Crankdrive Summary?

Punx0r

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Joined
May 3, 2012
Messages
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I'm seriously looking at doing a lightweight aluminium crank-drive bike as a project for the summer, but I'm kinda baffled by the amount of information available on here - lot's of makes & models with 100-page threads on each...

For myself and other newbies, would someone be kind enough to give a quick summary of the available options?

I see: Bafang, Cyclone, Panasonic, Bosch and GNG

I'd be interested in knowing:

* Standard and realistic modifiable power
* Rough geographical areas of availability (I'm in the UK)
* Relative quality and reliability (including required mods/improvements)
* Ease of use/fitment
* Internal/external controller
* Thumb throttle out of the box, or hackable? I can't stand the idea of pedelec...

With some basic info I can narrow down the options, check prices/delivery costs, and do some detailed research/reading about tweaking them etc.

Others may have different requirements, but I want something light and agile offroad that can climb walls... Basically, what my heavy, direct-drive hubmotor bike is bad at.

Thanks,
Ant
 
What are your skills and what are your weaknesses? (ex, machining, electronics, math, etc.)

Are you looking for something to bolt on and never think about again?
Are you looking for something that you can continuously fiddle with?
Are you looking for something to start you out and beef up as you go?

The gng kit is a great entry level kit for someone who tweaks a lot and likes to beef things up as they go. The belt drive version is definitely not recommended for someone who wants to bolt-on and forget about it. I think the cyclone is along the same lines...essentially a kit of parts to bolt together rather than a single bolt-on unit.

The bafang seems to be a lot better choice for a direct bolt-on and forget kit.

If you're into customizing your brackets/frame and have good experience with machining, I'd recommend looking into the stokemonkey. It's a converted hub and looks like it performs exceptionally well in a mid-mount setup.

I've only had personal experience with the gng 1.1...I'm super satisfied, but I'm a tinkerer and am always happy when something breaks...cause then I get to beef it up more everytime.
 
As R3volved said it all comes down to your skills, look through the 2 threads in my sig, both mid mount crank drives, both very different, almost at the 2 poles of midmounts, it might give you something to think about?
 
Thanks for the replies.

My level is I can MIG weld, make up brackets etc and I've upgraded the FETs in my current controller. I'm not electronic engineer, though, can't weld aluminium and no access to a lathe or mill (sadly).

So I am looking for a kit I can bolt on. I don't mind making the odd modification, bracket/spacer, torque arm etc, but I don't want to be attempting to build my own multi-stage reduction. I also don't mind doing a few upgrades to the motor/drive as long as I'm following a well trodden path.

I don't want to be re-engineering a kit that's badly designed and badly made. Nor do I want something that's a hobby in itself to keep it running. I want to be able to just take it out and ride it :) For comparison, my hubmotor bike is running a little over 3Kw peak, but it weighs 30kg (~70lb) and is unsuited to slow & steep riding.
 
Punx0r said:
Thanks for the replies.

Nor do I want something that's a hobby in itself to keep it running. I want to be able to just take it out and ride it :) For comparison, my hubmotor bike is running a little over 3Kw peak, but it weighs 30kg (~70lb) and is unsuited to slow & steep riding.

Then Bafang BBS02 750W would be at top of your list.
 
Thanks for the links and suggestions.

The stokemonkey looks a bit bulky and heavy, and the GNG kit also looks pretty bulky and low on ground clearance. So I think I'll look in detail at the BBS-02 and perhaps also the 1200W cyclone? I like the look of how they both mount.

Time to those long threads for some reading...
 
I have both the gng 1 and bafang bbs02 kits. The bafang is not 100% finished yet but with the temporary battery setup /test rides I have done, there is no comparison in the two. Get the bafang unless you want a new hobby modding the GNG. The GNG motor is a bit larger / more powerful but the kit needs a tremendous amount of work to get working well. Looking forward to what Bafang comes up with in a 1- 1.5kw drive.

cheers
 
A few random tidbits
-the 11t gear on your rear wheel will skip and grind itself to bits at around 1200 watts, 1800 watts or so for the 13t
-you can put gears on both sides of a mid-drive and use it like a jackshaft instead of using a Hammerschmidt or Schlumpf
-little high rpm motors are loud as hell (rc drive, GNG), low rpm motors are quiet but heavy (mid-hub, Stokemonkey)
-you totally don't need a freewheeling crankset if your stuff is geared properly
-chain drive is noisier than belt drive
-if you run the motor to the left side of the crank you can use all of your gears.
-a company called Velosolo makes gears that attach to disk brake holes.
 
