LightningRods mid drive kit

This is cross-chaining which is one of the drawbacks inherent in derailleurs. The low gears and the high gears put a pretty severe angle on the chain. This is one of the reasons that a single run chain can handle so much more power than a derailleur.

The good news is that you're rarely going to need the lowest gears. With a two stage reduction drive you'll spend most of your time in the middle to outside gears.

Another idea that I'm playing around with is a wide ratio 4 speed based on 8 speed spacing. The four cogs will be grouped in the center to minimize cross chaining. The outside two sprocket spaces top and bottom will be eliminated.

Try running the bike and see how it does. Derailleurs are made to run this way.

Remus said:
Hi folks,

I'm close to getting my 1500w rebuilt up and running.

I recently mounted the motor and chainring and noticed a fairly aweful chain line (Please review picture)
Does anyone have any idea's how I can improve my chain line ?

 
Derek,

Here is your replacement 15mm axle assembly. 15mm diameter 4140 hardened chrome moly axle, 15mm ID bearings, 15mm ID 13T driver sprocket, 15mm ID freewheel hub, 4mm keys and 15mm retaining clips. You should be good to go.

15mmJackAssy.jpg
 
Michael has been great at customer service. Response has been great and I have just finished up my single stage kit. Took it out for the first time today and with a little more tweaking it should be fun and reliable. Had to fabricate a bracket and modified the Ibera rack and bag to hold the EM3ev 14S7P Battery.

Pics or it didn't happen right?
 

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Super clean installation for the motor, but you've a problem with the battery rack :!: :!:

When you'll have a rough terrain, the battery will go into your saddle, pay attention.

Put your battery a bit backward.

Have a Nice Day.

Thierry
 
My Chainring freewheel is on its way out after about 250km of riding bush tracks.

What kind of life are you guys getting out of yours ?

Is there Crossfire branded Chainring freewheel that came with the kit the best one I could get for this purpose ?

Cheer's :)
 
Thierry, thanks for the heads up. The battery itself is below the seat. the bag will have extra storage. I am also going to replace the seat post with a straight one. I removed the rear shock to see what full compression looks like and I will be good. This is going to be 95% street commuter. Nice cush ride so far.
 
KarateDoc said:
Thierry, thanks for the heads up. The battery itself is below the seat. the bag will have extra storage. I am also going to replace the seat post with a straight one. I removed the rear shock to see what full compression looks like and I will be good. This is going to be 95% street commuter. Nice cush ride so far.

OK.

With a straight seat post it'll be good.

Thierry
 
Remus said:
Is there Crossfire branded Chainring freewheel that came with the kit the best one I could get for this purpose ?

The standard ACS Crossfire is not the best flanged freewheel available. The White Industries HD and UHD are the best freewheels. The W-I are much stronger and are rebuildable. The ACS costs $28 USD. The W-I HD is $80 USD. The W-I UHD was $120 the last time that I checked. The ACS is the best of the reasonably priced freewheels. I stock the W-I HD as an optional upgrade to my mid drives.
 
Remus said:
My Chainring freewheel is on its way out after about 250km of riding bush tracks.

What kind of life are you guys getting out of yours ?

Is there Crossfire branded Chainring freewheel that came with the kit the best one I could get for this purpose ?

Cheer's :)
The best for the money is Excess freewheel. You can read about it here:
https://endless-sphere.com/forums/viewtopic.php?f=28&t=47618&p=1249241&hilit=excess#p1249241
 
Is the Excess available as a five bolt flanged freewheel or only as a freewheel cog with teeth? I'd be interested if I could get a flanged version.
 
LightningRods said:
Is the Excess available as a five bolt flanged freewheel or only as a freewheel cog with teeth? I'd be interested if I could get a flanged version.
The Excess freewheel is only available as a cog with teeth and only right hand.
 
At first $80 seems stupid for a freewheel. The more you work with the W-I freewheel the better a value it becomes. Chainwheel mid drives put a huge strain on that chainwheel freewheel.
 
LightningRods said:
At first $80 seems stupid for a freewheel. The more you work with the W-I freewheel the better a value it becomes. Chainwheel mid drives put a huge strain on that chainwheel freewheel.
W-I freewheels are the best because they are precision machined, but they are designed with single row bearings. That is a big drawback. Also, the thin wall bearing, like the one used in W-I freewheel, should be press fit, but in W-I freewheels they are slip fit. It is like with everything else, "the devil is in the detail". I'm sure that, if they could, they would put two bearings, but the whole structure would be too wide for a bike use.
Cheap freewheel will do a good job, if set up properly. Before I use my freewheels, I open them up, remove the low grade grease, and remove one or two shims, so that the lateral slop is down to minimum. (.001 - .005"). That in itself will increase the life tenfold. It is amazing how far you can go with little TLC.
 
