Slashdot Mirror
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."
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...
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
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
The three top priorities for racing bikes are weight, weight and weight. Speaking as a lifelong rider, racer and former messenger, stuff like this never works out too well in practice. Anyone tried the electronic shifting systems? They (mostly) suck.
There have been may refinements, but as the article post says "few advancements in drivetrain technology" because what we have currently is very lightweight, works extremely well, is very reliable, and is easy to service.
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - BF
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."
Friends don't help friends install M$ junk.
I'll tell you what. As a mountian biker and someone that has witnessed some terrible accidents, you're an absolute IDIOT if you don't wear a helmet! I don't care if you're riding trails or on the street. Wear a helmet!!! By the way, not all helmets cost $100.
..What we need are cheap, effective helmets and cheap effective bikes. In that, you're totally right.
And a community designed where a bike is the most transportation a person needs to own. Much safer ride withou the cars... human-scaled cities.
Marco Pantani ain't no sprinter. You're thinking of Cippolini, or, even better, Nothstein.
I am a believer of momentum and curves.
...Yet nobody even remotely considers wearing a helmet before crossing the street or climbing in the car
Hey, I'm all for it
Driving helmets for soccer moms!
It'd be of absolutely no practical use whatsoever, especially as they're usually the ones who come out safe after they kill 20 people driving through a parking lot while on the phone and getting the baby's bottle, but who cares, it'd make them look ridiculous.
Maybe the helmets could be "Beware! Fucking idiot!" in big letters on the front or something. That might help safety
Who's with me?
Curiosity was framed. Ignorance killed the cat.
As long as you agree to waive all legal liability to any injury sustained - whether someone else's fault or not - while riding without one.
I don't want to be responsible for your serious injury or death when - if you were wearing a helmet - you'd have walked away with a minor case of road rash.
Is it just my observation, or are there way too many stupid people in the world?
Dude? Pantani's a climber. Or he was one, before he got all depressed and started hitting the canollis hard.
Cippollini, Petacchi, McEwen, and Zabel are the current cream of the sprinting crop. And you're indeed right that Cipo puts out over 1 horsepower in full flight.