Juiced Cycles with 12T MAC motor @ 48V doing over 30mph

Ken M

Active Member
#1
In this video Tora is cruizing at speeds over 30mph with the 12T MAC gear hub motor @ 48V (
). This is quite a bit faster than MAC indicates the 12T will assist to because it's supposed to be the lower Kv / higher torque wind. I would think only the 6T or 8T would provide assist at those speeds so I'm hoping someone can provide some technical feedback. I want to purchase a Luna Cycles MAC / ASI kit (only available in 6T or 12T) and run it from a 52V battery with peak amps in the 30-40A range. I would like to get the 12T kit but didn't think it would provide the top assist speed I'm looking for which is around 34-36mph.

Can I go with the 12T kit given the results shown in the Juiced Cycles video or should I go with the faster 6T wind just to be sure?
 

Ken M

Active Member
#3
I would think Luna should better have that answer.
Here's what Luna states on their site which doesn't match the ride speeds of the video:

Speeds of 30mph are easily obtainable with the 6 turn motor, the 12 turn motor top speed is typical around 23mph.

I may end up just getting the 6T because it's the only version they sell for rear wheels. If you visit MAC's website it seems an 8T or 10T would be best for 32-36mph with a 52-56V battery. I'm planning on providing most to all of the power to get the bike to 12-15mph and then assist via throttle to cruise at speeds higher than that so maybe I don't need to low end torque of the higher turn windings anyway.
 
#4
Ha, I have watched that video more than I care to admit, now add 1 more view. Its hard for me to stop so I watched the whole thing.

I was doing MAC motor research awhile back and noticed the same thing when researching the hyperfat. At that time I decided the 10t would be better speed/hill compromise for me (on 26 inch wheels and 52V)

Perhaps due to the big tires on the hyperfat, perhaps because Tora is supposed to be an exceptional athlete and it looks like he is putting muscle into it. Since Luna seems to favor the throttle and despise pedaling maybe their info is based on throttle only.
 

Ken M

Active Member
#5
Ha, I have watched that video more than I care to admit, now add 1 more view. Its hard for me to stop so I watched the whole thing.

I was doing MAC motor research awhile back and noticed the same thing when researching the hyperfat. At that time I decided the 10t would be better speed/hill compromise for me (on 26 inch wheels and 52V)

Perhaps due to the big tires on the hyperfat, perhaps because Tora is supposed to be an exceptional athlete and it looks like he is putting muscle into it. Since Luna seems to favor the throttle and despise pedaling maybe their info is based on throttle only.
Tora is a good athlete but unlikely putting a ton of wattage out given the high cadences. At the end of the video he rides under throttle alone at close to 30mph I believe.

If the specs on the 12T MAC motor are accurate any speed above around 25mph would not have any assist from the motor because the Kv would be exceeded. I'm just wondering if he was really riding a 12T or really on a 6T or 8T.
 
#6
I have a friend that has a HF1100 running the 12T MAC motor. With pedaling he was able to touch 40 mph momentarily. As soon as his stock controller started giving him problems, we ripped it out and put a GrinTech Phaserunner into it. This de-restricted the throttle output. The bike can now achieve 37-38 mph.

if I’m not mistaken his controller is programmed to limit the power to 36 amps on a 52v battery. The thing about the GrinTech controller is it’s a Field Oriented Controller that is capable of field weakening. Essentially raising the max motor rpm to achieve the higher speeds.
 

Ken M

Active Member
#7
I have a friend that has a HF1100 running the 12T MAC motor. With pedaling he was able to touch 40 mph momentarily. As soon as his stock controller started giving him problems, we ripped it out and put a GrinTech Phaserunner into it. This de-restricted the throttle output. The bike can now achieve 37-38 mph.

if I’m not mistaken his controller is programmed to limit the power to 36 amps on a 52v battery. The thing about the GrinTech controller is it’s a Field Oriented Controller that is capable of field weakening. Essentially raising the max motor rpm to achieve the higher speeds.
I have a friend that has a HF1100 running the 12T MAC motor. With pedaling he was able to touch 40 mph momentarily. As soon as his stock controller started giving him problems, we ripped it out and put a GrinTech Phaserunner into it. This de-restricted the throttle output. The bike can now achieve 37-38 mph.

if I’m not mistaken his controller is programmed to limit the power to 36 amps on a 52v battery. The thing about the GrinTech controller is it’s a Field Oriented Controller that is capable of field weakening. Essentially raising the max motor rpm to achieve the higher speeds.
Interesting feedback. The 37-38mph is pretty much the top speed performance I want from an ebike anyway. Going faster than that on something not designed to DOT standards kind of scares me a bit but I have ridden quality traditional bikes and ebikes at that speed comfortably (especially the on the newer robust mtn bike frames with 27.5" or 29" tires like the Schwalbe Moto Xs.

