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Bicycle Tech Drivetrain Advances Showcased
whoda writes "For many years, bicycles have had very few advancements in drivetrain technology. This is finally changing. The newly formed g-Boxx Standard has been incorporated into the new Nicolai Nucleon TFR bicycle frame. This bike uses an internally
geared 14 speed planetary gear system, mounted in the center of the bicycle, to drive the rear wheel using a conventional chain. The design allows the chain to run inside of the frame. This removes many fragile components from the bicycle, and allows a more rigid frame structure to be made. Evil Bikes have also shown a protoype
Evil 2013i hardtail which also incorporates this new standard - I've found the toy I want for the holidays."
Internal gearing in bicycles is not, new, it just never catches on.
This just means now that if something breaks down, it would be hard as heck to get at it. Parts inside the frame? Kind of hard to do trailside maintainence on that! (Especially since it's not from a well known component manufacturer.
I'll wait until I see it on the World Cup circuit before trying it myself...
How about shaft drive?
Look at that photo carefully. Notice that part of the chain is exposed. Now just were do you think all the road dirt and other muck is going to end up?
Sounds good for mountain bikes that need to protect the chain and sprockets but might add some unnecessary weight to roadbikes.
>16-19kg (35-40lbs) for a complete bike
Comment would be superfluous.
The Q looks horrific, the weight is high, the chain is still exposed, there's no easy way to clean the frame out when it gets filled with the muck and water that the chain will inevitably drag in, the lanetary gearing is less efficient than a pure chain drive. Yeah, I can really see why you'd want that setup: to look like an idiot with a fat wallet and a small brain. Oh, and prepare to be savaged by rec.bicycles.tech, where the posters actually know a bit about the technical issues.
They are raced on some of the most demanding downhill courses in the world.
They are strong and have an excellent reputation by hardcore mountain bikers.And 40 pounds for a complete bike of this type is fairly light to be honest.
There are videos available from the main Nicolai Home Page
I believe those were introduced by Shimano as the "Biospace" (or at least Bio-something) brand chainrings. Didn't catch on much because most people found the pedalling to feel jerky, or so I heard. I've also heard that they're still sold.
In the great CONS chain of life, you can either be the CAR or be in the CDR.
You could simply ride fifteen pounds of funk.
One gear -> stronger legs, more distributed workout, less to maintain, fewer parts to fail, just mo' fun
Every once in a while someone spends a crapload of money trying to change the fundamentals of the bicycle, but really, other than the derailleur, not much has changed in over 100 years.
Okay, I admit the chain-inside-the-frame thing is cool : less crap on the legs, cleaner, well lubed chain, etc... But somehow, there has been a notion that current bike drivetrains (i.e. chain+derailleur) are inadequats. There are continuously people who dream of making CVTs for bikes, or non-rotating drivetrains or whatever, to replace the "old" chain-and-derailleur. Well here are some facts :
...
- A chain/derailleur system is the only system that offers that many speeds under 2Kg
- Bicyclists don't need Continuously Variable Transmissions : human legs are incredibly efficient over a range of speeds from 0 to 13/140 RPM
- A bicycle is virtually the only vehicle where a chain drive is useful and needed, because the "engine" (you) is slower than the wheel, which is unique amongst all vehicles. This is also why any other kind of transmission will fail miserably compared to a chain drive in terms of efficiency (a chain drive routinely gets over 97% efficiency, and you need that with the 75W-100W power you get out of an average rider).
- A cyclist who's moderately used to shifting well will *not* feel impaired by derailleur actions.
- A chain + derailleur system is maintainable on the road. Just try to service a geared hub on the road
- Geared hubs are great for compacity and easy maintaining. However, their efficiency sucks. For example, a 7-speed Sachs hub can go down to 90% efficiency. That's a lot of power loss with under 100W of input power.
For more bicycling myth debunking, read the rec.bicycles.tech newsgroup and the Bicycle Science list.
I do over 10000Km/year and, apart from chain cleaning and re-lubing, I think the derailleur system is very adequate.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Reading these comments, it looks like 99% of the detractors of this concept fail to understand that the biggest plague of the downhill racer is the rear derailleur - it hangs in a VERY exposed position and is extremely easy to rip off. When you lose your rear derailleur in a DH race, your chances of making the podium are slim. Believe me, it happens a LOT, and it gets expensive and very annoying.
Another thing people fail to realize is that this concept is about DH bikes, not about cross-country bikes. It may weigh a lot, but a 40-pound DH bike is pretty light.
Too many opinions, not enough brain power to go around, if you ask me. If you ride a 23 pound XC-racer, you might as well comment on the suitability of an 8" travel, 12 pound, dual crown suspension fork for your riding style.
