++Giant Glory DH build + GMAC + PhaseRunner

This thread is about electrifying my Giant Glory, Full Suspension, Down-Hill bike as a 2nd e-bike project.
(pic from Giant Bicycle's web)





## Existing 1st E-bike : 11k+ km, with in 2 years of conversion.







My BBSHD + DIY 14S5P LG18650MJ1 on 27.5” Bianchi hard-tail MTB. Avg 8.xx wh/km with medium peddling over thousands of km. Bike weights around 35 kgs. E-part has been very reliable while the bike's M-part has been "fragile". I have replaced 1 Shimano cassette, 1 rear hub, spokes, 1 front rim, 3 chains, 6 tires+8 tubes, 3-4 brake pads, 2-3 disc rotors, etc. Even my riding is rather gentle and 99% on concrete/asphalt road, mechanical parts broke down like crazy. I do not use cheap important parts since I am too lazy to walk the bike back home but a lot of mechanical parts managed to fail. People said it was because I mis-used them while I understand that the parts are not built to last (at all).

With 2 times re-lubing the interior of BBSHD with MobilGrease 28, still in good shape. Happy with the e-part, BBHSD is reliable and well built. With this kind of ride and periodic service, it will last easily over 10+years and 50k kms. For bike, that is a lot.

Now, I am ready for the 2nd e-bike : Downhill Full Suspension Giant Glory 2013 I bought 2nd handed. Hoping that better parts should last longer.
(pic from Giant Bicycle's web)






I do not have much experience with hub motors but feel like to get more acquaintance with it.
So, rear hub is where to begin

...

..

## Wish List :

1) 70-80kmh+ on flat. Good acceleration. Powerful >1500w geared rear hub motor ? Durable & robust motor, controller, display & the whole system. Low-maintenance, water-proof, dust proof, protective ingress rating. Motor must not heat up easily even with long-term high speed. Frequent rain & flood in my area

2) Rear 26” existing wheel, if buy hub motor, possible to lace with 26” or 27.5” rim

3) Not hard to peddle without power assist, in case batt run out.

4) I can DIY my own batt pack, possibly 20S4P or 5P or so from LG18650 HG2 / 26650s, 21700s. But prefer lighter/smaller ones for daily use. Plan to install UNDER downtube with custom DIY fiberglass case for better CG and to blend nicely with the bike. The main batt pack is high power with reasonably range (20S4P = 864wh, 12Ah nom. but with 80A max). Can make a higher-energy dense spare pack for future longer ride if needed. The spare one will be paralleled (with 1 single BMS sensing wires to the parallel cells level) to the main pack to make 2 packs as one.

5) Regen is nice as a powerful brake, but not quite attractive for the 3-5% energy re-capped. Would love to be able to easily program level of brake power and sensitivity on the go. It should be programmable via PC connect, right ?

6) My bike’s brake is “HOPE” with luxury features like reach and brake engagement fine-tuning and I really love it. Prefer the e-brake cut-off is add-on type like magnet & reed switch like my BBSHD’s. So it won’t ruin my “HOPE”






7) Torque-sensing peddling assist : My 1st e-bike is equipped with PAS & throttle. So I’d like torque-sensing assist for this build + throttle. Just like the regen brake, prefer to be able to program torque assist sensitivity, amplification factor, ramp up & down, etc. on the go. My previous bike BBSHD’s PAS levels can be selected any time by thumb switch easily from 0-9 (or 0-5) just like changing gears. I am sure we can do all of that with laptop hook-up, right ? What about during riding ?

8) Nice & full function display. All parameters displayed. Program changes during riding is preferred.

9) Very powerful & reliable controller. Some tweaking features to make the ride more powerful, smooth and enjoyable will be nice.


..hope I didn't ask too much...

..

## Currently I am considering :
(pic from Grin Tech's web)







GMAC 8T (& torque arm) + PhaseRunner + CA3 from Grin’s Tech for it’s small size, reasonably light weight 3.8kg, Kv= 10rpm/V, regen brake and the stealthy look on rear with about same size as 203-mm disc rotor.
Total cost from Grin is around US$ 1,000.- without shipping and battery. Sounds like the right one except for the speed I want max 70-80kmh for few minutes at a time.


