Thoughts on new drive system/s. What would you like?

Hey Guys,

I am thinking about a few different drive systems to design and market (like I need something ELSE to add my my plate ). Anyway, I have had a number of requests for specific things. Some ask for light weight, some ask for ultra compact, some ask for crank drive, some ask for low cost. I know you cannot make everyone happy with one system. However, I can make a couple other systems to add to my product line that may apeal to people who are not looking for what is already available. I have thought long and hard about this and, for the most part, I would like to move in the lower weight and lower cost direction along with lower power. Those, actually, go hand-in-hand pretty well. I am staying away from crank drive systems for now because of the complexity involved, time consuming installation, and high cost versus single ratio (though I am open to doing a crank system in the future). What I am specifically looking at right now is a sub 1,000 watt continuous system that can be had for maybe 60% the cost of what I am offering now. I have been dead-set against the cheap chinese motors for a variety of reasons. But, there are other options out there. Heck, I could even spec a smaller system for a Astro 3205 and still be relatively cost effective.

Here are some price comparisions for you;

V4 drive $385
Astro 3210 $400
HV160 controller $300

Possible new light weight system;
Reduction unit $200 - $225
3205 motor $300
HV80 controller $150 - $170

The overall weight would be roughly half of the V4 system with a 3210. The power would also be about half.

What are your thoughts? If this is not a good idea, what would you guys prefer seeing marketted?

Matt

Hi Matt,
I think it will be hard to make a "low cost system" if you ignore the chinese motors - an I must say I've used a few turnigy 63mm motors with no problems. I think many folk have difficulty with the engineering and there might be a lot to be said for supplying the engineered parts and lettiing them buy their own motors, thereby 1) supplying the need and 2) insulating yourself from any motor issues. Just a thought ;^)
Bob
PS a single speed version of my mountain bike conversion could be made for a hundred dollars or so of engineered parts + motor + ESC + batteries. That's a sub 50$ motor & does 20mph up a a pretty reasonable hill - now up to 250miles or so & going strong... I've commuted 14miles to work on it (but it's now too dark & cold.....)

Simple, A 2 speed box Matt!

KiM

Hey Matt,

I agree with Bob. Making a reduction that could fit a couple of different motors easily, especially if it is low cost, would be the most viable. It would certainly expand your market and potentially make more money because of a higher number of sales.

Maybe a reduction with that can accommodate adapter plates for several different motors, even outside of the RC range.

Clay

I want a lower cost, definitely. You may want to look into making these units in mass, and making them compatible with cheaper motors such as the larger turnigy ones.

The weight advantage seems like a big improvement over a hub alone. But the cost does need to come down.
I'll stick my geared hub motors in the closet ( which i am very fond of and am a huge advocate for ) for a rig from you. But cost has always been a barrier to me.

Yres would definately like to see drives
Suitable for those craptastic motors :lol:
After seeing a couple of members fry their
Astro motors up recently I know I would be hesitant
In forking out the big $$ for one, even if I could afford it.

KiM

AussieJester said:

Simple, A low cost 2 speed box Matt!

KiM

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+1

Yeah there is no way i'd fork out for an astro considering how cheap other motors can get.

I could buy 3 hobbyking motors at that price and have well over double the continuous power.

I don't think your drive units should revolve around what is probably the most expensive large RC motor that money can buy.

large diameter low kv astro, direct drive - belt.

also while you are at it a disc brake caliper mount that has the area around the frame mount holes shaved to give back caliper alignment when using your sprocket adaptor.

and actually now that Im thinking more about it I have wondered whether the radial section (outer section) of the belt pulley on the rear wheel could be machined in 1/4ers instead of 1 piece....reducing cost etc...

then those outer parts are pieced together on a inner spider that could incorporate a disc, and seat the caliper inside of the belts pulley (might have to use a disc size smaller than 200mm due to trying to fit inside of the pulley)

anyway ramblings of a madman....

How about a higher power friction drive?

OK, the public has spoken!

I have a few good ideas to move forward on. I think I can encorporate a few things people want into one package.

I will keep this all in mind.

