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

[neptronix]

Oh i forgot to mention..
Outside of the front juddering and bouncy rear spring, the thing is fun to ride.

I'm so happy to have this thing up and running after years of discouragement and setbacks. This was the hardest build i've done.
Seemed impossible without a machine shop handy.

Something about this bike makes people wave, compliment, and cheer when they see it.
People go crazier seeing it than they did with the Cannondale.
I think they think it's a custom cruiser bike instead of an efficiency nerd's wet dream. nobody knows what a recumbent is out here.

I put the bike on the scale today and it came out to 75lbs.. and i haven't even come up with a cargo solution yet
The bike is unwieldy and the main problem is it doesn't have good 'handles' for which to grab.
Time to add on another pound!

 

[neptronix]

Okay usually on my morning ride, i'm on my pedal bike which is very unassuming, and i know a number of stores will allow me in here and i generally don't have trouble..

..but a 6 ft long 75lbs bike that's clearly motorized in a stretch... even for walmart.

Well, i decided to test the bike's charisma.. i got a little hassle from the guy up front, but the more he looked at it, the cooler he thought it was, and he let me through after a conversation about the bike.. lol



Coincidentally, the ride was good. It was 77f outside and i blasted it up a 1% grade @ 28-29mph for some miles and it got up to 50C.. i was really surprised.. there is room to add watts!

 

[The Toecutter]

Well, i decided to test the bike's charisma.. i got a little hassle from the guy up front, but the more he looked at it, the cooler he thought it was, and he let me through after a conversation about the bike.. lol

I did the same with my trike at a Texas shopping mall once. I had fat, donut-eating rent-a-cops chasing me on foot yelling "STOP! STOP!" as I hauled ass indoors at 25+ mph. I was drunk/stoned/drugged-up off my ass and decided to have a little fun. After leaving, I tore ass down a state highway never to enter that mall again.

 

[neptronix]

.. i just walked the bike in & around the store, for clarity!

That's pretty cray cray!

 

[neptronix]

Me and the bike are having good times. I decided to try setting the seat 1 notch backwards... and i did notice a few more MPH both uphill and on the flat!

On the flat, i can hold 32mph pretty nicely now! There is another notch that sets the seat back even further :O

The weather was great, so i went on a journey into the 'benches' of Salt Lake valley.

I climbed a 1.5% average grade for 13 miles / 21km at full power averaging 27mph / 43 kph, and this blew through half of the 52v 19.5ah battery @ power setting 5 ( 900W limit )

I'm a bit unimpressed by that range because my upright bike probably does the same course at 2mph average faster.



That tells me my net efficiency kind of sucks & i think the main reasons are:
- i'm running the motor through 2 chains instead of 1 ( i might be able to change this; just ordered some spacers )
- i might still need a lower gear ratio on the motor
- i have some 3-5mm offsets here and there & possibly this is sapping some power.
- The motorcycle tire isn't helping one bit.

I think if i can get the other 30% of the power i was promised at sale by unlocking this kit, i would be happy with it from a power perspective. Right now i don't have the confidence to take a 30mph road if i need to, and i don't like that.

We'll find out next week, i'm awaiting a response from bikee dudes on why my unit is only outputting 900w.

I did enjoy the ride. I really enjoyed how the bike power and human power converged. It didn't have enough power to mix with cars safely and that was dangerous out here in the land of very poor bike infrastructure. I could go the required road speed of 30mph only sometimes... and had to constantly stop and check for cars... i'm missing having a powerful hub!

After this experience, i understand the appeal of a mid drive. Unlike the much wider bafang BBS02, this motor doesn't hurt my legs,



Will readjust and re-evaluate laters.

 

[maiz]

Me and the bike are having good times. I decided to try setting the seat 1 notch backwards... and i did notice a few more MPH both uphill and on the flat!

On the flat, i can hold 32mph pretty nicely now! There is another notch that sets the seat back even further :O

The weather was great, so i went on a journey into the 'benches' of Salt Lake valley.

I climbed a 1.5% average grade for 13 miles / 21km at full power averaging 27mph / 43 kph, and this blew through half of the 52v 19.5ah battery @ power setting 5 ( 900W limit )

I'm a bit unimpressed by that range because my upright bike probably does the same course at 2mph average faster.

