Grin's rear all axle motor!

[offGridDownUnder]

a carbon fiber frame. I prefer it because for long rides they are much more comfortable than the aluminum ones. I'm considering this one (Aluminium frame) also.

The fellow who is helping me make my Trike (I don't have a workspace) is a professional frame builder who repairs carbon bicycle frames. Unless the carbon frame is designed for a particular load, it won't take it. They don't leave accidental excess reinforcements in carbon frames. I would abandon this idea.

For comfort, I would expect a steel frame to be best.

 

[fenomeno]

The fellow who is helping me make my Trike (I don't have a workspace) is a professional frame builder who repairs carbon bicycle frames. Unless the carbon frame is designed for a particular load, it won't take it. They don't leave accidental excess reinforcements in carbon frames. I would abandon this idea.

For comfort, I would expect a steel frame to be best.

I agree...
...But the stiffness that you can get in the bottom bracket with a carbon fiber is not comparable neither to steell nor to aluminum.
It is clear that to windstad impacts carbon it is not the best selection.

 

[uhmwpolyethylene]

Then I reached the point I wanted to 350w/1000w = 35% of the throle...

I knew that we were going to reach this point in the conversation. What in hell are you focusing on this product? It is pricy, weighty, 1000 watt!!!
I own this BMC with Mahle X20 bike. It works fine but I can't hack the speed limit. I ride with semiprofesional people (they ride 10.000km per season) and I'm not. It is hard for me to follow them with a 13 kilos bike, in flat terrain at 35km/h riding in a short steep slope after 100 kms of route. Then as it is impossible to hack what I own and after a season being able to follow them in the uphills, something that did not happened in the past, I want to DIMyself electric bike. If possible I'd like to focus in a thru axle rear hub motor (it is the next future) I'd like to focus in a cassette torque sensor (it is the next future) I'd like to focus in a light motor 250w continuous with no overheating (almost impossible for a geared)
And this where I am. It seams that I will have to wait until truckrun put the RN04 properly in the market or not if you give me your advice... (There is also this Bofeili rear hub motor but being honest I do not trust on them)

I you want to share your knowledge I will be more than greatfull...

Thanks

It's a shame there's no ultralight 100-250w / 500w DD rear hub on the market , maybe they could also incorporate Axial flux design to increase torque and shave weight

All Axle looking pretty tempting , weren't some people reporting issues with the max45, wondering if the single speed narrow 45 might be better and you could maybe use a few front gears instead to get some leverage . Might get the regular 27 one instead , has anyone had any issues with that.

 

[offGridDownUnder]

maybe use a few front gears instead to get some leverage

With a powerful motor, the gearing is more for the rider's comfort, or for the rare emergency when the motor does not work.

3 speeds on the crankset might be enough - it matches the 3-speed internal hub gears.

An Efneo 3 speed internal crankset would avoid a front derailleur and also shift when stopped - I have one on the cranks of my trike. For serious expense, a Pinion gear box offers many ratios, but requires a dedicated frame modification.

 

[uhmwpolyethylene]

With a powerful motor, the gearing is more for the rider's comfort, or for the rare emergency when the motor does not work.

3 speeds on the crankset might be enough - it matches the 3-speed internal hub gears.

An Efneo 3 speed internal crankset would avoid a front derailleur and also shift when stopped - I have one on the cranks of my trike. For serious expense, a Pinion gear box offers many ratios, but requires a dedicated frame modification.

Oh yeah , that product looks pretty cool, price point is quite high though. And eyeballing it I guess it's more like a complexishhh IGH (?) which kinda reduces the "zenlike simplicity" of a DD build , I'm sure it's a good option for snowy, dirty etc conditions though! Says it's made in Poland probably great for winter.

A discussion on SS / DD
Single Speed Conversion : Optimal Chainring-Cog Ratio Post in thread 'Single Speed Conversion : Optimal Chainring-Cog Ratio'

 

[kuromaku]

All Axle looking pretty tempting , weren't some people reporting issues with the max45, wondering if the single speed narrow 45 might be better and you could maybe use a few front gears instead to get some leverage . Might get the regular 27 one instead , has anyone had any issues with that.

I swear I'm not a shill for Grin, and Grin does not list maximum torque limits for their motors on their website and have been reticent to give one via email, but the folks having trouble with their TAs were running at torques far above what I think Grin had in mind when they designed it, which is the ~90A motor current limits of their own controllers. I haven't had a chance to run my Max45 yet, but have had various 27mm models in service since 2018 with ~100A motor current limits and haven't had any trouble with them aside from one that had been built with an incorrect thermistor value.

 

[neptronix]

One thing to consider is that 100A on the max45 is a lot more torque versus the 27nm version, consider it more like 120A or higher effectively.

Huge difference in the torque per amp, 27mm is really inefficient in the low RPM range unless you're in a small wheel.

I have no issues with the torque arm running 120A phase on my 27mm version.

 

[amberwolf]

I have no issues with the torque arm running 120A phase on my 27mm version.

The entire axle is built differently and connected to the stator differently on the regular GAA, and that may be a significant part of the problems seen with it so far.

I don't recall for certain but I think the torque arm itself is also different where ti connects to the axle (it's certainly very different than the GMAC).

Salsa Blackborow with Grin Max45

Taking a look at the grin page for the GAA, the adapter drawings appera to indicate a two part axle core for the rear versions, and a single part core for the front, but the torque-arm side is all one piece, so torsional stresses can't do what i described and twist one part of it differently...

endless-sphere.com

 

[offGridDownUnder]

Grin does not list maximum torque limits for their motors

Plug the motor into the Grin Motor simulator and that will tell you the maximum torque they have measured for the motor.

 

[smitty2k1]

My All Axle v3 rear seems to have developed a weird vibration. It almost feels like a very light regenerative braking is on. I can really feel it in the pedals. It seems to increase and decrease with speed but is always there. No reduction in performance from what I can tell but it's kinda uncomfortable to ride with the vibration.

Wheel was built by Grin, has 2500km and seems to still be tensioned and true. It's a small 20" wheel on my Edgerunner cargo bike.

Pulling apart the bike I noticed the cassette was not spinning straight. Replaced it with a new one and it spins straight but the vibration is still there, but not as strong. Freehub body seems fine?

Grin email support hasn't really had any thoughts. Only thing I can think of is if I slightly damaged a bearing?

It's my daily kid hauler so trying to diagnose without putting the bike out of condition.