Blue Dream: Maxarya Ray 2 Semi Recumbent w/high eff mid drive

Okay, to test a theory.. ( front suspension is too wimpy and bobbing while pedaling and front tire PSI is too low )
I did:
+5 PSI in the front shock.
+10 PSI on the front tire.
Keep 75PSI in the rear.

The bike is a little faster than my 29er now and surprisingly the front NVH hasn't degraded much.
Diametermaxxing all the way is the way to go.
I would call it 'okay' along the NVH test course. So there is room to adjust PSI downward for more comfort.
It is also much faster when pedaling uphill.

Speed wise, the fastest recumbent i've ridden is a bikeE, and this is a hair behind that now.
Finally after 5 years of tweaking and tuning, i actually like the bike.

I'm kind of shocked at the degree to which the front end can affect the rolling resistance.
Looking forward to this faster and slightly bigger rear tire.

Tire arrived really quick.

...and yeah, it is kinda flimsy and it feels like it has half the rubber thickness of the Kenda Drumlin Cargo.
But i have to satisfy the curiosity on how fast this bike can actually go with an optimal tire.

Too bad it has an unlisted spec here. 85 PSI min
Oh well, let's rock it @ 85 PSI and see what happens.



Looks like i have a meager 2mm of clearance between chain and tire when in my first gear.
The OS20 aka ~22" wheel upgrade is a necessity after this point!!



So how does it ride?



From a dead stop, i got up to and maintained 22mph on flat ground for a mile on pedal power. That's 1mph faster than i was able to do on the BikeE!
I used to struggle to maintain 16mph before!

After going down a hill and getting my speed up 32mph, when i transitioned to flat ground, i was able to keep going 30-31mph solid for half a mile until i hit a stoplight.

This thing is a thrill on pedal power and i can't imagine what a riot it would be with a motor!
This is on rims that are far too narrow, with a heavy tube, and the front tire still at 40 PSI.
So basically it's still unoptimized and i'm still getting awesome power.

The rear tire was surprisingly not sliding around along the gravel part of the test course.

What did we learn? the rear tire on a semi recumbent matters a hell of a lot.


NVH in the rear is verging on unacceptable at 85 PSI, but not as bad as i was expecting to to be.
For the crazy speed, it's practically worth the rattling.
I think i'm going to throw some stans in it and see if it can survive Utah's roads on some epic rides on pedal power.

These 1.6"-1.85" ~22" tires available for the larger rim are of the same high speed BMX type, and their weights indicate they're ~4mm of rubber kinda tires too.

Let's see how it goes to determine if i go crawling back to my 20 x 2.4" setup!

Minimum tire pressures are almost always horse puckey. Minimum is dictated by axle weight, speed, rim width, rim to tire size ratio, and surface conditions. No tire manufacturer can know those things. Kenda has a habit of slapping "50-85 psi" on any 700C tire between 35mm and 50mm wide. There's no making sense of that except that they have the tooling to put it on whatever tire.

Respect the maximum rating, within reason. (Snafu used to rate their 20 x 2.1" freestyle tires at 130 psi, despite lots of 20" rims being totally incapable of that.) Ignore the minimum rating except as a point of reference.

Also, front tire optimum pressure is a function of front tire axle weight. 40 psi might be about right for a lot of MWB recumbents. You only have to have enough pressure to cover the corners of the envelope (e.g. heavily loaded, hard braking, rough surface, downhill to uphill transition). And apart from those things, if the tire is fat and the rim is narrow, there's a minimum pressure to maintain lateral stability in the tire.

Interesting factoid about the PSI. I was scratching my head why there is a minimum PSI at all.
At approximately what point does the average, non-BMX rim blow up? I'm thinking 100 PSI.

I figured i might not get much additional speed from the front tire PSI going up. But i can't help my curiosity. I have to try +10 PSI on both wheels to see how far the rabbit hole goes.

My mind is still reeling from achieving those kinds of speeds on pedal power yesterday.

The shape of bicycle rolling resistance

The Cause of Bicycle Tire Rolling Resistance

Easily one of the best channels i've seen on youtube.
Been binging that from hours.
Thanks for introducing me to this channel.

Mind is reeling with possibilities!

