Has anyone thought of going chainless?

[consultantTW]

I reciently read an artical about an internal gearing system. I was wondering if anyone has thought of using a shaft from peddles to gears, instead of usein an open shaft.
Any thoughts on this matter?:scooter:
consultantTW.

[badcheese]

Shaft drive bikes are pretty interesting. There are shaft-drive bicycles on the market, but they are typically not high-end bikes. The main selling points are lower maintenance and not exposing the rider to chain filth. From what I've read, the drawbacks tend to outweigh the benefits. Drive shafts need to be rather beefy to handle the torque of human power, and they're less efficient. Here's the wikipedia article:
http://en.wikipedia.org/wiki/Shaft_drive_bicycle

The article mentions that a shaft drive can be a useful alternative in a recumbent, since it doesn't suffer from some of the problems of a long chain line.

[Gerald_G]

This guy claims to be running a hydrolic system of some sort. The last link has a video, but interestingly, you never see him pedal, so I wonder if the system is more still on paper than reality.

...


"Regarding the chain, this version of the bike uses an hydrolic system instead of the traditional chain. I have developed alongside another version which incorporates a chain drive or belt drive, which also works when the bike is folded up. On this hydrolic bike works by oil being pumped inside tubes through the frame of the bike to power the back wheel. This means that the bike doesn't have the oil and grease that comes with chains.

- Dominic Hargreaves, London"

http://www.thelondonpaper.com/thelondonpaper/news/bike-designed-to-be-carried-on-the-tube

http://www.thisislondon.co.uk/standard/article-23727060-details/The+bike+you+can+take+for+a+walk/article.do

http://news.sky.com/skynews/Home/UK-News/Student-Invents-Bicycle-Which-Folds-Into-26-Inch-Wheel-Circumference-For-James-Dyson-Prize/Article/200908115353249?lpos=UK_News_First_Home_Page_Featu re_Teaser_Region_0

[Greenhorn]

But you still are changing the direction of force about 3 times with a shaft drive (. Also, you would need one long shaft to transfer power from the cranks to the rear wheel (unless you do FWD)

I've seen some on TV---they tend to be marketted to the "haven't been on a bike in 20 years" crowd. I don't think you could get an effective spin with a shaft drive.

The technology has been around for quite a while.

[Big Moe]

I was researching using shaft drive for some of my builds but cost was higher than chain drive. The only way I could find to get the drive system was to buy a complete bike. $$$$! Then I would have to cut and lengthen the shaft. 2nd problem was torque. A longer shaft means more chance of twisting unless you make it fatter and heavier. 3rd problem: the shaft has to run under the seat so the seat may be higher than you want. Could redirect the shaft using universals but adds weight and drag and cost. Won't work with the Deltawolf or Marauder.
It may work with some front wheel drives though where chain management can be a problem.

MOE - three wheels and an old crank.

p.s. - If Brad can think of a way to run a shaft drive down the frame tube we could put it in that new Tadpole we're all waiting for!

[Locutus]

Hmmm....
Here's an idea (maybe not a good one but here goes):
What about using the snake drive from a weed whacker? It could run inside the tubing. I wonder if it would be strong enough for use on a bike? I think that they are just a coiled wire (like a spring) that tightens on itself when twisted in the drive direction. It can bend, and I assume in any direction. If an actual weed whacker drive coil is not up to the task, I imagine one could use a larger coil on a bike and run it through some 1 1/2" or 2" round frame tube. Has anyone tried this?

[badcheese]

The wikipedia article says (and I remember reading this sort of thing elsewhere):
Bicycles typically employ more torque (an adult man can easily generate more than 100 ft-lb) but at much lower rotational speed than motorcycles and cars.

That's probably one reason why shaft drive isn't suitable for high-performance bikes, which are likely to be fitted with a strong (human) engine, but might be okay for someone who hasn't been on a bike in 20 years.

I read a review for a shaft drive bike, and the tester said that when he really put the hammer down, the elasticity of the drive shaft was very noticeable.

It's still an interesting concept. Maybe it's just waiting for the right materials to be developed or for an inventor with enough ingenuity to figure out a way around the drawbacks. I loved the shaft drive on my BMW motorcycle. They've spent the better part of 100 years getting it right, and when all the other makers were using chain, BMW never gave up the shaft drive. They don't win a lot of races with their drivetrain, but when it comes to touring, the BMW is bulletproof.

[Steam Monkey]

if it could handle high torque, I'd be all for it.

[greenevegiebeast]

Hmmm....
Here's an idea (maybe not a good one but here goes):
What about using the snake drive from a weed whacker? It could run inside the tubing. I wonder if it would be strong enough for use on a bike? I think that they are just a coiled wire (like a spring) that tightens on itself when twisted in the drive direction. It can bend, and I assume in any direction. If an actual weed whacker drive coil is not up to the task, I imagine one could use a larger coil on a bike and run it through some 1 1/2" or 2" round frame tube. Has anyone tried this?

ive seen a prototype all wheel drive using a flexable shaft drive on the front wheel. i have even seen a two wheel drive motor cycle use a beefed up version

[Gerald_G]

My dad's table saw runs on a bent cable. Much like a speedometer cable, only heavier obviously. I think the outer sheathing is around 3/4".

I think it's a 10 inch Craftsman, which I saw somewhere on the net had a 2.7hp motor. It pulls quite a bit of torque when your ripping 2" or thicker wood.

I read the replacement cables can be had for around $40.00 on ebay.

Part #50 at this sears diagram I believe....

http://www.searspartsdirect.com/partsdirect/retrieveSubComponentPartsAction.action?diagramPage Id=00002&componentDescription=ARBOR%20AND%20BLADE%20ASSEMBL Y&documentId=00012438&modelNumber=113241691&productCategoryId=0744600&brandId=0247&modelName=DELUXE%2010-INCH%20FLEX%20DRIVE%20TABLE%20SAW&backToLink=Return%20to%20Sub%20Components