LightningRods mid drive kit

[Ozziebike]

ok, easy fix for my dropping chain problem (lets see if it works long term)... I just reinstalled my front derailleur and locked it out with the adjustment screws to be in the right position.

Now... back to my alignment issues... i not have a sneaky suspicion that its the front part of the kit moving towards the right, therefore putting the front jackshaft out of alignment with the 80T gear and slackening the chain... after a while...

i have seen a few peoples solutions to reinforcing it so the pipe clamps don't slip and allow the kit to pull over, but I'm just wondering if there is a LR approved method for fixing this...

 

[LightningRods]

The basic layout of the drive is sort of an "L" shape. An L is not particularly rigid. The tall upper arm flexes fairly easily, especially if it has a powerful electric motor pulling against it with 33:1 reduction. The solution is to add a brace between the bottom of the L and it's top to make a triangle out of it. A triangle is a very rigid shape. I provided a lug at the top of the right upper sheet for the purpose of adding a torque brace. That is the L-R approved fix. Add a rigid brace, like a piece of angle stock or a tube, that is bolted to the upper lug and some solid mounting point back on the bike. In line with the upper run of the secondary chain and mounting near the bottom bracket, like on the frame's seat tube, is preferable.

I'm developing an add on bracket that bolts to the lower mounting sheet and provides both chain guides and a mounting point for a torque brace. If people want them I'll also offer tubular torque braces with heim joint ends on them.

The manually adjustable chain tensioners are back from the laser cutter. I also have the new 4140 hardened chrome moly jackshaft axles back from the machinist. I'll be rolling these parts into production this month.

 

[zlagger]

Hey LightningRods,

I have a raptor 140 that I would love to convert to a big block kit. How is your conversion coming along? Any pics, info available?

Here's something else that I've been working on.

When I started designing the big block mid drive for the Qulbix Raptor 140 I could see right away that the entire drive needed to be bolted securely to the battery box of the Raptor. No adjustable lower bracket. So I designed a 219 chain idler tensioner.

It's completely manual but easily adjusted with two readily accessible M6 hex bolts. The idler is a regular steel 219 sprocket. It has a sintered bronze sleeve bearing in it for quiet, low friction rotation.

The lower bracket for the Raptor kit has no slides. Only holes for M6 bolts in fixed mount. I still needed a two part lower bracket to adapt the width of the motor (102mm) to the Raptor bottom bracket (83mm).

Everything went together super solid. Even without being bolted to the battery box the solid mount with adjuster was stout. It got me to thinking...

Most of the bitching about my mid drives has been the fussy lower slide adjuster with all of the bolts and screws and hardware. It's also a PITA for us to assemble here. So I've decided. Once the current stock runs out, they're history. No more slide lower adjuster brackets.

The good news for people with the slide lower brackets on their existing L-R mid drives is that the new sprocket tensioner will retrofit to your kit no problem. If you're not having problems with your brackets slipping (a lot of people didn't) you can just add the sprocket tensioner. If your brackets have been slipping you can just drill additional new holes and bolt the slide in place.

I'm having the first batch of these made right now and they're all going onto production kits. If there is a lot of interest in retrofitting I'll have as many made as necessary.

 

[LightningRods]

Hey LightningRods,
I have a raptor 140 that I would love to convert to a big block kit. How is your conversion coming along? Any pics, info available?

The only photo I have is from this test fitting that I did to confirm that the big block will fit the Raptor.

I have all of the parts to put the Raptor kit together and I still have the Raptor 140 frame in the shop. I'm working on the LunaCycle drive this week along with shipping regular mid drives. I'll get back to the Raptor as soon as I get the LunaCycle rolling.

The Raptor drive will have a solid lower mount and will have the upper mount bolted directly to the battery box. There should be no chance of flex. The primary and secondary drives will both be 219 kart chain.

 

[John Bozi]

I'm developing an add on bracket that bolts to the lower mounting sheet and provides both chain guides and a mounting point for a torque brace. If people want them I'll also offer tubular torque braces with heim joint ends on them........................I also have the new 4140 hardened chrome moly jackshaft axles back from the machinist. I'll be rolling these parts into production this month.

