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

Hm, don't notice much of that on either of my recumbents, but i do have the longest frames offered for both, so that might affect it.
I really don't like how shorter wheelbases corner/handle.

But i didn't think about this factor, yeah the narrower pedals could bat back that from developing. I'm about to go +5mm on the BB, but i think these pedals reduced more Q factor than that.
 
Warren said:
Pedal induced steering is how I ride no-hands on my recumbents. It is so easy that most of my riding is no-hands.
Click to expand...

on what kind of bike?
 
neptronix said:
Found this the other day:
Pendulum Pedal — Øutlier
Click to expand...
1st "look" (not quite a review) I see of this pedal on YT:


I've also been thinking that this pedal can effectively drop your bb height on upright bikes, changing the the geometry slightly (and handling?). On recumbents I think it's trickier but it would require an x-seam seat-crank readjustment. I also wonder it's mechanical effect on shorter cranks and oval chainrings.
 
Thanks a lot guys, i have been looking for updated news and the actual user experience for a while.
I know that the design recently got upgraded for extra strength. And in my application, where i'm never standing on the pedals, i think any weakness in them is no big deal.

These would work fantastic on my upright bike to lower CoG and also make staging seated at stops much easier in one fell swoop.

The unfortunate thing about these pedals is that they add some outward offset, and i keep getting moved in the direction of adding more. I'm near my limit already.
Right now, i use these pedals.. and the amount of outward offset is super small.. this helps counteract my wide cranks.. and the pedal is also as thin as it gets.

1744909574936.png

To utilize these on the Maxarya would involve sticking to the same fork, instead of going to a higher quality, wider one that will penalize me even more. I think moving up half an inch would have more impact than a better fork due to the weight balance issue.

I'm also thinking, i could probably tolerate 180mm long pedals to move up another 10mm for a total of an inch forward. The problem is that i won't get my cranks threaded the right way by using an aftermarket set to achieve that.

Maybe some loctite would do the job since i am never pedaling super hard on this bike.

Anyway, these new pedals are on my to-order list!
 
One pair ordered.
I'd like to cut the pegs down a hair to get even more drop while i'm at it. Since i'm scratching for millimeters.

Also ordered a 180mm used set of shimano cranks.
Hoping i can go at least 23mm forward.

If improvement is notable, i'll go from a 2.8" rear tire to a 3.0" and max out the front size ( 2.25-2.5""? ).
If that improves things more, i'll get this special long swingarm from Maxarya, and we'll call it good.
 
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neptronix said:
One pair ordered.
Click to expand...

They remind me of Shimano Dura Ace AX pedals from the early '80s. Those had much fatter mounting threads and bearings, having been built along with large eye cranks to support them. They still failed to thrive, and quickly went away.

s-l400.jpg
 
99t4 said:
At that point it's time to look at your shoes also. Remove the insoles? Grind down the outer sole? Go sockless?
Click to expand...

Yeah.. i guess we could consider that stage 4, lol.
I could easily lose 1/3rd of an inch of shoe.
 
Okay, i did the eccentric adjuster hack ( to the detriment of my chain tension ) and went from 170mm cranks to 180mm.
I also switched the seat to be in the middle position, aka semi-laid back.

max 2025.jpg

This pushed me almost an inch forward and i noticed a ~+7% improvement in ride quality.

I went down the crappiest road in town and noticed that if i moved my torso straight up, the jittering went away and it seemed like the front suspension was actually working. That confirms that this is a weight balance issue & my long legs don't help.

Ray of hope received!

Further steps i'll take when i have the cash, in order of expected frontend improvement:
- Beg Maxarya again for this +2 inch longer swingarm ( ~14% improvement )
- 1.75 -> 2.25" front and 2.4 -> 3.0" rear tires + much wider rims ( ~5% improvement )
- alternate tire path if i get maxarya swingarm: 20 x 2.5" front, 22 x 1.5" rear
- Install 12mm offset cranks when received ( ~3.5% improvement )
- Attach battery to front of bike ( ~3% improvement )

So about $1k invested to get a 25% improvement in frontend smoothness to make the bike tolerable, it's pretty ridiculous, but i have no other options for a full suspension semi recumbent that's capable of high speed, so i'm doin' it!
 