Matt

Matt,
There has been much talk and even more beautiful renderings of a custom suited rear hub for our needs, but sadly no one has taken the reigns on this project. I believe if anybody could do it, you could. I was thinking either a narrow (110mm) style spoke flange with a disc brake mount on left side to fit a sprocket adapter and a brake in 135mm dropouts. Otherwise, some sort of mounting system on the left side for a few pedal cogs and a drive sprocket. Any thoughts on this?

Well, there is only so much room for a disc and sprocket without the chain rubbing on the tire. In fact, you can run the offest sprocket adaptor and a disc next to each other and, with some effort, achieve left side drive and disc brake. Two of my personal bikes are built this way.

I think a large spoke flange hube with mounting for a disc and a sprocket is not a bad idea, however.

I will have to roll this around in my brain for a bit and see what I can come up with........

Matt

Yeah see.. aren't you glad you got a clear consensus on where to go from here? lol ...

recumpence said:

Well, there is only so much room for a disc and sprocket without the chain rubbing on the tire. In fact, you can run the offest sprocket adaptor and a disc next to each other and, with some effort, achieve left side drive and disc brake. Two of my personal bikes are built this way.

I think a large spoke flange hube with mounting for a disc and a sprocket is not a bad idea, however.

I will have to roll this around in my brain for a bit and see what I can come up with........

Matt

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Why not combine them? Use the sprocket as the disk for the brake? It just needs a deeper groove to clear the sprocket teeth.

Drunkskunk said:

recumpence said:

Well, there is only so much room for a disc and sprocket without the chain rubbing on the tire. In fact, you can run the offest sprocket adaptor and a disc next to each other and, with some effort, achieve left side drive and disc brake. Two of my personal bikes are built this way.

I think a large spoke flange hube with mounting for a disc and a sprocket is not a bad idea, however.

I will have to roll this around in my brain for a bit and see what I can come up with........

Matt

Click to expand...

Why not combine them? Use the sprocket as the disk for the brake? It just needs a deeper groove to clear the sprocket teeth.

Click to expand...

Yup, I started a thread on that very question a couple years back.

Matt

large diameter low kv astro, direct drive - belt.

Click to expand...

I was just thinking about this the other day.

What I like about your drive system's is the overall fit and finish and simplicity. I never find myself questioning if the drive is up to the task as its never the weakest link.I really like belt drives. smooth, clean, quiet and strong if sized correctly.

I hate to say it but what I don't like so much is the little RC motors.

I guess you can relate them to a highly strung 4cyl turbo engine. You need high rpm and every thing in perfect tune to make good power. From my past being a big Honda nut for many years. I am not against this line of light weight, highly strung and high rpm engineering.

What I have learned to appreciate especially for daily driving and reliability is larger capacity lower rpm lazy torque motors. Sure I still like a play with a 2stoke motorbike once a month with mates and its still fun.

I think rc motors have there place for people looking for a weekend worrier or racing power toys.

What I would like to see is a drive system that takes advantage of a larger diameter but not overly big. lower KV AC motor. Perhaps something that makes its power at 1000 - 2000rpm max. Your little sprag-clutch free-wheel pulley could then be Fitted directly to the motor shaft. It would be a single stage belt drive to the rear hub. Even if you offer this as a chain drive as well for frames that cant use belts. It would be super simple, very quiet and about as reliable as you can get. The motor would weigh more than the 1kg or so of a rc motor perhaps 3-4kg but you would save some in not needing the 1st reduction and jack shaft.


I feel this would open up a hole new line of drive-motor packages for people looking for that lazy power of the x53 and x54 motors but with some of the big advantages of your rc systems being... free-wheeling!!!, gearing options- faster- slower and weight balance-weight out of the wheel. Not to mention no lacing of motors to and keeping your rear gearing, wheel, hub and quick release system in tact.

I cant suggest a specific motor but I am looking into options at the moment for myself.

Kurt

Kurt,

I agree wholeheartedly. My niche has been the small hyper systems like the small 4 cyl turbo like you mentioned. I have used that analogy myself.

I am looking into other system types right now, different motors, controllers, etc.

I am glad to hear the suggestions!

