LightningRods mid drive kit

[ElectricGod]

Looks like a bike you could rock up somewhere and throw surprise a party full with ice and beer.

Apart from heat handling, my favourite thing about the LightningRods mid drive kit is a 20 minute gear change. That's about how long it takes to

1. remove primary chain
2. remove motor sprocket
3. chain break out a link or add a new one
4. reverse steps 1 & 2

It's much easier than changing out any of the other spots. I will be changing the 13t back to 18t though once other parts arrive. Just needed to slow it down for a weekend ride with what I had.

Try this on your cargo bike
[youtube]OEOlf80DfYI[/youtube]
On this ride my hub motor mate lost 5 spokes.....

That steep hill is where you lean way over the handlebars to keep the front wheel on the ground and then creep up the hill in your lowest gear. Let the big block do all the work.

 

[John Bozi]

That steep hill is where you lean way over the handlebars to keep the front wheel on the ground and then creep up the hill in your lowest gear. Let the big block do all the work.

No questions that's exactly what I did. Pedals only got in the way for clearing the ledges and ruts you can't see in the video. Pedalling does not increase your chances in anyways especially since I was not bogging down. The only thing it does is ruin your balance.

Creeping up is not an option because the wheel is already spinning double the speed you are moving or more. Traction does not exist to do it slowly. More momentum is the only way.

I went out there looking for the exact place from some enduro guys video. Notice the only way through is smashing it. https://www.facebook.com/ashley.camp1/videos/10154639199105480/

 

[ElectricGod]

That steep hill is where you lean way over the handlebars to keep the front wheel on the ground and then creep up the hill in your lowest gear. Let the big block do all the work.

No questions that's exactly what I did. Pedals only got in the way for clearing the ledges and ruts you can't see in the video. Pedalling does not increase your chances in anyways especially since I was not bogging down. The only thing it does is ruin your balance.

Creeping up is not an option because the wheel is already spinning double the speed you are moving or more. Traction does not exist to do it slowly. More momentum is the only way.

I went out there looking for the exact place from some enduro guys video. Notice the only way through is smashing it. https://www.facebook.com/ashley.camp1/videos/10154639199105480/

Yeah...that's how they got up that hill...run up it full speed and hope you make it.

 

[sn0wchyld]

looking at buying a bigblock from LR - anyone know what the phase resistance is? trying to decide between a revolt 120pro and this. chrs.

 

[John Bozi]

When your bike has so much torque to climb anything, but is noisy as hell,wouldn't be nice to have a stealth mode button for the suburbs?

[youtube]0DsL4f3oLDc[/youtube]

This is testing still, no idea if it will stay.

 

[broke]

Oops

 

[DirtEV]

Hi all

I'm planing to mount a small block on a norco shore 2. Do you guys think it will fit the odd frame? I'm affraid it could hit the front tire when the fork compresses.

 

[notger]

Hi all

I'm planing to mount a small block on a norco shore 2. Do you guys think it will fit the odd frame? I'm affraid it could hit the front tire when the fork compresses.

Exactly that will happen, or actually the standard kit will hang so low, that it will hit every log or Rock you'll roll over.
So that frame is really not ideal for those Kind of Mid drives.
You could ask Mike if we will make a custom mount for you, still it will not be fine on that kind of Frame.

 

[DirtEV]

well i hope there's a solution to mount it, i bought the bike specifically to convert it :|
Mike if you read this, whats your opinion?

 

[LightningRods]

I make a mount exactly for that type of frame. I make bottom brackets mounts in four different widths and three different lengths. I'll post photos once I've had coffee and my brain is working.

 

[DirtEV]

Well that was fast thanks!
I found this picture, the frame is similiar even though mine is a bit more "bent".
Anyways judging from the clearance of the bike in the picture, there might be just enough space to fit the motor inbetween the frame and tire.

 

[LightningRods]

That's a good example. When there are tire clearance issues it's usually between the large primary pulley on top and tire. You can fit a smaller diameter 219 sprocket on the primary if you don't mind a bit more noise than the belt drive.

 

[LightningRods]

This is my 219 chain primary drive. This one has a 40 tooth driven sprocket on it which is just under 4" in diameter. It's even with the front of the drive. It allows about an inch more tire clearance than the 90t pulley.

 

[DirtEV]

So you reckon it would fit with the chain instead of the belt? Does this effect the motor or power characteristics (smaller chainring = more rpm)?
Do you have a picture of the motor with chain reduction mounted?

 

[LightningRods]

The kit might fit with the pulley drive. I'd have to play around with that profile drawing that you sent. I'm sure it will fit with the small sprocket chain drive.