GMAC : It is a geared motor with locked clutch to enable it for regenerative braking but that also causes drag while peddling and Grin design their controller to overcome this drag by injecting some current and called it “e-freewheeling”. This is a beneficial unique feature in which Grin claims that there is no other system in the market that does this.












A little problem : off-the-shelves GMAC is for slotted type NOT for thru-axle rear drop-out. My Giant Glory drop-out is thru-axle, so there is no easy way to put a GMAC on this bike. I just do not want to cut-out the frame, in case that may be one day might wanna migrate this e-set-up to another bike and have the Giant Glory back to its original shape.

So, I am thinking of making a slot-type adaptor to accommodate GMAC onto this bike. This add-on adaptor will make the rear end 1-inch higher and 1-inch longer wheel base. To be installed to the drop-out on both sides, internally. {see pic}















It can be laser-cut and installed rigidly on the rear drop-out with several hose clamps on each side. Stainless steel 4 or 5-mm thick should be more than enough to handle the job. Have checked dimension clearances and it should be OK except for brake caliper mount, torque arm and etc. that need to be done during fitment stage.


..

..

GMAC 8T & 10T comparison from Grin’s simulator. What is the top speed I can get from each of them ? From graphs : 10T = 53.7kmh, 8T = 65kmh : are these correct ? I am new to these.

The slotted lines A & B bounced back to 65kmh while I was trying to slide it towards faster side on B (8T). Would love to have it a bit faster like 70+kmh on flat.

Again, this speed is just for only a few minutes at a time.







I made inquiry to Grin’s but the response took quite long and answer was not exactly what I asked. So, before I can reach to the point I can understand enough to make purchase, it will take months. Terrible.


..

..

Questions :

1) Is the above system OK, any comments ?

2) Giant Glory is factory downhill with very slack front fork angle. Is the installation with GMAC and extended brackets, causing 25mm taller in rear, 25mm longer wheel base OK ?

3) Will it affect riding much ?

I found that riding the bike itself on flat land feeling a little awkward, since it is built to perform the best during downhill. It is a little too quick in the front for normal ride. I live in flatland, and there is no mountains within several hundred kms. But I go to mountains with friends for fun rides couple of times a year.

4) Think about using a GMAC 8T for speed (geared, 3.82kg, 600-1200w,10.2rpm/V, 36-spoke holes) instead of the more common 10T (8.1rpm/V) . I enjoy the 70-80 km/h once in a while. Any drawbacks ?

5) Cannot find a comparison chart between the 8T & 10T on Grin's web.

6) Seriously, I do not like Grin’s CA3’s display, it seems outdated with 80’s look. But the functionality should be OK. Grin should do something about that before someone else does. Or may be they have been busy doing something else more worthwhile.

Is there any other reliable displays in the market that can do as much or better than the Grin’s CA3 with modern looks ?

7) Will I get the average consumption on this GMAC 8T+ 20S4P somewhere near my 8 wh/km as my good old BBSHD on 27.5” hardtail MTB ? My ride is not harsh with medium peddling and on flatland paved road, avg speed is 20-30 kmh. Max can be 50+ kmh on a daily ride.

8) Is the 20S4P LG18650HG2 (864wh, 12Ah, 80A max) appropriate for this job ?
I like it compact enough for UNDER downtube mount, hence will be sleek enough for the better DIY fiberglass batt case aesthetic look.

9) What kind of maintenance / major service I should expect in the long run.

Any reasonable comments will be appreciate. Thanks guys !!

..

Forgot to mention that the reason I pick GMAC is that its info is handy and I am not familiar with hub motors that much. I actually would like to have a bit faster bike like 70-80kmh once in a while. But the 3.8-kg, regen brake, e-free-wheeling, fully compatible with performance controller like Phase Runner (for its tweakable flexibility) are all the major plus sides of this pick, initially.

I am open to any other suggestion anyone might have re this build.

