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the gearbox thread

El_Chimichanga

El_Chimichanga

Monkey
May 3, 2004
383
0
Sanna Croooz
ioscope said:
Has anyone actually torn off a derailleur, or broken one?
I know it can happen, but I have only barely bent one, and it still works.
Click to expand...
Uhhh, throw a stick in wheel while you spin uphill and watch as you rip your dropout (not just the hanger, the whole dropout bunkie!) off of your Heckler and mangle your new x.9 short cage derailler. Hmm. That would be the 4th mangled derailler this year (mostly shimano).

I'd say we need to buy DW some doughnuts and like, a gallon of coffee, lock him in his office with a piece of paper and a pencil, and don't let him out till he figures out the the whole shebang; production logistics and all.
 
BMXman

BMXman

I wish I was Canadian
Sep 8, 2001
13,827
0
Victoria, BC
El_Chimichanga said:
I'd say we need to buy DW some doughnuts and like, a gallon of coffee, lock him in his office with a piece of paper and a pencil, and don't let him out till he figures out the the whole shebang; production logistics and all.
Click to expand...
second that...D
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
Has anyone actually torn off a derailleur, or broken one?
I know it can happen, but I have only barely bent one, and it still works.
Click to expand...
Are you serious? Look how many I've been through this last race season. I'm on SRAM now, but they're just as bad.

Someone's got to do something right quick.
I figure people will be quicker to accept the PeteSpeed box, and that will open the doors for the real gearboxes (Superboxes!) to follow.
 
S.K.C.

S.K.C.

Turbo Monkey
Feb 28, 2005
4,096
25
Pa. / North Jersey
EVRAC:
Isn't this quite like the Honda internals?

Rotary - Racheting - Rotary
Click to expand...

...in 2004 the Honda RN-01 used a Continously Variable Transmission (US 2003/0221892 A1).

But it wasn't really a gearbox so to speak: When you pedaled the 04' RN-01 the crankarms spun a camshaft inside the transmission... There are 4 cams and as they rotate, they rock a series of levers back and forth. The levers are attached to one-way clutches (like freewheel ratchets) and as the levers rock back and forth, the one-way clutches turn the final driveshaft in a series of pulses. The final drive turns the rear wheel w/ a conventional sproket and chain.

So basically it's like rocking your bikes cranks back and forth to go forward instead of pedaling in circles. That was the action happening inside the 2004 RN-01, but the pulsing of the clutches is smoothed out because they designed the camshaft to ratchet the roller clutches 44 times per crank revolution.

This was obviously genius, but too difficult to maintain or even thinking about mass-producing.

What Honda has been running since late 04' early 05' is the derailleur-in-a-box type of arrangement. Much lighter, and less complex - plus it's easy to maintain.
 
offtheedge

offtheedge

Monkey
Aug 26, 2005
955
0
LB
bcd said:
here is what i think wouldbe light, simple, cvt for a bike
Click to expand...

CVT would and probably will have a huge impact on the current drivtrains. Just got to maintain the energy.
 
Bicyclist

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
I've heard rumors Specialized is designing a gearbox for a Demo.

Absolutely 100% non-guaranteed but that's what I've heard. :drool:
 
ÆX

ÆX

Turbo Monkey
Sep 8, 2001
4,920
18
NM
got a email from a guy in NZ working on a bike.

i like the skill saw at teh bottom of the pic.

alex
 
Bicyclist

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
bcd said:
got a email from a guy in NZ working on a bike.

i like the skill saw at teh bottom of the pic.

alex
Click to expand...
I like that one. Nice and low slung. Maybe a little too low though?
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
S.K.C. said:
EVRAC:



...in 2004 the Honda RN-01 used a Continously Variable Transmission (US 2003/0221892 A1).

But it wasn't really a gearbox so to speak: When you pedaled the 04' RN-01 the crankarms spun a camshaft inside the transmission... There are 4 cams and as they rotate, they rock a series of levers back and forth. The levers are attached to one-way clutches (like freewheel ratchets) and as the levers rock back and forth, the one-way clutches turn the final driveshaft in a series of pulses. The final drive turns the rear wheel w/ a conventional sproket and chain.

So basically it's like rocking your bikes cranks back and forth to go forward instead of pedaling in circles. That was the action happening inside the 2004 RN-01, but the pulsing of the clutches is smoothed out because they designed the camshaft to ratchet the roller clutches 44 times per crank revolution.

This was obviously genius, but too difficult to maintain or even thinking about mass-producing.

What Honda has been running since late 04' early 05' is the derailleur-in-a-box type of arrangement. Much lighter, and less complex - plus it's easy to maintain.
Click to expand...