Matt

Good point Kurt. Matt, what about fitting one of the large BMC or other non-hub sensored motors to one of your drivetrains? Could be interesting...

http://www.thesuperkids.com/20wabmcbrpoe.html

-Warren.

www.recumbents.com said:

Good point Kurt. Matt, what about fitting one of the large BMC or other non-hub sensored motors to one of your drivetrains? Could be interesting...

http://www.thesuperkids.com/20wabmcbrpoe.html

-Warren.

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I've know Chandu for seven years now and he can come up with a specific design if you wish being an old Kollmorgen guy. We can set up an incoming test/dyno to check quality before passing on to OEM users. Made in India just keeps costs down.

http://bmcus.com/

Drunkskunk said:

Why not combine them? Use the sprocket as the disk for the brake? It just needs a deeper groove to clear the sprocket teeth.

Click to expand...

This can and has been done, you just need an unlubricated chain

Hi Matt, I agree with a lot of what Kurt says. A few additional ideas would be: A unit that would not modify the existing drivetrain so that one would not have to break his existing bike to install this one. For a broader appeal it would seem that a lower kv motor and a controller that wouldn't make you cry if it quit($) would hit the market pretty well. I would add some sort of two speed transmission to the list as well. It appears to me by the videos being posted that the same bikes are being used both on and off hard surfaces, sometimes on the same ride. Who wouldn't want to be able to reliably commute to work and have a little fun off the road with the same bike after work or on the weekend. A two speed trans would allow a safe and sane speed for recreational users or commuters, maybe 20mph, and a very capable off road bike at say 10-14 mph. The trans would not necessarily need to be shifted on the fly either which would save cost and complexity. Possibly a lever that you pushed while the bike was not in motion to shift from high to low range, or a belt shift from sprocket to sprocket? The lower range would allow for varying terrain, a way to get home when the battery was low(slower but lower amp draw), trailer pulling, girlfriend in the lap, etc. If you have even one of these requirements now you are forced into more expensive motors and batteries or to compromised performance. Even worse yet, giving up on ebikes all together. Again this would be for a broader appeal, not to those who want to go 70 mph, or climb straight up their house wall which are both cool but very expensive ventures. Good Luck and I can't wait to see what comes next.

www.recumbents.com said:

what about fitting one of the large BMC or other non-hub sensored motors to one of your drivetrains? Could be interesting...

http://www.thesuperkids.com/20wabmcbrpoe.html

-Warren.

Click to expand...

That's about the size motor I was referring to. Something nice and solid that's been designed with human propulsion in mind instead of toy aircraft.

I am just wondering what the KV of that 2000w BMC motor is? . As it would be nice to have a single stage drive directly from motor output shaft to rear wheel pulley. Its got to be lower rpm than a typical RC motor we are using now 5000-10000rpm. 130 - 200kv. I understand you can have the rc motors wound to give a lower KV.But then I feel then you get to the point were you are watering down your power advantage of the RC and loosing the torque you had through high RPM and gearing down.

looks like a 12 or 18 fet lyen controller would work well with a motor like the BMC. motor and controller could be $400 -$450ish. Really then you would be just designing a universal motor mount and front , rear drive sprocket or pulley and your good to go . Perhaps a complete system could be had for $750 - $1000 ? + battery

Compare that to a good size DD Hub motor $350, controller $130 - $200, Strong rim and lacing $150 - torque arms $50...... your already at $700 .

A few additional ideas would be: A unit that would not modify the existing drivetrain so that one would not have to break his existing bike to install this one

Click to expand...

This is one of the reasons I like the mid mount drive system over a hub motor. I can keep my bikes rear hub,9 speed gearing,Shifters, stock wheel and quick R all intact (keeping front and rear QR makes transporting your bike a lot easier) . If you get a flat tyre to your not removing torque arms, motor wires and carrying a 19mm spanner with you everywhere.

Kurt

There's got to be a motor between an RC type and a hub motor used as a mid drive. I really like how the low kv hub motors are really quiet and all, but they are way overbuilt to carry the load of a wheel. Something like a BMC inrunner or a cyclone type might be good.

Lenk and I have a few ideas going. Check his build for pikes peak. The MAC motors are the perfect in between I think if mounted in the triangle or under the down tube like I am planning
..