LightningRods mid drive kit
- Thread starter spinningmagnets
- Start date
LightningRods
1 MW
It is kinda pretty, isn't it? 
My own testing and early feedback from customers reinforces what I expected: speed. The low strain at the rear gears really lets you put the power down. Less motor torque multiplication meeting less final drive resistance. It's pretty simple. 3000 watts on a two stage drive makes the bike frame creak and groan. Not so with the single stage.
My own testing and early feedback from customers reinforces what I expected: speed. The low strain at the rear gears really lets you put the power down. Less motor torque multiplication meeting less final drive resistance. It's pretty simple. 3000 watts on a two stage drive makes the bike frame creak and groan. Not so with the single stage.
KarateDoc
100 µW
Hey Michael,
Did you get my two emails about a new bracket? I sent a drawing of something that may work. Let me know what you think the turnaround time would be.
Looking forward to getting this thing wired up and running.
Doc
Did you get my two emails about a new bracket? I sent a drawing of something that may work. Let me know what you think the turnaround time would be.
Looking forward to getting this thing wired up and running.
Doc
LightningRods
1 MW
Email sent.
LightningRods
1 MW
Hi! I'm good thanks.
The largest 104 BCD chainring that I use is a 48t. I had planned to make a custom 52t chainring from stainless steel but then realized that lots of reduction plus lots of overdrive, like you get from a big chainring, is what tears things up. I now use a 44t chainwheel on my two stage reduction drives and a 22t on my one stage reduction.
What's your plan for the big chainring? Wanting to stay off of the 11t sprocket on the rear derailleur?
The largest 104 BCD chainring that I use is a 48t. I had planned to make a custom 52t chainring from stainless steel but then realized that lots of reduction plus lots of overdrive, like you get from a big chainring, is what tears things up. I now use a 44t chainwheel on my two stage reduction drives and a 22t on my one stage reduction.
What's your plan for the big chainring? Wanting to stay off of the 11t sprocket on the rear derailleur?
LightningRods said:
Hi there
Yes I cant go down to 11, 13 or 14T because the chain skips a lot. But at 18T on the rear cassette it work almost perfectly. So im wanting to go higher on the front chainring from 48T to 52T. If you make a 52T in the future Id surely pick up a few
LightningRods
1 MW
A 52t chainring combined with an 18t rear on a 26" wheel will give you a top pedaling speed of about 25 mph. Trying to have high top speed with a chainring drive, and wanting to be able to pedal along at speed, is really difficult. The more motor power you run (which you need to go fast, right?) the less well the chainring system works this way.
If you can give up on pedaling along with the motor everything gets easy. Even on one of my two stage drives you can run larger drivers on the motor and jackshaft and get much higher speeds on the larger rear sprockets. Halving the motor reduction to 15:1 will give you a top speed of 40 mph on the 18t rear sprocket with a 44t driver chainwheel. You'll also find that because you're producing half of the motor torque from reduction that you can use a smaller sprocket on the rear wheel and get even more speed.
On my single stage drives a 28t rear wheel sprocket makes the speed of an 11t on a standard 30:1 mid drive. An 18t sprocket is higher than you'd ever need. Pedaling with the motor is for low powered chainring drives. I also make drives that don't run through the chainring, which solves this problem, but those drives don't fit on a standard bicycle. You need a cargo bike or cruiser where there is more room between the chainring and rear wheel.
Despite all of this I would make a 52t or even larger chainring if there were demand for it. I use stainless steel for my custom sprockets. I'm looking into hardened tool steel for small sprockets that get lots of wear on them.
If you can give up on pedaling along with the motor everything gets easy. Even on one of my two stage drives you can run larger drivers on the motor and jackshaft and get much higher speeds on the larger rear sprockets. Halving the motor reduction to 15:1 will give you a top speed of 40 mph on the 18t rear sprocket with a 44t driver chainwheel. You'll also find that because you're producing half of the motor torque from reduction that you can use a smaller sprocket on the rear wheel and get even more speed.
On my single stage drives a 28t rear wheel sprocket makes the speed of an 11t on a standard 30:1 mid drive. An 18t sprocket is higher than you'd ever need. Pedaling with the motor is for low powered chainring drives. I also make drives that don't run through the chainring, which solves this problem, but those drives don't fit on a standard bicycle. You need a cargo bike or cruiser where there is more room between the chainring and rear wheel.
Despite all of this I would make a 52t or even larger chainring if there were demand for it. I use stainless steel for my custom sprockets. I'm looking into hardened tool steel for small sprockets that get lots of wear on them.