Keep in mind that rolling resistance as they define it is in the tire tread and casing-- and that definitely matters-- but that's only one source of tire-related energy loss. What a huge segment of the bike market has only recently realized is that bump energy transfer to the bike, rider, and cargo is also energy loss, and it can quickly overwhelm hysteresis losses as surfaces get rough or pitted. Bigger, softer, poofier tires almost inevitably pack more hysteresis and contact patch scrub than narrow hard tires, but they can often/usually be a net win by diminishing the energy that gets passed to you and the bike by surface texture.

Most "gravel bike" (God I hate that marketing term) tires are constructed with this kind of optimization in mind.

Makes sense!

Thinking about extra tire width vs uneven surfaces, gravel is a lot like our road surface - very large grain fragments. What i do know is that the tire noise on my car went WAY up after moving here from the west coast.

I'm thinking that the extra width of the contact patch is helping the added jitteriness disappear.... even as i bump up the PSI.


Today, I pumped the rear to 90 PSI and the front to 50 PSI ( it's max! ) and pedaled the bike 3 miles up a steady 1-2% grade.
The ride quality didn't degrade as much as expected, even on the way down at very fast speeds.

The bike doesn't seem to have a climbing penalty versus my 29er like before.
I think this is because as the bike is tilted upwards, more of the human weight is on the rear proportionally, therefore the rolling resistance goes up, unless you counteract with PSI.

Didn't bother testing the top speed on the flats ( wind direction is all over the place ). But i had some moments of ~3mph wind pushing at me headed down the 1-2% grade and i could still maintain 33-35mph pedaling down it.
Previously, i'd have to kick on the mid drive to get that kinda speed.

Lovin' it!


Like my 29er, this bike has problems with wobbling/chaos-steering during crosswinds. Ours are pretty bad out here, so any bike does bad. My rims are rectangle shaped ( both designed for rim brakes ) and i have tires that are 3x wider than them and this probably isn't helping. Neither is the bag on my front handlebar.

There's a lot of lateral movement in cross winds and i think the biggest cause is my rim - tire situation.



I decided to spec out the rims and tires for maximizing what can be stuffed into the bike.

10mm wider, 50g lighter, and much more aerodynamic 20" rim for the 2.8" front tire:




It looks like for the rear, 21.75" 23mm internal rims are about 100g lighter and the rear 1.85" tire would be 300g lighter.

I could throw a TPU tube in the front 20" since the 2.8" tire is fairly puncture proof and get a combined rotating weight reduction of 550g between both wheels.

Between switching out the two wheels, i suspect i'll get:
5% better NVH on front, 5% better on rear ( 20% air volume reduction is negative, but lower unsprung weight + 0.5" of added diameter overcomes that )
4-8% better acceleration
3-6% lower rolling resistance ( much better rim width to tire width match on both sides + 5% more rear diameter + TPU tube )
5% better bump compliance in the rear
Substantially better lateral stability
Some improvement in cross winds


But here's a thought.
On the NVH assessment, i'm missing:
- pendulum pedals that will put me 7mm forward
- 12lbs battery that sits on the front

These combined are an easy 10-15% gain in front NVH.
This gives me some room to reduce front NVH for lower weight.

What about a 21.75" x 1.85" front wheel also? And in this case, i could use a super light rim:

Rotating/unsprung weight would go down by:
rear: 325g ( 300g tire, 25g smaller inner tube )
front: 500g ( 300g tire, 150g rim, 50g much smaller tube )
total: 825g or 1.81lbs.


I guess the question is, how much can a reduction in unsprung weight improve suspension?
On my car, it did improve the NVH ~10% when swapping to rims that were 3.5lbs lighter, about a 15% reduction of rim weight.
In this case we have a ~40% drop in the front wheel weight..
..but the front fork has an unusual amount of stiction due to tiny stanchions, and poor weight balance so the positive effect maybe cut by 1/3rd
..but we also have a 28% drop in total air volume ( versus having a WAY generous amount already )
..and only a 1% diameter gain

I feel like maybe i am splitting hairs.. what do you think?

The answer came to me last night in a dream - i need to favor front NVH. When i finally put a motor back on this thing, the higher speeds will worsen it.

neptronix said:

I feel like maybe i am splitting hairs.. what do you think?