Less reduction means two things: (1) You can't pedal along with the motor when it's going full speed (2) You'll be in the lower rear gears with higher tooth counts more of the time. #2 is a good thing because the higher tooth count gears can handle more power without skipping.

The photo above is the motor with the chain reduction on it. Did you want a different view?

 

[DirtEV]

My Mistake, i meant a picture of the small block with chain reduction mounted on a bike. It would help to Imagine the size of the motor in my bike.

 

[LightningRods]

As luck would have it I've been playing with that photo you posted.

Because of the big dogleg in the Norco's front downtube and the amount of travel in the front suspension it appears that the front wheel would hit the current drive layout. Even with the small sprocket. So let's try something else.

This is something that I've been wanting to do for some time on these "dogleg" frames. The motor is pushed so far out that there ends up being room for the reduction shaft in between the motor and chainwheel. It's actually kind of brilliant. Having everything more or less in a straight line makes the entire structure much stronger. Plus we won't have as long a chain run as with the old way of doing things.

The only problem is that this doesn't exist yet. So I guess I'd better get to work.

 

[DirtEV]

Thanks for your work mike! I didnt expect such great visualisations, very helpful!
Just for my understanding, the smaller reduction would mean less torque on the wheel right? I need the bike to climb steep trails up in the mountains.

I think your new assembling style looks great! Much less bulky.
Could it be used with a pulley aswell? Do you think there's enough space for the feet amd legs, since the reduction is placed right between both of the riders legs.
I live in Switzerland, so i couldnt supply the bike for design purposes. Do you think you would need a frame like that on hand in order to design the new drive? And finally how much time would a new design like this take?

I'm very excited!

 

[LightningRods]

Up until now my mid drives have had 30:1 overall motor reduction. This reduces 3200 motor rpm @ 50v down to a bit over 100 crank rpm so that it's possible to pedal along with the motor at full speed. It seems that most users are finding that at 2000-3000 watts pedaling makes very little difference and the low gearing gives too low a top speed. They wear their 11t rear sprocket out and rarely get into the lower gears.

The reduction that I have planned for this new drive is 15:1. So rpm are double at the chainwheel and torque is half at the chainwheel. The cool part is that if you use a lower rear gear, which you can with more rpm, the rear wheel torque is exactly the same. You will get the speed out of a 22t sprocket that you previously got from the 11t. A 22t sprocket can take a lot more power without having the chain jump teeth.

If you use a 32t chainwheel driver and have a 32t low gear sprocket on the rear wheel, that's 1:1 final drive. When you pedal in that low gear you have a lot of climbing power. With this new drive you'll have up to 3,000 watts running through 15:1 reduction using that same low gear. That is a lot of climbing power! Because of having twice your pedaling rpm the motor can also provide that climbing power at twice your previous speed.

I'm going to mock this new drive up with thin plywood before having it laser cut in metal. If I can make the side panels work in aluminum to save weight that is my plan. I'll know better once I make the mock up whether there is room for a belt primary instead of chain. My concern is the width of the belt and pulley that close to rotation of the crank arm.

I'll keep posting progress here. The basic components are the same as before, just rearranged. This should come together pretty quickly. I don't need the bike but I may ask for measurements.

 

[recumpence]

Up until now my mid drives have had 30:1 overall motor reduction. This reduces 3200 motor rpm @ 50v down to a bit over 100 crank rpm so that it's possible to pedal along with the motor at full speed. It seems that most users are finding that at 2000-3000 watts pedaling makes very little difference and the low gearing gives too low a top speed. They wear their 11t rear sprocket out and rarely get into the lower gears.

The reduction that I have planned for this new drive is 15:1. So rpm are double at the chainwheel and torque is half at the chainwheel. The cool part is that if you use a lower rear gear, which you can with more rpm, the rear wheel torque is exactly the same. You will get the speed out of a 22t sprocket that you previously got from the 11t. A 22t sprocket can take a lot more power without having the chain jump teeth.

If you use a 32t chainwheel driver and have a 32t low gear sprocket on the rear wheel, that's 1:1 final drive. When you pedal in that low gear you have a lot of climbing power. With this new drive you'll have up to 3,000 watts running through 15:1 reduction using that same low gear. That is a lot of climbing power! Because of having twice your pedaling rpm the motor can also provide that climbing power at twice your previous speed.

I'm going to mock this new drive up with thin plywood before having it laser cut in metal. If I can make the side panels work in aluminum to save weight that is my plan. I'll know better once I make the mock up whether there is room for a belt primary instead of chain. My concern is the width of the belt and pulley that close to rotation of the crank arm.

