GMAC vs MAC and Infineon vs Phaserunner

RyanC

100 mW
Joined
Oct 9, 2016
Messages
48
Location
Denver, CO
Hello all-

I'm planning a new build on an edgerunner and was hoping for any feedback here. I've pretty much settled on a MAC or GMAC motor and was looking at the Grin kit vs the EM3V kit vs a bit of each. My priorities are relatively lightweight, would like to have ~1500w acceleration available, but would use that rarely, low-maintenance, torque sensor (Sempu looks best here) and will generally commute on the fairly flat bike path so not a lot of braking.

I'm a bit torn between the MAC and GMAC because with no clutch, the GMAC is probably more reliable, but with not much to be gained via regen, the clutch might be nice.

So one question is, with 1500w acceleration being rare, will the clutch be reliable? Even 1200w would be plenty. Looking at a 8T in a 20" wheel.

The other main question is Infineon/EM3EV vs Phaserunner for the (G)MAC. I found older posts that the PR isn't a great fit, but it sounds like Justin has it working well now, and he says he has firmware about ready to go for the GMAC that will counteract the drag of the GMAC.

I would appreciate any input here. Thanks!
 
I bought the GMAC from Grin. I wanted a clutch because I want to be able to coast like a regular bike. I am new to ebikes, so I could be wrong about how I will use the bike. However, I think I want to ride it like a regular bike and have some assist when I need. The GMAC looked interesting though because it has an integrated torque arm and standard 10mm axles. I wasn't thrilled about having to file my dropouts to accommodate a larger axle. I also wanted the Phaserunner because it is small in size and is an FOC sine wave controller so the motor will run quieter. The GMAC uses a new L1019 Higo connector and the kit comes with a version of the Phaserunner with the same connector.

I emailed Grin to ask if I could install a clutch in it and Justin offered to sell me a prototype of the GMAC that had a clutch. He had ordered half a dozen during the testing phase. So that is what I bought. I haven't installed the motor yet. It is a frame up build and I am just getting the last of the parts I ordered this week. I will start the build of the bike this weekend.

I bought my battery from EM3EV and they were very good to work with as well. I don't think you could go wrong with either vendor, but the new GMAC checked some boxes for me that EM3EV's motor did not.
 
How fast are you looking to go?

I've done my first geared motor ( ezee ) in a 20" wheel and was disappointed by the efficiency in the smaller wheel where RPM must be higher vs a 26".
A non-clutched MAC will drag like crazy when the power is off. This drag will be accentuated by the small wheel. I wouldn't recommend it, unless low weight at the expense of everything else is your ideal.

For a small wheel, a 27mm or 30mm DD would be a lot nicer. I'd have my eye on the new 212h 9C as a DD equivalent to the MAC. the smaller the DD, the less rolling resistance.. i imagine a 27mm DD spins pretty well in a 20" wheel.

You can actually get a lot of energy back by regen. My last bike had around 90% of it's braking force come from regen. You can get the energy you spend accelerating back using regen. Really matters if you are in hilly territory or in the city ;)
 
neptronix said:
How fast are you looking to go?

Around 25mph or so, maybe a little faster, but we have less air up here in Denver so that's a little easier than the calculators suggest. I'm not going to loose sleep over +/- 1-2mph though (or +/- a couple lb). My main commute is almost all bike path, so no real stop and go other than about a mile at the end, just braking for tight turns. All my other riding will be less than 36mi round trip, so I'm not terribly concerned with efficiency outside of the bike path, which is not much for hills or stopping.

Hmmm that 9c looks interesting...6.3kg ins't too bad. I won't need much zippy accel for my main commute (and won't be able to afford the wh), but riding through town (on shorter trips) I would like to be able to have pretty zippy acceleration. Everyone has an SUV here, so it can be hard to see cars coming when stopped at a stop sign- nice to be able to shoot through the intersection.

I had a q128c in a radwagon, and I loved it when it was working, but it (they) weren't very reliable. One died with the wires getting frayed (my fault) and on another I broke the clutch with my legs (standing on cranks)...only way to fix was to swap the whole core. I could hold ~27mph on the fairly heavy radwagon (2 11ah dolphin batteries from BMS, bags, kid, me) with my legs and LCD06 showing about 350w. That type of performance, slightly better 0-20mph, and better reliability would be my ideal. That was a 26" wheel though. They do make a 368rpm 36v q128c it seems, but I would like something more robust and trade for it being heavier.

