I don't think your formatting worked as intended.

 

That's better.

1. No.

2. No.

3. Benefits are obvious. If it had the same range as expected with no weight penalty, and were reasonably affordable, I'd take it.

 

1) Yes

2) Yes, but also some cons associated with doing so.

3) This doesn't really exist. All internal gear hubs have a problem with stepping to an easier gear under torque (entering base-of-steep-hill-with-poorly-timed-shift situations). They just do, same with manual transmission automobiles.

It does exist for stand-still and going to a harder gear under torque.

Your word "likely" regarding patents concerns me a bit. Check for prior art!! Existing patents are present, and some of them are still in effect. German, French, and Italian guys made - and are making anew, currently - some gearboxes over the years.

Check as much of the prior work as you can. Learn from their mistakes.

Also, have fun with the crank clearance work. Haha, whoa.

 

One prominent example: a google images search of Katz Bicycles

It appears they decided to look for someone to buy the company, and discontinued operating.

I thought it was cool.

 

1) Do you have any problems with the current chain and derailleur system?

Yes. I will not have one on my bike under any circumstance.

2) Would you see a benefit to an enclosed chain (built into the frame)?

Definitely. My 1935 Sunbeam is on its original drivetrain.

3)What benefit would you see to a gearing system which allows for gear change at a stop or at full load?

Being able to change while stationary is a benefit that hub gears currently offer. It is a good feature when you get stopped on a steep hill and need to restart in a lower gear.

As Drew points out, there is considerable prior art involved - going right back to the 1890s. Basically almost any cycling device you can think off was patented back then, and it continually surprises me that mtb patents aren't challenged more often on that basis.

Personally I am not interested in lumping a heavy gearbox around, so light weight would be important. I would prefer fewer and more widely spaced gears rather than a box of many all close together, 3 very widely spaced gears would keep me happy. Basically top for the road sections (about 65"), a direct drive normal for usual trail stuff (about 40"), and ultra low for bogchurning and deep snow (about 25").

 

...there is considerable prior art involved - going right back to the 1890s. Basically almost any cycling device you can think off was patented back then, and it continually surprises me that mtb patents aren't challenged more often on that basis.

Probably because a lot of them don't see legal battles as being within their budget.

I've been warned, "Don't get into bikes if you want to get rich." (fine by me, just wanna pay the bills)

 

I would only be interested in a system like this if it can be made at a competitive weight with the traditional external drivetrain, and with an equal or greater range in gearing.

I haven't had the opportunity to ride a Pinion-equipped bike, but I got to see a few recently. They're very cool and I would absolutely own something like that. My sticking point is the internal chain drive. If I had a bike with a Pinion, I'd be looking hard at a Gates belt drive.

 

1. chain stretch and cog wear are my only issues.

2. no, Sounds like it would be heavy

3. if it wasn't heavy, I'd be all for it.

 

For what it's worth, Nuseti's Kickstarter campaign last year failed to find enough backers.

 

Thanks for the responses so far guys,

On the patent question: We definitely need to do our homework on prior art in gear trains systems. Obviously transmissions have been around for many years and have been widely developed and patented by major OEM's, however Im optimistic that the developments in internal gearbox applications of bicycles will be minimal. Patenting is neither a cheap nor a quick endeavour and I agree we'll need to proceed with caution.

Weight: The weight of the internal chain housing will be slightly offset by the lack of a rear derailleur. We are aiming to have no more than a 2.5 pound weight penalty overall.

Any other responses to the questions are always appreciated!

 

...however Im optimistic that the developments in internal gearbox applications of bicycles will be minimal...

I've seen one in a veteran bike, and it may be worth researching the Mervil Mervilex from the 1940s which I think was a 5 speed epicyclic.

There are many others, but my memory needs jogging. I have a pretty extensive library of books and cycling magazines dating from 1879 to the start of WW2, so I'll keep an eye out for anything of interest.

I hope you succeed, the place for gears is enclosed in an oilbath, and in the centre of the bike's wheelbase, not dangling off the rear.