View attachment 358741

That tells me my net efficiency kind of sucks & i think the main reasons are:
- i'm running the motor through 2 chains instead of 1 ( i might be able to change this; just ordered some spacers )
- i might still need a lower gear ratio on the motor
- i have some 3-5mm offsets here and there & possibly this is sapping some power.
- The motorcycle tire isn't helping one bit.

I think if i can get the other 30% of the power i was promised at sale by unlocking this kit, i would be happy with it from a power perspective. Right now i don't have the confidence to take a 30mph road if i need to, and i don't like that.

We'll find out next week, i'm awaiting a response from bikee dudes on why my unit is only outputting 900w.

I did enjoy the ride. I really enjoyed how the bike power and human power converged. It didn't have enough power to mix with cars safely and that was dangerous out here in the land of very poor bike infrastructure. I could go the required road speed of 30mph only sometimes... and had to constantly stop and check for cars... i'm missing having a powerful hub!

After this experience, i understand the appeal of a mid drive. Unlike the much wider bafang BBS02, this motor doesn't hurt my legs,

View attachment 358739

Will readjust and re-evaluate laters.

Why do you thinking scooting the seat back is helping with speed?

 

[neptronix]

Why do you thinking scooting the seat back is helping with speed?

Aerodynamics.

 

[neptronix]

To be more clear, i adjusted seat tilt, which puts my torso back maybe 3-5 degrees.


Anyway, gave the bike a workup..

1) Rear chain was way too tight; added 4 additional links to it.
2) Front chain had no lube on it!
3) Swapped the moto tire for a 20" x 2.4" bike tire ( same diameter )
4) Removed the PAS sensor ( it adds friction and it's dead weight, i like throttle )
5) Rear brake was dragging a bit, fixed
6) Bought 2.0mm chainring spacers so that i can get some chainlines within a few mm of perfect.

My measurements indicate the rear will accommodate at least a 20" x 2.8" tire..
But the 20 x 2.4" already prevents me from going into the largest rear gear, so anything wider in this 135mm dropout is just bad news!

But.. a 22" x 1.75" has 7mm smaller diameter than 20" x 2.8", so it should fit
I'm pretty happy about that. That might improve the mid drive gearing enough that i can skip this dual chainring configuration too. I might also see a small increase in efficiency due to having way less rubber deforming as the wheel moves. Two birds, one stone!

I'd like to see about dropping this 10mm spacer on the front too, then dropping to a 20" x 1.75" up front. In total, i should see 15mm of geometry correction & i'm really hoping that's enough & gets this bike closer to riding like my ol' cannondale or bikeE..

 

[Zambam]

2) Front chain had no lube on it!

What kind of lube are you using? With so much exposed chain, how easy is it to get your legs branded? What's your regimen of keeping the chain clean?

I must say chain maintenance is the least enjoyable task. I'd love to have a belt and IGH someday.

Looking at the non ideal location of your battery, how feasible is it to make a custom hanger that clamps onto the frame so the battery is under it (below the chain)?

 

[neptronix]

I've been using boeshield T9 lubricant since forever.
My chain maintenance routine is: add lubricant every once and a while. Never cleaned a chain in my life. I think i've pedaled a collective 40k miles.

The chain in question was in my used chains pile, i must have picked the dry one and not thought about it.

No problem with chain - leg contact. I ride with shorts, but have massive calves. The minimum amount of clearance from leg to chain across the pedal rotation is 1 inch. Clearance with stock bike is better, but i had to enlargen the front gearing to fit the freewheel thingy.

Looking at the non ideal location of your battery, how feasible is it to make a custom hanger that clamps onto the frame so the battery is under it (below the chain)?

Pretty hard. The chain would hit the battery, even though i've got the chain out ~7mm from stock and the battery is not designed to be run upside down ( as stated by the manufacturer ).

So yeah, it's a pain in the ass.
I realize that the battery is creating some counter-pendulum effect when making quick turning maneuvers. it's as if the entire body is flexing. The battery position can move backwards ~30mm w/o hitting my legs. So i might as well do that.

You bringing this up got me thinking though. The ebikes.ca bottle bob has significant gaps where it doesn't support this heavy battery. Some of the wagging might be due to the fact that it's on stilts.



Not a huge problem, but annoying!

 

[Zambam]

I did the same with my trike at a Texas shopping mall once. I had fat, donut-eating rent-a-cops chasing me on foot yelling "STOP! STOP!" as I hauled ass indoors at 25+ mph. I was drunk/stoned/drugged-up off my ass and decided to have a little fun. After leaving, I tore ass down a state highway never to enter that mall again.

