Rear All-Axle, Fst HG Grin Hubmotor with Phaserunner, CAv3, and 52V in FS 29inch MTB

[hjns]

Nice!
Note that the phaserunner is nice and compact, but won’t support a lot of torque from a hub motor due to very low phase amps. If you try the 40A controller in the simulator (IRFB4110 FET version), you double the torque off the line (85Nm). But the phaserunner is much tidier for your build though, and sounds like it’s delivering enough to have lots of fun with, and meets all of your requirements.

Correct. I know the Phaserunner can handle momentary high bursts, so let's see what power we can tweak out of the current system. I really dont need a lot for longer times. No hills in the Netherlands.

 

[hjns]

Nice work finishing the build!
-What's the weight before and after?
-Will you add fenders/ will you ride in the rain?
-I suppose bike is not legal in Switzerland as is? Are you worried you may get stopped?

Thanks! Much appreciated.

• Weight now: no clue. Weight before: 15kg
• Yes, will add fenders, yes, will ride in teh rain.
• No, bike is not legal in Switzerland, nor in Netherlands. I am not worried I may get stopped, because in the Netherlands, there are soooooo many bikes and now also sooooo many speed-pedelecs.

I will try and see if I can find a scale large enough for my bike.... I would not be surprised if I just added 10kg (motor, batterie, other stuff).

 

[hjns]

I want to include this basket and fixate it on top of my Thule rear Tour Rack, to include the big battery there.

 

[neptronix]

I want to include this basket and fixate it on top of my Thule rear Tour Rack, to include the big battery there.

Up high and in the back of the bike is the worst location to mount a big battery.
It will induce steering effects which are very undesirable and somewhat dangerous on a bike that goes high speeds.
With really big batteries, the possibility of the seat tube snapping is real.

You really want that battery somewhere in the center of the bike, ideally in the center triangle.

 

[E-HP]

Correct. I know the Phaserunner can handle momentary high bursts, so let's see what power we can tweak out of the current system. I really dont need a lot for longer times. No hills in the Netherlands.

It's a good controller for your application and you may be able to get closer to your speed goals with field weakening.
Did you try flipping the battery? The angle on the front lines up better for shock clearance when flipped. You may have barely enough room to get it in and out in that orientation, but maybe not. Worth a try.

 

[Zambam]

I want to include this basket and fixate it on top of my Thule rear Tour Rack, to include the big battery there.

Is that a carbon fiber swing arm the Thule rack is mounted to? Not sure if that's a good idea with such a heavy battery. Carbon fiber is difficult to inspect for stress cracks under the clamps w/o removal.

 

[chuyskywalker]

Ok, I made an important mistake here. I had measured the space within the triangle, and the very large 52V battery pack should fit exactly. Well, when I put the pack inside the triangle, it did fit, but I would never be able to remove the battery pack from the bike to charge it. I

You've got a lot of clearance on that bike, too. Depending on your riding style/terrain, you could consider mounting it under the triangle (ie, hanging). Plenty of setups do this without too much hassle, and bringing that weight down is a big plus.

 

[artbo]

i have a similiar setup, Full suspension with Grins all axle but in standard winding, phaserunner and CA. it "was" originally a chinese bafang ultra frame, but after errors and fails with bafang i gave up and ordered the Grin Products, i had to weld a BSA bottom bracket "adapter". The phaserunner is in the place where the bafang motor was.

you could build a triangle battery case and put the phaserunner in there and make all the cables more hidden but it wouldnt be removable.

i have fitted a 154cells battery, 14s11p with 18650ga cells in this triangle. its not removale because i only charge at home or at the camper van and a removable case is more complex.

here is my setup shortly after i finished it months ago and one picture with the bafang ultra motor. i now have front and rear schwalbe johnny watts(great tires) and a front fender. my torque arm is also in the wrong position on this photo, it had to move to the upper part of the swing arm.

 

[hjns]

Up high and in the back of the bike is the worst location to mount a big battery.
It will induce steering effects which are very undesirable and somewhat dangerous on a bike that goes high speeds.
With really big batteries, the possibility of the seat tube snapping is real.

You really want that battery somewhere in the center of the bike, ideally in the center triangle.

Ah, yes, good point! I had not thought of that.
So, for this big battery, the top tube is the best place. I am still considering whether I will pull the trigger for the smaller downtube battery. It is also slightly lower voltage than my current one, so I will also have to give up some speed (in addition to giving up a lot of range).

