My new Custom GMAC build, now a BBSHD as well

linklemming

Well-Known Member
I just passed 1k miles on this build and I still absolutely love this bike and am glad I built it. While it can output up to 1500W and around 36mph, Im happy just pedaling it at 1.5 to 2.0 assist while I output 150 to 200 watts human watts Not much else to say here so I will just address certain areas

Cycle Analyst 3
Sure its big, bulky and downright ugly but functionally its perfect for an ebike unless you just dont care about all the options and programmability it provides. Im not sure how I would live without it these days. One of the most used functions is the Wh used. This is so much more accurate than simple voltage only capacity indicators although I have figured out how to read those accurately as well. Also a big fan of the presets (up to 3). I have one preset that is basically a US legal class 1 ebike (750W, 20mph). The second preset is used as 1000W PAS only (no torque sensor) with no speed limit. I use this preset for playing around with all the PAS options as I want to do another 52V DIY surly ebike build with a CA3, BBSHD and phaserunner. This preset is also fun for really low effort rides (ghost pedaling) where I prefer the PAS assist as opposed to using the throttle. I have the PAS setup to be power assist based (each assist level is a set amount of power). I also am using a cadence based power increasing/decreasing feature which I like. Basically after cadence of 50rpm, you can increase or decrease power based on rpm. I have found settings that I can actually live with although I still prefer torque sensing. The 3rd preset is 30amp limited(1200W just before 42V cutoff) torque sensing and no speed limit and where I ride 95% of the time.

GMAC 10t motor
Its a beast...nuff said. Without going into all the details which have been outlined before, its likely the only hub motor which would work on the surly troll frame without custom machined adapters/spacers. Havent run it in the summer yet but it usually runs around 61degrees C running 300-500W although I did get it up to 85C going up a 4-6% grade for a mile or so bucking a 20-30mph headwind doing around 25mph and about 1500W. The CA will start limiting current at 90C.

Phaserunner
This controller was overkill for this build as a baserunner would have suited me fine. That being said, there is more upgradability with this controller (like 72v).

Erider Torque Sensing BB
The main reason I even considered this build. Not as responsive as my Brose bikes but good enough for the intended use of this bike as pedal feedback isnt as important (to me) at higher speeds. Pedal feel is about as good as a DIY TSDZ2 I ran back in 2018 with opensource software. I have had the unit stop working once while riding thru a few puddles which got the bike quite wet (throttle got me home). I am running the cable from the BB to the CA under the downtube so its connector which is just in front of the BB is getting splashed by the front tire. Just bought some waterproof heatshrink to cover this connector that I will install soon.

Miranda Cranks
As noted before, the first set I just installed like I have all other square taper BB cranks over the years (pretty tight). After a few hundred miles the crankarms came loose and were destroyed (throttle got me home). I bought a second set and torqued them to 35ft-lbs (on the high side of the torque spec). I retorqued them for 10 rides, each time marking the position of the bolt with paint. Overall, the bolt was tightened ½ additional turn overall. This was done at around 400 miles so no problems for 600 miles. I also bought a set of low offset/qfactor bafang BBSxx and Shimano 6100 crankarms to have as backups.

2020 Deore brakes (2 piston)
I mention these brakes because most people would not recommend two piston calibers on a bike this powerful. I got the 2020 2 piston version at ½ price. They added 4 pistons for 2021 but at twice the price ($190). The surly frame is limited to a 160mm rotor in the rear so putting a quad piston in the back seemed silly. That being said, even with the stock resin pads, I have had no braking issues although I will eventually use a better pad compound.

Roxim X4 ebike light
Bought thru Grin, I wanted a light around 400 lumen with good cutoff so as to not blind pedestrians on many trails I encounter at night. I always run with 4 niterider lumina 850 lights in my backpack so I can supplement lights as needed. This light is about perfect for me and the cutoff works well and I have noticed people not shielding their eyes like they do with the lumina 850s even at 200 lumen. This light plugs into a power plug supplied by the CA. The SPL-01 grin sells is likely a better light for the price at 1900Lumen but I didnt want that on this bike. Only issue if if the light is switched on with the CA already on, it will reset the CA and trip settings (distance etc…). If I want to turn on the light, I turn off the CA, toggle the X4 switch, then turn on the CA again. Turning the light off has no issues.

