[atrokz]

That's probably pretty true. Not a problem only new riders face entirely though. You see at least a broken mech at virtually every DH race. But still a valid point in regards to the gearbox Vs Mech argument in relation to risk of damage or poor performance from damage.
There's no need to worry about smashing a mech though with a gearbox. Something everyone keeps in mind. With a gearbox there's no need to time gear changes and pedal strokes, no need to get caught in the wrong gear. No need for shifting performance to get weird as **** wears out(not on the same scale anyway), no need to replace chain and sprockets anywhere near as often, cables also don't wear as quickly as they're not forcing something under as much mechanical load. and so on, and so on. Yes they cost more, over the life of the bike, it's probably not that much different.
Get used to a gearbox bike, then ride a bike with mech and you realize how compromised shifting is with the mech. Don't ride a gearbox bike, only ride your bike with mech, be happy ;-)
Just looking at the chain-line of a bike with mech in either and of the gearing range should be enough to make any mechanical minded person cringe.

Stop with that logic or the hoplophobe SDD troll may smite you.

 

[atrokz]

View attachment 115410

That looks awesome. Scratch the lefty, add a nice Fox float, and away you go for miles and miles without a missed shift. Who makes it?

 

[Wetbed0]

That's an absurdly incorrect comment, and surprising from someone who apparently has ridden a bike off-road before.

For starters, I can shift very well. Been doing so for a few decades, through thousands of miles or road and dirt, and to the podium at local DH races. So I 'learned' to shift a long time ago, probably before you could even bike. Imagine that. To me you are new.

Now that that's established, I'll tell you I've gone through many derailleurs. To the point I was buying 105's because they were cheap and less expensive than the modified short cage XTs I raced on. I also have an XTR that's reaching the end of it's life after three seasons of use.

How does this happen? Well, it's simple:

- Racing and riding DH in rock infested areas like St. Anne and Bromont probably cost me 4 or 5 drls to rocks alone. Sure, I could levitate, but I try to save my super powers for other things. Crashing, leaning too low, making an error during a race (it happens) have all broken drls. If this hasn't happened to you, it's probably because you're new

- They wear out. all that up and down with tension applied in various directions. The moment loads it sees from impacts, etc. All kill them . They are an incredibly weak link on otherwise well evolved bikes. There is no arguing this. cast aluminum, CF, a bunch of weak ass pulleys, and bushings to rotate on that wouldn't make it past my approval (I sign off designs and dwgs in the defense industry. I worked on that plane in my avatar amongst many others so take from my words what you will).

- They aren't cheap anymore. My XTR costs over $200. For a piece of cast aluminum and few bits of 'exotic' material that slowly degrades in performance every season, and is prone to damage. If I go cheap the lifespan is even shorter. Every shift I take, every move I make, I'll be wearing them.


The problem with gearboxes is price. If that could come down, and the disposable mindset in this fickle 'industry' (I laugh as I type that....), then we'd see more of them. I for one welcome the idea.

What's the cost difference of going with a gear box vs regular? Because $100 cassette and 4 $100 x9 rear deraliurs in two seasons should come close to the same price. I like them, maybe a few more seasons when I have more cash flow.

 

[StiHacka]

What is wrong with a $50 SLX Shadow+ RD? They are cheaper to replace than a single tire. Do not tell me they are heavy if you are seriously considering multi-lbs gearboxes as their replacement.

 

[atrokz]

What is wrong with a $50 SLX Shadow+ RD? They are cheaper to replace than a single tire. Do not tell me they are heavy if you are seriously considering multi-lbs gearboxes as their replacement.

Well, remember a lot of us started using cheap 105's to save money. Nowadays a SLX could be a great option for something bound to break or wear out in a season or two. However, the gearbox doesn't just replace the drl. Remember that.

The retail for an SLX is about $100 here. What if I told you I could get a deal on a pinion, then wouldn't that render the whole point of a reduced price, moot? There are multiple variables to factor in when doing a price comparison over the course of ownership that nobody here has done properly. So what's the point? In a Porsche a DSG gearbox costs more than a regular automatic. A hardened steel gear lasts longer than a titanium cassette sprocket. Whats the point of comparing anymore? Who cares....