I'll keep posting progress here. The basic components are the same as before, just rearranged. This should come together pretty quickly. I don't need the bike but I may ask for measurements.

I couldn't agree more. Most of my bikes are setup for a max pedal speed of about 26 mph, but a max electric speed of 35mph. I figure it is pointless to pedal above 25 mph or so anyway. Also, at 35 mph or faster, I find it distracting to pedal. At that speed I would rather focus on the road or trail than trying to pedal to somehow keep up with the drive system. I do enjoy pedaling. But, I reserve pedaling for general cruising at 25 mph.

Matt

 

[Joe T.]

If I may add my experience to the discussion… My bike has been fabulous since going to 35 to 1. Top speed is about 25 MPH depending how much I want to help. My bike is not built for top speed. My bike really shines when hill climbing.

I have a fellow ebiker that I helped put a BBSHD on his fat bike. He was having hill climbing problems and added a 30T drive gear for torque. It did improve the power but the cadence is so far off that it made adding human power to the hill climb almost impossible. In the end you just sit there and let the motor do all the work.

For me, I like to be part of the equation. Battery mileage is greatly enhanced if I add respectable human power to the mix. I’m not one who likes to pedal my brains out. The same goes for hill climbing. I like to help but for me slow and steady wins the race.

PS: 36T crank gear into a 14T driven gear with a NuVinci 360 on 29” wheels.

 

[LightningRods]

Totally valid points Joe. My drives can be run at lower than maximum power and used as power assists, like the Bafangs. If you wanted to make an energy efficient commuter, running a small block at 36v 20a would give you better than human power and spectacular battery range. Especially if you're an enthusiastic peddler.

The Small Block is easily capable of 3000 watts. The Big Block considerably more than that, 5000 watts or more. At those power levels 30:1 reduction is unnecessary and only adds to the strain on the bicycle driveline. The standard scenario for driveline problems is 3000 watts reduced 30x trying to run through an 11t rear sprocket. 3000 watts reduced 15x running through a 22t rear sprocket will put the same power to the ground with a lot less driveline stress.

What power level are you running, Joe?

 

[Joe T.]

My bike is based on a bone stock GNG belt drive from 2013. 48V 10Ah battery. It has been updated with your wide belt and 219 chain secondary. I think the stock controller is 20A max?

I guess my point is the power I have is all I need to climb steep hills with my help. Many of the hills I climb are almost too steep to go down! When I had a 9 speed cassette I rarely used the 11T. Only when I was looking for top speed would I shift past 5th gear. Most of my riding is about 6 MPH through the trails. Now I have a NuVinci so "gears" are not in the picture. I broke a master link one time and have had some chain issues but nothing that required a re-design.

My concern with focusing on top speed potential is the fact that speed itself will get you noticed. I like being under the radar so to speak. IMO the ebike wave could be burdened with crippling regulation if the wrong people see us having fun.

 

[LightningRods]

Perfect. You set the gearing up just right for 1,000 watts. Looking at 1kW from the perspective of a bicyclist, it's a lot of power. Three years ago my goal was to get the GNG type kit to work reliably at that power level. Now people want more power.

I share your concern about e-bikers showing poor judgement on a fast rig and spoiling the hobby for everyone. I've intentionally avoided engaging in the top speed contests that a lot of the high power builders go for because it's dangerous and will probably end up bringing strict legislation down on us. I like having more power for climbing hills faster. In the area where I live there is a very steep and long hill where the car traffic is doing 35-40 mph. It's a lot less scary to have them pass with a closing speed of 15 mph rather than 30 mph. Plus I like doing wheelies and power slides off road. 3,000 watts is a lot of fun.

You did a great job on your build. You could get a more powerful controller and get a lot more out of it. Your NuVinci rear hub wouldn't last long. Hot rodding is a great way to run through parts and money.

 

[LightningRods]

The new downhill drive is making great progress. I decided to completely redesign the mounting brackets. The right side bracket will be a one piece cut from .190" aluminum. The left side will be two piece to make the bottom bracket mount adjustable for different BB widths.

Here it is on the Norco again.

Here it is on a Specialized Stump Jumper.

I tried mocking this layout up on a more traditional frame with a straight front downtube. The standard drive with the motor below the jackshaft works better on those frames. So this will be a new drive specifically for downhill bikes with the "dogleg" bend in the front downtube. I have some other tricks planned for the drive enclosures, but I'll make more progress before I start talking about it.

HAPPY 2017!