FUTR Beta with Lightning Rods Mid Drive

Here is the stainless steel rear sprocket with Shimano spline spacers that I'm working on. I'm traveling at the moment but will have these finished very soon.

Front.jpg


Back.jpg


Spline.jpg


The FUTR Beta drive is finished other than this rear wheel sprocket.
 
JC that's perfect. I'm just gonna leave this post as a placeholder to come back to. I'm looking forward to seeing that bike completed and what it will be capable of.
 
The owner of the bike picked up the frame last week. He promised to send completion photos.

These Betas may not have the battery capacity of some of the other "box bikes", but it has to be the best looking. I really had fun working on this one.
 
wow that bike is freaking awesome! Well done

it is going to be the best ride ever compared to a hub

pedal capability and torque all in one neat little package!
 
yes, I collected the bike last week during a trip down the West Coast from Seattle to San Francisco - it was great to meet Mike in person, to see his immaculate workshop and all the exceptional work he is doing.

I will post up pictures once completed - I already have all the parts, including a 20s6p 30Q battery from Allex. The only constraint is time - I am off to Australia for a couple of weeks - but if I can get the rear wheel built up while I am away, I will build it up in January. Really looking forward to this one!
 
Spline Height on a typical Shimano/Sram Freewheel Hub Body and Cassette/ Cog
is only 1.1-1.2 mm .

Would custom made freewheels and your spacers/cog be possible to be made with 2.5-3 mm spline height ?

I know that would add to the cost of the Kit , as a custom made Freewheel Hub Body would have to be made/machined, but for high power systems would the extra cost be worth it so as to not strip the stock freewheel hub body found on all standard hubs ?





LightningRods said:
Here is the stainless steel rear sprocket with Shimano spline spacers that I'm working on. I'm traveling at the moment but will have these finished very soon.

Front.jpg


Back.jpg


Spline.jpg


The FUTR Beta drive is finished other than this rear wheel sprocket.
 

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I'm pretty sure that with the splines as they are the pawls or the ratchet inside of the freehub would break before the external splines gave up. The damage that usually happens to freehub splines are from knife edge sprockets cutting into them.
 
So with the way it is setup it definitely looks single speed. What's the outside sprocket for in that case?

Do you manually swap the chain to that ring for a different gear ratio? That seems like a real hassle if that's the case :)
 
That large sprocket on the chainwheel is the driven sprocket from the motor. The chain wasn’t installed yet. Yes it’s single speed. Manually changing sprockets would be a hassle, and messy.
 
LightningRods said:
That large sprocket on the chainwheel is the driven sprocket from the motor. The chain wasn’t installed yet. Yes it’s single speed. Manually changing sprockets would be a hassle, and messy.

That makes everything a lot simpler to understand. I was wondering why it was sitting out like that.

Anyways, since you put this together can I ask what voltage and amps PRW planned to run this bike at?
Also if you could give me a full quote of this system :) i've got the same exact frame and if the price works right I might drop my hub motor. I'd be sacraficing pedalling ability with my bmc v4 but noise might be the real killer for my type of riding while using a mid drive like this.
 
With the so called concentric bottom bracket of the Beta were you worried of any possible binding or friction caused by the side mounting plates? There is only a small contact patch before it gets to the c clips of the bearings etc.
No friction from attaching the drive like this afterwards?
 
I was concerned about the BB mounting plates binding the swingarm based on the photos I had seen prior to receiving the frame. Luckily the center BB tube is just a bit longer than the bearings and C clips. There is zero rubbing or binding.

Beta_BBfit.jpg


The primary reduction chainwheel is spinning at 500 rpm at 50v. It makes chain noise. If silence is your top priority a hub motor is going to be quieter. This drive is more energy efficient, runs far cooler, improves the bikes handling considerably, and also vastly improves the suspension compliance and the ride quality. You will have far fewer rear wheel problems than with a hub motor. But yes there is some chain noise. I'd use belt drive all the way except for the fact that belt drive needs to be wider to handle this much power. There isn't room at the chainwheel for two 25mm wide drive belts.

This drive is $645.
 
hello lightning rods

mounting the pivot on the bottom bracket how much the pedal efficency(anti-squad)?

best regards
 
Alrighty I'm interested now then... I have the same exact frame.
I've got a 42v 30ah pack I want to use with a mid drive. My battery likes high amps but I could rewire it if I really needed too (higher voltage).
How many amps could be run through this system? Peak/continuous a rough estimate is fine.
 
Hi Guys,

Sorry I haven't been responding to this thread. I wasn't getting notifications that there were posts.

"mounting the pivot on the bottom bracket how much the pedal efficency(anti-squad)?"

The main advantage to having the swingarm pivot on the bottom bracket (where the drive sprocket is mounted) is minimal change to chain tension when the suspension droops or compresses. It makes it a lot easier to keep the chain on the sprockets. I haven't had a chance to ride one of these Betas completed so I can't say how the suspension and chainline works in the real world yet.

"How many amps could be run through this system? Peak/continuous a rough estimate is fine."

Amps are good for this drive. This "Mid Block" 3.5" wide motor should be good for 50 amps continuous with 70 amp bursts. Gear single speed low for high voltage, high for high amperage. You can build torque with either reduction or amps.

"Where is the vid of this thing pulling power wheelies?"

I'm still waiting for one of the customers to finish their build and post some vids. I wish that I had the resources to build a complete bike for every drive that I design (and keep it to play with) but I keep myself plenty broke doing too much development work. Repetition of the same thing over and over is what's profitable. It's just boring as hell.

-Mike
 
ha - I just haven't had time to get on with this build: overseas travel, then Yosemite, then having to work all weekend. Next up is to collect the rear wheel (not sure if it is ready yet), and get on with the build...
 
Hi.
Is this project moving forward?
This construction is awesome and I am waiting to hear some news from you.
 
TomBe said:
Hi.
Is this project moving forward?
This construction is awesome and I am waiting to hear some news from you.
yes, finished! Sorry, should have cross-posted to/ from other thread - https://endless-sphere.com/forums/viewtopic.php?f=6&t=71666&p=1375772&hilit=futr#p1374617
will have time to go for a long ride tomorrow!
 
These drives are available now. I just had ten sets of alloy brackets made. I’m thinking about having them all black anodized.

I ordered some special low kv/high torque motors to compliment this design. The motor runs slower and quieter and can handle up to 100 amps at startup. You can run single speed on the right side or through an 8 speed cassette. Because of the high chainwheel rpm the cassette runs on the larger sprockets which can handle more power.

The downside of this drive is that the chainwheel is running too fast to pedal with the motor. The final drive chainwheel is 22t so the pedal gearing is only 2:1 on the 11t rear sprocket. This gives you a 15 mph “limp home” model under pedal. The drive will run about 4.5x as fast on motor as it will on 100 rpm pedal power.
 
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