Orign8 Strongbow Handlebar
I ran this handlebar on my Juiced CCX for a few months and loved it. Basically like a Jones bar with less sweep. I love the aero positions which also seem to allow for better use of my leg muscles. Ran a normal handlebar until just a week ago and just got frustrated on many rides where I encounter high headwinds. I can now ride faster and with less effort (rider and motor). Bike handling in the aero positions takes some getting used to.

27.5x2.6 tires
Although the Surly Troll originally was a 26inch frame, it accommodates 27.5 just fine wth same BB height as most of my other ebikes. I did run 26x2.3 Smartsams for a few hundred miles but felt the ride was too harsh as the surly frame is very stiff. I really noticed the additional harshness due to less tire rollover and will likely never ride 26 tires again. I built a new set of wheels to accommodate 27.5x2.6 Smart Sam tires and they fit the frame just barely(5mm clearance) with the rear axle at the front of the rear horizontal dropouts. I see no reason I couldnt run 27.5x2.8 tires if I slid the rear tire back in the dropouts although all the adapters/spacers would be a nightmare with the GMAC motor. While I like the SmartSams, I also bought some Johnny Watts and ran them for a few rides, settling in on running one in the rear for better tire wear.

Battery
Currently running a 52V 13.5AH Panasonic Battery purchased from Luna in 2018. Powers the bike fine but this pack probably isnt the best/safest for offroad use as it doesnt use cell holders to get all the cells required into the smaller shark case. It also doesnt use individual cell fuses which could prevent a fire if a cell shorts and all the other parallel cells dump current into the shorted cell. Will either go with a Luna Wolf Pack or a pack from EM3EV soon.

Any suggestion/comments on the Luna Wolf Pack orEM3EV batteries would be appreciated
 
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opimax

Well-Known Member
Do you build for others , love the sound of what the GMAC does. Tried to buy a Hilleater with it but they won’t ship to US currently. Your bike sounds awesome.
 

linklemming

Well-Known Member
Do you build for others , love the sound of what the GMAC does. Tried to buy a Hilleater with it but they won’t ship to US currently. Your bike sounds awesome.
Nope, dont build for others. Im more of an engineer type than a customer service type. Almost started several technical based businesses but customers are so finicky :D

Have you considered a juiced CCX? I have one and while it was crude (like the hilleater), it was a great bike especially with the HUGE battery.

While the overall power of the GMAC is awesome at up to 1500W, the CCX was very good at 700W-1000W.

I punished my CCX for 4k miles and it held up fine (visually inspected the motor). The CCX did everything I needed 95% of the time, I just wanted to go down the DIY path
 
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opimax

Well-Known Member
I am after a quality bike with the GMAC motor. I loved riding Stromers but had too many quality issues and also would like to pick up the speed a little from 28mph. I am waiting on WattWagons Helios currently which in mid drive . So far prefer rear hubs and of those DD of the bikes I have owned, hoping Helios changes my mind but following the n+1 theory I will need more than just Helios....enjoy your bike , iwill be reading anything you post on it :)
 

penserv

Member
Region
Canada
City
Calgary, AB
I wish I had found this forum before I started my build, but as it turns out I can see how similar other builders' experiences have been to my own. My buiild started with a 10T GMAC hub motor. Initially I had a Specialized Curve frame but had to sell it when I found that the triangle between the upper and lower tubes was not large enough to fit the battery (52V, 20 Ah). I ended up buying a cheap mountain bike in a large size with a big triangle and that worked well.