Edit: found this pic from the EMBACHER/COLLECTION - MERVIL Mervilex

Thought I'd add some interesting links (well, they interest me )

Edyson CVT ? Gearbox continuously variable transmission | multibody.net

Young Aussie Designer?s World First | Bicycling Australia

Transparent gearbox on a homemade bicycle (Drew will like this one)

Honda's version

I won't post up the modern stuff like Pinion etc. That's well known now.

Some more edit:

This one is interesting, although the Alenax was a more elegant solution

from Gears - Math in Context

and look! It's really very modern - the bike has "modern trail geometry'

 

What advantages would this offer over a belt drive with a Rohloff hub?

Never used a Rohloff myself but I've read they are pretty bomb proof and the belt drive system eliminates chain maintenance.

 

The main advantage is that the mass of the gearbox is centralized in the bottom bracket area of the frame and not in the center hub of the rear wheel. This provides a low center of gravity that will translate into a more stable and balanced ride.

As far as the advantages and disadvantages of using a belt drive, a good review can be found here:
CyclingAbout.com ? Gates Carbon Belt Drive: Everything You Ever Need to Know

With an enclosed gearbox and chain, the drive train is sealed from any contamination so it will not require frequent maintenance. The chain runs smoothly in a single line so it will not break or wear from torsional stress. Adjusting the chain tensioner and servicing the oil will essentially be the only maintenance required after many kms of riding (e.g., ~30,000 km).

 

Velobike, you predicted my tastes correctly.

Sounds like I'll have some competition

Don't forget the NoSmoke / Phaser gearbox. Whatever happened to those guys?

OP, this is a good read, in PDF format: http://iris.lib.neu.edu/cgi/viewcontent.cgi?article=1068&context=mech_eng_capstone

 

this is either relevant or apocryphal, i can't really tell:
TPC Museum Series #4: Myles Rockwell?s 1998 Cannondale Fulcrum | IMB | Free Mountain Bike Magazine Online

 

Relevant enough, as it involves geometry that non-concentric gearbox bikes are going to be required to deal with.

It's like... many people have been around this block before, and the idea showed promise... yet the only gearbox available these days is in a price bracket few can afford. Not to diss on Pinion or Effigear (I'm lusting after either), but the rest of us need something a little less top tier.

OP, also, look up Dave Camp's bike. He was in HIGH SCHOOL at the time! Incredible.

 

If I wanted to make my fortune from a enclosed gear system for bikes, I'd make it for the rear hub.

Anything that requires a special frame is going to fail unless it is done by one of the majors like Giant. The requirement for a special frame means the idea will fall by the wayside because of lack of market traction.*

I'm saying that even though I'd prefer a central location for the gears.

Where I would direct my efforts would be for a gearbox that was a plugin replacement for a freehub.

Modern freehubs are quite wide to allow the fitment of 10 or 11 razor thin rapid wearing cogs. There is certainly enough room in there for at least a 5 speed epicyclic. When it comes to fatbikes with 197mm rear OLDs, there's room for a Rohloff equivalent.

Make it QR with the gears staying attached to the frame, and you'd be on a winner because it would be a simpler removal than a derailleur or existing hub gears. The Edyson looked promising in this regard.

*Edit: There is a standard for a specific frame mount for eBikes where the motor is mounted forward. This could be used as a means of getting some traction for centrally mounted gearboxes. The problem with that is that existing eBike frames aren't exactly "sporty" but getting a supplier for frames would be easier than starting a new standard from scratch.

 

Velobike, something that occurred to me this past summer:

It's not the delayed-shift behavior of derailleurs that bugs me. Just the notion that they hang out so far.

For instance, I could address my gripe about pedaling being required in downshifting-while-cornering situations by making my freewheel fixed, and equipping the crank with a freewheeling spider. Several two speed cranks have that freewheeling behavior built in.

Still... I don't feel drawn to any of the derailleur guards out there, because they all have to deal with interference from the tensioner arm of the derailleur.

