[Damn True]

Spent some time looking at the G-boxx stuff.
Very interesting. I question though the efficency assertion. Are you not taking into account the amount of parasitic power loss from the drive train itself?
Seems to me that regardless of gear type (helical, straight, planetary) there will be a greater than 2-4% loss.

 

[CreeP]

that much?
how many cogs are engaged at one time?

 

[dw]

Originally posted by Damn True
Spent some time looking at the G-boxx stuff.
Very interesting. I question though the efficency assertion. Are you not taking into account the amount of parasitic power loss from the drive train itself?
Seems to me that regardless of gear type (helical, straight, planetary) there will be a greater than 2-4% loss.

Are you talking about the G-boxx.org website? I did not have any input at all into that site's development or the text there, and since last fall, I am personally no longer pursuing the use of planetary gearboxes for use in bicycle frames. There is a fair amount of incorrect info on that site.

The efficiency on the Rohloff based system is poor when you take into account seals and all of the ancillary devices that support it as a gearbox. It would be a massive technical challenge to make the it more efficient than a conventional chain drive.


dw

 

[dw]

Hey True, I just went and read what I think you saw, and those #s do not coincide with what my measured and calculated numbers indicate. Hopefully someone will correct it.

Dave

 

[binary visions]

Originally posted by dw
Are you talking about the G-boxx.org website? I did not have any input at all into that site's development or the text there, and since last fall, I am personally no longer pursuing the use of planetary gearboxes for use in bicycle frames. There is a fair amount of incorrect info on that site.

The efficiency on the Rohloff based system is poor when you take into account seals and all of the ancillary devices that support it as a gearbox. It would be a massive technical challenge to make the it more efficient than a conventional chain drive.


dw

Interesting. So, as far as you are concerned, the g-boxx concept is D.O.A.?

Is Nicolai continuing to persue it?

 

[dw]

Originally posted by binary visions
Interesting. So, as far as you are concerned, the g-boxx concept is D.O.A.?

Is Nicolai continuing to persue it?

From a planetary gearbox perspective, I will not be pursuing this project anymore. I am still interested in the structural concerns surrounding building gearbox frames, and other more efficient/ simpler/ cheaper gearbox designs and we are still testing and developing to that end.

I believe that Nicolai has skipped over the vast majority of development steps that I originally laid out for this project (it was a multi-year, multi-phase plan) and will be attampting to push forward more quickly. Im not really sure though. Maybe Orven or Danny has some info on that?

Dave

 

[Nately27]

mind telling us what kind of gearbox you have in mind, if not a planetary style one?

 

[dw]

Originally posted by Nately27
mind telling us what kind of gearbox you have in mind, if not a planetary style one?

I really do dig the linkage IVT like in the Honda bike, and there are a few other ways that just as out of the norm, but equally interesting.

Dave

 

[binary visions]

Originally posted by dw
I really do dig the linkage IVT like in the Honda bike, and there are a few other ways that just as out of the norm, but equally interesting.

Dave

Ahahaha.. Typical DW response to questions about unreleased projects.. Answer the question without really answering it.

Hey, DW, the question was what kind of gearbox do you have in mind, not what kinds you think are cool or whether or not other weird ones exist :devil:

 

[Espen]

I have heard rumors about a Shimano gearbox.

E

 

[binary visions]

Originally posted by Espen
I have heard rumors about a Shimano gearbox.

E

More than rumors.. Do a search for "Nexus". It's been discussed.

 

[Espen]

A new gearbox inside one of the big brands new DH bikes.

E

 

[binary visions]

Originally posted by Espen
A new gearbox inside one of the big brands new DH bikes.

E

Yeah, a GT I believe... There were shots from EuroBike. It's just a frame mounted Nexus hub.

 

[Espen]

That proto was old. I have heard this was something all new.
I might be wrong though.

Does Nexave boxes stand out hard DH abuse?

E

 

[binary visions]

Originally posted by Espen
That proto was old. I have heard this was something all new.
I might be wrong though.

Does Nexave boxes stand out hard DH abuse?

E

Not the current ones. The current ones are rated for town bikes only, not even any kind of mountain riding.

Supposedly (though this is only rumor as far as I know) the new ones will be much burlier, though whether or not they will be DH-burly is open to speculation.

 

[BigMike]

So this is the Evil day, eh?


so what about those pedals eveyone is wondering about?

 

[Slugman]

Originally posted by binary visions
Not the current ones. The current ones are rated for town bikes only, not even any kind of mountain riding.

Supposedly (though this is only rumor as far as I know) the new ones will be much burlier, though whether or not they will be DH-burly is open to speculation.

But when mounted in the frame they would be shielded from the abuse that they would take if mounted as a hub (i.e. Nicoli design).

I've known guys in the NE who ride XC on Nexus hubs... they require some frequent maintenance, but they still work. Not that I would ever try it.

Couldn't the gearing ratio be used to compensate for the loss of efficiency? Are we talking single digit loss in efficiency? For FR or DH what effect would that really have?

 

[binary visions]

Originally posted by Slugman
But when mounted in the frame they would be shielded from the abuse that they would take if mounted as a hub (i.e. Nicoli design).

Well, somewhat. The hub will still be jarred constantly, and no matter where you mount it it's not safe from the effects of a 240lb. DH'er slamming on the pedals as hard as he can, straining to get out of the gate fast.

 

[ssaddict]

I think the original Nexus had bushings (may still) that wore out quickly, I seem to remember Alex talking about them as he built a bike around one of these.

 

[ragin-sagin]

to further the derailment (pun intended) of this thread....About 8 years ago when Shimano first came out with the Nexus hub, I used them as the centerpiece of the drivetrain in couple of Kinetic sculptures for the yearly race from Arcada to Ferndale...Although each one did not see many miles, they were thrashed severely, through water, sand, mud you name it. They were used on vehicles that weighed over 200 pounds+ the rider. We never had any failures, but after a few years of neglect, the initial crispness of the shifting was no longer there, most likely as a result of sitting around a year between uses. These things were cheap too, I don't see why the hell they can't be improved upon further...where was I going with this? Oh yeah Bush sucks, vote his a$$ out. And I like the smell of Russian olive in the spring.

 

[Yeti DHer]

dave... can you check your dwlink email? Thanks!