Some of the modifications I've done to the bike is that I put on a 220 mm rotor on the rear wheel to get more clearance between the brake rotor and the edge of the GMAC motor. I think 200 mm might have worked as well, but with the COVID supply shortage this winter, there were no 200's and only a few 220's. I also put on Magura MT5 brakes as the calipers are slightly narrower than Hope calipers.

Mine is a commuter bike designed to be ridden out to the golf course and back, about a 40 km round trip, but very hilly. I put Blumel Commuter II fenders on to keep me dry and clean(er). On the front fender, I had to notch out the fender to get more clearance on the tire. I found a wonderful product called Mouldable Glue. You simply knead it up into a ball and squish it in place. It hardens into a stiff silicone rubber. It sealed the cutout in the front fender and it doesn't rattle.

I put on the SPL-01 light from Grin Technologies. They are still out of stock but I got one from Hilleater. It's a wonderful light and I really like the 40 LED daytime running light feature. I also added a USB adapter so I could charge my cell phone or Garmin. That is also a Grin product, out of stock, that I got from Golden Motor. I learned the hard way that not all USB adapters are created equal, after I fried my cell phone. I didn't include the cost of the new cell phone into my grand total for the bike, which is currently estimated at around $4K CAD.

I went with the 24 pole PAS sensor rather than the torque sensor, since it looked like it would suit my riding style better. I've been having some difficulty setting it up, as the Grin manual is pretty basic. I've gotten more help from linklemming's posts than from Grin, mostly due to COVID. They don't answer their phones now so all correspondence is by Email, which might mean 2 or 3 days. I've already had one ride where the PAS wasn't set up right and didn't kick in when demanded, but I have a throttle and it sure beats pedalling a 65 lb bike uphill.

Another modification I put on this bike was to add an N-lock stem lock. When you take the key out, the handlebars move independently of the front fork. Not good for someone riding off with your bike, but great for storage, since the bike is only as wide as the pedals. I also added Pinhead locks on the N-lock, Brooks saddle, seatpost and wheels.

Today I'm going to add mirrors to the handlebars and by Saturday it will be warm enough to ride. Really looking forward to that. Hope the PAS is working.
 

theemartymac

Well-Known Member
Nope, dont build for others. Im more of an engineer type than a customer service type. Almost started several technical based businesses but customers are so finicky :D
My favorite movie quote of all time:
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penserv

Member
Region
Canada
City
Calgary, AB
linklemming said..

Also a big fan of the presets (up to 3). I have one preset that is basically a US legal class 1 ebike (750W, 20mph). The second preset is used as 1000W PAS only (no torque sensor) with no speed limit. I use this preset for playing around with all the PAS options as I want to do another 52V DIY surly ebike build with a CA3, BBSHD and phaserunner. This preset is also fun for really low effort rides (ghost pedaling) where I prefer the PAS assist as opposed to using the throttle. I have the PAS setup to be power assist based (each assist level is a set amount of power). I also am using a cadence based power increasing/decreasing feature which I like. Basically after cadence of 50rpm, you can increase or decrease power based on rpm. I have found settings that I can actually live with although I still prefer torque sensing. The 3rd preset is 30amp limited(1200W just before 42V cutoff) torque sensing and no speed limit and where I ride 95% of the time.
Where do you find presets or do you have to create them? My setup is essentially the same as yours, except I have the 24P PAS sensor. I've got my PAS levels setup in increments of 100 W up to 800 W and running at level 3 or 4 (300 or 400 W), I get about 60 km and then I'm about 1/2 charge or so. I get a bit antsy running below that level because I know what a pig this thing is to pedal with no power. Is there a setting that tells you how much battery you have left? I've got the 52V 20Amp battery and the battery guage seems to be getting pretty low by 48 V, but it could still be 20%. Hard to tell from a guage icon on the CA. I've got about 150 km on my bike now and I'm still fine tuning it, but I love riding it. Nothing to compare to though, except my road bike, since this is my first Ebike, but hills are a lot more fun under power.
 

mclewis1

Member
Region
Canada
City
Fredericton, NB
I have a CA controlled bike (just a little less powerful and a 12p PAS) but also with a 52v battery. I've been planning to fully customized the CA displays but so far haven't bothered to. I have customized the power ramp up (or whatever it's called) slightly to keep things very smooth (helpful in the winter) but otherwise it's stock. I was planning on creating presets for limited power levels but so far I haven't felt the need to.