What if just the tensioner arm was moved? Basically the rear derailleur would be made of the parallelogram arms, spring, and jockey wheel.

You'd then need some way of taking up chain slack through different gears, of course. Word on the street is that chainstays are pretty long, and chains are completely unaware of HOW they are tensioned, just THAT they are tensioned...

If you basically addressed the dangly "feel free to kick me in the balls" position of the tensioner arm were changed, I think we could enjoy some benefit from a light touch - keep the familiar drivetrain behavior, keep the free market parts interoperability, just compact the existing parts enough to fit it inside a meaningful guard.

 

Velobike, something that occurred to me this past summer:

It's not the delayed-shift behavior of derailleurs that bugs me. Just the notion that they hang out so far.

...If you basically addressed the dangly "feel free to kick me in the balls" position of the tensioner arm were changed, I think we could enjoy some benefit from a light touch - keep the familiar drivetrain behavior, keep the free market parts interoperability, just compact the existing parts enough to fit it inside a meaningful guard.

My objection to derailleurs isn't the mechanism or the shift. It's their delicacy.

Enclose aderailleurs within a protective casing with an oilbath and they would be superior to anything else.

After all they have evolved to work efficiently (albeit briefly) in a very hostile environment, so if we spoilt them and protected them from knocks and flying crud, they would be wonderful.

Your idea is very similar to some of the early derailleur designs.

 

Still in response to Negotiator50:

Well, I forgot my friend picked up his bike, so here's my pavement bike instead.

It started life maybe 8 years ago as a Specialized Centrum. Wanted a commuting mule. It was my E-bike chassis, I had the battery all taped up in the front triangle. Yes, taped, it lasted.

The crankset is a Metropolis Patterson internal two speed with the 130 BCD adapter. Bigger BCD mean bigger front chainring, which means a large enough rear cog to handle the ridiculous torque so that it wouldn't skip teeth anymore.

It has a dumb too-long rear brake hose because I'm a moron.

I didn't capture the bullnose bar that Origin8 no longer makes

The fork represents the relatively highest mass of all the components. All I have to do to hop a curb is loft the front end, and give the handlebars a forward shove, and the bike takes care of the rest.

I wanted to show my friend's bike that is basically a bullhorn / fixie looking bike, transformed into this ultra functional mutant with rear fenders, two gears, brakes, interrupter levers, etc. I'll grab a shot later, it's a goofy looking but very loyal bike.

 

I have mixed feelings about belt drives, I have one on my day to day hybrid with a Nexus 8 hub (I very much agree with the point about the weight at the back of the bike rather than the total weight) and the first belt/sprocket only last 18 months which was far shorter than I was expecting. I spoke with Gates and they advised if the belt was frequently used in wet and cold conditions it would wear much quicker despite boasting about the all weather capabilities of the belt.

That link above is interesting though in the reference to rear sprockets wearing out prematurely as that's what had happened on mine and the bike shop said it had worn the belt down as well which made sense. They fitted a steel sprocket which has lasted longer than the first.

I don't do big miles on the mountain bike, only out for a few hours each time so the chain and derailleur works fine for me whereas with the hybrid being out every day including through a lot of salt the belt drive is more useful.

John

 

I've got a belt drive hybrid as well, but mine is SS so I haven't experienced the weight of an IGH. Haven't had it long enough to really speak to longevity, but so far I like it. I've been using it almost exclusively in the cold and wet weather so we'll see how it holds up.

 

With the much shorter life than I was expecting I did weigh up converting to a chain drive instead but decided that the belt drive was worth the cost as despite being used daily and over the winter constantly covered in salt it's worked silently the whole time with no maintenance while the chain drive bikes need far more frequent attention.

I have toyed with converting to single speed as well to get rid of the weight off the back as I've been expecting the hub to give up since most people don't get that long out of them (it's a cheap Nexus 8) but it keep soldiering on so puts the decision off for now.

John