I think I speak for everyone that this should be as plug and play and not fail as possible.

I have no idea where to connect a torque brace on my bike and want the real steel.

 

[Ozziebike]

The basic layout of the drive is sort of an "L" shape. An L is not particularly rigid. The tall upper arm flexes fairly easily, especially if it has a powerful electric motor pulling against it with 33:1 reduction. The solution is to add a brace between the bottom of the L and it's top to make a triangle out of it. A triangle is a very rigid shape. I provided a lug at the top of the right upper sheet for the purpose of adding a torque brace. That is the L-R approved fix. Add a rigid brace, like a piece of angle stock or a tube, that is bolted to the upper lug and some solid mounting point back on the bike. In line with the upper run of the secondary chain and mounting near the bottom bracket, like on the frame's seat tube, is preferable.

I'm developing an add on bracket that bolts to the lower mounting sheet and provides both chain guides and a mounting point for a torque brace. If people want them I'll also offer tubular torque braces with heim joint ends on them.

The manually adjustable chain tensioners are back from the laser cutter. I also have the new 4140 hardened chrome moly jackshaft axles back from the machinist. I'll be rolling these parts into production this month.

Ah! I had wondered what that little extra bit was for! Ok, this is the next step for me! i'll report back once reinforced and let you know if I'm still getting the same lumpy chain issue.

Cheers LR.

 

[LightningRods]

Here's a torque brace that I made out of $2 worth of aluminum angle stock. In this case I ran the brace from the lug on the top of the right upper bracket down to the lower shock mounting bolt. It doesn't take a lot. The brace needs to be a tube or angle stock, something with compression strength. A flat bar will bend unless it's heavy gauge.

 

[r3volved]

That's cool with metallic accent on the guards and black everywhere else. Sharp

 

[LightningRods]

Thank you!

 

[LightningRods]

Number One of the first four LunaCycle mid drives coming together. The big block motor is down drying in the paint room. Once it's dry I can finish the main assembly.

In the photo you can see the upper and lower jackshafts with 6061 billet housings and 4140 hardened chrome moly axles. I've been holding this basically completed design up for months while I looked for the right material for the axles. You can also see the eccentric lower adjusters and the base plate that bolts to the Luna frame. All of the main sheets are made from 10 gauge steel.

I should have this drive completed this week.

 

[Mammalian04]

Sweet Mike! I still have my place in line from 6 months ago right?

Are you shooting me an invoice like before or is there a new checkout process?

Any accessory options that may be offered/needed?

 

[LightningRods]

I'm going to finally reach the sub 60 day mark on the regular mid drive production queue this month. I'm working the catch up on the Luna orders, which are my oldest standing orders, in with the others. Everyone with a LunaCycle drive will get their drives as soon as they're finished. You are all essentially 'first in line' since you've been waiting the longest.

One accessory that I'm working on for the Luna started with the Big Dummy drive. I'm working on putting together a torque sensing throttle that measures the strain on the pedal only chain line. Unlike the torque sensing bottom brackets this system will measure the torque from both cranks. In the case of the LunaCycle, it uses a 100mm BB with a 148mm long axle. There are no torque sensing BBs anywhere near that size.

 

[Mammalian04]

Woohoo! Super stoked!
Torque sensing throttle sounds cool too!

I was thinking about building my own battery for this one but will just buy one since the kit is almost ready. Is the 60v 20ah battery from Eric the recommended choice or should we go higher voltage?

 

[r3volved]

One accessory that I'm working on for the Luna started with the Big Dummy drive. I'm working on putting together a torque sensing throttle that measures the strain on the pedal only chain line. Unlike the torque sensing bottom brackets this system will measure the torque from both cranks. In the case of the LunaCycle, it uses a 100mm BB with a 148mm long axle. There are no torque sensing BBs anywhere near that size.

Justin has some done some really neat and novel stuff with torque and strain sensing on various vehicles. Might be someone good to ping some ideas off. In the YouTube tour of Grin he shows a bunch of cool old prototype ideas

 

[LightningRods]

Is the 60v 20ah battery from Eric the recommended choice or should we go higher voltage?