Thanks again guys

if youre going to machine adapters to the rear drop-outs it will shrink the inside measurement and will probably be stuck with a single gear.you might need to step out the plates and possibly make them clamping TA's. i thought about putting the mxus xf40 in my Marin, i think grin calls it the 3005rc/ high speed for 20inch wheels but lace it to a 26" od tire

https://endless-sphere.com/forums/viewtopic.php?f=6&t=104027&p=1556192&hilit=marin#p1524041

i dont know gmac

im going to start cycling testing a hg2 in a couple days to compare to 30q, 4p of 25r i get about a 20km ride and about 20wh/km i think, no pedalling. i plug my back pack battery into my main pack for range

..

Thanks for your comment Mr.goatman :

goatman said:

if youre going to machine adapters to the rear drop-outs it will shrink the inside measurement and will probably be stuck with a single gear.you might need to step out the plates and possibly make them clamping TA's. i thought about putting the mxus xf40 in my Marin, i think grin calls it the 3005rc/ high speed for 20inch wheels but lace it to a 26" od tire

https://endless-sphere.com/forums/viewtopic.php?f=6&t=104027&p=1556192&hilit=marin#p1524041

i dont know gmac

im going to start cycling testing a hg2 in a couple days to compare to 30q, 4p of 25r i get about a 20km ride and about 20wh/km i think, no pedalling. i plug my back pack battery into my main pack for range

Click to expand...

Re : Clearance of the hub, wheel, cassette, rotor, torque arm & drop-out. I just figured from Grin Tech's GMC drawings and my actual measure :



View attachment GMAC.png



It is 137mm OLD ID(including the Shimano 8-10Spd), my Sram is 9 spd on rear. Actual measurement of frame L-R drop-out internally is 149mm :







The 149mm - 2x5mm (2 x adaptor plates thickness) = 139mm. Should be enough for hub, wheel, cassette, rotor, torque arm & etc.



Plus, my 3D CAD model tells me that I should have approx 137mm space between the adaptor plates :







Since mounting the adaptor plates "inside" the drop-out will look a lot cooler (to me, at least ).

So, re clearances, it should be OK ? Please let me know if I missed something here.


Anyway, I really have to make sure that everything is accounted for and towards the right directions before ordering the parts.


Re : LG18650HG2 >> From spec, I think it is one of the most optimal choices for cell config 20S4P in my case. Actually, 4P is kind of low to get 80A from it's spec of 20A max cont. Considering GMAC max current drawn from batt for 65kmh (which is less that I'd like at 70-80kmh) should be less than 40A :






So, max batt amp drawn at 40A, I still do not torture the cells that much for the sake of cell longevity.

Plus, if you see LG HG2's spec, the life cycle is 300 at max 20A discharge (3,000mAh discharged down to 2,250mAh or 75% of new cell, cut-off @2.0V every cycle) >> Nobody will deplete their pack that much every cycle and I always do the shallow cycles chg/dischg 98% of the time. So, actual life cycles of pack should be doubled of 300s easily.

I really wanna know if this GMAC, PR, 20S4P config with my not-harsh riding style will get me close to the 8wh/km (medium peddling) as I get from my 1st e-bike of 27.5" MTB BBSHD+14S5P LG18650MJ1.


Mr.goatman, please keep us posted here re what you find out about this LG HG2 performance.

I really would appreciate :thumb: :thumb: any comments/suggestions re "reliable" hub motors (+controller) with regen brake, weight not much more than 4-5 kg, and all the goodies and more power than the GMAC (1000-1200w) that can get me to 80kmh for like 5-10 minutes on my 20S4P pack.

Any other comments are welcome.


..

BTW, my 1st build of 14S5P LG18650MJ1 :

The BMS app on phone shows around 85 charges for the 10k+ km rides which is wayyy too less actual number of charging. I figure it should be x 3.5 that is about 300 cycles already. I feel the pack degrades a little, but not much. Charging time is a little longer. Same riding distance with initial charging of 40-45 minutes last year is now about 50-55 minutes at about same wh usages. I do shallow cycles 98% of the time. and charge to 4.0-4.1 V per cell. @5-6.5Amp. I had 2 broken CC-CV chargers already (1 Luna's in less than 6-mo & 1 Wate's in about 15 months / they are both made in you know where).