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engineering wise this is the solution. The motocross looking "I'm a big boy" type forks with telescoping, seals and stiction especially the air sprung ones are really a pet peeve of mine. I wish more like these were available, but of course marketing would never do it because they look weird and nobody wants to have a bike that looks weird.
 

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marka-ee said:
engineering wise this is the solution. The motocross looking "I'm a big boy" type forks with telescoping, seals and stiction especially the air sprung ones are really a pet peeve of mine. I wish more like these were available, but of course marketing would never do it because they look weird and nobody wants to have a bike that looks weird.
Click to expand...
Is that currently available?
 
So for reference.

I just ran my hardtail 29er up and down the test to compare..
It has a 100mm spring fork tuned too stiff..
A suspension seatpost tuned too stiff..
And 29 x 2.5" front tire and 29 x 2.0 rear tire, both at 60psi.
IE, in a disadvantaged state as far as ride quality goes.

Meanwhile the maxarya's suspension is set to medium..

The two bikes handle the juddery part the same, but the maxarya handles the ruts/potholes worse. The bumps hit slower but have a higher total amount of motion.. it's a lot more drama.

This shows me diameter trumps suspension more than i expected and i think i'd be open to a recumbent with dual 700C wheels that could have a front suspension fork added, and max out the tire size.
If my last attempt to make this bike OK riding at higher speeds doesn't work out, that's the next route.

One thing that sucks about this bike is that no matter what, it's pretty slow to pedal. It's the slowest recumbent i've ridden. But you put a motor on it, and it rips, like any other recumbent.
I don't think this is a function of the wheel size - the Cannondale Bent and BikeE were a lot faster. I think it's the drag of pedal power going through two bottom brackets. ( The Cannondale had a nicer chain to chain interface and the BikeE had a long single chain and was the fastest. )

But yeah, in hindsight, i'd go with a steel 700c frame! i think i would get a better pedal and electric bike out of it.
 
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Well, i feel estupido.
Tried 75PSI on the rear. The bike on pedal power is within a hair of as fast as the 29er now ( at least on the flats ).

The ride quality didn't degrade as much as i thought it would.
The front is still ~40% bumpier than the rear.
I think the right PSI for the rear is 70PSI for the efficiency/comfort middle ground.

I looked at my previous Schwalbe Super Moto X 20" x 2.8" tire and noticed that it lists 50PSI as the max pressure. I'm very careful to not over inflate tires, so i knew i ran 50PSI.
I think that explains the mysterious rim dent as i went through the NVH hell-course. I've never had a rim dent on any bike. So this tells me 50PSI is way too little, even with a huge tire.

When i did ghetto weight measurement on this bike, approximately 70% of my weight sits on the rear, so it makes sense to have a roadbiker's PSI on the rear tire.



On to the next topic:

1746470246932.png

I'm a little concerned that these 180mm cranks might result in pedal to tire contact when i go from a 1.75" tire to 2.25-2.5". So i checked some angles:

max1.jpg

The end of the crank lines up with the end of the crown but.. we've filed 2mm off the sides of the necessary areas to make it clear at all angles of rotation and have a 127.5mm wide BB ( the largest i can find for 68mm ), so, the 180mm cranks are working out fine.

max2.jpg

It looks like foot to tire contact won't happen with the front fork uncompressed in any scenario.

max 3.jpg

Under maximum compression ( i'm sitting on the front! ), and an extreme turn angle ( more extreme than you would normally ride at ), it looks like tire to foot contact could never happen. In real riding, my foot is pointed upwards.. so it's pedal to tire contact that i have to worry about.

Looks like a good safety margin (y)

I really want to remove this 10mm head spacer to reduce the angle of the fork, then max out the front tire size.
But i'm thinking if i add this pendulum pedal, i might enter the danger zone... not in terms of foot to tire strike, but pedal to tire strike:
1746472078092.png


I'm assuming that by removing the 10mm head spacer, due to the angle, i get the pedal 8mm closer to the tire
and the pendulum pedal gets the crank 12mm closer. To be safe, let's just say it's a 25mm reduction of the safety margin.

I think a good way to experiment with that would be:
- buy wider rim'd front wheel ( the 18mm internal maxarya rim is WAY too narrow )
- fit schwalbe 20 x 2.8" tire to it ( 13mm higher vs my existing 1.75" )
- take air out of the front shock until it's 60% compressed when i sit on it, to lower the height by at least 25mm versus where i normally ride at
- go hunting for bumps to make sharp turns on while pedaling

This is an intentional nightmare scenario to see what the outer edge of the safety margin looks like.

