Building a new CruzBike recumbent - I have a plan, looking for advice (eGO battery? Grin All Axle kit?)

[llavalle]

Hey guys!

Been riding a mid-drive Trek for a few years now so I got hooked on having assist when I go too far away or on a big climb...

I've been having neck issues so I decided to go recumbent with Cruzbike. Picked up a frameset this week of their new A4x model. It was delivered today. For those who don't know, CruzBike are front wheel drive so the rear wheel is actually a 12x100 TA, like a front wheel of a gravel bike. The front wheel is where the drivetrain sits. 12x142 TA.

I really want a throttle to help starting from a stop on the recument - it's amazing... and actually legal here (Canada). I don't need but would like to get torque sensing. I don't need / want to go above 20-25mph. The idea is to be as close as a Class 2 ebike. Not looking to ride in traffic so I don't need to keep up with anyone. Think "getting off from a stop with the throttle and getting a helping hand during climbs and if I went too far away"

As for range, I'm doing this for fitness, not commuting. To give you an idea, my Trek as a 500wh battery and I never drained more than 50-60% of it - usually less than 20% in a typical ride.

• Skarper is out of the question : not available here and no throttle
• BiMotal - love the idea - don't need more capacity. Problem is the rear of my bike uses flat mount holes - 70mm apart with M5 threaded holes. While they are telling me I can just run that with a flat mount to post mount adapter (and compatible 4 pots calipers) I'm not sure how I like the idea of the torque PULLING on those thread
• CYC Photon - overkill for my needs and might upset the ride quality - the BB actually pivot with the steering on a CruzBike. I might have to test with some weights to see how it affects the handling
• Grin All Axle Rear (on the front in that case) : would give me torque assist but might also upset the ride quality. Also can't run micro-spline cassettes for a Shimano 1x12 setup
• Grin All Axle Front (on the rear) : seems like a legit idea. Could get torque sensing with a custom BB...
• Batteries for the CYC Photon or Grin : 36 or 48V pack from Grin that I would have to fab a custom mount for... OR one of the MANY EGO battery I already have (2x 12AH, 2x 10AH, 1x 7.5, 1x 5). Mounting is going to be a challenge anyway because of the shape of the frame.

Anything I'm missing here? I'm leaning towards the Grin Front (installed in the back). Bike has 27.5in wheels so a Standard wind seems to be a good fit for a 52V nominal voltage range of my ego batteries. I read about the low voltage cutoff being in the tool so I would configure the controller to be on the safe side. The BaseRunner seems fine and I just need to decide if I go with their super harness thing, cycle analyser or headless.

Any controller or alternative supports broadcasting ebike info over Ant+? I could install a nice Garmin or Wahoo head unit and get everything (battery, range, etc). I guess I could build one to interface with the protocol of the Baserunner (I have firmware coding experience).

Regarding connectors : I REALLY like XT-90S to avoid a spark when plugging in (using them for my RC stuff and my home inverter with a tesla battery module) but I see those PP45 everywhere. What gives?

Also, super odd ask : let's say I go with a standard winding (10rpm/V)... Seems to be a good fit for the EGO battery.. but if I wanted something super lightweight, a bottle battery running a 36V could be nice. How bad would it be? Again, don't really need top end speed... if it can climb and get off from a stop.

 

[offGridDownUnder]

Hello,

Check out my conversion - 2d in signature below. Major details on the Cruzbike forum.

Note that the latest V3 All-Axle is redesigned to prevent the issue of the brake rotor cutting the motor cable, and comes with a flattened cable to this end. I don't think the adapter I made for my V2 All-Axle is required. The rest is fairly straightforward, and it worked well.

If you put a V3 rear All-Axle in the front, then you can't instead put a Rohloff there - which has been done, including using a Gates Carbon Belt instead of a chain. This was done by Aldo Contarino of Quantum Bicycles in Perth for another member of the Cruzbike forum. It turned out that for the thru-axle Q45, the sprockets and belt exactly matched the distance from the crank axle to the wheel axle and provided adequate tension. Something to consider for your future plans.

I no longer have the machine.

 

[neptronix]

How hilly is your terrain?
You might be able to get by with a Shengyi SX2 and a 48v battery if the hills are not too intense.

Interesting machine!

 

[llavalle]

Hello,

Check out my conversion - 2d in signature below. Major details on the Cruzbike forum.

Note that the latest V3 All-Axle is redesigned to prevent the issue of the brake rotor cutting the motor cable, and comes with a flattened cable to this end. I don't think the adapter I made for my V2 All-Axle is required. The rest is fairly straightforward, and it worked well.