I monitor my battery levels via the displayed voltage levels. After getting used to how fast it depleted the battery I learned to judge distance left from those voltage levels. With a 52v battery I've got between just over 58v (and often just 57v if I've only charged to 90%) and 46v (25% - my arbitrary low level). So half capacity was around 51-52v. For distance I'm getting approximately 7km/v with my 14amp/hr battery. So fully charged I've got 85-90km of capacity and when I see 50v I've got about 30km left (allowing for the inevitable initial sag and slight recovery).

Or more simply I don't start experiencing range anxiety or paying real attention to the voltage levels until they hit the 40s.
 

penserv

Member
Region
Canada
City
Calgary, AB
It would just be nice if there was a single definitive statistic that said how much battery you have left. I have a vested interest in this, as I live at the top of a hill. After having to pedal home once with no power, I'm not eager to repeat the experience. It's not like a cell phone - you can't carry a portable power booster. Actually, I guess that's not completely true, is it? All bikes have a portable power booster sitting on a saddle.....:confused:
 

mclewis1

Member
Region
Canada
City
Fredericton, NB
It would just be nice if there was a single definitive statistic that said how much battery you have left. I have a vested interest in this, as I live at the top of a hill. After having to pedal home once with no power, I'm not eager to repeat the experience. It's not like a cell phone - you can't carry a portable power booster. Actually, I guess that's not completely true, is it? All bikes have a portable power booster sitting on a saddle.....:confused:
There's much that could be discussed about the current CA and the limitations of it's monochrome character based display. Part of the concerns are also based in it's flexibility, since it can display info about and provide controls for just about any battery powered vehicle it's necessarily full of information, so what's displayed is always a compromise.

I find the state of charge indicator difficult to read/interpret at speed on the bike (I think it needs to be bigger with more resolution), and that's why I pay more attention to the actual voltage display (since it's a big simple easy to read number). As the CA learns about your battery (and you are resetting the trip odometer with each battery fill up right?) I guess with a little work it could offer a "how much mileage is left" number but it will always be widely affected by how hard you ride at that point in time. This to me could be a good step before a better graphical based CA ever shows up.

penserv - in your case I'd get an idea of how much mileage you are normally getting per volt (this can vary a bit depending on the state of charge of the battery so the number is very much a rough guess) so you have an idea about remaining distance available, and also do a few test runs on your hill getting home (notice how many volts the hill takes out of your battery). Then figure out what voltage needs to be left when you get to the bottom of the hill and use that number as your "empty" number for your rides.

In my case I've gotten pretty good at my 7 times table :)
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
The ONLY way I would build a GMAC is if they updated that display. That move WAY past due....
 

linklemming

Well-Known Member
Where do you find presets or do you have to create them? My setup is essentially the same as yours, except I have the 24P PAS sensor. I've got my PAS levels setup in increments of 100 W up to 800 W and running at level 3 or 4 (300 or 400 W), I get about 60 km and then I'm about 1/2 charge or so. I get a bit antsy running below that level because I know what a pig this thing is to pedal with no power. Is there a setting that tells you how much battery you have left? I've got the 52V 20Amp battery and the battery guage seems to be getting pretty low by 48 V, but it could still be 20%. Hard to tell from a guage icon on the CA. I've got about 150 km on my bike now and I'm still fine tuning it, but I love riding it. Nothing to compare to though, except my road bike, since this is my first Ebike, but hills are a lot more fun under power.
If you are asking how to get to the presets thru the CA menus, I have no idea.

I use the CASetup Utility on my PC to program my CA although I have changed a few things with the CA while on rides.

