Considerations on parallel drive set-ups

[Miles]

A "bi-drive" BMX hub? Not that there's anything wrong with that ( ), but what exactly is this? Are there chains on both sides?

They can be for us In BMX they're either LHD or RHD, though, see:
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=11495&start=17

 

[Miles]

So, the 3-sprocket widget you had links for hs its own freewheel? That would open up some more options, I think. I'm curious about what this was originally intended for, do you know? What other application needs a separate FW from the one on the splined hub? Tandem maybe?

It's just a 3 speed freewheel.... Once upon a time 3 speeds was all you got...

 

[GGoodrum]

It's just a 3 speed freewheel.... Once upon a time 3 speeds was all you got...

Ah, so the freewheel is in the cassette? I always assumed the FW was part of the splined hub.

 

[Miles]

Originally, hubs came with a screw thread, that's all. The freewheel was incorporated into the sprocket assembly which itself was called the "freewheel". So the number of speeds on this "freewheel" increased to 7 or 8.

The cassette type hub does indeed integrate the freewheel mech into the splined driver - a generally more robust and flexible arrangement.

 

[gwhy!]

The cassette type hub does indeed integrate the freewheel mech into the splined driver - a generally more robust and flexible arrangement.

Sorry miles, seen loads of broken cassette hubs and no stripped threads on a threaded freewheel hub ( lots of broken freewheels though) . Threaded freewheel hub every time for strength.

 

[Miles]

Well, usually more robust freewheel mech.......

The cassette arrangement also puts the RH bearing further outward (less stress on the axle)....

 

[deecanio]

I didn't want to thread anything onto the eno i was thinking of just attaching the extron to the eno and then have the 15t right beside it on a freewheel cassette thread giving me two freewheels, one for the motor chain and one for the bike chain? that would give me independance no? :? :? :?

Yes, but...

How would that work with such a short thread: http://www.sheldonbrown.com/freewheels.html

Or, your planning to put a thread on the splines of a cassette driver?

If it were possible then the motor sprocket would have to be on the outside.

mmmmmmm.
well you have a point :lol: .
it's a shame the splines on a cassette driver are just a little bigger than the eno size otherwise we could sleeve it with splines on the inside and threads on the outside, you'd get two freewheels on that no worries i assume the splines are hardened to the point a die wouldn't touch it? and likewise unable to spline a freewheel?
there must be a way :lol:

D

 

[Miles]

You can cut splines into some freewheels, as we were discussing earlier, but not the ENO, because it's constricted at the shoulder where the tabs for the removal tool are.

 

[liveforphysics]

Maybe I'm not getting a good angle from this limited photo, but is there some reason that necked-down area couldn't be bored open wider, and splines cut into the threaded area. We will obviously no longer need the spline engagement area for the freewheel removal tool. It appears to have have enough material there to make it possible to slide on cleanly. These things are very tough to judge without holding one in your hand though.

-Luke

 

[mud2005]

Hi there, just found this topic and didn't read all 6 pages but it sounds like your all discussing the best way to put 2 freewheels on the same side of a hub. I've done this a couple times, once with 2 shimano freewheels, and once with an adapter for a #25 sprocket from electricscooterparts.com and a shimano freewheel.
I threaded a small piece of aluminium tube to screw the freewheels together.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=7791

 

[Miles]

Maybe I'm not getting a good angle from this limited photo, but is there some reason that necked-down area couldn't be bored open wider, and splines cut into the threaded area. We will obviously no longer need the spline engagement area for the freewheel removal tool. It appears to have have enough material there to make it possible to slide on cleanly. These things are very tough to judge without holding one in your hand though.

-Luke

I guess it's just about possible - there wouldn't be much material left around the lock ring threads, though...
See the photo here: http://www.tartybikes.co.uk/product.php?product_id=2054&category_id=65

I'll wait to see how you get on with yours

 

[mud2005]

just had an idea regarding this thread , hope this hasnt already been mentioned.
how about using a cassette hub, remove the freehub body then bolt on a custom threaded adapter using the bolt that holds on the freehub normally.
now you have a hub that can accept one eno freewheel.
next bolt another custom adapter that fits atop the last one with smaller bolts on each side of the middle bolt or in a 4 bolt pattern.
now you can screw another eno on!
I have a hub and some parts thrown together and was going to post a pic, but my old digital camera finally died

 

[John in CR]

Even if the White FW is mod-able I have a tough time getting past a FW that costs almost the price I paid for motor+controller before shipping that pushes fat me to 50mph. Where's the competition? With China putting 20 million new 2 wheel EVs on their roads each of the past few years, why haven't all the issues we deal with all been solved already? Did the communist system really suppress creativity to that extent?

John

 

[spinningmagnets]

Mud, could you find links to the parts you mention, so I can get an idea about what you mean.

I have read that when you have lots of power, you don't need as many gears as before. A common front MTB chainring set and derailleur would very cheaply provide 3 gears for pedaling. If what you are describing could put two ENO's on the right side of some geared hub (like a nexus-3) that would provide even more options.

 

[liveforphysics]

Maybe I'm not getting a good angle from this limited photo, but is there some reason that necked-down area couldn't be bored open wider, and splines cut into the threaded area. We will obviously no longer need the spline engagement area for the freewheel removal tool. It appears to have have enough material there to make it possible to slide on cleanly. These things are very tough to judge without holding one in your hand though.