Did this really happen? Cameras are all over the place in malls. The cops didn't try to i.d. / find you?

 

[Zambam]

I've been using boeshield T9 lubricant since forever.
My chain maintenance routine is: add lubricant every once and a while. Never cleaned a chain in my life. I think i've pedaled a collective 40k miles.

I'll have to look into boeshield T9. Is it a dry lube? Do you ever wipe the chain with a rag?

 

[The Toecutter]

Cameras are all over the place in malls. The cops didn't try to i.d. / find you?

They probably tried. I don't have a photo ID, drivers' license, or arrest record of any sort, so good luck to them on that!

 

[The Toecutter]

I climbed a 1.5% average grade for 13 miles / 21km at full power averaging 27mph / 43 kph, and this blew through half of the 52v 19.5ah battery @ power setting 5 ( 900W limit )

I'm a bit unimpressed by that range because my upright bike probably does the same course at 2mph average faster.

That tells me my net efficiency kind of sucks & i think the main reasons are:
- i'm running the motor through 2 chains instead of 1 ( i might be able to change this; just ordered some spacers )
- i might still need a lower gear ratio on the motor
- i have some 3-5mm offsets here and there & possibly this is sapping some power.
- The motorcycle tire isn't helping one bit.

I suspect the mid drive's motor also has slightly less efficiency in steady state cruising than the 1500W Leafbike. Couple this with thee chain, and you could be losing upwards of 10% vs using a Leafbike. So for a given electrical input, much less is actually being output by the drive wheel.

 

[neptronix]

I'll have to look into boeshield T9. Is it a dry lube? Do you ever wipe the chain with a rag?

Wet lube, i'm sure it's a bit above average in terms of quality.
I never wipe with a wet rag. I'm horrible to chains. I think it's a habit picked up from some decade of riding hubs, lol.

I suspect the mid drive's motor also has slightly less efficiency in steady state cruising than the 1500W Leafbike. Couple this with thee chain, and you could be losing upwards of 10% vs using a Leafbike. So for a given electrical input, much less is actually being output by the drive wheel.

Do you really think i'm losing 10% of my power to this second chain? if so, there's a lot to gain.

 

[Zambam]

Wet lube, i'm sure it's a bit above average in terms of quality.
I never wipe with a wet rag. I'm horrible to chains. I think it's a habit picked up from some decade of riding hubs, lol.

I meant wiping with a dry rag (not a wet one) to get the black oily crud off that usually sticks to the chain. Is sticky black oily crud on the chain not a problem with Boeshield T9?

 

[neptronix]

Ok, went out and rode the bike after all the work.
Rear 20 x 2.4" tire was at a conservative 38 PSI ( tire is rated for 75PSI )

I can feel the bike is a bit faster on flinstone power immediately.
Up a 0.5% grade on full charge, i sustained 30mph.. on the flat, 33mph.. down the 0.5% grade, hit a record at 37mph ( very close to topping out the gearing )

So overall these changes gave me +1-2mph.
I just have just enough power to take the car lane at 30mph, and my minimum for what i need in an ebike is met now.
Very happy about it.

I'll give the bike another ride tomorrow at 60PSI rear.. i think my speed on the flat might go up to 34mph.

I imagine the flat cruising speed of this bike is 37-40mph if i ditch the dual chainwheel config and unlock the other 400W.
Feeling very good about this build and resisting the urge to just rip out the electronics and run a VESC on it, lol.

 

[The Toecutter]

Wet lube, i'm sure it's a bit above average in terms of quality.
I never wipe with a wet rag. I'm horrible to chains. I think it's a habit picked up from some decade of riding hubs, lol.



Do you really think i'm losing 10% of my power to this second chain? if so, there's a lot to gain.

The two chains coupled with a less efficient motor, yes. The second chain by itself, maybe 3-4%.

 

[neptronix]

Here's an audio-visual of the bike:

 

[neptronix]

Yeah, 60psi rear was the right move, i hit 35mph briefly and was able to hold 34mph on the flat. The downside is that i can now feel road inconsistencies.

They claimed this motor is ~90% efficient. Here's the watts/speed of a motor at 87.4% efficiency. It approximately lines up with what's expected.

