LightningRods mid drive kit

[LightningRods]

Currie motor? You're on the wrong thread.

I want to point out that chain growth is not chain stretch. Chain growth is caused by the geometry of the rear suspension on the bike. The distance between the bottom bracket and rear cog(s) is less with the suspension compressed. This causes the chain to go slack. So the chain doesn't really grow. The frame of the bike shrinks. Bicycle engineers do this intentionally because it makes the bike bob up and down less under the force of pedaling. Unfortunately when we run motor power through this suspension it compresses and the chain goes slack. For our purposes the less chain growth a frame has the better it will be as an e-bike.

 

[eTrailster]

Maybe the chain quality too?

When stonezone is talking about chain growth, he is talking about the slack that occurs when the rear suspension flexes. The greater the suspension travel, the longer the chain required and the more slack for which the tensioner needs to account. He may want to consider re-engineering his rear tensioner to achieve better wrap with repositioning the mount/upper wheel forward. Then use a longer "cage" whose arc of swing between the 2 wheels is long enough to account for the slack. I don't think a single wheel tensioner can be made to pick up the slack from 140mm rear travel. It would need to squeeze the pull and return sides so close together, they would need to touch. It seems the chain needs to be suspended with a second wheel like a classic derailleur. Then again, I could be wrong. I'm simply using my bicycle of the imagination.

Mike responded while I was writing. Sorry for the repeat.

 

[t0me]

Thank you both for the clarification.

 

[LightningRods]

"Chain growth" is sort of a dumb term. It sounds like what you thought it was- chain stretch.

 

[LightningRods]

This

Plus this

Build thread coming soon.

 

[spinningmagnets]

Can't wait! one good thing after another...

 

[crossbreak]

Yay! another dual freewheel jackjshaft drive!

 

[LightningRods]

That's right. That silver freewheel cog connects to the normal chainwheel on the bike. No freewheel in the BB, no motor power in the BB. The only power running through this freewheel cog is from the rider.

 

[crossbreak]

High Power Cycles tried this with a Crystalite Motor https://www.youtube.com/watch?v=6FNsyduYgVE

After I trashed 3 chains within 500km with the converted 2500W Bafang BPM, i was fed up with derailleurs :lol: Yep i do not live in the mountains...

I added a picture and link to the wiki http://endless-sphere.com/w/index.php/EBike_Motors_Middrive#Jackshaft_Dual_Freewheel_Config

 

[Green Machine]

That drive system looks like pure bike porn...i cant wait to see it on the bike.

They look like they match up super well aesthetically.

I am so excited!

Thats the first time i saw the mid drive system whole!!

 

[stonezone]

my suspension stroke results in the distance between sprockets to grow when compressed, not shorten ... so there is plenty of slack when unsprung but quickly goes away with load and suspension stroke... I haven't measured it yet (need to unbolt the shock) but it's a hell of a lot more than other bike's i've seen. I think the derailleur style tensioner should fix it... I need to take my rig for a spin today and see how it holds up, just been busy. 219 chain for the final drive would work but then i'd have a "live chain" as mentioned before. probably not an issue, and I kind of have a feeling that once i work out the tension and chain/gear interface so there is no more slip, i'm going to blow the rear cassette, but maybe not. I wonder how strong it is but if that's the case then 219 final drive it may have to be.

 

[--freeride--]

That dual freewheel is nice, so you can speed up the chain a lot get away from small rear cogs and take force off the chain. I would try to set up the bike with 8speed stuff and 18T-22T-28T-34T-40T.
That should be good for the wear and will give you a neat reduction for hills.

I would prefere a bike that has a flatter steering angle, 68°deg is state of the art on fatbikes that are good for high Speeds(e. g. surly Icecream truck). Although a more straight tube design.

 

[Green Machine]

I would prefere a bike that has a flatter steering angle, 68°deg is state of the art on fatbikes that are good for high Speeds(e. g. surly Icecream truck). Although a more straight tube design.

Lol "state of the art" fatbikes built for speed? Forget steering angle...can you point me out to some speed rated fat bike tires?

I have done 50mph on the Luna Cycle frame pictured below with an astro mid drive and it felt stable on street use. 5 years ago i had a electric pugsley that could go 35 and it did not feel as stable and it was the motivation for building this frame. The mid mount motor bay, centralized battery pack, and stretched frame is the key. The lengthened cargo bike like frame make the bike remarkably stable at high speed and makes it less prone to unexpected wheelies at high power.

Where you gonna mount a mid drive and a battery pack in the surly ice cream truck? Nice color though. Cute name. $2500 though. Ouch.

THe luna cycle has a thick plate behind the battery pack designed for mounting a high power system. The second version you see in the pic has a bay even larger than the first, and the fenders were put in not just for looks but to shelter the motor from tire spray which we had problems with in first frame.

 

[LightningRods]

There are so many advantages to having the mid drive between the bottom bracket and the rear wheel. One is the two stage pedal chainline which adds 44% more overdrive. With the 52T front sprocket that the Luna comes with that lets you do 35 mph @ 80 crank rpm with a 16 tooth rear cog. On a more conventional bike you get forced to use low tooth count rear sprockets to get any speed. That causes chain skipping problems.

Where I live in Oregon there are a lot of steep hills and also open country roads where I want to be able to open it up and do 50 mph. I'm initially building the Luna with 4" fat tires on 100mm rims and a single 16T rear cog. With the amount of torque produced by the big block this will work really well with the fat tires. When I complete the bike for my own use I'm going to put 2.25" wide speed rated street tires on it and a Rohloff Speedhub. I have no doubt that equipped this way the Luna will do 50+ mph at 48V.