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On one hand, I feel like your standards and attention to detail, as well as sensitivity to the ride quality mean that you'd only be fully satisfied with either:
- a real motorcycle with motorcycle tyres, seat and suspension, which would just glide over the road
- a custom built recumbent that would fit no-compromise parts.

On the other, both seem out of reach one way or the other, and if you're having fun experimenting, why not.

I would perhaps introduce a bit more rigor in quantifying the results. With pressure, it's easy to pick a 500m road segment, pump tyres in 10psi increments and ride it back-to-back. That would make the comparisons much easier. I'm also a fan of recording during my rides. A 240fps sports camera could show you a lot of how the bike behaves through the bumps, which is something impossible to observe while riding.

This thread is turning into a trove of information on picking the right wheel/tire. I'm impressed that you are sticking with recumbents. Reading the discussion's on tires always sways me to get fatter tires. Have resisted because my little 20" 1-1/4 Schwabe marathon's really roll. for comfort reason's don't always run them at 100psi, mostly 80psi. This is great for bike trails (15mph) but open road at speed (30mph) all I do is try to avoid any holes. Have not ridden in over a year, been busy, soon very soon.

bananu7 said:

- a custom built recumbent that would fit no-compromise parts.

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You're not wrong. That's exactly what i want - basically this bike but with a 24 inch rear wheel, better geometry, some space for cargo, and way better suspension.

I previously had a Cannondale Bent and got spoiled by it's excellent design and ride quality.
The bottom bracket was 2-3 inches forward and it had great suspension on both axles and rode and cornered like a BMW.
The rear swingarm broke during an experiment, and the front 16" wheel and proprietary front angled fork kept me up at night, when it comes to hitting a pothole at high speed. So i never put a motor on it except once as an experiment.

Currently i am an apartment dweller, so making my own frame is out of reach. Making do with the second best option.

bananu7 said:

I would perhaps introduce a bit more rigor in quantifying the results. With pressure, it's easy to pick a 500m road segment, pump tyres in 10psi increments and ride it back-to-back. That would make the comparisons much easier. I'm also a fan of recording during my rides. A 240fps sports camera could show you a lot of how the bike behaves through the bumps, which is something impossible to observe while riding.

Click to expand...

I would do that if it would benefit some people. But I have not encountered a Maxarya owner on the internet in 5 years since buying the bike. I think that's because this bike totally sucks out of the box.

I do have a standardized NVH test course that's a like a sampler platter of all the most difficult Utah road conditions i've been using this entire time BTW.

ZeroEm said:

Reading the discussion's on tires always sways me to get fatter tires. Have resisted because my little 20" 1-1/4 Schwabe marathon's really roll. for comfort reason's don't always run them at 100psi, mostly 80psi. This is great for bike trails (15mph) but open road at speed (30mph) all I do is try to avoid any holes. Have not ridden in over a year, been busy, soon very soon.

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I think the only good answer for high speed + potholes is both huge tires and suspension.
Hard to find that on a 3 wheeler.. and if you do, it's insanely expensive.
This is why i stick with 2 wheelers.

I have 1-2 inch curbs to hit, but any potholes are usually minor and infrequent. My big problem is the sheer crappiness of the road surface.

The only bike that took the rare 1-2 inch deep pothole like a champ was a full suspension downhill bike with very expensive and long travel suspension and 26" x 2.2" wheels.

3 inch tires might get you closer to that, lol.

Surely there is a subscription maker space in SLC where you could build a frame for yourself. Most folks I would advise against trying that, but you have enough restless motivation that I think you could teach yourself that new trick with success.

Chalo said:

Surely there is a subscription maker space in SLC where you could build a frame for yourself. Most folks I would advise against trying that, but you have enough restless motivation that I think you could teach yourself that new trick with success.

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I looked into that. It won't work for me for welding. Major bummer.

neptronix said:

You're not wrong. That's exactly what i want - basically this bike but with a 24 inch rear wheel, better geometry, some space for cargo, and way better suspension.