FYI.

4p of lg at 10amps/cell provides good mah at 10amps look at data sheet. im noticing these high power batteries get close to delivering 100% capacity at 10amps



real mah 3.25v c/o 1800mah/10amp but "real" use will probably be 2500mah at 3.2v c/o



i dont know gmac, i forgot they have good torque arms so you dont need clamping TA. the only thing left to look at is how your brake caliper and rotor line up. you have 2mm to spare

Would any experts please tell me whether I can get 65kmh max on the 8T GMAC and 53kmh max on the 10T GMAC according to Grin's simulation above ? Which one should I go for: 8T for speed or 10T for better stability ?

I'm trying to finish this new Giant Glory build for my son's birthday within this November and time is running fast. He's going to be 16 at the very beginning of this December. I have about 40 days now and parts are not even on order yet. Just trying to get the young man a decent BD gift. But first I need to get the answer for above questions - just do not want to be stuck with things I might incorrectly order from my limited knowledge.

Any comments for the above lengthy questions will be greatly appreciated.

Thanks, guys !

ichiban said:

Would any experts please tell me whether I can get 65kmh max on the 8T GMAC and 53kmh max on the 10T GMAC according to Grin's simulation above ? Which one should I go for: 8T for speed or 10T for better stability ?

I'm trying to finish this new Giant Glory build for my son's birthday within this November and time is running fast. He's going to be 16 at the very beginning of this December. I have about 40 days now and parts are not even on order yet. Just trying to get the young man a decent BD gift. But first I need to get the answer for above questions - just do not want to be stuck with things I might incorrectly order from my limited knowledge.

Click to expand...

This isn't the expert advice you're looking for, but I think given those components - PhaseRunner and GMAC - vs. a 16 year old boy, I would be looking for the slowest setup that's reasonably possible. Just in the interest of increasing his odds of survival, and minimizing medical expenses. An ordinary 48V battery, for example would be better than an exotic high voltage battery. If the 10T motor is slower than the 8T, go with the 10T. Etc. The 10T motor will deliver a little more acceleration from a stop, which is arguably a more useful performance factor than top speed - you can get a perilous street crossing over with faster.

Thanks donn.

You're talking 4, maybe 5 HP tops here. Sure, you may have 60 lb-ft of torque, but you can control that in the settings and increase the performance as he gets familiar with the bike. Too little power and he'll lose interest. Think of all the crap and dangerous stuff you did at that age. An ebike is way safer, so if he stays interested, that's a lot better than the alternatives.

Sure, he'll be able to figure out how to up the power on his own, just like he'd be able to figure out that you built him a slow ebike, if you go that route. Just set up some rules around off road vs. road riding, and get the right safety gear.

E-HP said:

You're talking 4, maybe 5 HP tops here. Sure, you may have 60 lb-ft of torque, but you can control that in the settings and increase the performance as he gets familiar with the bike. Too little power and he'll lose interest. Think of all the crap and dangerous stuff you did at that age. An ebike is way safer, so if he stays interested, that's a lot better than the alternatives.

Sure, he'll be able to figure out how to up the power on his own, just like he'd be able to figure out that you built him a slow ebike, if you go that route. Just set up some rules around off road vs. road riding, and get the right safety gear.

Click to expand...

Thank you, E-Hp. This is a very intriguing comment and I totally agreed with you. :thumb:

Purpose of this build is to get my teenager other useful things to spend time with, other than school & devices with screens. Hopefully, it will inspire/encourage him with DIY attitude.

Of course, some risk involved here but that's part of his learning process and I just can't keep him pampered forever. Safety gears are readily avail. Better encourage him to learn, plan, adapt and make better decision for/by himself for the better him in the long run. World is changing fast and one important skill one has to learn is to adapt to the continuously changing new norm, no matter how challenging it will be.