I don't like the feel of drag, for the sake of keeping things bike-like. When the Rad got stolen I got a stromer and I don't really care for the drag. Justin says the forthcoming phaserunner firmware can 'coast' with 20-40w to overcome the drag though...
 
The MAC/GMAC is probably more of a motor than you'll need, in a 20 inch wheel. I remember it hauled my then fat ass ( 270lbs ) up some pretty steep hills in the Denver area.

[youtube]UD_K_TRGcs4[/youtube]

Here is me flogging an old 8T ( circa 2011 ) with thick 0.5mm lams in a 26" wheel hitting ~45mph. Can't imagine how much goose a new one can kick out... in a 20" wheel... with a nice helping of volts or at least a 6T winding... :)

Just remember, a dd, especially in a 20 inch wheel, is quite a bit more efficient overall. You'll also like regen if you're doing rides in hilly areas. If you are going up and down hills frequently, you'll need to budget for brake pads. No joke!
 
neptronix said:
Just remember, a dd, especially in a 20 inch wheel, is quite a bit more efficient overall. You'll also like regen if you're doing rides in hilly areas. If you are going up and down hills frequently, you'll need to budget for brake pads. No joke!

Ok cool, and yeah I did eat through brake pads on my old commute, which was more through the city. I am planning quad piston brakes on this bike for the larger pads if nothing else...

That does make the 9c 212 more interesting to me though, less drag then the gmac, only 4lbs heavier and if it is significantly more efficient then the weight can be somewhat offset with less batteries for the same range.

Does anyone know more about it? How many watts and how high of volts it can handle?

Thanks again-
 
Been riding a trike with MAC10T, Phaserunner & Thun a few years now. Quiet, efficient, powerful, with ideal response.

Really appreciate the clutch.

I've bought and tested over a dozen systems and played with configurations, this one is by far my favorite.
 
Are you running the Thun via a CA, and how much on/off lag time does the torque sensor have compared with a 12 or 24 pole PAS?
 
Just thought I would post a quick followup-

I ended up doing the GMAC with a phaserunner and a 60v 17.5ah blue battery with a Sempu BB. This is on an edgerunner in a 20" wheel.

So far I love it. The drag from the clutchless GMAC isn't bad at all, in spite of the numbers, in a 20" wheel it seems to coast as good or better than my Stromer. I'll probably still mess with the coasting function when the firmware comes out, but I would be perfectly happy as is. OTOH the variable regen is awesome, the MT5e brakes I have are basically a backup/emergency brake. I bet these brake pads will last me for thousands of miles. For me this is a worthwhile tradeoff.

The overall efficiency is also great for my use. On the flats with no wind I can hold around 25mph with around 300w from the bike and a good effort on the pedals. I went on a 42mi ride with my 4 yo daughter, and her bike strapped to my bike the other day and did about 17wh per mile. I used the throttle plenty and wasn't trying to hold back. Pretty good for rolling at ~350lbs all together. With roughly a 60mile range, I'm starting to plan some bikepacking trips where I can ride the bike the whole way.

All this and the big edgerunner is actually a little bit lighter than the Stromer. This is important to me so I can carry it inside.

My only 2 issues are the Sempu is sometimes acting a little strange, but Justin is going to RMA it, and over 600w or so the GMAC is a little on the loud side...I'm guessing a DD would be a tad quieter here, but as far as tradeoffs go I'm happy with the light weight of the bike.
 
3000 miles on a MAC 10T and Phaserunner at 52V 30A. Another 1000 miles before the Phaserunner with Infineon at 52V 40A.

That's on 65 lb trike with 180 lb rider on mountain roads. No trouble or noises or backlash. Solid.
 
RyanC said:
So far I love it. The drag from the clutchless GMAC isn't bad at all, in spite of the numbers, in a 20" wheel it seems to coast as good or better than my Stromer. I'll probably still mess with the coasting function when the firmware comes out, but I would be perfectly happy as is.