I previously had a Cannondale Bent and got spoiled by it's excellent design and ride quality.
The bottom bracket was 2-3 inches forward and it had great suspension on both axles and rode and cornered like a BMW.
The rear swingarm broke during an experiment, and the front 16" wheel and proprietary front angled fork kept me up at night, when it comes to hitting a pothole at high speed. So i never put a motor on it except once as an experiment.

Currently i am an apartment dweller, so making my own frame is out of reach. Making do with the second best option.

I would do that if it would benefit some people. But I have not encountered a Maxarya owner on the internet in 5 years since buying the bike. I think that's because this bike totally sucks out of the box.

I do have a standardized NVH test course that's a like a sampler platter of all the most difficult Utah road conditions i've been using this entire time BTW.



I think the only good answer for high speed + potholes is both huge tires and suspension.
Hard to find that on a 3 wheeler.. and if you do, it's insanely expensive.
This is why i stick with 2 wheelers.

I have 1-2 inch curbs to hit, but any potholes are usually minor and infrequent. My big problem is the sheer crappiness of the road surface.

The only bike that took the rare 1-2 inch deep pothole like a champ was a full suspension downhill bike with very expensive and long travel suspension and 26" x 2.2" wheels.

3 inch tires might get you closer to that, lol.

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My trike has rear suspension and I can live with that but with no front suspension it crazy going to fast. Have it setup to cruse at 28 mph, top speed is 32-34 mph, hitting a pot hole at that speed is crazy, have not crash but have pulled over to get myself back together.

Utah trikes has a KMX frame kit again, think about doing the after market front and rear suspension like toecutter. It would be more for running around not much pedaling maybe single gear all wheel drive. (toy)

My trike needs a new battery but still happy the way it is. think abut a trailer with a spare battery but the one gets me about as far as I can ride up to 50 miles (4hrs) with pedaling.

So anyway i was checking out my rear suspension, thinking the rear 21.75" would make it worse, and it already bottoms out.
I don't expect another 0.5" of diameter to improve this much.

What i currently have is a Rockshox Monarch R 152mm long with 31mm of travel.
And 152mm is a rare size, and i already have the best one available in that size.

It looks like i can get a Manitou Mara in 165mm with 45mm of travel; if i lower the PSI a little bit, i'd end up only slightly higher.
The benefit would probably be in what looks like 20% more air volume.



I've emailed Maxarya again requesting a 2 inch longer swingarm with the bridge/shock mount moved backwards some millimeters so it could fit this shock without me having to counter-adjust for height.

A side benefit of this would be that i could run a 22" x 2.0-2.5" wheel

3 birds, one stone; fingers crossed.

Okay i took the 29er up the same 3 mile 2% grade course. Then, i pedaled another 4 miles up hill.
It seems very slightly slower than the recumbent. I had to take more breaks.
This spits in the face of the idea that recumbents are slower climbers.

This isn't fair competition though, the recumbent has a racing tire on the back, the 29er has a heavy kenda tire on the rear. Both have a wide BMX-y tire on the front.
I put a 420mm lighter rear tire on the 29er and i'll run the course again a few times and report the average.
Maybe i bust a myth here, maybe i confirm it.

UPDATE: I found a minor disc brake rub happening on the 29er, need to retest

I got an email back from Maxarya. it looks like they might not be able to relocate the shock mounting point backwards, but they can make the longer swingarm. Awesome!

neptronix said:

This spits in the face of the idea that recumbents are slower climbers.

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Who, foolishly, implied 'bents were slower?.... certainly not me. 'Twas 2009, IIRC, Rans mopped up the 4-man RAAM (Race Across America) category, with Randy's X-Stream LWB 'bent.

"Amazingly, the Rans team averaged nearly 21 miles per hour in the nearly 3000 miles of the Race Across America endurance event. The second four-person team to finish, riding upright bicycles, arrived about 7 hours after the Rans recumbent team.

"Official media coverage of Team RANS included this commentary from Adrienne Johnson in the Race Across America blog (emphasis added):

"RANS is and has been leading the 4 man race for two days. Their nearest competitor is over 100 miles back. The very best part about Team RANS is that they're so darned comfortable on the bikes. Recumbents allow the riders to ride with nothing but sore legs. No neck pain, no hand pain, no butt pain. A pretty good thing for a 3,000 mile bike race."

neptronix said:

I got an email back from Maxarya. it looks like they might not be able to relocate the shock mounting point backwards, but they can make the longer swingarm. Awesome!