One other great aspect to the Lunacycle is that Eric at electricbike.com is having great battery packs with BMS built specifically for the big battery box. 40Ah is an easy fit. The BMS allows 40 amps continuous with 60 amp bursts.

I'm really looking forward to this summer!

 

[markass530]

40 AH's that's what I'm talking about, Right at that 2 KW/hr sweet spot for an ebike , range for days

 

[dekes1]

Hi all,
I won one of these bikes in a contest and want to convert it. It hasnt arrived yet so i dont have any info and can't seem to find detailed mesaurement specs anywhere. I'm interested in the LR Big Block kit so can anyone comment on any hurdles or challenges i may face? i currently have a Cyclone mid-drive built on an old diamondback hardtail so i'm not worried about any normal build challenges but rather any major customization that may be required.

And although it looks like a standard 68mm BB, i cant be sure so does anyone have experience with this (or the FSX2.0) bike?

Bike in question: http://www.bikesdirect.com/products/gravity/fsx_1.htm

 

[pff7]

Pardon me for not being able to go thru whole thread, but when no juice is being applied what parts are being turned aside from your normal crank,gears to wheel torque,ect.(via just pedaling) needed to push bike forward?

Another way of saying this,besides extra weight near bottom bracket, controller/battery weight is their any drag? I'd imagine turning some freewheel to be neglible.

Thankyou as this would be a concern to me....

PS: Do I turn the motor just using pedal power when not applying voltage?

 

[spinningmagnets]

The jackshaft is the heart of the system. When power is applied to the motor, the pedals can freewheel if you want, but you can also add pedaling if you want (to extend battery range, or just get some exercise).

When the motor is off, the pedals turn the jackshaft, and the jackshaft turns the chain to the rear wheel, so...when you pedal, the motor does not turn.

 

[r3volved]

ie. No peddle drag, no coast drag

 

[pff7]

Thanks guys.....
seems like an advantage over the regular hub motor deal. Bigger the hub motor more drag in my experience.

It's a big thread,I'll keep reading....

 

[stonezone]

seems like an advantage over the regular hub motor deal. Bigger the hub motor more drag in my experience.

The best thing about mid drive is where the weight is placed on the bike. It's so central and low that if anything, your bike actually feels better at speed. A heavy hub motor, with that moving mass in the rear would be night and day from a kit like LRs. My Glory with big block weighs in just over 50lbs (battery on my back), but still feels as flickable as it did stock.

 

[eTrailster]

I just saw these for the first time and haven't seen them mentioned here. KMC now apparently produces mid-drive e-bike chains in 10,9,8 and single speeds.

They say: "Specially designed for middle engine driven e-bikes such as Bosch, Panasonic and AEG, these chains have higher torsion resistance to cope with ruthless shifting and hi-torques."

KMC X10E Ept Ebike 10 Speed Chain
http://www.chainreactioncycles.com/us/en/kmc-x10e-ept-ebike-10-speed-chain/rp-prod120625

KMC X10E HP Ebike 10 Speed Chain
http://www.chainreactioncycles.com/us/en/kmc-x10e-hp-ebike-10-speed-chain/rp-prod120636

 

[stonezone]

from what i could tell the standard 3/32 mtb chain (even if it's strong enough) will slip on the cogs under enough power. To my untrained eyes, mtb chains don't seem to seat as deep as kart or moto chains do; probably a tradeoff in order to enable shifting. It may work on the larger cogs and I don't know if the 14t lower limit is even realistic and then you run into problems with your chainline... where you're getting enough teeth, the chainline is way off.

Here's what I found can handle more than 3000watts:

3/16 bmx chain
1/8 or 2x3/3/2 or ideally 3/16 front sprocket
2x3/32 rear cogs sandwiched fit perfect with the 3/16 chain. I don't think you can go smaller than 16t on the back, and a tensioner with 2 rollers is a must to allow for maximum cog/chain interface as well as the massive chain growth (unfortunately you can't use a standard derailleur with the 3/16 chain)

(Credit goes to sascha2770 for the above setup)

and here's a few good links if anyone is interested:
44t 3/16 104bcd front sprocket: http://www.ebay.com/itm/181636381383
Single deep tooth CrMo 3/32" cogs for $4/each: https://www.outsideoutfitters.com/p-1125-gusset-steel-cog.aspx (I'll let you know how these work once they arrive)
KMC 910 chain (I had to buy 2 to get enough length): http://www.amazon.com/gp/product/B000AYHAB8/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
This is the tensioner i'm using. I added a second roller to keep the chain on but so far this s the one weak link (I'll probably make something in the future): http://www.amazon.com/gp/product/B007WTVMA4/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
These rollers would probably work: http://m.jensonusa.com/Singlespeed-Cogs-and-Freewheels/Surly-Singleator-Upgrade-Kit and I'd like to incorporate them in something custom similar to this: http://www.amazon.com/Paul-Components-Melvin-1-spd-tensioner/dp/B000VYKBY0/ref=sr_1_6?s=sporting-goods&ie=UTF8&qid=1429839616&sr=1-6&keywords=single+speed+chain+tensioner

 

[Overclocker]

Quick question...

Would a clutched rear derailleur dialed all the way up help against slipping under power at 11t?

 

[stonezone]

Quick question...

Would a clutched rear derailleur dialed all the way up help against slipping under power at 11t?

Depends on how much power you throw at it. I had a brand new Zee with new chain and cogs, and there was still slip at any power but if you have the chainline perfect it may work...