I know that even if i can't get away with this..
Moving weight forward > tire diameter > reducing excess fork angle... in terms of reducing front judder.
Thus if 2.4" is as tall as i can get the front tire, to make the pendulum pedal work.. so be it. But i'd like to see if we can get even bigger.

Ordered this front wheel with a 25mm internal rim for experimentation:
Front 20x1.75 Wheel Disc Brake with QR HUB

🤞​

 
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neptronix said:
So this tells me 50PSI is way too little, even with a huge tire.
Click to expand...

For reference, standard pressure for a modern mountain bike meant for downhill, jumping and landing from considerable height, as well as crossing rock ledges and similar obstacles, on contemporary 2.6-2.8 tyres, lands at about 20-25 PSI. Maybe some heavier folks or people who ride in more rocky terrain would go as high as 30-35.

I suppose this must be the recumbent weight (im)balance that would require such a high pressure.
 
So i got the new wheel and the 2.8" front fitted.

Under full compression, we not only hit the tire but also the fork bridge.

1747167608410.png

At half compression, i can barely strike the tire.

1747167481763.png

With 66% of the PSI on the front fork that i usually run, i was able to get some mild rubbing happening while testing turns in a parking lot.
So yeah, it looks like the 10mm lower headset riser gets to stay.

I put a few PSI into the front fork ( now about 75% of what i'd run ), with 35PSI in the 2.8" tire for a stress test to see if i ever got foot->tire or fork contact. Nope.

In this case, the frontend is now massively improved. This fat air volume really soaks up the impact to these 1.5-2 inch curbs and the rear tire at 75PSI is the rickety part now, i'm really impressed!

I feel like i lost 1mph of pedaling speed, however. I don't know if it's because i went full fat tire on the front, or i'm experiencing greater pedal bob due to having a loosey goosey pressure on the front. Maybe some combination.

I do like the extreme gain in confidence while riding over a gravel section that'd usually have the 20 x 1.75" MTB tire feeling skittish.

What i do know is that diametermaxxing is working, and raising the frontend way beyond stock doesn't seem to have detrimental effects on handling/cornering.

I expect when electrics are hooked back up to it, the front fork will compress more while riding as a function of speed. So i think i should drop the front from a 2.8" to a 2.5" for a few extra millimeters of safety margin, and also fitting the 25mm wide internal rim a bit better.

Wow, i might get to acceptable ride quality!
 
I've gone through the ringer trying to find a taller rear tire that can take up to 70 PSI.
Beyond 20 x 2.5", the maximum available pressure goes from 65PSI to 30 PSI once we get to 3.0".
All crappy fatbike tires at that point. My bare minimum is 70PSI capable, so that's not going to work.

I was looking online today for the world's smallest 22" tire and found out about OS20 rims for BMX.
Information on this is generally misleading and vague online. Took a while to sort out.

Looks like:
Regular 20" rim = 406mm bead seat diameter
"OS20" rim = 451mm beat seat diameter, sometimes referred to as 20" as well ( ??? )
Regular 22" rim = 457mm bead seat diameter

Visual on the size difference between 20" and ~22" aka OS20.

1747528126549.png

The only reason this wheel size exists is to maximize the total wheel diameter around the absolute limit for BMX racing, apparently :rolleyes: ( and it's usually paired with 1.25" tires when crammed into a regular 20" frame )

I'm going to refer to OS20 as ~22" from here on. Because that's what it is.


~22" tires get as small as 1.125". I think the bike could fit this.
Let's do some calcs to see how much margin we have though.

Size chart from Cateye Japan covers these odd sizes and their diameters.

1747524768557.png

The Maxarya will accept a standard 20" x 3.0", which i don't have a diameter for. So we have to compute it.
From a .7 inch difference in tire size on the above chart, we see a diameter change of 115mm
1.95" + 0.7" = 2.65"
2.65" + 0.35" = 3.0"
115mm added diameter x 1.5 = 172.5mm added
Therefore the 20 x 3.0" tire should = 1737.5mm total diameter ( assuming that these values scale linearly )

Looking at the 451mm rim, we see that each 0.25" = a 70mm diameter gain
A 1 5/8" tire should have a diameter of 1685mm.
If we make that a 1 6/8" tire, we'd be at 1720mm. ( add 35mm or half of the 70mm diameter gain )
This translates a ~22" x 1.75" tire, with a little space to spare. Not bad!