I spend a lot of time on high-performance Human Powered Vehicles (HPVs), and efficiency is a big thing among high-speed bikes. The main problem with these internally geared drivetrains is that they are not very efficient at all. They rob you one heck of a lot more power than chains and derailers. The regular chain and derailer design is something in the neighborhood of 97-98% efficient, while these geared drivetrains are about 70% or less.
The main advantage of the internal gears is for downhill mountain bikes. Drivetrain efficiency is not as much of an issue since gravity is doing most of the work, and there is no risk of losing your chain in mid air at 40mph.
Joao "member of far too many HPV and bicycle clubs and associations" de Souza
Great. The Bike was just released and we already broke it. =D
in girum imus nocte et consumimur igni
All bicycle innovation is welcome, but...
It usually is absurd, pointless, and only of interest to either professional racers or the people who will spend for a bicycle than a used car.
What we bike riders really need is:
1) Tires that don't go flat! Or, rather, I should say... tires that don't go flat and only cost two or three minimum wage units. $15 US. Yes there are Kevlar tires that are as thin as your thumb and cost $200, hold 100 PSI air pressure, and rarely go flat, but they don't count.
2) Something to keep the rain and road dirt from putting a big skunk stripe up our backs when riding in wet climates. There are fenders, but they don't work well.
3) The ability to fold the frame so that it can fit in the back of a small car or on the bus.
4) Brakes that work in the rain.
5) Tires that don't go flat. So important, I'm saying it twice.
We don't need auto transmissions, $150 helmets, $1500 frames that weigh next to nothing, and stupid yuppie mommies who want to pass stupid yuppie mommie laws to protect us for our own good.
The ones who drive around Oregon and California with the east coast Ivy League college decals on the back window of their Volvo's, almost kill you when they cut you off in the bike lane ("I didn't see you, and besides, you should be wearing a helmet!" "Well yeah, dumb bitch, you were changing the tape, dialing the phone, and reaching for the babie's bottle on the floor while changing lanes."
In fact, I HATE bicycle helmets. Their sole purpose is to show all the people driving around that the person on the bike is middle class, has a car at home, can afford a $100 helmet, and is seriously concerned about saving the environment to the point of actually going out into the public on a bicycle. The guys who don't speak English and ride a bicycle because they make $7 an hour and have four kids aren't wearing helmets.
"But," the yuppies tell me, "you NEED a helmet for safety! It should be illegal to ride without one."
Bull. The same people who say this think nothing about strapping two skinny long little boards to their feet and flying down an snow-covered mountain at 50 MPH with nothing on their heads but designer sunglasses!
When they put a Burger King on the top of the ski slope then all the yuppies will start wearing $200 ski helmets to show how concerned about safety they really are (and to make sure that no one confuses them with the people who work at the BK and ski home.)
100W? are you kidding me? I am not a fast cyclist by any stretch of the imagination (I just do triathlons, any cat4 cyclist can kill me easily) and I can do 200W sustained over fairly long (1h+) periods of time, Armstrong IIRC can do 400-500W sustained, and sprinters (Pantani) can generate up to 2000W for short periods of time.
:)
Also the most efficient cadence (in terms of power generation) is more like between 90 and 110rpm (of course you have to train to have a 'round' pedal stroke, 'mashers' tend to pedal around 70rpm) and the range of maximal power generation is not that wide (in terms of rpm), that's why the latest geartrains have 10 cogs at the back (and 2 or sometimes 3 at the front). If human legs were =incredibly= efficient we'd all be riding single speed bikes
Agreed about the rest, internal drivetrains are a fad that doesn't seem to want to go away: the only application where IMHO they make some sense is pure downhill, where hitting your derailleur on a rock can put you out of the race and where pedaling power doesn't really matter that much...
-- the cake is a lie
I've ridden 10s of thousands of miles and I'm here to say that a bicycle helmet is an absolute necessity, period. I've completely destroyed two helmets and scraped several more. I once scraped right through the plastic cover of a helmet and well into the insulation. If I hadn't been wearing it my scalp, hair, and a decent chunk of skull would have been left behind on the road.
Yes, you do. It's a matter of when, not if. Every cyclist wrecks, and some wrecks you land on your head. Why would you not want to protect your head?
On this we agree: the government should stay the fuck out of decisions that affect only my own health. Anyone above the age of consent should be able to ride anything with as much or as little safety equipment as they desire, as long as no one else is at risk of harm. Mandatory helmet laws are like anything else the government does "for your own good:" dangerous.
This isn't as much "normalization" as it is "don't take so many drugs when you're designing tables."
sorry if I sound like a troll, but I've been a serious cyclist for over 20 years now, done competition at the USA national level (okay, I got waxed, but I was there!), worked in the industry (local shop, major retailer, manufacturer), and have read way too much hype about new stuff. reading the comments here reminds me of a bunch of bike guys sitting around talking about how cool Windows ME was when it came out.