Grin's Phaserunner is based on the ASI technology in the Luna Cycle MAC/ASI kit but they only have the 6T wind for the rear tire which is kind of strange. If I can get 38mph from the 12T at 52V / <40A that is really preferred given the torque advantage the 12T would have at the slower speeds. I may end up just ordering the 12T kit as it will likely be a bit more efficient at the higher cruising speeds for commuting overall anyway. I was just hoping to understand how Tora was hitting 38mph in the Juiced Cycles video with a 12T when the specs indicated that is faster then the Kv of the winding would continue to assist to (I understand some of that may be them also running a FOC controller but I think he just runs a sinusoidal).
 

AHicks

Active Member
#8
You keep bring up the potential to reach the speeds you seem to be looking forward to. What I have failed to see though, is how far you think you are going to get at these speeds. Battery draw will be enormous, and I would think that unless you are figuring a pair of very high capacity batteries, your commute at the speeds you require, may not be possible.....
 

Ken M

Active Member
#9
You keep bring up the potential to reach the speeds you seem to be looking forward to. What I have failed to see though, is how far you think you are going to get at these speeds. Battery draw will be enormous, and I would think that unless you are figuring a pair of very high capacity batteries, your commute at the speeds you require, may not be possible.....
The range is a concern but in reality 95% of my riding (and probably anyone else riding a bike with >30mph potential) will be below 30mph but the battery capacity is still important. The standard battery I'll have should be over 600wh but long term I want to have dual batteries with the 2nd battery being a large rack mounted battery that would likely be 14S8P battery using 21700 cells that should result in something upward of 2kwh. I just want the range to do up to 50 miles a day but mainly plan on pedaling with significant effort much of those miles.
 

Ken M

Active Member
#10
One of the comparisons I'd really like to see is how much difference there is with the same battery capacity on the Yamaha and/or Bosch mid drive ebike vs a DD hub motor like the TDCM motor on a Stromer and a geared hub motor like the MAC with all the bikes being ridden at a sustained fast speed of 25mph. I know the general perception is that mid drives are way more efficient than hub drives but I'm pretty sure that at high speeds that is not the case.
 
#11
One of the comparisons I'd really like to see is how much difference there is with the same battery capacity on the Yamaha and/or Bosch mid drive ebike vs a DD hub motor like the TDCM motor on a Stromer and a geared hub motor like the MAC with all the bikes being ridden at a sustained fast speed of 25mph. I know the general perception is that mid drives are way more efficient than hub drives but I'm pretty sure that at high speeds that is not the case.
I plan on doing such a test here in the near future.

I have an old rigid 26" MTB that I put an 52V TSDZ2 on with opensource software using FOC, Its kindof my DIY cheap speed pedalec. Its limited to about 26mph or so with a 42x11 and cadence of around 90. Its a fun bike but in the 42x11 I dont feel its the most efficient at speed.

I will be getting a juiced CCX on friday and plan on doing back to back comparisons between the two(I will be replacing the CCX 52t chainring with a 42t), Hills everywhere but probably nothing more than about 6% grade on the rides I will use these 2 bikes on.

I also have a Bulls Evo 3 27.5+ brose motor hardtail ebike, It has a 38/28 front chainring and 11/42 rear cassette, It is great in the really steep climbs (up to 30%) but unfortunately limited to 20mph
 
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Feliz

Active Member
#12
I plan on doing such a test here in the near future.

I have an old rigid 26" MTB that I put an 52V TSDZ2 on with opensource software using FOC, Its kindof my DIY cheap speed pedalec. Its limited to about 26mph or so with a 42x11 and cadence of around 90. Its a fun bike but in the 42x11 I dont feel its the most efficient at speed.

I will be getting a juiced CCX on friday and plan on doing back to back comparisons between the two(I will be replacing the CCX 52t chainring with a 42t), Hills everywhere but probably nothing more than about 6% grade on the rides I will use these 2 bikes on.

I also have a Bulls Evo 3 27.5+ brose motor hardtail ebike, It has a 38/28 front chainring and 11/42 rear cassette, It is great in the really steep climbs (up to 30%) but unfortunately limited to 20mph
I wish Tora would have a 42T chainring as an option with the CCS/X. I just bought a Biktrix Juggernaut Classic BBSHD and I was able to choose the tires, chainring, display, battery, and other options. The stock Bafang chainring is 46 and I had them put on a 42. I find the Juiced 52T way to large for where I live.
 

Ken M

Active Member
#13
I wish Tora would have a 42T chainring as an option with the CCS/X. I just bought a Biktrix Juggernaut Classic BBSHD and I was able to choose the tires, chainring, display, battery, and other options. The stock Bafang chainring is 46 and I had them put on a 42. I find the Juiced 52T way to large for where I live.
I find that what matters is the gear ratio at you typical cruising speed which for a typical speed pedelec is probably in that 24-28mph range. A 4:1 (like a 44T front / 11T rear) is close to ideal because it results in a cadence from 70-90 thru that speed range. For those occasions where you may want to come close to 35mph the cadence is still doable for most riders at ~100rpm. In reality at speeds over 28mph the average rider really isn't capable of providing a significant percentage of the power/torque needed to sustain that speed on an upright bike because of aerodynamic drag so having a powerful drive system becomes more important (and it really needs to be in a rear hub so it's not going thru that 4:1 gear ratio which is the equivalent of low efficiency - an issue that no manufacturer that promotes mid-drives really likes to talk about).