It's not the point of this thread. This thread is about gearboxes. Not a soap box for luddites ,retro grouches, and the technically impared.

 

[Bikael Molton]

New gen derailleurs are also a lot more low profile (side profile) and less smashable.

My Zee vs say an '09 X9 are worlds apart. The industry is learning some things.

I'm also gonna wager that in 2005 there were a fair more hacks running long cage derailleurs on DH or Freeride bikes. Widespread availability of short cages in mountain/DH specific models is something else we can be thankful for in 2014.

 

[Sandro]

Nothing new here, but damn tasty looking:

 

[no skid marks]

800grams heavier than the derailleur version. Maybe less if you ran a chain. Not sure if the derailleur version comparison is with a chain guide or front mech or Narrow Wide ring.

 

[Wilhelm]

Zerode P1.18 Prototype

En esta entrada voy a analizar otro prototipo que he visto hace poco, aunque en este caso no está claro si va a salir a la venta o no. Este modelo es ademas un gran ejemplo de la polivalencia de una caja de cambios tipo Pinion, en la que el punto de giro principal de la suspensión trasera no está definido. Con una transmisión tipo G-Boxx el sistema de suspensión estaba básicamente predefinido, los fabricantes podían decidir que tipo de bieletas utilizar, pero el basculante siempre era muy similar y esto condicionaba mucho la efectividad de pedaleo. Con una caja de cambios tipo Pinion hay basicamente dos grandes opciones: utilizar un sistema mas o menos convencional, con el punto de giro principal cerca de la linea de la cadena (Nicolai, Alutech, etc...) o utilizar un sistema con un Pivote alto y una roldana Idler, que es lo que ha hecho Zerode. La gran diferencia entre un G-Boxx y el sistema de Zerode es que en este caso el punto de giro, la roldana, y los desarrollos empleados están mucho mejor elegidos, por lo que la Eficacia de Pedaleo roza la perfección y el Pedal-kickback es inexistente.

Como podéis ver en los primeros gráficos el sistema de esta Zerode tiene una eficacia de pedaleo en torno al 100% y no hace falta realizar la tabla de excel, ya que este porcentaje va a ser el mismo en todos los desarrollos (18V, 640% Ratio...). En la comparativa he incluido a una Nicolai Helius y a una Alutech Fanes, ambas en versión Pinion y como podéis ver la eficacia de pedaleo es muy buena en los tres casos, pero la Zerode lo consigue con un Pedal Kickback mucho menor. Si repasais la definición de Anti-squat en la página de I-Track vereis como este parámetro depende de la "geometría" del basculante y del incremento en la longitud de las vainas. Alutech y Nicolai utilizan un sistema convencional en el que el porcentaje de Anti-squat viene derivado de la tensión de la cadena y por eso el PK se queda en un nivel medio-alto, mientras que en el caso de la Zerode casi todo el Anti-squat viene derivado de la "geometría" del basculante, por lo que el Pedal Kickback es prácticamente nulo. El Brake-squat (155%) sin embargo se queda en un valor muy alto.

En la gráfica del Leverage Ratio vemos como el sistema es completamente lineal. En el modelo G2 de DH Zerode utiliza un sistema de bieletas bastante progresivo, pero la colocación de la caja de cambios en esta versión complica un poco el diseño y ademas hay que tener en cuenta el tema del peso. Una caja de cambios tipo Pinion aumenta en unos 2 Kilos el peso del cuadro, pero un sistema Monopivote sin ningun tipo de bieletas y un cuadro fabricado en carbono compensan posiblemente mas de la mitad de este sobrepeso, por lo que el resultado final debe de ser bastante bueno. El tema del LR se puede compensar con un CCDB Air, y el Brake-squat también se puede reducir con una pinza flotante... En fin, un sistema muy interesante, y un I+D impresionante si tenemos en cuenta que Zerode es una marca pequeñisima.

Un saludo.


3 comentarios:

Unknown dijo...