/. anyway. there are several posters here that seem to be actual riders, but the great majority don't seem to be very discerning cyclists.
okay, okay, we're just off our usual topic set here. but someone tell me why this story is on
first, this supposedly new and supposedly cool design is, as others have already pointed out, just recycled concepts, the main function of which is to separate the consumer from his/her cash.
these concepts have all been relatively stillborn over the years mainly because they are more expensive, less reliable and heavier than existing designs. plus, internally geared hubs are fine for the grandpa and grandma riding around the retirement community, but they are notoriously inefficient for someone trying to actually go fast.
reasonable cost is important because stuff breaks. always. even the unbreakable stuff.
reliability is important because we'd all like to ride home, not walk. plus it keeps us from having to pay for more stuff. this looks like stuff designed for freestyle use, and that stuff gets thrashed.
light weight is important if you ever have to (a) accelerate the bike (including changing its direction, or (b) go uphill. maybe also (c) put the damn thing on top of your car.
anyway, these bikes look like expensive pigs using minimally tested technology. we should all be sneering at this.
I mean, shit, if you don't want your shoelaces to get caught in the chainrings, double tie them. put a fucking rubber band around your pants cuff.
Comeon. Let's be serious.
Bikes with drailleurs have the most efficient transmission possible. Because a chain, unlike gears, has no inherent inefficiency caused by the gear teeth engaging and disengaging themselves. With a pair of gears, the distance of point of contact between teeth and the axis varies as each gear teerh engage and disengages the opposing gear teeth.
The result: non-constant velocity at the output of the geartrain. This induces vibration and is a source of drag.
On a chain, the distance of the point of contact of the chain link with the teeth remains constant WHERE THE POWER IS APPLIED TO THE CHAIN. Of course, the distance varies when the link engages the teeth, but as it happens for a very small percentage of the time the links are around the wheel, the gear teeth can be cut in a shape that does not allow any teeth to contact the chain until it is firmly seated against the gear.
A chain transmission will therefore offer the most efficient power transmission possible.
This is why race bicycles have chain drives. They cannot afford to lose the slightest erg of effort!!! This is why many motorcycles have chain drives, too. And the drailleur offers the best solution: variable diameter sprocket gears! The number of intermediate points between the cyclist leg and the pavement is kept to a minimum. How many inner gears and clutches does that 14-speed planetary gearcase have???
And a planetary gear change is not the most efficient design around. Ford-Ts had planetary gear transmissions. Cars have evolved a little bit since then, in case you haven't noticed.
Sorry to pick on you but the fact that you are chronically destroying helmets may be a good argument for you to wear a helmet but is not enough to prescribe a universal need. People both inside and outside the US (the Europeans sometimes call helmets the "American Obsession") have been riding bicycles to get where they are going for over 100 years and they have not been dropping like flies, regardless of what the fear mongers would have us all believe.
Despite common knowledge to the contrary, cycling properly on the road just isn't that dangerous relative to other ways of getting around.
As anyone who has followed the Helmet Wars in Usenet knows, the rate of fatalities due to head injury while cycling is similar to that of motorists (per hour it is less, per mile it is more) while the motorist FHI numbers are about 50 times that of cyclists - which deflates the 'cost to the system' argument for helmet compulsion quickly. Pedestrians who walk near traffic fare even worse per hour than either of the above groups. Yet nobody even remotely considers wearing a helmet before crossing the street or climbing in the car even though their is a more sound basis for either of those groups than cyclists. Perceived risk is often very different from actual risk and these decisions are often based on emotions rather than logic.
Whole population studies done to compare injury and fatality rates before and after the implementation of Manditory Helmet Laws (Australia being the basis of much of the study) has shown no long term benefit to these laws. One study pointed out that cyclist head injuries had dropped about 35% but failed to mention that the number of cyclists had decreased slightly more which indicated an increased rate of head injury. Such duplicity is the norm - helmet laws are still being lobbied for with the false "85%" figure which even the authors of the 15 year old study have abandoned.
Promotion of bicycle helmets has done two things: First, it has completely and utterly connected Cycling and Head Injury/Death in nearly eveyone's mind (this site being lots of evidence in itself!); parents are afraid to let their children ride anymore even though cycling is statistically safer than it was 20 years ago - rather they let their children safely get fat while being raised by a TV.
The second effect is that helmet manufacturers make oodles of money even though they are shrinking their customer base thorough their vile anti-cycling marketing tactics.
Bicycle helmets are excellent proof that marketing works and that emotional hysteria is the best way to get laws changed.
This mean, among other things, that shifting gets harder when you are putting a grater load through the chain... which is often when you most want to change gear!
Nevertheless, this is how front derailleurs work - they crudely shove a tensioned chain around from one chainring to another. It's not elegant and even with recent improvements in the shape of chainring and sprocket teeth to make it easier to move the chain between them, it sometimes works poorly.