 

[PaPaSteve]

Well done !
Thanks for the virtual test ride.

 

[neptronix]

Bad news here.

20-25 PSI on the front wheel was causing the tire to rotate inside it's casing.
The front tire blew quickly and unexpectedly @ 15mph from the valve tearing.



I instinctively death gripped the handlebars inward and kept the front wheel straight as the bike rapidly slowed down. I fell sideways at a few MPH. The very wide handlebar absorbed the majority of the impact.



The landing was very soft!

The damage seems to just be road rash. A system check of my joint function on the day of the injury and then repeated 24hrs later reveals no damage to my joints. My right elbow and knee skin is damaged.



This is the easiest going bike crash i've ever had. If only the seat was wider, or had some bars on it, i might have been able to just fall over and have the handlebar & seat take 100% of the impact/dragging.. all i need to do in that case is hold on & keep those handlebars straight.

It's time to fix this geometry problem. It's obviously not safe to run a tire at such low pressure, because that's very close to the threshold of innertube / tire slippage. The 18mm internal diameter front rim is not helping things.

Some calcs on how to drop the frontend.

front tire: x 18 x 2.2 = 1465mm lots of tires in this size
          18 x 2.4 = 1495mm
          20 x 2.0 = 1593mm current size

Front drop: 128mm / 2 = 64mm
+ 10mm spacer removal
Total: 74mm

rear tire:
        22 x 1   = 1731mm
        20 x 2.8 = 1720mm   MTB super knobby treads only :(
      x 20 x 2.6 = 1688mm     Schwalbe pickup!
        20 x 2.4 = 1655mm    current size

Rear gain:
33mm / 2 = 16.5mm w/ 2.6"
65mm / 2 = 32.5mm w/ 2.8"

Total frontend correction possible:
-90.5mm or 3.5 inch w/2.6" rear
-106.5mm or 4.2 inch w/2.8" rear

I think 3.5 inches frontend drop should do a good job reducing the crazy frontend suspension angle such that i can add more PSI to the tire, have better tube to rim/strip contact, etc. The downside is that the reduced wheel size eats into this improved suspension i gain.

I would guess that cornering improves somewhat so there is a net gain here in terms of safety + cornering at the very least.

.. i just know that cannondale got some things right & the more i shift things towards cannondale's design, the better!

 

[Cowardlyduck]

Ouch! Had similar things happen to me, including the valve stem issues. There are alternatives to just increasing the pressure....I've resorted to heavily taping up opening to the valve stem hole through the rim to prevent any movement or cutting action. You can also put double-sided tape between the rim tape, then again on the underside of the tube or on top of the rim tape and it will hold pretty well.
That being said, there are other risks to running such low pressure in a lower volume tire....so it's understandable if you just prefer to increase it now!

Cheers

 

[Zambam]

This is the easiest going bike crash i've ever had.

Glad you're OK! Looks like just minor scrapes. This suggests you've had bike crashes that are worse. Care to share circumstance of previous crashes?

 

[neptronix]

Glad you're OK! Looks like just minor scrapes. This suggests you've had bike crashes that are worse. Care to share circumstance of previous crashes?

The only serious crash i've had was when a large railroad groove was at a ~2 degree angle parallel to the road that suddenly appeared after a hill.. i had a 2.5" front and rear tire but the groove sucked up my wheel despite trying to counter-correct around it.. i went flying at 20mph and sustained some major cartilage damage.. which is now mostly healed.

- no bike lane to the left or right, so no option to pull over, let cars pass, then slowly go over the railroad groove
- large amount of rocks to the left/right so pulling over = crashing and getting hurt
- way too many cars behind me to panic stop in the middle of the road.

..the guy who pulled me off the road told me he crashed in the same spot on a motorcycle 10 years ago.

Lots of stupid infrastructure here.

Ouch! Had similar things happen to me, including the valve stem issues. There are alternatives to just increasing the pressure....I've resorted to heavily taping up opening to the valve stem hole through the rim to prevent any movement or cutting action. You can also put double-sided tape between the rim tape, then again on the underside of the tube or on top of the rim tape and it will hold pretty well.

Did you have these issues on a recumbent because you needed to 'add suspension' to a front wheel also?

I think taping/gluing the rim strip would be a great idea. That probably eliminates a lot of motion on it's own.
I think also going to a 2x wider rim means more ~2x more tube to rim strip contact.