All bicycle suspension geometries involve design compromises. Still, some bikes seem less confounded by these compromises than others. The Zerode is such a bike. Its pedaling performance is superlative and pedal kickback is all but non-existent. That is pretty remarkable. Isn't it reasonable to ask why we should continue patronising other brands when we could have a bike like this? I am not going to try to answer that question. I just want to point out that the Zerode is a disruptive technology that will cause us to rethink where we stand. Well it would if it is ever released.

Despite its brilliance there are issues with the bike. The designer often opts for very simple implementation details to deliver the more radical design concept. That does not always lead to the best results. The AR curve, for example, could be vastly improved if the suspension were to use a split pivot or horst-link (somewhat similar to the Devinci Wilson linkage) to permit the IC to be projected forward during suspension compressions. Also, there are obvious ways to improve LR escalation - think the Scott Gambler.

And what about the Pinion gearbox? Well, it is obvious the the Alfine, whether 8 or 11 speed, couldn't suffice. The Pinion (the alternative would have been augmentation of the 11 speed Alfine with a Hammerschmidt) in this situation is a good choice.

Un saludo
Chris
12 de marzo de 2014, 8:29


Antonio Osuna dijo...

A lot of people are happy with the 420% ratio of the XX1, so the Alfine 11 doesn't need anything else, 409% it's almost the same. Anyway, I still think the Pinion it's really nice.

Best regards,
Tony.
12 de marzo de 2014, 13:22


Corrochano dijo...

Pienso algo parecido a Chris, también en la línea de que hay mucho campo de mejora. Aunque intuyo que es la propia presión de la industria (marcas consolidadas) la que frena bastante el desarrollo de este tipo de innovaciones. Cuando algún gigante se tome en serio dar el salto podría producirse un salto cualitativo importante, en el que muchos comiencen a actuar como seguidores. Es una intuición. Muy interesante el análisis, saludos
12 de marzo de 2014, 21:19​

Courtesy of Antonio OSUNA aka Vrock

 

[Wilhelm]

Mechanical Engineering Undergraduate Capstone Projects

Internal Gearbox for Downhill Mountain Bikes by Joshua FILGATE, Jesse KUHN, Morgan MISEK, Jay SEITER & Michael WITONIS

Abstract
In the realm of competitive downhill mountain biking, there is a need for advancement of the drive train. The conventional sprocket, chain, and derailleur drive train is not well suited for the high speeds, impacts, and harsh environmental conditions inherrant to the sport of downhill racing. The gearbox created in this project replaces conventional drive trains on downhill mountain bikes. The initial design and proof of concept were designed to provide a comparable gear range and capabilities of a conventional drive train, while providing increased protection, strength, durability, and performance. The scope of the project was to provide a working prototype capable of demonstrating the ability of the gearbox to provide the overall system gear ratio range of 2.1-3.3 when interfaced with industry standard components, as well as a detailed design of a complete prototype system.

Publication Date
12-4-2007


Courtesy of The Northeastern University, Boston, MA

 

[Wetbed0]

I've read through that paper. Very cool. Anyone know what the msrp is on just the gear box alone? It would be a nice project to put a frame together and try it out.

 

[ianjenn]

I've read through that paper. Very cool. Anyone know what the msrp is on just the gear box alone? It would be a nice project to put a frame together and try it out.

A fair amount be around $1400 I would guess a little more than High End SRAM would be....

 

[Wetbed0]

About the same

 

[Wilhelm]

I've read through that paper. Very cool. Anyone know what the msrp is on just the gear box alone? It would be a nice project to put a frame together and try it out.

Dunno if that Boston gearbox ever made it into production, guess it didn´t. Current production gearboxes (spring 2014):

• EFFIGear 6-7-8-9-speed gearbox (gear range 260%-300%-360%-444%, 6-7-8-9 uneven increments)
• NICOLAI 14-speed G-Boxx 1 (modified ROHLOFF SpeedHub 500-14 inside, gear range 526 %, 14 even 13,6% increments)
• PINION 18-speed P1.18 (gear range 636%, 18 even 11,5% increments)
• SR SUNTOUR 9-speed V-Boxx GB10-VB-FR9-BAZ* (gear range 610%, 9 uneven increments).