My new alloy two stage drive is shipping. This design is based on my previous "stretch" brackets made to clear the bend in the front downtube of DH bikes. I found that by adding 25mm I was able to move the reduction jackshaft inline between the motor and chainwheel. This creates a lighter, more compact, more rigid structure. The sheets are aluminum for further weight savings. The sprockets are stainless steel, the jackshaft axle is 15mm 4140 chrome moly. Reduction to the chainwheel is 22:1.

While the Big Block would fit I think I'm going to produce this as a Small Block drive. The Small Block benefits from more reduction, the Big Block has so much torque on it's own that too much reduction just puts more strain on the bicycle driveline. If you want to pedal with the motor, get the Small Block with the two stage. If you want an electric motorcycle with pedals get the Big Block with a single stage.

The Small Block easily handles 2000 watts @ 14s or 3000 watts @ 20s. 14s is better for pedaling with due to the lower motor rpm.

IMG_7549.jpg


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IMG_7553.jpg
 
Alloy Artwork !

The whole system sitting there including the crank/freewheel/BB weigh's how much ?

With the first reduction/ jackshaft , will it clear the down tube of Down Hill/ Enduro bikes like mine ?
 
The mid drive weighs 10.5 lbs. Six lbs of that is the motor. The chainwheels, bottom bracket, crank arms, freewheel and pants ring weigh 5 lbs. 15.5 lbs for everything.

Whether this drive will fit your particular bike or not depends on how much space is between the BB shell and front tire. This drive can be rotated up to run completely inside of the frame triangle. Many downhillers like to have their battery in a backpack anyway to keep the bike light. If you send me the make model and year of your bike I can work up a scale drawing to see if this drive would fit either way.

I'm already working on a third drive which will have the motor in front of the BB and the reduction jackshaft inside of the triangle. I'm going to talk to a couple of battery vendors about getting triangle packs made with just the bottom tip of the pack left off to make room for the jackshaft.
 
I am guessing on my weight of the Mack build, but think the Motor/controller/crankset/bb is around -12 pounds ( less batteries )
so
Looks like your two stage Small Block is just about 3.5 pounds at most , more in weight.
But
It should run on almost twice or perhaps a little over twice the power.

From what I have seen on the weight of the DD hub motors your two stage Small Block kit should be less in weight than a 2K-3K watt DD Kit.

I have the 2015 Santa Cruz Bantam, I bought the frame and built it up for a couple of reasons.
It is one of the few bikes that has a swingarm that allows for a very large Chain ring at the Bottom Bracket area,
not important to non-e-bikes but as you know when riding any speed over 25 mph you need a 50 or even 52/53 tooth Chain ring to have any input to the rear cassette I think the Bantham could have space for a 54-56 tooth size Chain ring. ( so that means you can design a large chainring that is connected to the motor for higher than usual reduction directly from the motor )
and
I have always liked the simplicity of the Single Pivot and the Strength of Santa Cruz Frames.

In Regards to your Third drive you are working on with the second stage inside the frame, there are different F.S. designs, on mine space in needed for the swingarm to move in about 2.5 inches, so the bottom 3 inches of the inside of the front triangle is not usable.
I think a design like the newer Giant bikes would be good, or any other Make/Model that has the shock vertical , next to the seat tube.
 

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First the Norco "dogleg" DH frame that I used to lay the drive out:

Norco_Frame.jpg


Now your Santa Cruz Bantam:

bantam-profile.jpg


The two bikes are very similar but the Norco has the BB set back further in the frame. Just enough for the front tire to clear the motor when the suspension is fully compressed. Unfortunately it looks like the motor would contact the front wheel on your Bantam.

The distances between the sprockets are at minimum on this drive. I will be experimenting with a 3" diameter motor very soon. That motor would clear on your SC frame. It puts out 7kw, which you might like.
 
Mike,

Great work there on superimposing it on the bike picture. When I saw the picture of the 2 stage you have just completed, I of course wanted it right away.

Well I am still trying to raise funds to pay for a mid-drive, and I have been waiting for the smaller motors to be made available , as complete kits anyway. And now the Rainy Season has come to where I live.
So , Yes I would be much happier with the kit you will be developing, as I am ready for more power and can do 14s or take 3 of my 6 cell packs to make an 18s pack .


BTW , as you can see in your picture of my Bantam, since you already make your own front chainrings , of steel that run to the motor , you could make a chainring 3-4 teeth larger for even more reduction from the motor .
This is true for all Santa Cruz single pivot frames, and for other frames that have copied the Santa Cruz Superlight/Julianna/Bantham style of Frame.
 
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