LightningRods said:
Hi thx for the info..however i shouldve stated that im looking for the highest speed possible with my system without pedaling. At the moment, 48T to 18T works the best until i find new combinations if its possible. Thats why if i bumped up to 52T then I might get extra mph with chain slipping on the rear cassette.
I understand you would need a demand for 52T...ill keep on eye on your site if you ever have them for sale!
LightningRods
1 MW
I have secondary driver sprockets in 15t and 18t. The 15t will increase your speed by 15%. The 18t will increase your speed by 38%. I also have 25t motor drive pulleys that increase speed by 39%. Combined with the 18t secondary sprocket you get the 192% speed increase that I mentioned. With your 48t chainring top speed would be 43 mph @ 48v.
I'd like to hear more about this 15kW motor setup, is it going to be rear swingarm kit compatible? What motor is it, it isn't something like an RC motor is it? I know some of those motors can put out a lot of power, but they are loud as shit, lol.
Every time I come in this thread I think, maybe I should sell my hub+adaptto controller setup, and get the swingarm kit, to lower the unsprung mass. But it would be expensive for not a huge change in performance since I haven't really had much issue with the unsprung mass yet, that I can tell. But for a 15kW rear swingarm, I think I'd have to chain myself to the radiator to not buy it!
Every time I come in this thread I think, maybe I should sell my hub+adaptto controller setup, and get the swingarm kit, to lower the unsprung mass. But it would be expensive for not a huge change in performance since I haven't really had much issue with the unsprung mass yet, that I can tell. But for a 15kW rear swingarm, I think I'd have to chain myself to the radiator to not buy it!
LightningRods
1 MW
I probably shouldn't have talked about new motors. I don't know for certain that it will work or that I'll even like it as well as what I have now. Once I've put one in a drive and run it I'll know whether I want to brag about my achievement or dig a hole and try to bury my mistake. Even if the motor is awesome it requires a new level of output from the battery and controller. The new drive wouldn't be hugely more expensive than the current one. But the battery is going to be a whole lot more.
One big reason for how loud the RC motors are is the high rpm that they typically run. This is not technically an RC motor. It's kinda too big for that. It's an outrunner but a low kv outrunner made for hang gliders, not RC airplanes. The current Big Block is 62 rpm/volt and the candidate is 50 rpm/volt. If the 15kW turns out not to be terrifying enough, there is also a 25kW version. That's really a motorcycle motor. But it would physically fit in a Qulbix or EEB swingarm drive so I may have to at least try it.
The same bike does handle a lot better with the mass out of the wheel. I wish I could have two Q76s, one with a hub motor and the other with a swingarm mid drive, and let people try them both. If the new motor does put out 15kW while trimming still more weight off of the bike that is going to make it pretty tempting. We'll see. Hopefully I'll have some good news.
One big reason for how loud the RC motors are is the high rpm that they typically run. This is not technically an RC motor. It's kinda too big for that. It's an outrunner but a low kv outrunner made for hang gliders, not RC airplanes. The current Big Block is 62 rpm/volt and the candidate is 50 rpm/volt. If the 15kW turns out not to be terrifying enough, there is also a 25kW version. That's really a motorcycle motor. But it would physically fit in a Qulbix or EEB swingarm drive so I may have to at least try it.
The same bike does handle a lot better with the mass out of the wheel. I wish I could have two Q76s, one with a hub motor and the other with a swingarm mid drive, and let people try them both. If the new motor does put out 15kW while trimming still more weight off of the bike that is going to make it pretty tempting. We'll see. Hopefully I'll have some good news.
LightningRods
1 MW
The Cyclone 7500 motor is physically huge. It weighs 7.9 kilos or 17.4 lbs. It's also way too long to fit on a bicycle.
LightningRods
1 MW
Here's Cyclone's 18kW bike:
http://www.cyclone-tw.com/18kwbike.html
This motor has no internal planetary reduction. So this is also essentially a single stage reduction drive. The final drive is reduction instead of overdrive as with a typical bicycle. If Cyclone had tried to run more motor reduction with an overdrive final drive the entire thing would explode immediately. Torque multiplication x resistance = destruction.
They are being very sly in only showing side views of this drive. They used to have a 3/4 view that showed the width of the motor. It's so huge that this bike has a crazy BB axle that's extended about 6" beyond the BB shell on the left side. Not that you would ever pedal this bike.
http://www.cyclone-tw.com/18kwbike.html
This motor has no internal planetary reduction. So this is also essentially a single stage reduction drive. The final drive is reduction instead of overdrive as with a typical bicycle. If Cyclone had tried to run more motor reduction with an overdrive final drive the entire thing would explode immediately. Torque multiplication x resistance = destruction.