If you put a V3 rear All-Axle in the front, then you can't instead put a Rohloff there - which has been done, including using a Gates Carbon Belt instead of a chain. This was done by Aldo Contarino of Quantum Bicycles in Perth for another member of the Cruzbike forum. It turned out that for the thru-axle Q45, the sprockets and belt exactly matched the distance from the crank axle to the wheel axle and provided adequate tension. Something to consider for your future plans.

I no longer have the machine.

I was actually looking at a Rohloff + belt drive (since you essentially have an open triangle for the belt! I was curious our tensioning would work. Maybe a Rohloff + chain with a tensioner would be great too. Good to know - the Rohloff website was pretty specific on the measuring kit that is required and that only a authorized dealer could take care of this.

And I've seen your project on the Cruzbike forum, thanks for sharing! Great info!

How hilly is your terrain?
You might be able to get by with a Shengyi SX2 and a 48v battery if the hills are not too intense.

Interesting machine!

I'm around Montreal - unsure how hilly that would be. The SX2 is available with a thru-axle?

 

[offGridDownUnder]

The SX2 is available with a thru-axle?

No.

 

[neptronix]

I'm around Montreal - unsure how hilly that would be. The SX2 is available with a thru-axle?

Aw shoot, i forgot about that...

 

[E-HP]

Hey guys!

Been riding a mid-drive Trek for a few years now so I got hooked on having assist when I go too far away or on a big climb...

I've been having neck issues so I decided to go recumbent with Cruzbike. Picked up a frameset this week of their new A4x model. It was delivered today. For those who don't know, CruzBike are front wheel drive so the rear wheel is actually a 12x100 TA, like a front wheel of a gravel bike. The front wheel is where the drivetrain sits. 12x142 TA.

I really want a throttle to help starting from a stop on the recument - it's amazing... and actually legal here (Canada). I don't need but would like to get torque sensing. I don't need / want to go above 20-25mph. The idea is to be as close as a Class 2 ebike. Not looking to ride in traffic so I don't need to keep up with anyone. Think "getting off from a stop with the throttle and getting a helping hand during climbs and if I went too far away"

As for range, I'm doing this for fitness, not commuting. To give you an idea, my Trek as a 500wh battery and I never drained more than 50-60% of it - usually less than 20% in a typical ride.

• Skarper is out of the question : not available here and no throttle
• BiMotal - love the idea - don't need more capacity. Problem is the rear of my bike uses flat mount holes - 70mm apart with M5 threaded holes. While they are telling me I can just run that with a flat mount to post mount adapter (and compatible 4 pots calipers) I'm not sure how I like the idea of the torque PULLING on those thread
• CYC Photon - overkill for my needs and might upset the ride quality - the BB actually pivot with the steering on a CruzBike. I might have to test with some weights to see how it affects the handling
• Grin All Axle Rear (on the front in that case) : would give me torque assist but might also upset the ride quality. Also can't run micro-spline cassettes for a Shimano 1x12 setup
• Grin All Axle Front (on the rear) : seems like a legit idea. Could get torque sensing with a custom BB...
• Batteries for the CYC Photon or Grin : 36 or 48V pack from Grin that I would have to fab a custom mount for... OR one of the MANY EGO battery I already have (2x 12AH, 2x 10AH, 1x 7.5, 1x 5). Mounting is going to be a challenge anyway because of the shape of the frame.

Anything I'm missing here? I'm leaning towards the Grin Front (installed in the back). Bike has 27.5in wheels so a Standard wind seems to be a good fit for a 52V nominal voltage range of my ego batteries. I read about the low voltage cutoff being in the tool so I would configure the controller to be on the safe side. The BaseRunner seems fine and I just need to decide if I go with their super harness thing, cycle analyser or headless.

Any controller or alternative supports broadcasting ebike info over Ant+? I could install a nice Garmin or Wahoo head unit and get everything (battery, range, etc). I guess I could build one to interface with the protocol of the Baserunner (I have firmware coding experience).

Regarding connectors : I REALLY like XT-90S to avoid a spark when plugging in (using them for my RC stuff and my home inverter with a tesla battery module) but I see those PP45 everywhere. What gives?

Also, super odd ask : let's say I go with a standard winding (10rpm/V)... Seems to be a good fit for the EGO battery.. but if I wanted something super lightweight, a bottle battery running a 36V could be nice. How bad would it be? Again, don't really need top end speed... if it can climb and get off from a stop.

View attachment 385892

You will need to go with all Grin stuff if you go with the all axle, based on what you’ve described. Your trek allowed you to coast or even ride without assistance. Direct drive motors don’t coast, and you need to be in really good shape to pedal more than 10mph unassisted. Grin controllers have a virtual freewheeling feature that feeds the motor enough power to feel like coasting, but you should be aware it’s not ‘free’ coasting since your are using power to ‘feel’ unassisted.

