter cranks would also help with fork-crown clearance. I'm running a set of 154 mm cranks on the Electrom and they feel great.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Mar 09 2021 12:35pm

Thanks so much for your valuable feedback, tig. I really appreciate it.

I see and feel exactly what you mean in terms of rear wheel to rider distance issues. It's why i ride the largest frame possible. Shortening the rear with a 15mm taller suspension is worrying. The long term solution for this is building a swingarm that is at least 3 inches longer. I do see a custom frame design in my future, just like you.

I know the bike will not ride as well as the Cannondale. The main difference is how far the cranks are from the seat. The maxarya dictates you sit further backwards than the cannondale due to this.

I have not encountered the neck/head bob issue much since i don't recline nearly as much as you do. I imagine the best solution is a headrest, the more you lean backwards. Perhaps the use of a DD, which dulls rear suspension action, exacerbates this. This is why i'm fixated on using a mid drive. I want even more of the Cadillac ride quality that the Cannondale has.. no, i want it to be more like a Bentley.

I have anime character proportions. The legs of someone 6'5, torso of someone 5'0 tall. The 170mm cranks are as short as i can tolerate. Otherwise knee pain develops. I just have severe fitment issues with any bike.

I'm reaching out now to maxarya to see if they will accept these insights.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 05 2021 6:17pm

Some updates.
The rear shock finally arrived, so i can put the bike back together and start working on the electric aspects. :mrgreen:

I've been aero modding and lightweighting my car in the meantime:
viewtopic.php?f=1&t=111011

..and have had amazing success from just one aerodynamic modification.. a grill block off... and have many more aero mods planned. I now know how to make complex shapes out of coroplast, and lexan is next.


I wasn't planning to put fairings on this bike. But i'm thinking some conservative ones on this bike would be nice... in particular, it would be nice to use lexan in places where visibility is important.. and painted cloroplast where it isn't.


A fairing like this would be nice.
https://t-cycle.com/collections/windwra ... 9685973051

Image

Except premade ones tend to rely mounting on the airing to the bottom of the fork, which simply won't work.

I'm thinking a 'conservative fairing' blocks the mid-upper body where most of the drag happens, and extends a bit further out towards the rider. It also includes a short tail box fairing which doubles as a trunk.

Is mounting a fairing on the handlebars a fail due to directional wind issues, though?
Attachments
Untitled-1.jpg
Untitled-1.jpg (136.73 KiB) Viewed 327 times
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

99t4   100 W

100 W
Posts: 206
Joined: May 10 2020 10:31pm
Location: PNW

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by 99t4 » Apr 05 2021 10:50pm

You would have to test it with the particular bike/fairing. I would think with a consistent side wind it would be manageable, easy enough to compensate. But with gusts, or passing trucks it could get tricky.

In the '80s I rode a Moulton AM7 with their tall "vertical" bubble fairing. The base mounted to the (low because of the small tires) front rack, and IIRC it had a couple of standoffs that supported the fairing about mid-height. The top half was without support, as the bubble compound curve was enough to stabalize it by itself. The top was about even with the top of my head in riding position.

Better even, was when I tested their "cocoon" for them: a large rectangular lycra sling where the ends attached nearly full height top to bottom to the sides of the fairing, and wrapped around my butt. My entire upper body was inside the (now stretched tight) cocoon. Kept me warm and dry during the cold winter, and the ride became eerily silent, except for the magnified sound of the chain/gears/derailler. No wind noise at all. Plus gave an easy extra couple MPH.

So I'm saying there are definite benefits, but you may end up mounting the fairing on some thin tubular aluminum (or possibly carbon fiber?) standoffs mounted to the frame. Additionally, a lycra enclosure would be easier to work up, and give much the same benefits as plastic sheeting, while likely being less bunglesome.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 06 2021 1:40pm

Thinking about this and what you said gives me a bit of pause because this area can have gusts of wind up to 80mph from all directions. more typical is 10-35mph. A typical fairing connected to the handlebars would easily produce some unwanted steering effects and be extremely dangerous. basically, it's putting a sail on a bike.