It also looks like some ~22" BMX tires exist in 1.6", 1.75", and 1.85" sizes:
Vee Speed Booster OS20 Tire
https://us.sourcebmx.com/products/tioga-powerblock-os20-race-tyre#:~:text=Tioga's%20Powerblock%20OS20%20tire%20is,Price%20Match%20Request
..and they take 110 PSI, so that fits the requirement 😅

These tires are on the lightweight side so i think stans is required so that i'm not popping tubes all day.
The bonus is that this would require a lot less stans ( and therefore add less rolling resistance ) versus the 20" x 3.0" setup i was thinking.



Plan of action?
Lace up a rear ~22" bike wheel with a 1.75" tire ( will get a 1.85" if i have a few millimeters left ).

VS my current 20" x 2.4", this wheel should have 4.8% larger diameter.
So i'd expect:
- 2.4% less motion when hitting curbs ( reduced air volume somewhat negates the diameter gain )
- 2.4% better rear NVH when going over choppy roads ( same idea )
- ~5% reduction in rolling resistance because there's less rubber to deform + i'm going from a non-ideal rim to tire width match to an ideal one.
- ? additional rolling resistance reduction because the above tires are BMX racing tires :)

This is a better scenario than going to a 20" x 3.0" and worsening the existing rolling resistance problem because i can't get the PSI high enough.

As for this front 20" x 2.8".. i think it's a keeper.. i won't reduce the size of the tire unless i find that i have issues with the pendulum pedals, when they arrive.

1747531934097.png

Looks like it's time to feed the bike more parts!
 
I thought I was going to be able to give you an option, but either they changed it in the time since I first saw it or my brain just screwed up the memory...I looked at the CST Big Boat 3" for the SB Cruiser's rear wheels at one point when i wore out one of the Shinko SR714 16x2.25" I''ve beren using for years on there. Didn't get it because the Shinko was much cheaper and thicker, but I thought it was at least 60psi capable.
shop.csttires.com

BIG BOAT

Experience unbeatable durability and performance with the CST Big Boat Tire, specifically designed for fat bikes. Equipped with a robust Aramid layer, this tire is built to withstand the rigorous demands of e-bikes, providing puncture resistance and peace of mind during your off-road adventures...
shop.csttires.com shop.csttires.com
It *is* 60TPI for the thread count in the casing, which might be what I remember...but nowhere can I find the PSi actually stated; looking at the tire sidewall images I can find it appears to say 30PSI (hard to read). :(
 
I've owned those shinkos before and their rubber is great and almost subs for a rear suspension, but the rolling resistance is the problem.
I want to make sure the bike is pedalable w/o a motor. So ~22 is where it's at.

The 'big boat' and some other CST tires are what i looked at - the fat ones don't take high PSI.
 
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99t4 said:
Why the 70 psi requirement?
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Covered by the above posts, but here's the short version:

Due to the weight balance of the bike, the rear tire requires unusually high PSI.
50 PSI = the bike is quite slow on pedal power and you could both pop a tube and dent a rim if you hit an odd sized bump at 20-25mph. ( this happened to me )

bananu7 said:
Maybe it would be an option to carry a pump and pump up to uncomfortable but efficient pressure when you have to pedal, and use lower pressure when efficiency isn't as much a priority.
Click to expand...

The bike is intended for long distances, is always pedaled, so it should always be very efficient.
 
I'm slightly closer to an ideal 20". This tire is 1.5lbs and takes up to 110psi.
That's 0.7lbs lighter than my otherwise impenetrable Kenda drumlin 20 x 2.4". So it should be a faster roller.
I think this would make a good front or rear tire. So i ordered it.

1747683670815.png

I think i should talk to Maxarya about this +2 inch swingarm they can manufacture for me before i get a custom rear wheel built.
This would allow me to run a 22" x ~2.0 rear and 20" x 3.0" on the front and i think that this would produce best results.
22" definitely has better tire availability than 'OS20"..
It would also correct the fact that the front crank is 2-3 inches backwards more than it should be, i think it'd ride more like my cannondale.

In the meantime, i'll run this incremental upgrade on the rear.
 
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