Again, thank you for your comment here E-HP.

you could just get the gmac and get the bike running for his bday and if its too slow get a DD for him later. if youre going for regen, you might want a 40T pack. i tested the vtc6 and a 30Q with no wait times in between charge/discharge cycles and the vtc doubled its capacity loss/cycle and the 30Q seemed to like that there was no no break between cycles, it performed better than it did with wait times.

lets say your son goes for a long ride comes home plugs bike in for a recharge and goes off again, the 30q would like that but it would kill a mj1 and harm a vtc6

cant find an hg2 right now for testing to see what happens to it

you could always use grins thru axle motor but the crystalyte thru axle is for the rear tire with a 12mm axle if he needs more power later

goatman said:

you could just get the gmac and get the bike running for his bday and if its too slow get a DD for him later. if youre going for regen, you might want a 40T pack. i tested the vtc6 and a 30Q with no wait times in between charge/discharge cycles and the vtc doubled its capacity loss/cycle and the 30Q seemed to like that there was no no break between cycles, it performed better than it did with wait times.

lets say your son goes for a long ride comes home plugs bike in for a recharge and goes off again, the 30q would like that but it would kill a mj1 and harm a vtc6

cant find an hg2 right now for testing to see what happens to it

you could always use grins thru axle motor but the crystalyte thru axle is for the rear tire with a 12mm axle if he needs more power later

Click to expand...

I 've seen a guy powered his e-converted-moto with hugh pack of LG HG2. It was a smaller race e-bike like the 100-150cc gas-engine equivalent, not for the super-powerful 500-1000CC ones. He claimed that the HG2 works very well with this kind of project. My riding is not going to take that much current. But the 20S4P is just for the compact size of the pack of only 80 cells, 12Ah but can be maxed to 80A continuous according to specsheet.

I really have to wrap up all these loose ends and start ordering parts within these few days.

Thanks again for your comment goatman.

im not knocking the hg2, lg data sheet states a mj1 needs to wait between charge/discharge but the datasheet on the hg2 doesnt mention it and then you have people here on the forum saying their mj1 pack died young but their hg2 is still going strong. i havent heard anything bad about the hg2 but i have about 30Q. i like my 25r the 40T is good, i like the 30Q but you hear bad stories about them so thats why i wanted to test the hg2, it shares the same capacity discharge curve as a 25r,30q,40T which is different than most other batteries.

I am another witness of MJ1 good story. After 11K km (in <2 yrs) and 250+charges or so, it is still going strong. But my usage is about 50% of pack capacity, with shallow cycle 3.6-4.1V and charge just hours before each rides most of the time.

Actually, the my phone Xiaoxiang bluetooth app shows only 85 cycles but I figure from km, trip avg, charges that it should be 3.5X more = almost 300 charges.

With factory spec of 400 cycles 100% DoD, it can go as far as 400*3.5 = approx 1400 charges in my case. And with my average trip of 32 km -->> about 44,800 km which should last for about 7 years with 60-70% capacity left. I am more than happy with it.

I have the same dropouts problem...
On my old bike, did a plate and work very well. Some screws and 3m dp420, and its done.
On this bike, it's going to be, more or less, the same, but this frame its carbon...
What company, you will use to cut the plates ?

Luis.

soaresdacosta said:

I have the same dropouts problem...
On my old bike, did a plate and work very well. Some screws and 3m dp420, and its done.
On this bike, it's going to be, more or less, the same, but this frame its carbon...
What company, you will use to cut the plates ?

Luis.

Click to expand...

Same problems without readily available product to solve that. Another thing we have to overcome to get what we want. Expect the finish work with these brackets to be blended in nicely, probably not noticeable by untrained eyes.

When you can, please post some pictures how you made your brackets, mounting and solve it. So I might follow your footstep. Thanks in advance.

I figured from information I have re dimensions of the hub we choose and bike's dropout opening. Seems like it should be OK. Some complications are to make the brake caliper mount and deraileur hang. I think it will come out OK and just want to make it neatly.

I design my own brackets (as shown in the pictures above) and have a machine shop laser cut it for me. I also laser cut my BBSHD's torque arm there too and it works well - no problem with BBSHD loosen at all. They are good at this and can cut this without problems. Their concerns are just some certain materials that conduct heat very well like copper and aluminium that will dissipate heat so fast and hard to laser cut. I chose stainless steel for its worry-free and just forget about it once finished.

.