Despite of V-Boxx is close (but deliberately not exactly) to G-CON standard each of those gearboxes have its own mounting specifications (EFFIGear and G-Boxx 1 welded-in). The only G-CON compatible production gearbox I´m aware of (except for tinkering with a bolt-on G-Boxx 1 variation in the 2.000er years), NICOLAI resp. UNIVERSAL Transmission´s G-BOXX 2, was shelved in 2010.

EFFIGear, NICOLAI G-Boxx 1 and SR SUNTOUR V-Boxx each allow for single pivot design concentric to power output. Only the EFFIGear box comes with a trigger shifter option (3 options in all).

Gearbox sales price penalty:
1. EFFIGear
Surcharge for NICOLAI model Ion 20 EFFIGear** (€€4,300.00, 19% VAT included) vs. classic derailleur-type Ion 20 (€2,299.00, 19% VAT included) is €€2,001.00.

2. NICOLAI G-Boxx 1
Surcharge for NICOLAI model Nucleon E2*** (€5,299.00, 19% VAT included) vs. classic derailleur-type Ion 20 (€2,299.00, 19% VAT included) is €3,000.00.

3. PINION P1.18
Surcharge for NICOLAI model Helius AC PINION**** (€€3,699.00, 19% VAT included) vs. classic derailleur-type "Helius AC" (€1,949.00, 19% VAT included) is€ €1,750.00.

Gearbox weight penalty (approx.):
EFFIGear (800g) < PINION P1.18 (from 1.5-2kgs) < NICOLAI G-Boxx 1, SR SUNTOUR V-Boxx (from 3-3.5kgs).



* ... V-Boxx was originally designed by Karlheinz NICOLAI fitting G-CON standard and sold to SR SUNTOUR as a working prototype. SR SUNTOUR made some modifications (e.g. beefed-up bearings in 2011), not least the gearbox housing was moved away from G-CON configuration.
** ... 170mm proprietary EFFIGear crank arms, BB, twist shifter (three different versions) included.
*** ... Nucleon E2 is G-Boxx 1 derivative of derailleur-type model Ion ST (= predecessor of contemporary model Ion 20). Modified TRUVATIV Holzfeller crank arms, BB, twist shifter, proprietary COR rear hub, front chain ring and rear sprocket included.
**** ... Proprietary 175mm PINION CNC crank arms, BB, twist shifter, front chain ring, chain tensioner included.

 

[Wetbed0]

Yeah, I was looking at gear boxes on and off. Maybe two bikes out I'll pick up a Nicolai dh. But for now I've been working with bikes a lot and the standard size of them appeals to me and gives me the confidence to make the frame before buying a gear box. Really cool tech

 

[Wilhelm]

There are and have been a few one-off bikes with production gearboxes running for years. Don´t forget sharing pics at this forum once your project is to start someday.

 

[no skid marks]

I've read through that paper. Very cool. Anyone know what the msrp is on just the gear box alone? It would be a nice project to put a frame together and try it out.

They're really hard to get them off Pinion unless you're a reputable brand, so OEM only for now. Having said that, we(Crankin) in Australia got a few for small frame builders, but it was hard and they won't sell us anymore for now. Effigears are available to buy though.

 

[no skid marks]

I wish the Cavalerie 170 and 160mm bikes were in those graphs. Even the Zerode g2, Lahar and GT IT, some BCDs etc for comparing.

 

[Wilhelm]

I've read through that paper. Very cool. Anyone know what the msrp is on just the gear box alone? It would be a nice project to put a frame together and try it out.

They're really hard to get them off Pinion unless you're a reputable brand, so OEM only for now. Having said that, we(Crankin) in Australia got a few for small frame builders, but it was hard and they won't sell us anymore for now. Effigears are available to buy though.

The same is for SR SUNTOUR´s V-Boxx*, it´s OEM only, too.


* ... BTW, I was told they´ve stepped into the Asian cargo bike and rickshaw market with that heavy-weight V-Boxx (4.52kgs including cranks, sprockets, shifter & cables).

 

[no skid marks]

The same is for SR SUNTOUR´s V-Boxx*, it´s OEM only, too.