-Luke

I guess it's just about possible - there wouldn't be much material left around the lock ring threads, though...
See the photo here: http://www.tartybikes.co.uk/product.php?product_id=2054&category_id=65

I'll wait to see how you get on with yours

Thank you for the picture Miles. It does look like it would be very close fit. From thinking about it a bit, even if the major diameter of the splines on the cassette receiver was nearly pushing through the threads, the area left in the minor spline areas would be adequate for strength. I can't tell from the picture, but even if we ended up with something like the end of a castle nut, I think it would function fine. If you happen to have one handy, could we burden you to take a few measurements for us? 9spd spline major and minor diameter, and OD on the necked down area of the freewheel. If the Minor diameter of the splines and the OD of the threads have a at least 3mm of difference, I think it would be possible to simply slide modified freewheels onto the hubs.

The ability to purchase a properly modified inside freewheel race would be outstanding for the end user, as assembly would simply involve siding it onto a hub. Making the required jigs would be a lot of work to create that modified inside freewheel race, much more work than actually using the jig to modify the freewheels. Seems like a perfect opportunity for someone to fill this niche in the market. I know I personally would buy 2, and I would gladly pay $100 apiece to save me the trouble of making the jig. I imagine there are many others who would do the same, which could create a worthwhile hassle of creating a jig that involves $1000+ in labor to build.

 

[mud2005]

Mud, could you find links to the parts you mention, so I can get an idea about what you mean.

um, if by parts you mean the "custom adapters" I mention, there is no link. I meant parts made on a lathe for this purpose. I have just recently gotten a lathe so I think I will make the parts tomorrow as I have the day off. may have to go buy a new camera also :|

 

[Miles]

Thank you for the picture Miles........If you happen to have one handy, could we burden you to take a few measurements for us? 9spd spline major and minor diameter, and OD on the necked down area of the freewheel.

Ok, I took mine off the bike and disassembled it

OD for the retainer ring threads is 37.8mm. ID of the neck is 30mm.

Minor diameter for the dual-drive spline driver is 32.2mm - major diameter approx. 34.5mm. The driver on the SRAM dual-drive is a bit undersized, though. Maybe someone could measure a Shimano driver?

So, not as close as I imagined.

To do the mod. would require 3 operations, I think..
- Mill off the tabs.
- Bore out to the minor spline diameter.
- Broach the slots for the splines.

The ENO parts are quite hard.

I'm not sure this is an economically viable proposition, as a mod.

Now, if we could persuade W.I. to make a splined version.......

 

[deecanio]

i'd be in too price Luke sais would be reasonable imo?
i do have a spare cassette hub at home on a 26" wheel, i'll have to have a look when i get home, just need to find my acs freewheel so i can see whats involved.
With all the clever guys we have here not to mention the local machine shops we all have access to surely we can find someone somewhere that can make this happen? (looks at Matt :lol: )

persuade W.I. Miles
this is reminding me of when we tried to get those dual freewheels from SUN
financially viable or not, personally i'd cover someones time and effort to make me one :wink:

D

 

[Miles]

persuade W.I. Miles

Luke seems to have the greatest persuasive power.... LOL

Well, they were obviously amenable to producing the front freewheels "exclusively" for Sick Bike Parts.......... and they retail for no more than the single freewheels.........

It would be nice. With a splined inner you'd have potential access to all the ENO variants, including the dual sprocket version 8)

I could be persuaded to model what it would look like, if there's an interest - that would be the logical first step.

 

[deecanio]

well just being greedy here but i'd want one of the toothless sick bikes ones for my eno and a 15t
You know Matt machined off my eno teeth for the freewheel that went into my pulley, i wonder if he could machine a spline into a eno?
Would be awesome if W.I. made us some custom ones though - fancy trying to Persuade them Luke?

Cheers,

D

 

[Miles]

Would be awesome if W.I. made us some custom ones though - fancy trying to Persuade them Luke?

Anyone have any Mafia contacts?

Once I've done the model, maybe Matt would be the best person to approach them about it?

 

[deecanio]

aye, Matt could be "the one"
lets see what our cousins from across the pond think when they come on later.
I'd be interested to see if Matt has any thoughts on machining our own if a original is not forthcoming - have you ever had an eno apart Miles? i understand they are serviceable so i can't help but think we (someone) could machine a new body?

D

 

[gwhy!]

This is what we need ( well some of us anyway ) "Cassette hub converter converts any Shimano cassette hub except silent cluth and pre 1997 Dura Ace, to a fixed gear" . but longer, with a step down threaded portion and the outer edge to accomodate the bmx style small freewheels. wonder how easy it would be to make something like this..... matt :wink:

 

[Miles]

This is what we need ( well some of us anyway ) "Cassette hub converter converts any Shimano cassette hub except silent cluth and pre 1997 Dura Ace, to a fixed gear" . but longer, with a step down threaded portion and the outer edge to accomodate the bmx style small freewheels. wonder how easy it would be to make something like this..... matt :wink:

For how much longer will the small BMX freewheels be available.....? They all seem to be converting to erm... cassettes.

I agree, it's a good idea, though... :wink:

 

[gwhy!]

This is what we need ( well some of us anyway ) "Cassette hub converter converts any Shimano cassette hub except silent cluth and pre 1997 Dura Ace, to a fixed gear" . but longer, with a step down threaded portion and the outer edge to accomodate the bmx style small freewheels. wonder how easy it would be to make something like this..... matt :wink:

For how much longer will the small BMX freewheels be available.....? They all seem to be converting to erm... cassettes.

I agree, it's a good idea, though... :wink:

Fare shout

some of the bmx freewheels are tiny 13t how can this fit over a cassette.. :|