We're just now in the broader beta test phase for this feature and the software that enables you to play with it can be downloaded here:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=65031&start=1175#p1478783

I've now got a few months of test riding in with the GMAC and electronic freewheeling feature, but I agree too that I never found the drag to be at all problematic in the first place. I can't say that I appreciably tell the difference between having a constant 20-40 watts of background power when I'm not using the motor power vs there being a little bit more drag.

In my case with a Big Dummy cargo bike, whenever I'm pedaling I would tend to have at least some PAS assist active no matter what, even if it's just 100-200 watts, and the times that the freewheeling kicks in is only when I am coasting or going downhill with the PAS turned off, in those cases I'm more inclined to want the motor to do regen rather than constantly expend a bit of energy so that I coast just a little bit faster.

So my take is that for most ebike riders this feature is a little bit 'gimmicky' in that it doesn't materially affect how you ride or the ride experience. It's only the small class of ebike rider who do substantial portions of their commute pedaling without any assist where it would have a worthwhile effect. But if a gimmick is what's needed to get people to drop the freewheel and embrace clutchless motors with regen, then I'm all for it!
 
justin_le said:
So my take is that for most ebike riders this feature is a little bit 'gimmicky' in that it doesn't materially affect how you ride or the ride experience. It's only the small class of ebike rider who do substantial portions of their commute pedaling without any assist where it would have a worthwhile effect. But if a gimmick is what's needed to get people to drop the freewheel and embrace clutchless motors with regen, then I'm all for it!

Maybe it's a little gimmicky. But I also see it as a nice feature if you find yourself with near depleted batteries and are limping on home.

I can also see it as a nice feature if you want to toss in some "unpowered" "workout" rides in your mix of riding.
 
So Justin, when are we gonna see a tuaxle version of the GMAC? Paul/cell_man had a prototype shown at interbike 2015. It would be dope if you guys at grin can pick up the torch on this one. This would make us AWD ebike builders have more choices of front suspension forks for our AWD builds. =D
 

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I just passed 3000 miles in a little less than a year with my MAC + Phaserunner combo, including occasionally feeding a full 40A at 52v on my short hill climb home, and it's still working great. This weekend I opened the motor up to add some more grease, since I was noticing that it was getting a little noisier, and aside from the old grease, everything inside still looks practically new.

I have an 8t in a 20" front wheel, and I know sooner or later I'm going to put a GMAC 10t in the rear wheel in addition. Right now I have a belt drive and Nuvinci that I really like, and I don't really want to give it up...but all of that extra torque would great for climbing the hill with a lot of weight, and replacing the pads on Shimano Zee brakes is awfully expensive.

I'm also curious about sticking a GMAC on an old mountain bike that doesn't have disc brakes, since it'd provide the all weather stopping - though, I don't totally know if I'd want to rely too much on a system that complicated for stopping.

Here's my hope - that the front GMAC hasn't come out yet because it's going to be thru-axle compatible. 🤞🤞🤞
 
Has anybody tried to use the GMAC plate that carries the planetary gears in place of the clutch in a MAC? I have a MAC and I want to get rid of my clutch...it was great when it was working but I push the motor harder than the clutch can handle now.

To answer the original posters question...MAC vs GMAC, I like the GMAC better, several reasons...
A. The wiring comes out the side of the axle which makes working on the motor a lot simpler as well as it protects the wiring better than when it comes out the end of the axle like on the MAC.
B. No clutch to have issues.
C. Integrated torque reaction arm.
D. The GMAC is sealed better than the MAC so I can liquid cool it easier if I hot rod it.
E. Regen is just icing on the cake.

Controllers...Phase Runner vs Infineon, that is a tough one...it depends.
The Infineon is cheaper but has less capability where the Phase Runner cost more and has more capability. If I was going with a GMAC I'd get the Phase Runner but if I was going with the MAC I'd probably go with the Infineon...just my weird way of matching things up.
 
I'm running a Mac 10T front hub motor.

I was previously using a KT sine wave controller (PSWPower 20A 6fet), and it resonated badly, which made the forks vibrate - it was terrible.

Now I'm using a phaserunner, and it's buttery smooth and quiet. It's a massive improvement, and I should have spent the money on the phaserunner in the first place. It also looks much smaller and tidier on the bike.
 
Just out of curiosity, would this mod be able to simulate freewheeling in the GMAC?

http://endless-sphere.com/forums/viewtopic.php?f=2&t=37190&p=582952#p546409
 
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