* ... BTW, I was told they´ve stepped into the Asian cargo bike and rickshaw market with that heavy-weight V-Boxx (4.52kgs including cranks, sprockets, shifter & cables).

Effigear is good with two different output sprocket options.

 

[Wilhelm]

Effigear is good with two different output sprocket options.

Yes, the same is for PINION P1.18 with two different chainring options (24T, 30T), too.

 

[no skid marks]

Yes, the same is for PINION P1.18 with two different chainring options (24T, 30T), too.

Yes but not what I meant. The Effigear has a three internal axle high output sprocket option(good for higher than conventional chain height pivots(so medium height) and a two internal axle low output sprocket option(and lighter), ideal for hardtails or bikes with idlers.
So you could design a frame around them however you liked pretty much.
Effigear has something like 440% gearing. So more than XX1 but less than Pinions huge 660%. Or get a lighter 6, 7 or 8 speed Effigear gearbox that's lighter still.

 

[Wilhelm]

In place of refining their own G-Boxx concept the NICOLAI guys seem to team up with the French EFFIGear company for an all-new 2014 27.5-inch wheeled 9-speed gearbox "Ion" DH bike. According to the latest newsletter (July 24 2013) NIC will unveil that model at the 2013 open-house (August 16-17), prior to Eurobike.

The EFFIGear website shows schemas of three variants of 3-shaft 9-speed gearbox configurations allowing for input-output shaft distances of 55mm-102mm and a more compact quasi-2-shaft configuration whereby the third shaft is located coaxial to the crank shaft (output). The weight is indicated similar to a derailleur-type drivetrain with a two-chainring setup. Interestingly they offer not only a typical twist-shifter but two modified versions for sequential shifting including a quasi-trigger shifter, too.

Yes but not what I meant. The Effigear has a three internal axle high output sprocket option(good for higher than conventional chain height pivots(so medium height) and a two internal axle low output sprocket option(and lighter), ideal for hardtails or bikes with idlers.
So you could design a frame around them however you liked pretty much.
Effigear has something like 440% gearing. So more than XX1 but less than Pinions huge 660%. Or get a lighter 6, 7 or 8 speed Effigear gearbox that's lighter still.

I see. I referred to the four modular EFFIGear gearbox configurations in a preceding post before (#587). Those are really great options for the frame builder no other gearbox manufacturer offers one-stop today. If all of the four configurations make it into production then EFFIGear becomes the most versatile gearbox by far.

@no skid marks
Are you aware of any plans for a production version of all those EFFIGear variants?

Frame integration
Effigear´s gearbox has been studied in order to be placed in the central position of the frame and include bottom bracket axle, pinion or sprocket and suspension pivot. The frame design is simplified and the gearbox brings manifold advantages.
The carter can be welded to the frame, it’s the choice made on CAVALERIE bikes and NICOLAI.
It can also be screwed to the frame through a fixation interface and include anchoring of latch link or upending frame.

More freedom
The 3 axle gearbox allows to design several carter shape.
Bottom bracket/out of box pinion pitch may vary between 55 to 102mm.
That unrestraint is interesting for big travel bike design (140mm or more).
The rear arm pivot is free and allows to optimize the rear wheel route without being limited by the line chain issue.

Modular and compact
The 3rd axle on which is located the output pinion of the box can be coaxial with the bottom bracket axle.
We get a gearbox named “2 axles” in which the secondary transmission pinion turns around the bottom bracket. Overcrowding and weight are reduced.​

 

[dhmtbj]

Mechanical Engineering Undergraduate Capstone Projects

Internal Gearbox for Downhill Mountain Bikes by Joshua FILGATE, Jesse KUHN, Morgan MISEK, Jay SEITER & Michael WITONIS

Abstract
In the realm of competitive downhill mountain biking, there is a need for advancement of the drive train. The conventional sprocket, chain, and derailleur drive train is not well suited for the high speeds, impacts, and harsh environmental conditions inherrant to the sport of downhill racing. The gearbox created in this project replaces conventional drive trains on downhill mountain bikes. The initial design and proof of concept were designed to provide a comparable gear range and capabilities of a conventional drive train, while providing increased protection, strength, durability, and performance. The scope of the project was to provide a working prototype capable of demonstrating the ability of the gearbox to provide the overall system gear ratio range of 2.1-3.3 when interfaced with industry standard components, as well as a detailed design of a complete prototype system.

