Dual freewheeling bottom bracket design
- Thread starter Miles
- Start date
crossbreak
1 MW
ok.. i'm wrong, the cyclone one is still in my bike. The one I measured with 30mm: "Shimano BB-UN52 68", the other one may com from a centurion bike, but i'm not sure
where are yours from?
Edit: After dinner I can measure the original cyclone one (don't remember the brand atm), maybe I should simply buy a 31mm one, which leaves more space
where are yours from?
Edit: After dinner I can measure the original cyclone one (don't remember the brand atm), maybe I should simply buy a 31mm one, which leaves more space
crossbreak
1 MW
sry, I have too leave. I'll measure my cyclone one tomorrow..
Edit: the cyclone one has 31mm inner dia... let's say this is standard
btw the two cups i measured are made of plastic. Maybe they are mostly 30mm ones to gain more material.
Edit: the cyclone one has 31mm inner dia... let's say this is standard
btw the two cups i measured are made of plastic. Maybe they are mostly 30mm ones to gain more material.
MotoMel
100 mW
http://BearingsDirect.com (USA) might be another source, depending on your location. And I've found some odd bearings through http://LocateBallBearings.com, though their service is a might sketchy.
Miles said:
Cyclebutt
100 W
Nice thinking! I like this.spinningmagnets said:
Cyclebutt
100 W
If not too expensive, I would buy this today. Checked the eBay link and only found odds and ends. Looking for the complete crank set-up as pictured in your profile photo and demonstrated on youtube.MotoMel said:
MotoMel
100 mW
The problem is the "not too expensive" issue. We're working hard on finding engineering changes and manufacturing sources so that cost (and therefore price) are at a reasonable level.
We have, in the meantime, figured out how to use our custom spiders to create a crankset with 4 chainrings, where the outermost chainring is motor-driven. The motor can be mounted on an extraordinarily sturdy structure that, like the LHS drive, attaches to the bottle bracket mounts and makes the entire triangle part of the motor bracket. The motor itself is not mounted inside the triangle but rather outside the triangle, forward and upwards a tad from the crankset. (The motor chain cannot be allowed to interfere with the front derailleur, which has the nasty characteristic of overlapping the outermost chainring when shifted to the largest of the 3-chainring set. That requires the motor to be mounted outside the triangle. Live and learn, eh?)
The other difference, which may be more of aesthetic interest than performance, is that the motor chain goes into motion anytime the chainrings are revolving. So pedaling moves that chain. But with a freewheel at the motor spindle, you lose negligible efficiency.
Oh, the other difference is that, because no sophisticated engineering has to go into the bottom bracket shell, the total bottom bracket expense is limited to the switching out the BB for a wider (but still stock) BB. On most of the builds we have done so far, we have traded in a ~113mm wide BB for a ~127mm model. As a result, the entire RHS drive crankset (with spiders, spacers, freewheel, and cranks) can be had for between $135 and $155, depending on what BCD spider drives the rear cluster. Not included in that costing are a wider BB as necessary, chainrings (2 or 3 of which would be reused from your bike), and screws, bolts and nuts.
It'll fit the White, ACS, ENO, Dicta and other freewheels. If you want to go upscale with a non-square taper crankset, that's cool too.
We've successfully tested with a Cyclone motor and with the Unite MY1080. For the MY1080 we had to design a motor shaft adapter that a small ACS 13-tooth M30x1.0 freewheel screws onto. When there's a chance, I'll upload some photos.
We have, in the meantime, figured out how to use our custom spiders to create a crankset with 4 chainrings, where the outermost chainring is motor-driven. The motor can be mounted on an extraordinarily sturdy structure that, like the LHS drive, attaches to the bottle bracket mounts and makes the entire triangle part of the motor bracket. The motor itself is not mounted inside the triangle but rather outside the triangle, forward and upwards a tad from the crankset. (The motor chain cannot be allowed to interfere with the front derailleur, which has the nasty characteristic of overlapping the outermost chainring when shifted to the largest of the 3-chainring set. That requires the motor to be mounted outside the triangle. Live and learn, eh?)
The other difference, which may be more of aesthetic interest than performance, is that the motor chain goes into motion anytime the chainrings are revolving. So pedaling moves that chain. But with a freewheel at the motor spindle, you lose negligible efficiency.
Oh, the other difference is that, because no sophisticated engineering has to go into the bottom bracket shell, the total bottom bracket expense is limited to the switching out the BB for a wider (but still stock) BB. On most of the builds we have done so far, we have traded in a ~113mm wide BB for a ~127mm model. As a result, the entire RHS drive crankset (with spiders, spacers, freewheel, and cranks) can be had for between $135 and $155, depending on what BCD spider drives the rear cluster. Not included in that costing are a wider BB as necessary, chainrings (2 or 3 of which would be reused from your bike), and screws, bolts and nuts.
It'll fit the White, ACS, ENO, Dicta and other freewheels. If you want to go upscale with a non-square taper crankset, that's cool too.
We've successfully tested with a Cyclone motor and with the Unite MY1080. For the MY1080 we had to design a motor shaft adapter that a small ACS 13-tooth M30x1.0 freewheel screws onto. When there's a chance, I'll upload some photos.
crossbreak
1 MW
I need such an adapter for my current project (http://endless-sphere.com/forums/viewtopic.php?f=28&t=45392&start=75#p663896). Is it possible to make one for me either?
johnamon
10 W
Hi Mel,
If your LHS drive double freewheel bottom bracket design has proven to be reliable in your testing to date, it would certainly be interesting to know what price you can sell it for. A number ES members spend $hundreds (or more!) on batteries. High hundreds for a elegant drive solution may be palatable enough to some members to allow you to run either single or low volume production at a US machine shop?