 

[offGridDownUnder]

Grin controllers have a virtual freewheeling feature that feeds the motor enough power to feel like coasting, but you should be aware it’s not ‘free’ coasting since your are using power to ‘feel’ unassisted.

And Grin swears that you will recover enough in regen to offset this virtual freewheeling trickle input. With my All-Axle, I rarely see less than 3% recovered by regen. I often see 8%, as I've set the brakes to have a short but definite range where the 'regen' switches engage before the mechanical brake does, and I can stop just using the regen. I still have the mechanical brakes for emergency stops.

With the switches engaged, the throttle modulates the regen braking, and I can apply enough to skid the tire without engaging the mechanical brakes.

 

[E-HP]

And Grin swears that you will recover enough in regen to offset this virtual freewheeling trickle input. With my All-Axle, I rarely see less than 3% recovered by regen. I often see 8%, as I've set the brakes to have a short but definite range where the 'regen' switches engage before the mechanical brake does, and I can stop just using the regen. I still have the mechanical brakes for emergency stops.

With the switches engaged, the throttle modulates the regen braking, and I can apply enough to skid the tire without engaging the mechanical brakes.

Ya it doesn’t take much power. I made a coasting button on an earlier version of my bike, that applied 18w, which was enough to coast a long ways. I miss regen :-(

 

[offGridDownUnder]

I miss regen

What led you to abandon all Light and Good, and rather embrace The Darkness?

It may be too late for you, but you might yet steer some of the younger posters away from a life of shame and penitence...

and worn-out brake pads...

 

[neptronix]

You will need to go with all Grin stuff if you go with the all axle, based on what you’ve described. Your trek allowed you to coast or even ride without assistance. Direct drive motors don’t coast, and you need to be in really good shape to pedal more than 10mph unassisted. Grin controllers have a virtual freewheeling feature that feeds the motor enough power to feel like coasting, but you should be aware it’s not ‘free’ coasting since your are using power to ‘feel’ unassisted.

Have you owned one of these motors?
Even in a 24" wheel ( more drag vs a big wheel ), i found mine very pedalable.
That's the advantage of the 27mm wide stator.

 

[BlueSwordM]

I was actually looking at a Rohloff + belt drive (since you essentially have an open triangle for the belt! I was curious our tensioning would work. Maybe a Rohloff + chain with a tensioner would be great too. Good to know - the Rohloff website was pretty specific on the measuring kit that is required and that only a authorized dealer could take care of this.

And I've seen your project on the Cruzbike forum, thanks for sharing! Great info!


I'm around Montreal - unsure how hilly that would be. The SX2 is available with a thru-axle?

Hmm, Montreal, trhat makes it a lot more interesting in my case

 

[E-HP]

Have you owned one of these motors?
Even in a 24" wheel ( more drag vs a big wheel ), i found mine very pedalable.
That's the advantage of the 27mm wide stator.

I’ve probably gotten too soft.

 

[kuromaku]

I have a Cruzbike T50 that's electrified. I personally found that even 1kg on the front really messed with my handling ability at very low speeds, so ended up with a rear motor and underslung battery. Truckrun makes (made?) a "front" thru-axle motor that's in the neighborhood of 2kg that should fit the bill for your minimal assist needs. Has a torque sensor built in.

FWIW I've got a v2 "front" All-Axle in a 20" wheel on the rear of mine, and it works great on sustained 10% climbs (about 9km) in the T50.

 

[llavalle]

I have a Cruzbike T50 that's electrified. I personally found that even 1kg on the front really messed with my handling ability at very low speeds, so ended up with a rear motor and underslung battery. Truckrun makes (made?) a "front" thru-axle motor that's in the neighborhood of 2kg that should fit the bill for your minimal assist needs. Has a torque sensor built in.

FWIW I've got a v2 "front" All-Axle in a 20" wheel on the rear of mine, and it works great on sustained 10% climbs (about 9km) in the T50.

Good to know. What voltage is your battery with the 20in wheel? Which winding do you have on your V2 ?

You will need to go with all Grin stuff if you go with the all axle, based on what you’ve described. Your trek allowed you to coast or even ride without assistance. Direct drive motors don’t coast, and you need to be in really good shape to pedal more than 10mph unassisted. Grin controllers have a virtual freewheeling feature that feeds the motor enough power to feel like coasting, but you should be aware it’s not ‘free’ coasting since your are using power to ‘feel’ unassisted.

Yeah, was planning to go all Grin anyway (Well maybe except the battery). I just went though the manual and it looks like freewheeling only works if you've engaged the throttle (after stopping, where the freewheeling also stops). Any reason NOT to go all Grin? well.. "all" meaning Motor + Controller.

