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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."
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.
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.
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