Perhaps the ideal handlebar mounted fairing would sit in the absolute center of the steering tube and also partially intersperse the handlebars or have a cutout for handlebar access. This central location would greatly reduce the lever effect of wind forces. The closer position to the rider would improve aero also. In addition to this, i could enclose part of the back of the fairing to reduce the sail effect as well.
2021-04-06 12_16_49-Adobe Photoshop CS4 Extended - bluedream fairing.psd @ 50% (Front fairing, RGB_8.jpg
2021-04-06 12_16_49-Adobe Photoshop CS4 Extended - bluedream fairing.psd @ 50% (Front fairing, RGB_8.jpg (44.06 KiB) Viewed 292 times
This would require a lot of cardboard based experimentation but could be done.

Too bad i don't have under seat steering! i could create a fairing that's more in the center of the bike.. with a tail fairing, side/rear winds would have a super small impact.

Or maybe i could wear a fairing on my chest, lol. Bicycle fashion crime of the century.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

maiz   100 µW

100 µW
Posts: 9
Joined: Sep 21 2008 5:50pm

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by maiz » Apr 06 2021 7:09pm

neptronix wrote:
Apr 06 2021 1:40pm
Thinking about this and what you said gives me a bit of pause because this area can have gusts of wind up to 80mph from all directions. more typical is 10-35mph. A typical fairing connected to the handlebars would easily produce some unwanted steering effects and be extremely dangerous. basically, it's putting a sail on a bike.

Perhaps the ideal handlebar mounted fairing would sit in the absolute center of the steering tube and also partially intersperse the handlebars or have a cutout for handlebar access. This central location would greatly reduce the lever effect of wind forces. The closer position to the rider would improve aero also. In addition to this, i could enclose part of the back of the fairing to reduce the sail effect as well.

2021-04-06 12_16_49-Adobe Photoshop CS4 Extended - bluedream fairing.psd @ 50% (Front fairing, RGB_8.jpg

This would require a lot of cardboard based experimentation but could be done.

Too bad i don't have under seat steering! i could create a fairing that's more in the center of the bike.. with a tail fairing, side/rear winds would have a super small impact.

Or maybe i could wear a fairing on my chest, lol. Bicycle fashion crime of the century.
linear and/or hp velo have a USS kit you might be able to modify and fit on your bike.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 06 2021 7:27pm

maiz wrote:
Apr 06 2021 7:09pm
linear and/or hp velo have a USS kit you might be able to modify and fit on your bike.
Cool. That would probably enable a very extreme fairing on the Cannondale at some point. Let me pocket that idea for now. :mrgreen:
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

User avatar
tigcross   100 W

100 W
Posts: 152
Joined: Oct 18 2015 10:47pm
Location: Victoria BC
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by tigcross » Apr 08 2021 1:43am

Hey, I've just caught up to your thread. I can say that with my bike the fairing presents a petty large surface area, but because it is not connected to my steering it's manageable. I've tested it in some pretty strong winds and while you do feel it, it is not too bad.
Of course if you went to USS you could do the fairing however you wanted and would not have to worry about fairing induced steering issues. If you do decide to take the USS plunge let me know, I have some thoughts on it.
Have you looked the options made by Karl at zzipper? his LWB fairing might be a good fit for your bike. If you switch to a suspension fork it would require some extra thinking for the lower mounts.
Image

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 13 2021 1:46pm

I'm very aware of karl at zzipper :)

Glad to hear that a non-steering mounted fairing works well.. i think on this bike since i want to be conservative, i will stick to a steering mounted fairing but custom design it with minimizing cross wind interference in mind.


Anyway, the bike is back together with the new rear shock and smaller front tire. The geometry came out to approximately the same, so that's awesome.
img (2).jpg
img (2).jpg (167.85 KiB) Viewed 169 times
The crank to suspension fork interference is still within 4mm, and that's a bit too much metal to comfortably take off the cranks. And moving the cranks backward is not really going to work.

Instead of tilting the eccentric bottom bracket backwards, i'd like to tilt them forward and downwards so that i can scoot the seat forward a tad to get a tiny bit better on the center of gravity and also compensate for the 15mm rear height raise, which moves the swingarm forwards an estimated 5mm. I'd guess i can move the pedals forward by 10mm, so that's good. :)

Also since the bike is now taller, i can lower the seat about 15mm if i want, but i'll give up the small gain in sitting forward if i do that, so i dunno if that's necessary at all.

I'm going to play it safe and go with a 122.5mm bottom bracket to give me an additional 4.75mm clearance to account for things like the pedals and suspension fork twisting a bit under load.