Thanks SKC, I know. That post was in '04 as well.
I make a point of staying up to date on all my gearbox topics:)
 
dhkid

dhkid

Turbo Monkey
Mar 10, 2005
3,358
0
Malaysia
sram bought the patents to another cvt gearbox invented by some other dude. there was a tread about it on here a while ago. cant wait for that to come out.
 
dhkid

dhkid

Turbo Monkey
Mar 10, 2005
3,358
0
Malaysia
nope, not that one. how the hell does that one work? :eek: :confused:
it was pretty much like the honda system with cams.
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
Apparently the rights to develop the NuVinci system have been bought by a bicycle mfg. but it's not SRAM, they found a different one. The prototype I saw in the article on SRAM was a shoebox sized box. This one is (so far) designed as a hub and is already in a ridable format. The problem is the huge spikey torque loads we can put out. While they say it's not friction based, it is also not positive drive (no teeth). The drive elements must be super-presision and ride on a film of oil. I figure it might work on a coffee-shop bike, not a DH rig.
 
zedro

zedro

Turbo Monkey
Sep 14, 2001
4,144
1
at the end of the longest line
EVRAC said:
The problem is the huge spikey torque loads we can put out. While they say it's not friction based, it is also not positive drive (no teeth). The drive elements must be super-presision and ride on a film of oil.
Click to expand...
yeah, its too bad really, since it's hands-down the cleanest and simplest system
 
ChrisRobin

ChrisRobin

Turbo Monkey
Jan 30, 2002
3,410
212
Vancouver
Here's the thing about the Rohloff driven frames...

Despite the weight, the 14 gears, the thing that might bother a lot of people is the shifter. No one uses twist-type shifters anymore. While riding DH with a trigger system, you don't have to think about which way to twist the shifter (maybe it's just me), and it's easier to hold on the bike while you're shifting with rapid fire.

That's always been something that I've complained about with my Rohloff hub.

As far as reducing the 14 gears...zedro mapped it where the the first set of 7 gears would work for downhill riding. I don't remember the gear ratios but it resembled something like having a road cassette in the rear. You don't lose any weight and the twist shifter but at least you limit the number of gears you have to fumble through.

Having 14 gears might be cool if you have an all-mountain-type frame or even freeride. You still need to pedal uphill. I've tried pedalling my Nucleon uphill...it sucks!! I almost had a heart-attack.
 
Bicyclist

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
Looks like not everyone has access to those pics. Take a screenshot of them and then re-host and post as usual.
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
V-BOX V-17 - final step almost done


On the first sight it's still the same yellow frame, the same polished
gear box housing, but inside we have the gear box evolution V-17!
And it's working better than any other gear box before. We're very close
to say "finished". Though we will never stop researching and developping.
But you will soon enjoy our rideable prototype for sure.


Some people already had the opportunity to test, to touch and to
watch at Bike Festival Willingen.
 
SOil

SOil

Chimp
Jun 24, 2005
82
0
Everyone in Europe seems to be going gearbox crazy (nicolai, knox, alutech, Solid bikes, MSC, Be one, RB, MBK), but how about in the US?

There is talk in another forum of Santa Cruz having a gearbox frame. Does anyone know anything that substanciates this?

Those CAD pics of the orange, kona and RM, are those for real or just a mockup from the guys at g-boxx?

The Suntour gearbox seems to be an important step, as a big manufacturer gets involved. It does seem heavy.
3kg is a lot more than the components it replaces (even if it's used as a stressed component of the frame.

Even if it is still early days, there soon will be two "off the shelf" gearboxes that follow the G-CON standard, are not based on a gear hub: the G-Boxx2 and the V-Box.

How different are these?
I know the V-box uses spur gears on different shafts, but I'm not aware of what's in the G-boxx2 (other than it's not a Rohloff like the previous version).
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
SOil said:
Everyone in Europe seems to be going gearbox crazy (nicolai, knox, alutech, Solid bikes, MSC, Be one, RB, MBK), but how about in the US?

- Not really. Don't know why.

There is talk in another forum of Santa Cruz having a gearbox frame. Does anyone know anything that substanciates this?

- I've heard nothing. That would be rad. I heard rocky mountain had something designed, but it was a cheesy bolt-in option for either a rohloff or nexus hub.

Those CAD pics of the orange, kona and RM, are those for real or just a mockup from the guys at g-boxx?

- Just a mockup to show how it can be incorporated into many different designs.

The Suntour gearbox seems to be an important step, as a big manufacturer gets involved. It does seem heavy.
3kg is a lot more than the components it replaces (even if it's used as a stressed component of the frame.

- It's not really that much more, just add the weight of a gearhub and crankset.

Even if it is still early days, there soon will be two "off the shelf" gearboxes that follow the G-CON standard, are not based on a gear hub: the G-Boxx2 and the V-Box.

- 3 if you count the G-Boxx 1

How different are these?
I know the V-box uses spur gears on different shafts, but I'm not aware of what's in the G-boxx2 (other than it's not a Rohloff like the previous version).
Click to expand...
- G-Boxx 2 is 9 speed sram trigger compatible and uses planetary gears of their own design.