The presets are VERY obvious when using the CA Setup Utility
 

linklemming

Well-Known Member
It would just be nice if there was a single definitive statistic that said how much battery you have left. I have a vested interest in this, as I live at the top of a hill. After having to pedal home once with no power, I'm not eager to repeat the experience. It's not like a cell phone - you can't carry a portable power booster. Actually, I guess that's not completely true, is it? All bikes have a portable power booster sitting on a saddle.....:confused:
There most certainly is and I use it all the time (although the battery icon seems pretty accurate).

Its the WH used per ride. My CA shows this on the one rollling/changing display
 

linklemming

Well-Known Member
An update on the second set of Miranda cranks....they are toast as well.

Noticed they were loose the last ride and they required tightening every few miles.

Just installed a set of Shimano FC-E6000 crankarms, hopefully these will work better
 

penserv

Member
Region
Canada
City
Calgary, AB
An update on the second set of Miranda cranks....they are toast as well.

Noticed they were loose the last ride and they required tightening every few miles.

Just installed a set of Shimano FC-E6000 crankarms, hopefully these will work better
I've been using Shimano Hyperdrive cranks on my build and I've never had a problem with them coming loose. I always have to use a crankset extractor to remove the cranks as they're on the square taper quite solidly. I just did it again yesterday when I changed from a 42T front ring to a 44T.
 

linklemming

Well-Known Member
I've been using Shimano Hyperdrive cranks on my build and I've never had a problem with them coming loose. I always have to use a crankset extractor to remove the cranks as they're on the square taper quite solidly. I just did it again yesterday when I changed from a 42T front ring to a 44T.
I only need the crankarms as the chainring and spider are seperate from the crankarms.

Not sure what the deal is here. I have only had one square taper crankset ever come loose before this and that was over 20 years ago. I have never been all that precise when tightening the crankarms down, just using a longish allen wrench and have never had to retighten.

Hopefully the new shimano FC-E6000 crankarms will fair better. They required a fair bit of tightening after the first ride but not so much after the second.

I have several spare Shimano Hollowtech MTB cranksets I could use if need be but would have to go to PAS only.

I specifically did this build to have a torque sensor, it would be a serious bummer to go to PAS only.
 

penserv

Member
Region
Canada
City
Calgary, AB
I specifically did this build to have a torque sensor, it would be a serious bummer to go to PAS only.
I hear you on the PAS only. I went with PAS because I found an explanation on the internet that said if you just want a certain level of power assist, go with PAS, which suits my riding style. It further said that with a torque sensor, the faster you pedal, the more power assist you get. That may or may not be true, as it appears that you have your torque sensor set up with increasing levels of PA. Over the weekend, I found out the hard way, that I did not have the throttle configured correctly. If I had PAS at 300 W and hit throttle, expecting full power, I was only getting 300 W. So after a couple of falls, from not getting up to speed on a steep slope, I've now got my throttle to provide a lot of power when I need it.

With these DIY's, do you ever come to a place where no more fiddling is involved? Is "Set it and Forget it" a myth?
 

linklemming

Well-Known Member
I hear you on the PAS only. I went with PAS because I found an explanation on the internet that said if you just want a certain level of power assist, go with PAS, which suits my riding style. It further said that with a torque sensor, the faster you pedal, the more power assist you get. That may or may not be true, as it appears that you have your torque sensor set up with increasing levels of PA. Over the weekend, I found out the hard way, that I did not have the throttle configured correctly. If I had PAS at 300 W and hit throttle, expecting full power, I was only getting 300 W. So after a couple of falls, from not getting up to speed on a steep slope, I've now got my throttle to provide a lot of power when I need it.

With these DIY's, do you ever come to a place where no more fiddling is involved? Is "Set it and Forget it" a myth?
I have been playing around with PAS (non-torque based) settings on one of my presets. One of the things I really like about the CA is the ability to not only have a set power level for each power level but to increase/decrease it based on cadence above a set rpm. I currently have this preset setup to have 9 PAS levels (100-1000watts) and to increase power based on cadence. I have it setup such that around 90rpm its matching the next higher assist, i.e. assist 1 goes from 100-200 watts, assist 2 goes from 200-300 etc.