Note: I think a speed pedelec, or even just a throttle ebike, that can achieve speeds upwards of 36mph is fast enough to be very serious for most urban mobility needs without being some crazy fast & unsafe bike (mainly because I have hit those speeds on my road bike for over 30 years but only did that when the conditions were smooth and safe).
 

Jerry LM

Active Member
#14
Wow, when he cuts off the main road to the path where those cars are parked he's moving much faster than I would, passing buses and cars is a trip for sure, at my age though going down at those speeds could put some serious hurt on me. I would love it but think I will stick with my 25mph for a while. Not real sure the tire technology is up to these sustained speeds on a bicycle either.
 
#15
Just to clarify for people about these higher speed eBikes, I think it should be noted that one has to take extreme caution when riding besides parked cars and in traffic. I’m usually under 20mph in the city. Half of my ride takes me through a nature preserve with an empty two lane road, its mostly flat and straight for 3 miles. That’s the only place where you can cruise over 30mph. Over a 17 mile commute, the faster bike will get me 5-7 minute savings over my class 3 haibike.
 

JRA

Well-Known Member
#16
Just in case you are at all interested in providing effective human input at speeds over 26mph, exactly where as you suggest a 44/11 loses it no matter what cadence, I would suggest this option:

https://www.cyclemonkey.com/bottom-brackets/schlumpf-high-speed-drive

The fact that you can launch using the 27t and switch to a 67.5t once beyond its effectiveness may be the way to go if you want to minimize your available gear ratios and depend more on motor output.

Figure wh/mi use to be commensurate with mph at speeds over 25mph on level ground also.

I would also suggest that you will get more information from the endless sphere forum re your quest, there are many on there that have been building within your parameters for years.
 

Ken M

Active Member
#17
Wow, when he cuts off the main road to the path where those cars are parked he's moving much faster than I would, passing buses and cars is a trip for sure, at my age though going down at those speeds could put some serious hurt on me. I would love it but think I will stick with my 25mph for a while. Not real sure the tire technology is up to these sustained speeds on a bicycle either.
You should watch some of the pro racers that hit upwards of 100kph on downhill sections of the Tour de France and they are very narrow high pressure tires. New urban tires like the Schwalbe Moto X, Kenda Kwicks, Pireli Cycl-e tires are designed for higher speed ebikes and provide handling characteristics very much like mopeds. I have no clue why some riders have mtn bike tires on fast ebikes they are riding on streets - there is no such thing as a knobby tire that will provide good handling on streets.

Tora was riding a bit fast on some stretches where there seemed to be some potential risks of cars doing something he didn't anticipate. But overall I think the video shows that even on knobby fat tires it's not so crazy to ride at 30-35mph when the road is wide open.
 

Ken M

Active Member
#18
Just in case you are at all interested in providing effective human input at speeds over 26mph, exactly where as you suggest a 44/11 loses it no matter what cadence, I would suggest this option:

https://www.cyclemonkey.com/bottom-brackets/schlumpf-high-speed-drive

The fact that you can launch using the 27t and switch to a 67.5t once beyond its effectiveness may be the way to go if you want to minimize your available gear ratios and depend more on motor output.

Figure wh/mi use to be commensurate with mph at speeds over 25mph on level ground also.

I would also suggest that you will get more information from the endless sphere forum re your quest, there are many on there that have been building within your parameters for years.
I'm aware of the schlumpf ... you are correct it would allow reasonable cadence at much higher speeds but I'm not sure if it's worth the expense or extra maintenance because most riders really will still provide only a small % of the overall power to sustain a speed over say 30mph.
 

Ken M

Active Member
#19
Just to clarify for people about these higher speed eBikes, I think it should be noted that one has to take extreme caution when riding besides parked cars and in traffic. I’m usually under 20mph in the city. Half of my ride takes me through a nature preserve with an empty two lane road, its mostly flat and straight for 3 miles. That’s the only place where you can cruise over 30mph. Over a 17 mile commute, the faster bike will get me 5-7 minute savings over my class 3 haibike.
I think you commute is pretty typical. Only on certain sections would most riders hit those speeds over 30mph on a bike that is capable but that in some cases will still save the time to maybe justify a ride wanting the faster Class 3 (or even "unlocked" mode ebikes like the Juiced bike that Tora was riding in the video). Time is money so if a faster ebike can save someone 15 to 30 minutes of commute time that is compelling.