Thanks for that. Particularly the bit about the rear sprockets. I'm used to a 14T on a 6-speed freewheel, so will stick with a 13 or 14.

I think I'll need a freewheeling crank as I often find myself in situations where there isn't enough ground clearance to turn to the cranks, but need to keep moving.

It looks like the BBS-02 isn't quite officially available yet? I'll wait a little while, see if they revise the design any or announce a more powerful version to come. It's way too wet and slipperly to climb anything steep here at the moment (lot of clay soil) so I've got time :)
 
Check out AFT ebikes in Aus. They were the best thing I could find. Gotta buy your own battery though. I'll let you know when I get mine set up. http://www.af-tech.com.au/Products_Ebikes.html
 
So I set up my bike with the aft kit, and I have been riding it for 6 months or so and today the planetary gearbox ate it. I am going to check prices on a replacement gearbox and also other kits.
 
How many kms did you do before it failed ? Did you change the oil in the gearbox ever? as dirty oil will make things wear out quicker

One advantage of these cyclone style kits is that even if the planetary teeth wear out its pretty cheap and easy to replace them compared the BBS02 complex gearbox design. Cyclone has them I think for 30 usd and its very easy to replace them compared to the bafang.
 
Hello all. Does any one have a source for an IPS crankset that allows input on the left and a three chainring output on the right?
 
I'm a little confused by your question/response. I have been trying to locate a dual side freewheel crank, known in the bike world as a tandem IPS (Independent Peddling System). A company called Bikemotive intoduced me to the idea and I designed my build around the product they developed. On their website the sell a "freewheel crankset kit" but the product the company was setup to sell never made it passed the prototype stage and they don't tell you in the webstore what they sell is not what they describe as their "revolutionary" product.
 
That depends on the IPS, its a kind of a generic acronym. There have been many different types and only a handful are still around. A crossover IPS is basically what Bikemotive was trying to produce. I was really annoyed when I went to order their product and realized what they displayed was not what they sold, so I began researching alternatives.
 
Yup. Tandem parts tend to be antiquated because its a dying sport. No one has made a cross over IPS in a few decades, you can still come across them but I plan on running 6Kw through it. I am probably just going to do a right side freewheel power input sprocket for now. I have a 5 axis CNC mill on order and I'm half decent at CAD design. I will eventually have my left side input, right side 3 chainwheel output, and a freewheeling crank.

-150 pages includes a lot of drawings, calculations, charts, part and material sourcing, ect. Its not 150 typed pages. I purposely made the system I'm implementing overly complicated and modular to the point that its similar to having a giant ebike lego kit. I am designing components and eventually a complete central computer system to control all the aspects of the bike. I have built several networked quadcopter drones that incorporated localized mapping for commercial PI applications. I have been redeveloping the computer I made for the drones for light electric vehicles.

I am extremely happy in the new job/location I have found myself in that I can really apply myself to my creations and tremendous assistance from my coworkers in accomplishing my feats :D
 
Hey folks. I was wondering if I could get some community feed back to see how many people would be interested in a freewheeling ebike IPS like the one shown in this video. I'm thinking something beefed up to handle 10-20Kw.

https://www.youtube.com/watch?v=B35qqQ_uHQk&list=UUvPtqfSnlRnktJ4Ue6kf-xA
 
Hi Paradigm,

A couple of us started designs for something like this (before we knew about the Bike Motive prototype).

It's definitely a non-trivial undertaking..... :wink:

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=35846

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=37224

But, why would you want to put 10 to 20 kW through a crankset? Even if it was remotely possible (@ 90rpm that's over 2000Nm!) :?
 
I want the product and BikeMotive seems to have dropped the project after the prototype was finished. Mel, the owner, has not responded to any many messages I sent him over the last several months. I did a patent search and he never made any attempts at reserving his intellectual rights. I have contacted several manufacturers capable of producing the product and I am going to try to crowd fund a variation of it. I'm just putting my dream specs to the idea and I will see what the manufacturers can offer. I'm not the kind of person that will wait around for someone else to produce the thing that I want, I'll just make it myself...

Nothing is impossible, its all a matter of engineering.
 
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