This is better than just a set power level but still feels dead and non responsive. My impression is like I am just adding power to a BIG flywheel like an exercise bike. This effect seems to decouple me from the riding experience somewhat. That being said, on some rides its useful like if Im sore from the day before. I definately notice a lower heartrate and less overall exercise.

I like this bike so much, I have been contemplating another build and just having my ebike stable be 2 DIY bikes and my Bulls eMTB.

Finding another surly frame(Ogre, ECR or bridge club) has been a challenge. I passed on a few due to not liking the colors and then realized I might not be able to find one at all(they sell out quickly) so I have spent the last week searching every inch of the internet. I had given up and started looking at getting a frameset to support a bafang ultra and was ready to lay down the cash for a Wattwagon UC Commuter Pro frameset but they dont have anymore non fatbike frames. I would have ordered a Helios if they were available.

Low and behold I found a black surly bridge club by a stroke of luck and ordered it tonight. Hopefully the shop actually has it.

So the question becomes do I do another MAC 10t motor with torque sensor, phaserunner and CA or a BBSHD with phaserunner and CA. I have tried a BBS02 before and could never warm up to the non torque based PAS experience eventhough I played with many settings. The CA and phaserunner seems alot more versatile.

I have also been considering a CYC stealth torque based mid-drive kit: https://www.cycmotor.com/x1-stealth

Still debating what to do.

It would be interesting to put on a BBSHD and do a back to back comparison with the MAC10t on some local trails and climbs to ptrovide some hub motor vs hub drive data to fan the flames. In the end though I really just want a torque based system.
 
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Johnny

Well-Known Member
I have been playing around with PAS (non-torque based) settings on one of my presets. One of the things I really like about the CA is the ability to not only have a set power level for each power level but to increase/decrease it based on cadence above a set rpm. I currently have this preset setup to have 9 PAS levels (100-1000watts) and to increase power based on cadence. I have it setup such that around 90rpm its matching the next higher assist, i.e. assist 1 goes from 100-200 watts, assist 2 goes from 200-300 etc.

This is better than just a set power level but still feels dead and non responsive. My impression is like I am just adding power to a BIG flywheel like an exercise bike. This effect seems to decouple me from the riding experience somewhat. That being said, on some rides its useful like if Im sore from the day before. I definately notice a lower heartrate and less overall exercise.

I like this bike so much, I have been contemplating another build and just having my ebike stable be 2 DIY bikes and my Bulls eMTB.

Finding another surly frame(Ogre, ECR or bridge club) has been a challenge. I passed on a few due to not liking the colors and then realized I might not be able to find one at all(they sell out quickly) so I have spent the last week searching every inch of the internet. I had given up and started looking at getting a frameset to support a bafang ultra and was ready to lay down the cash for a Wattwagon UC Commuter Pro frameset but they dont have anymore non fatbike frames. I would have ordered a Helios if they were available.

Low and behold I found a black surly bridge club by a stroke of luck and ordered it tonight. Hopefully the shop actually has it.

So the question becomes do I do another MAC 10t motor with torque sensor, phaserunner and CA or a BBSHD with phaserunner and CA. I have tried a BBS02 before and could never warm up to the non torque based PAS experience eventhough I played with many settings. The CA and phaserunner seems alot more versatile.

I have also been considering a CYC stealth torque based mid-drive kit: https://www.cycmotor.com/x1-stealth

Still debating what to do.

It would be interesting to put on a BBSHD and do a back to back comparison with the MAC10t on some local trails and climbs to ptrovide some hub motor vs hub drive data to fan the flames. In the end though I really just want a torque based system.

I would be very interested in that CYC kit. It looks like a good design, very powerful, coming with a very good controller, torque sensing bottom bracket etc.