I know that I'd rather buy a premium priced US / European produced piece of equipment that had been designed and built by a 'real person' rather than having me ripped off by a cheap manufacturer in the far east that has taken a design and reduced costs by making design comprimises..
If it's possible to have your LHD bottom bracket manufactured & profitable for under $1000 - I reckon you'd do well to at least offer it up without performing a full (expensive) production run
If your LHS drive double freewheel bottom bracket design has proven to be reliable in your testing to date, it would certainly be interesting to know what price you can sell it for. A number ES members spend $hundreds (or more!) on batteries. High hundreds for a elegant drive solution may be palatable enough to some members to allow you to run either single or low volume production at a US machine shop?
I know that I'd rather buy a premium priced US / European produced piece of equipment that had been designed and built by a 'real person' rather than having me ripped off by a cheap manufacturer in the far east that has taken a design and reduced costs by making design comprimises..
If it's possible to have your LHD bottom bracket manufactured & profitable for under $1000 - I reckon you'd do well to at least offer it up without performing a full (expensive) production run
MotoMel
100 mW
Hi all. You're giving me every incentive to find a way to get them out there. I'll rattle the chains to our manufacturing suppliers over the Thanksgiving holiday and see what new quotes we can get. If the response is positive, then I'm likely to put the venture up on KickStarter to finance the first production run.
The design is proven, with some tough testing on and off road behind us, and only un-sealed bearings being something that we'd like to change. But these are caged needle bearings, fitting in a quite tight space, without even room for a cupped version.
Mel.
The design is proven, with some tough testing on and off road behind us, and only un-sealed bearings being something that we'd like to change. But these are caged needle bearings, fitting in a quite tight space, without even room for a cupped version.
Mel.
MotoMel
100 mW
In the meantime, we posted a very primitive video on a RHS drive we concocted and have been testing over the past several months:
https://docs.google.com/folder/d/0BwuAyZBgbD_MMk1obU90TU8tdmM/edit
I'd enjoy knowing what your thoughts are on it.
Mel.
https://docs.google.com/folder/d/0BwuAyZBgbD_MMk1obU90TU8tdmM/edit
I'd enjoy knowing what your thoughts are on it.
Mel.
Cyclebutt
100 W
Electric and gas applications here. Well worth marketing, IMHO.
emotionsadel
1 µW
- Joined
- Feb 7, 2013
- Messages
- 1
The left side drive, with the modified bottom bracket, is the most perfect way to power a (human electric hybrid vehicle) of any kind.
You beat me to it by a few months and I congratulate you for that. This cost of production is nothing considering the possible applications, it's the way of the future.
Even though I am small guns, I have an extensive background in mechanical engineering to know what it is I am looking at, this is an accomplishment.
I have a dream to make the island of Maui, where my electric bike shop is, an electric human vehicle (Mecca), and this BB system is the ultimate ingredient.
I can't believe that the higher ups haven't come running to you with millions to invest if putting this engineering marvel to work for the masses.
As for me, I am eagerly waiting to hear back from you, and learn how I can make this space age unit, work for us here on earth.
With my best regards
You beat me to it by a few months and I congratulate you for that. This cost of production is nothing considering the possible applications, it's the way of the future.
Even though I am small guns, I have an extensive background in mechanical engineering to know what it is I am looking at, this is an accomplishment.
I have a dream to make the island of Maui, where my electric bike shop is, an electric human vehicle (Mecca), and this BB system is the ultimate ingredient.
I can't believe that the higher ups haven't come running to you with millions to invest if putting this engineering marvel to work for the masses.
As for me, I am eagerly waiting to hear back from you, and learn how I can make this space age unit, work for us here on earth.
With my best regards
Welcome emotionsadel!
I think quite a few of us have come up with designs based on this principle. I know Mel has been working on his design for a long time.
Feel free to ask if you have any specific questions.
Good luck with your plans!
I think quite a few of us have come up with designs based on this principle. I know Mel has been working on his design for a long time.
Feel free to ask if you have any specific questions.
Good luck with your plans!
liveforphysics
100 TW
It's a great way to add a very modest amount of power to a bicycle, and I really love the setups for that reason.
It's not the ultimate solution though, because just running a few kW through bicycle chain tends to lead to short lived chains and frequent chain-suck type events of chains wadding up in derailleurs etc. (at least that was my experience, perhaps with a single speed freewheel and good chain guides and good chain angles it can be more reliable at higher power levels)
It's not the ultimate solution though, because just running a few kW through bicycle chain tends to lead to short lived chains and frequent chain-suck type events of chains wadding up in derailleurs etc. (at least that was my experience, perhaps with a single speed freewheel and good chain guides and good chain angles it can be more reliable at higher power levels)
crossbreak
1 MW
made a similar approach once, using the hollowshaft2 37x25x7mm bearing cups and a common tapered 16mm BB shaft and 31x16x10mm bearings. Abandoned it since the jackshaft drive is a much simpler and cost effective dual freewheel solution. On top it has the unbeatable advantage of additional overdrive. This way one finally gets rid of the large and ugly 52T+ chainrings. Wrote a wiki article about that: http://endless-sphere.com/w/index.php/EBike_Motors_Middrive#Jackshaft_double_freewheel_configuration
This was my concept, including some assembly problems (hollow shaft)
Edit: IMO your first attempt was the best, miles
This was my concept, including some assembly problems (hollow shaft)
Edit: IMO your first attempt was the best, miles
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