They are being very sly in only showing side views of this drive. They used to have a 3/4 view that showed the width of the motor. It's so huge that this bike has a crazy BB axle that's extended about 6" beyond the BB shell on the left side. Not that you would ever pedal this bike.
SlowCo
1 MW
LightningRods
1 MW
That's the one.
gman1971
10 kW
- Joined
- Oct 17, 2015
- Messages
- 997
LightningRods said:
Sly? ... Its big, its a giant 25 horsepower (18kW) e-motor for Pete's sake... Cyclone isn't being sly about their kits, they make no apology for being what they are; if you buy a Cyclone you know full well its not going to be a Picasso out of the box... but ppl still buying them.
G.
LightningRods
1 MW
The Big Block is 125mm in diameter, 102mm in length and weighs 4.5 kilos. For Americans that's 5" x 4" weighing 10 lbs.
gman1971
10 kW
- Joined
- Oct 17, 2015
- Messages
- 997
LightningRods said:
A 3.8 kilogram difference when you're talking about 7.5kW (or 10hp) on a 110 kilogram vehicle, rider + eBike package is like talking about removing the heavy passenger power seat of your car to do auto-crossing at the parking lot... again, we're splitting hairs. You're better served by improving aerodynamics than losing 3.8 kilos from the motor...
Having a heavier motor with more copper also means that the power hungry guy who buys it can easily push the hell out of the 7500 Cyclone motor, run a wadload of RPMs and insane amps without melting the motor... I wouldn't be surprised if 20+kW could be extracted out of the 7500XL motor... again, its inexpensive power.
Unless you were to price your stuff at Cyclone level, convincing anyone yours is better b/c Cyclones are big, wide, or heavier... etc, is just pointless... Cyclone kits are what they are.
G.
gman1971
10 kW
- Joined
- Oct 17, 2015
- Messages
- 997
LightningRods said:
The 7500XL motor on the left, the C3000W on the right.
They seem pretty much the same length to me... so if you have a C3000W in your eBike, going the 7500 route won't change much, except maybe how quick you get to 50 mph, or how fast the batteries drain...
G.
gman1971 said:LightningRods said:
The 7500XL motor on the left, the C3000W on the right.
They seem pretty much the same length to me... so if you have a C3000W in your eBike, going the 7500 route won't change much, except maybe how quick you get to 50 mph, or how fast the batteries drain...
G.
I like the thick face and rear plate on the 7500W motor. Makes me wonder if it could be ported and run with liquid cooling. That said, it doesn't look like, width wise, it would be an issue to put the 7500W into the rear swingarm kit, the issue comes from the diameter, it's over an inch difference, and that is significant. I just did a quick measurement on my bike, which has a 19" holmes rear rim and a Shinko241 tire, a rather standard rear setup, the motor wouldn't fit, I'd want the swing arm to be at least 1" longer to feel comfortable stuffing a 7500W motor in there.
Which means it would either require a custom swing arm, or to redesign the 2 stage setup. I wonder if anyone has extended the Qulbix swing arm like 2 inches....
gman1971
10 kW
- Joined
- Oct 17, 2015
- Messages
- 997
If you're interested, the Cyclone 3000W thread also covers some of the 7500 stuff, and ppl who have tested it can probably chime in, that way we can take it out of this thread. Cyclone thread: https://endless-sphere.com/forums/viewtopic.php?f=28&t=69867
G.
G.
atarijedi said:gman1971 said:LightningRods said:
The 7500XL motor on the left, the C3000W on the right.
They seem pretty much the same length to me... so if you have a C3000W in your eBike, going the 7500 route won't change much, except maybe how quick you get to 50 mph, or how fast the batteries drain...
G.
I like the thick face and rear plate on the 7500W motor. Makes me wonder if it could be ported and run with liquid cooling. That said, it doesn't look like, width wise, it would be an issue to put the 7500W into the rear swingarm kit, the issue comes from the diameter, it's over an inch difference, and that is significant. I just did a quick measurement on my bike, which has a 19" holmes rear rim and a Shinko241 tire, a rather standard rear setup, the motor wouldn't fit, I'd want the swing arm to be at least 1" longer to feel comfortable stuffing a 7500W motor in there.
Which means it would either require a custom swing arm, or to redesign the 2 stage setup. I wonder if anyone has extended the Qulbix swing arm like 2 inches....