The big block doesn't need volts as much as amps. It's a big motor and will make a ton of power at low rpms with enough amperage. The Samsung 25r batteries that Eric sells are primo because they will push 50 amps without getting hot and will handle bursts higher than that. 60V x 50 amps is a lot of continuous power!

 

[LightningRods]

Justin has some done some really neat and novel stuff with torque and strain sensing on various vehicles. Might be someone good to ping some ideas off. In the YouTube tour of Grin he shows a bunch of cool old prototype ideas

I've been writing to Justin and he's offered to help me with torque sensing. He just sells the printed strain gauges so I'll have to create the flexible structure that they bond to. I will probably start out with a BEAMts which is a cool hall-based torque sensor that plugs right into the CA3. We used it on on the Big Dummy cargo bike and it seems to be working very well.

The BEAMts is the small black box with an idler wheel located on the chainwheel run of chain.

 

[LightningRods]

One of the other bikes that I'm working on right now is a super cool Surly Moonlander for Ray G. The 100mm BB Big Block mid drive is going onto the Moonlander like it was custom made for it.

A trick that Russ T. brought to the game when we were working on his Motobecane fat bike was using a 100mm BB with a 170mm axle. This gets the chainwheels out away from the wide ass chain stays so that you can get a chainwheel onto the bike along with the 219 driven sprocket. Everything still has to be reduced in diameter to fit, but it does fit very nicely. I have a 64T 219 driven on here and a 32T driver chainwheel. Pedaling cadence is up to 115 beats and top speed is limited to about 25 mph @ 50V, but if you're wanting to pedal a lot and go fast you shouldn't be riding a fatty anyway.

This Moonlander is going to be able to go anywhere and roll over anything.

 

[spinningmagnets]

Great news!! Mikes drives have a paragraph and a pic in a "mid drive round up" in Electric Bike Action magazine, he is on page 58, october 2015 issue.

http://www.electricbikeaction.com/

https://www.facebook.com/ElectricBikeAction

 

[LightningRods]

Cool! I couldn't find a thing online, but... cool!

 

[r3volved]

Right on! Congratulations!

 

[Remus]

Great news about the "219 chain idler tensioner"

Mike I know you've been having some trouble with receiving emails from outside the USA due to a email server problem, I'm in need of a BB extension to get around the curve in the downtube of my bikes frame. I've sent through about 4 emails so far over the last few weeks.

Is there another way I can try to get a parts order to you other than email ?

Thanks,
Remus.

 

[LightningRods]

PM sent

 

[nubrian]

It seems like the biggest weakness in this kit is with the drive chain constantly stretching. From what I hear is chains never stop stretching until they break.

Wouldn't it be better to use a belt instead of that chain?

 

[LightningRods]

I don't think that it's accurate to say that chains never stop stretching. They get seasoned and then are pretty stable. I prefer belts personally but there isn't room on the chainwheel side for an inch wide belt. The single greatest shortcoming of belts compared to chains is width vs power capacity.

Chain stretch has been more of an issue than I anticipated. I was hoping that adjusting the secondary chain would be a very infrequent event. But it seems like it's pretty frequent, especially at first. People who keep running the kit without retensioning the chain will start throwing the chain. That's why I've started developing idler tensioners that are easier to reach and adjust.

I've never heard of anyone breaking one of these 219 chains on one of my mid drives. They handle 25 hp and do 100 mph in racing karts.

 

[spinningmagnets]

There are a dozen compromises for every engineering choice. Any benefit you get from one change, you have to give up something else. The current configuration is pretty fantastic, and especially wonderful for a full-suspension off-roader.

The primary reduction from the motor to the jackshaft would run louder if you used a chain, but a chain would handle more power. The secondary reduction from the jackshaft to the bottom-bracket chainring experiences less speed, but more torque...perfect for a chain. Chains are narrower, belts that can handle this level of power are much wider.

The customer base for an all-belt drivetrain is very small, and much more expensive. I'm not saying it will never happen, but...it is very unlikely as long as the current version is selling as well as it is, and I am absolutely certain it's popularity will only grow from here on out.