Check out the "tech-talk" blog at g-boxx.org even though it hasn't been updated in ages.
 
SOil

SOil

Chimp
Jun 24, 2005
82
0
I read that blog before (the tech talk link) but it doesn't actually say what the G-boxx2 consists of (just what it doesn't - an internal gear hub as the previous version).

So that means that there are two fundamentally different gearboxes following the same standard. Any idea of the pro and cons of each of them?

A sceptical could say that considering Nicolai designed them both, sold one design to Suntour and will sell the other (G-Boxx2) himslef, that the best of the two would be the G-boxx2 (unless he sold the "better" design to the "competition" :))
 
LaharDesign

LaharDesign

Monkey
Jun 16, 2006
159
0
I need to make a list of as close to all as I can get of the company's with gearbox projects.

Lahar, Honda, GT, B1, Nicolai, BCD, Hayes, Suntour, Peatspeed, Universal Transmissions,Orange, Rocky Mountain, Kona, SantaCruz?, Specialised?...

Might turn out to be all of them!
 
no skid marks

no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
ChrisRobin said:
Here's the thing about the Rohloff driven frames...

Despite the weight, the 14 gears, the thing that might bother a lot of people is the shifter. No one uses twist-type shifters anymore. While riding DH with a trigger system, you don't have to think about which way to twist the shifter (maybe it's just me), and it's easier to hold on the bike while you're shifting with rapid fire.

That's always been something that I've complained about with my Rohloff hub.

As far as reducing the 14 gears...zedro mapped it where the the first set of 7 gears would work for downhill riding. I don't remember the gear ratios but it resembled something like having a road cassette in the rear. You don't lose any weight and the twist shifter but at least you limit the number of gears you have to fumble through.

Having 14 gears might be cool if you have an all-mountain-type frame or even freeride. You still need to pedal uphill. I've tried pedalling my Nucleon uphill...it sucks!! I almost had a heart-attack.
Click to expand...
I just got back from riding a Lahar for two days at Whakarewarewa forrest in NZ. The trails are all spread out over a collection of steep hills and most of the trails are a cross between XC and DH.The only thing I noted as a hassle on the Lahar whilst climbing was the slack head angle but if this was the type of riding you did you could easily get away with a shorter fork. It's obviously no XC bike but with shorter forks I think it would be on par with say a Giant Reign.
The shifter is really trivial,you barely notice it at all,and it's reasonably stiff so no accidental shifts(I had none in two days of vary variable terrain riding),if you did find it a problem you can always run a longer grip so your hand isn't touching the shifter,this would require no bigger hand movement than with normal shifters. Any head trip due to the shifter is greatly out nullified by being able to shift alot quicker and being able to dump as many gears as you want in one hit.
I can't wait for my Lahar to get here.
 
xy9ine

xy9ine

Turbo Monkey
Mar 22, 2004
2,940
353
vancouver eastside
i wondered if rocky was developing something. a buddy saw some cad drawings of a gearbox design @ the factory a while back... be cool to see something new / innovative out of them for a change. kona is working on something as well?!
 
EVRAC

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
I would scratch orange and kona. Those drawings at g-boxx.org are just mock-ups of what is possible, unless you have some new news.
I guess Evil is out of the game.
I doubt Rocky Mountain will push forward with their design.
The specialized e-rumor persists.
I'm not sure at all about santacruz. They're quite sold on VPP.

You've got to dig a little deeper.
Here's a bunch more:
MBK
MSD
Solid bikes
NOX cycles
Racebike
Alutech
Ellsworth
Richi-engineering

AND one more awesome US built DH machine I'm not allowed to blow the lid on yet. No one has guessed it yet. You'll all freak.

Not a bad list eh?
Hopefully it will be even bigger after euro/interbike.
 
LaharDesign

LaharDesign

Monkey
Jun 16, 2006
159
0
So we have:
Lahar, Honda, GT, B1, Nicolai, BCD, Hayes, .
Suntour, Peatspeed Universal Transmissions.
Orange, Rocky Mountain? Kona, Specialised?, santacruz?
knox, alutech, Solid bikes, MSC,RB, MBK,MSD,NOX cycles
Racebike,Alutech,Ellsworth
Richi-engineering,Evil?
AND one more awesome US built DH machine I'm not allowed to blow the lid on yet. No one has guessed it yet. You'll all freak.
foes?

Seriously anyone saying they're keeping a lid on the project? this is a basic result of physics well understood since early 1900's and IMO no-ones got anything new worth hiding. Hiding means more work needs doing.
 
Bicyclist

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
US built, eh?

Also, I wouldn't count on Spec. doing a gearbox anytime soon. From the local rep: "when was the last time a pro complained about their derailleur?" I would think it'd be at least 09 before we saw anything from them if we do at all.

Did you mention Nicolai?
 
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