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That's great !

On the 29er, i took off the rear Kenda 700c x 2.0" tire and replaced it with a relatively light 700c x 1.5" for a ~450g weight savings.
NVH is significantly deteriorated at 80 PSI from just 0.5" of diameter reduction. Same effect as on the recumbent.

Pedal power up a shorter but steeper hill is massively improved. I made it to the top on a gear 1 step smaller.
Flats speed is 0.5 - 1mph better, really marginal.

Rotating weight seems to be the enemy of hill climbing power, big time.

On the flat and downhill, i can feel massive air resistance compared to the recumbent.
I think having my handlebars 6 inches above the seat isn't helping. I dropped them to seat level and will retest because it's unfair to be comparing such an unoptimized upright. We want a fair match!

I think i will find that the Maxarya gets smoked uphill by the 29er on the long hill climb course. So it's imperative to lower it's rotating weight as much as possible.
Less rotating weight is also good because downhill, the bike can get too fast very easily. Less momentum is better.

Sent an email to Ikon rims inquiring about the strength of their 318g 451 rims. If they are really equivalent to others, the Maxarya could run one on the rear and front, and that'd be badass.

Can't complain about the look of them, i think they'd look awesome on the bike.

I took the 29er on the 8 mile 2% climb and it felt notably faster. I took way less breaks. I required much less water.
I noticed that i was down into a smaller rear cog a good % of the time.
Really impressed at this change.

The first time i managed this, it was a personal record because i am out of shape AF and currently weigh 255 pounds.
I think an aspect of what is happening is that i'm getting back into shape more on each run.
That will screw up any results.

Going to alternate between the upright and recumbent up the hill for the next few weeks, then i'll do formal testing.

Do you run power meters on them? That would tell you exactly how much energy each of them needed for a particular segment.

I thought recumbents were bad on hills because you can not stand up on the peddles. Should make it up on the way down. My trike would roll down a hill faster than uprights.

bananu7 said:

Do you run power meters on them? That would tell you exactly how much energy each of them needed for a particular segment.

Click to expand...

That would be interesting to know but this is a one time curiosity and not worth paying for.

ZeroEm said:

I thought recumbents were bad on hills because you can not stand up on the peddles. Should make it up on the way down. My trike would roll down a hill faster than uprights.

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On my upright, at most, i will stand on the pedals for a few seconds for a quick acceleration.
Not a factor here since it's a continuous, moderate climb.


Recumbents and uprights use different muscle groups. Most comparisons do not factor in this.
When they do factor into it, the best theory i've heard is that you cannot leverage your body against the bike very well while pedaling. I think this is true, and the mesh seat is also probably consuming part of the power stroke as well.
( but would you really want a hard seat..? )

I can't do much about that, but i can think about rotating weight:
Maxarya Ray 2 tire weight: 1475g
Upright 29er tire weight: 1635g
Rim weight, tube weight, etc should be within 10's of grams. The 29er has narrow rims.

The 29er should have a bit higher rotating weight. But the rotating weight is much further out.
The 20" wheel spins ~45% faster; so i'm thinking that rotating weight effects it more.

Maybe switching to wheels that are both taller and lighter at the same time could have a big impact.

Why am i obsessed about this, it's not a pedal bike..
I want to use either a Shengyi SX2 or lightest.bike mid drive.
~1400w is around the edge of mechanical limits of both motors.
If reducing rolling weight and friction can reduce 10's of watts of energy, it's possible to use these lightweight motors to achieve 35mph on the flats, and at least 'okay' hill climbing power.

My trike has a fiberglass seat. Would like to try a mesh seat. My seat fits me good so have no complaints. I know from riding with up right bikes that once we top a hill and everyone coasting my trike would leave the pack, had to use regen to stay with them.

My back is bad so can not peddle up any hill lol. The whole reason my tike is like it is to pull good size hills. When I first joined here and was planning my build. Talked to you and others here that guided my build and still can not improve on it for the purpose it was built for. Thinking of another build but for a different reason. I did not expect my trike to hold up as well as it has. So I enjoy the direction you have gone and follow your builds.