Looking at batteries, it looks like I might be able to fit a CYC A52 under the frame. I like the rugged construction and the fact that the mounting is all metal (and supports installing it under the downtube).

I'm currently 3d printing a model of the A52 battery to see how it would fit. I would need to fab an adapter but it should be pretty nice.

 

[kuromaku]

Good to know. What voltage is your battery with the 20in wheel? Which winding do you have on your V2 ?

102.4V nominal (32s LiFePO4) and 5T ("fast.") For your use case, I would think the "slow" 8T winding in a 650b wheel paired with one or more of your EGO batteries could make for a slick setup below 40kph giving you maximum opportunity for torque from a stop and regenerative braking at low speeds, but even a 36V battery should keep you above 35kph if you need it. Haven't been in Montreal in many years, but the largest climb I remember was the Mount Royal Camilien Houde, which couldn't have been more than 2km or so at 8%. Totally doable with a 36V battery.

Highly recommend staying away from the Anderson PP45 for main power (OK for charge port.) The contacts tend to rapidly fret under vibration and burn up.

 

[llavalle]

102.4V nominal (32s LiFePO4) and 5T ("fast.") For your use case, I would think the "slow" 8T winding in a 650b wheel paired with one or more of your EGO batteries could make for a slick setup below 40kph giving you maximum opportunity for torque from a stop and regenerative braking at low speeds, but even a 36V battery should keep you above 35kph if you need it. Haven't been in Montreal in many years, but the largest climb I remember was the Mount Royal Camilien Houde, which couldn't have been more than 2km or so at 8%. Totally doable with a 36V battery.

Highly recommend staying away from the Anderson PP45 for main power (OK for charge port.) The contacts tend to rapidly fret under vibration and burn up.

Thanks for the input - looks like the "slow" wind is still pretty fast for my needs indeed. And I'll stick with XT-90 (the ones with the resistor to avoid the spark while I'm at it), I prefer them anyway and I've soldered many.

Looking at batteries, it looks like I might be able to fit a CYC A52 under the frame. I like the rugged construction and the fact that the mounting is all metal (and supports installing it under the downtube).

I'm currently 3d printing a model of the A52 battery to see how it would fit. I would need to fab an adapter but it should be pretty nice.

Reached out to CYC regarding the battery. Wanted to know if the BMS was active when on regen. They told me that the battery does NOT support feeding back power into through the main wiring.

"Our battery BMS is not designed to work with Regen and I would suggest against doing so as if the battery fails we will not warranty the failure." -> makes sense I guess, it's not like you can regen with a mid drive....

Also, regarding the BiMotal device. They told me it would fit with proper adapters (for the disk mount) and sent me pictures of the setup on other CruzBike. I found that the 180mm rotor was awfully close to the frame on their pictures so I tried on mine by installing a 180mm shimamo rotor I had lying around. DOES NOT FIT.

So - Bimotal (the 180mm version which is the smallest) does NOT fit a CruzBike A4X :S See picture here :

llavalle's A4X Build

Edit : see this post for the recap. Bike is almost 100% done. I did the math on the cost and all : https://forum.cruzbike.com/threads/llavalles-a4x-build.16591/page-3#post-192687 Posting here (the Adventure series forum) since this is likely where the A4X will end up :) I'll document my...

forum.cruzbike.com

Right now I'm 3d printing some batteries to see where I could fit them in the frame. I might end up with a super super small 36V system with Grin's LiGo's line : lol

 

[offGridDownUnder]

all Grin anyway (Well maybe except the battery)

WARNING: If you don't buy the battery from Grin, they will not solder the battery connector onto the black and red pigtails comiing out of the Base-or-Phaserunner controller. If you are rolling your own, you are expected to do that yourself.

When I tried that myself, the plastic holding the 4 blades melted before the blades heated enough to flow the solder. My framebuilder had a powerful temperature settable soldering station that could heat up the blade fast enough to flow the solder before melting the plastic frame.

Otherwise, perhaps work out what battery connector you need once you've chosen the battery, see if Grin stocks it, and ask them to solder that onto your controller.

 

[llavalle]

WARNING: If you don't buy the battery from Grin, they will not solder the battery connector onto the black and red pigtails comiing out of the Base-or-Phaserunner controller. If you are rolling your own, you are expected to do that yourself.

When I tried that myself, the plastic holding the 4 blades melted before the blades heated enough to flow the solder. My framebuilder had a powerful temperature settable soldering station that could heat up the blade fast enough to flow the solder before melting the plastic frame.

Otherwise, perhaps work out what battery connector you need once you've chosen the battery, see if Grin stocks it, and ask them to solder that onto your controller.

Thanks for the tip - I've got the proper equipment to solder XT90 connectors, I've done plenty !