Publication Date
12-4-2007


Courtesy of The Northeastern University, Boston, MA

Well that looks familiar! Fun project

Even earned us a patent...

 

[Wilhelm]

Mechanical Engineering Undergraduate Capstone Projects

Internal Gearbox for Downhill Mountain Bikes by Joshua FILGATE, Jesse KUHN, Morgan MISEK, Jay SEITER & Michael WITONIS

Abstract
In the realm of competitive downhill mountain biking, there is a need for advancement of the drive train. The conventional sprocket, chain, and derailleur drive train is not well suited for the high speeds, impacts, and harsh environmental conditions inherrant to the sport of downhill racing. The gearbox created in this project replaces conventional drive trains on downhill mountain bikes. The initial design and proof of concept were designed to provide a comparable gear range and capabilities of a conventional drive train, while providing increased protection, strength, durability, and performance. The scope of the project was to provide a working prototype capable of demonstrating the ability of the gearbox to provide the overall system gear ratio range of 2.1-3.3 when interfaced with industry standard components, as well as a detailed design of a complete prototype system.

Publication Date
12-4-2007


Courtesy of The Northeastern University, Boston, MA

Well that looks familiar! Fun project

Even earned us a patent...

Cool project!

Sequential planetary stack transmission system
US 8449427 B2, US 20100298084 A1, WO 2009073705 A1

...

 

[no skid marks]

Well that looks familiar! Fun project

Even earned us a patent...

Cool, BUILD IT, or we're all just missing out on it, as the patent will stop others using your great idea ;-)

 

[Wilhelm]

Dlogic aka Martin WEIDNER´s SR SUNTOUR V-Boxx repair instructions (Dlogic´s V-Boxx Clinic):

Part 1

Part 2

Part 3

 

[Wilhelm]

The website gearboxbike.com is down (not so surprising).

 

[Wilhelm]

NUSETI Inner Drive System (IDS) - a fresh Polish gearbox project on Kickstarter.

 

[Wilhelm]

 

[Wilhelm]

Quoted Gregory ZIELINSKI´s (PL) NUSETI Inner Drive System (IDS) gearbox tech specs according to Kickstarter:

• Full ecapsulated waterproof drivetrain consisting of planetary gearbox + chain drive
• 16 effective gears
• gear range 570 %
• max. input torque 250 Nm (184 lb-ft)
• gear change possible under full pedaling load (upshift/downshift?) and while not pedaling
• 2 interconnected trigger shifters
• CF frame set (26", 27,5", 29")
• proprietary rear hub w/ through-axle.

 

[Wetbed0]

Does that torque number seem low to anyone else? That's only around 300lb on a regular crank arm. Either someone with some legs or a botched landing and pop. Maybe I'm looking at things wrong.

 

[frango]

Is it just me, or innerdrivesystem.com doesn't work/exist?

 

[Wilhelm]

Gregory ZIELINSKI´s website innerdrivesystem.com seems to be down.

 

[Wilhelm]

Another Polish "gearbox-like" project: Stefan MIGASZEWSKI´s (PL) EFNEO:

 

[frango]

It's like a Hammerschmit, right?

 

[Wilhelm]

... sort of ...

 

[csermonet]

http://www.ebay.com/itm/291180361021

 

[Wilhelm]

Mechanical Engineering Graduation Project

Multi-Speed Internal Bicycle Gearbox by Alejandro SAMPER, Charles G. & Garett B.

British Columbia Institute of Technology (BCIT), Burnaby, British Columbia
January 2013 to June 2013

 

[HardtailHack]

Has anyone ridden a Rohloff equipped bike, I know the indexing is done at the hub but does the shifter need to have some friction to stop it changing on it's own?

I want to buy one but hate Gripshift and the avaliable paddles look like they were done in the 90's and cost silly money. It would have to possible to make something up at home, I'd ideally like to cut one cable short and fit a return spring so only one cable went to the bar. I should sleep, my brain jurts.