The ride quality of the bike should be awesome. The smooshiest CLWB on the market... :)
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

BalorNG   1 W

1 W
Posts: 61
Joined: Nov 10 2019 7:22pm

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by BalorNG » Apr 14 2021 10:51am

Even non-steered fairing will present steering disturbance with large side force magnitudes due to trail level arm creating a steering moment.

Unfortunately, partial fairings are hardly worth it unless your bike is un-aero to begin with (they DO help on LWB/CLWB bents because, well, they are).

A combination of pivoted front fairing on LWB and stretchy lycra sock actually improve handilng because lycra, attached to the bars, acts as a steering stabilizer and actually gives the 'tail' section any chance of working at all.

Image
This image is particularly revelatory when it comes to form drag... yes, imperfect tail fairing is WORSE than no fairing at all.
Tail section is for 'pressure recovery' and you cannot have with highly turbulent air.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 14 2021 1:25pm

I don't want to go so far as to enclose the sides of the bike no matter how much benefit that would bring. I want the bike to be an example of practical aerodynamics and design much like the angle taken on the Tesla Model 3.
But a fairing mounted partially or fully behind the handlebar would do a much better job of reducing the air gap of a front handlebar which also exacerbates crosswinds. And make flow to the tail box much more useful.

I've read many times that a tail box yields improvements on bikes with no front fairing. I'd like to test my theory in real life.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

BalorNG   1 W

1 W
Posts: 61
Joined: Nov 10 2019 7:22pm

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by BalorNG » Apr 15 2021 8:58am

neptronix wrote:
Apr 14 2021 1:25pm
I don't want to go so far as to enclose the sides of the bike no matter how much benefit that would bring. I want the bike to be an example of practical aerodynamics and design much like the angle taken on the Tesla Model 3.
But a fairing mounted partially or fully behind the handlebar would do a much better job of reducing the air gap of a front handlebar which also exacerbates crosswinds. And make flow to the tail box much more useful.

I've read many times that a tail box yields improvements on bikes with no front fairing. I'd like to test my theory in real life.
It usually does (after all human body is not a flat plate), just don't expect much - in fact expect nothing and you'll hardly, if ever, be disappointed :)

But here is a caveat:
http://www.recumbents.com/wisil/misc/no ... efault.htm

Read this and ask yourself: can you do better? But at least tailfairings don't create much, if any, steering disturbance and a good place to hold stuff, so by any means go for it. It might give a particularly nice speed boost in a right side wind due to sail effect, but again that would depend on actual implementation - if you want it to work at all, that article has good advice.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 15 2021 12:26pm

I can see how the front of that fairing could contribute to added drag.. especially near the butt.
There's also increased frontal area around his shoulder, which is bad.

http://www.recumbents.com/wisil/misc/no ... CT0015.jpg

..yet it still provided some improvement.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

BalorNG   1 W

1 W
Posts: 61
Joined: Nov 10 2019 7:22pm

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by BalorNG » Apr 15 2021 2:06pm

neptronix wrote:
Apr 15 2021 12:26pm
There's also increased frontal area around his shoulder, which is bad.
I see you are not an expert in aerodynamics :) Well, neither am I to be frank, I've just learned the basics and spend a few (ok, a a lot) hours playing with CFD, but his logic is actually impeccable:
Are you familiar with modern aero rims? They are actually wider than the tire, so they can work properly. Same logic here.

Image
Those are optimised around 25mm tires, btw. And yes, it's faster this way. And human body is less aero than a tire... it is likely they didn't go FAR enough, actually.

I do agree about the 'butt area', though. It's too blunt.

User avatar
neptronix   100 GW

100 GW
Posts: 15499
Joined: Jun 15 2010 5:56pm
Location: Utah, USA
Contact:

Re: Maxarya Ray 2 Semi Recumbent w/high efficiency mid drive

Post by neptronix » Apr 15 2021 3:04pm

I'm not an expert but i've been studying what experts have to say for months now and think i have a hang of it.

The rim shape makes complete sense since the tire looks like it would complete the shape.
This guy's fairing starts at beyond his width and creates additional frontal area near his shoulders and other areas.
The bottom part is a disaster. This was not properly measured before creation.

Despite these design disadvantages the fairing works well enough to increase speed, but was too impractically shaped.

So a badly designed but well built tail box does work. :)
..just like a kamm tail works on a car.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Post Reply