 

[hjns]

It's a good controller for your application and you may be able to get closer to your speed goals with field weakening.
Did you try flipping the battery? The angle on the front lines up better for shock clearance when flipped. You may have barely enough room to get it in and out in that orientation, but maybe not. Worth a try.

No, I did not try flipping the battery; excellent suggestion. I will try it.

 

[hjns]

Is that a carbon fiber swing arm the Thule rack is mounted to? Not sure if that's a good idea with such a heavy battery. Carbon fiber is difficult to inspect for stress cracks under the clamps w/o removal.

Correct, both main frame and swing arm are carbon. With now multiple people telling me that the rack is the worst place to put my battery, I will abandon that idea.

 

[hjns]

You've got a lot of clearance on that bike, too. Depending on your riding style/terrain, you could consider mounting it under the triangle (ie, hanging). Plenty of setups do this without too much hassle, and bringing that weight down is a big plus.

Also an excellent idea. I will do hardly any off-road driving, and definitely no jumps or rocks. Therefore, I will first try the mounting under the triangle idea. Thanks!

 

[hjns]

i have a similiar setup, Full suspension with Grins all axle but in standard winding, phaserunner and CA. it "was" originally a chinese bafang ultra frame, but after errors and fails with bafang i gave up and ordered the Grin Products, i had to weld a BSA bottom bracket "adapter". The phaserunner is in the place where the bafang motor was.

you could build a triangle battery case and put the phaserunner in there and make all the cables more hidden but it wouldnt be removable.

i have fitted a 154cells battery, 14s11p with 18650ga cells in this triangle. its not removale because i only charge at home or at the camper van and a removable case is more complex.

here is my setup shortly after i finished it months ago and one picture with the bafang ultra motor. i now have front and rear schwalbe johnny watts(great tires) and a front fender. my torque arm is also in the wrong position on this photo, it had to move to the upper part of the swing arm.

Nice setup. However, for me the removal battery is non-negotiable, due to the frequent charging in house and in the office that I need to do, whilst not being able to bring the whole bike inside. I thought about putting the phaserunner somewhere hidden. However, the thing gets hot, and I like that at least part of it is in the open to manage the temp.

 

[Zambam]

To allow removal of battery under the triangle (for charging indoors). What about using magnets backed up with a velcro /bungee that provides the holding power? Magnets just has to be strong enough to hold the battery in place while you attach the bungee.

 

[chuyskywalker]

Luna made a battery pack that famously uses some ABSURDLY strong magnets that could handle ebike bumps and jumps, but it's long since discontinued. Sadly, even if you can find these packs, they're basically e-waste because they potted the whole thing :/

 

[99t4]

I will try and see if I can find a scale large enough for my bike....

Just use a regular scale. Weigh yourself first, then weigh yourself again while holding the bike. Subtract the first from the second-- that's the weight of the bike.

 

[lnanek]

I saw in a CYC conversion video recently the guy used horizontal rails to slide the battery in sideways. Allowed a tighter fit than something where you bolt in within the plane of the triangle.

Not sure I'd want a heavy battery attached to a carbon frame, though. I bought carbon handlebars recently and I can get a scary crack from them just tightening stuff to the handlebar with my multi tool even with a bunch of electrical tape underneath to provide some "rubber' padding. Also tried a 5nm torque key, but that was too loose for the stem clamp so the handlebars kept turning even with carbon grip paste added.

Carbon is nice and light and strong in the direction it's laid up to be strong in, but just not trustworthy for random directions.

 

[hjns]

OK, I found the perfect spot for the battery. I did try all potential ways to get it within the triangle. It would fit right in, however, in no way was I able to then remove the battery for charging. Hence the only better place was indeed under the triangle. The stability of the bike has improved tremendously. So, this works best.


I turned the bike upside down to look at the torque arm again. This is the final position, giving the rear brake disc about one centimeter of space, which is more than enough.


I will continue to ensure the fixation of the torque arm remains strong.


Testdriving showed another weak point. In this position, the battery connector into the Phaserunner tends to slip down, and of course, then out of the Phaserunner. The first time this happened, I saw the electricity leave the CA, and I started looking online if I hit some kind of programmed threshold or blew an unknown fuse or so. After 5 min searching, I decided to check the connections, and the Phaserunner was the first thing I looked at. Of course, it was then immediately clear what happened. Anyway, I will use a ziptie to keep it in place.

Conclusion
I am very happy with the current configuration. FS is totally comfortable and luxurious. Lots of places to go faster than 50kph safely and without detection, so I am having a blast.

Let me know what you think?