Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Driven – A bicycle drivechain concept without derailleurs and chains

ceramicspeed.com

Post reply on HN
Print view View original

11–20 of 49 posts

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#11

Post by Xylakant »

acomjean wrote: post #10

chains are a pain. But belt drives have been around for 10 years now and you hardly see them. Chains are the most complex part of the bike with the most moving parts. You have to lubricate them, they stretch.. But they work well in all variety of conditions (even rusty and squeaky) and are fairly cheap. Sheldon Brown's (RIP) bike pages have some good articles on the good old chain. old school html ahead: https://www.…

Belt drives are comparatively expensive and don’t work with derailleur gears. Internal gears, especially cheap systems, still cannot offer as many gears as a derailleur. Belts also need to be pretty tight and thus cannot be used on most bicycles with a rear suspension as the distance between the pedals and the sprocket changes under load. So many people opt against belts.

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#13

Post by rhinoceraptor »

acomjean wrote: post #10

chains are a pain. But belt drives have been around for 10 years now and you hardly see them. Chains are the most complex part of the bike with the most moving parts. You have to lubricate them, they stretch.. But they work well in all variety of conditions (even rusty and squeaky) and are fairly cheap. Sheldon Brown's (RIP) bike pages have some good articles on the good old chain. old school html ahead: https://www.…

Chains are inexpensive, very efficient, and easy to replace or service. There's a reason bicycles have used them for over 100 years.

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#14

Post by joerickard »

jtms wrote: post #7

Would this system be legal in professional competition cycling?

No, this violates current UCI rules.

"The front wheel shall be steerable; the rear wheel shall be driven through a system comprising pedals and a chain"

However, the rules do change and have been recently (like the removal of the 3:1 restriction).

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#16

Post by jandrese »

falcolas wrote: post #6
AstralStorm wrote: post #2

As far as I'm aware chain was introduced to allow for light weight while keeping vibration resistance. Can't this pulley system be trimmed down even further to one bar transmission?

Based on my experience with motorcycles, chains are better than shafts for transmitting torque. Shafts tend to twist over their length in high torque settings, whereas chains just "pull" with minimal stretching. Specific to this product, how the hell would you keep the 20-30 "gear" bearings on the shaft clean and operating smoothly in anything but lab conditions?

I have concerns about the longevity of those itty bitty ceramic bearings in real world conditions where you're hitting bumps and cracks in the road while under load from pedaling.

Also, literally every part of that page screams "expensive AF" including the part where they don't talk about the price.

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#17

Post by AmVess »

falcolas wrote: post #6
AstralStorm wrote: post #2

As far as I'm aware chain was introduced to allow for light weight while keeping vibration resistance. Can't this pulley system be trimmed down even further to one bar transmission?

Based on my experience with motorcycles, chains are better than shafts for transmitting torque. Shafts tend to twist over their length in high torque settings, whereas chains just "pull" with minimal stretching. Specific to this product, how the hell would you keep the 20-30 "gear" bearings on the shaft clean and operating smoothly in anything but lab conditions?

You can seal the bearings, but that cuts efficiency. That's not the only problem, though. The interface between the bearing and the bearing sprocket will make it rather unusable in very dirty conditions.

Their setup seems like an answer to a question no one was asking.

Re: Driven – A bicycle drivechain concept without derailleurs and chains

#18

Post by simongr3dal »

falcolas wrote: post #6
AstralStorm wrote: post #2

As far as I'm aware chain was introduced to allow for light weight while keeping vibration resistance. Can't this pulley system be trimmed down even further to one bar transmission?

Based on my experience with motorcycles, chains are better than shafts for transmitting torque. Shafts tend to twist over their length in high torque settings, whereas chains just "pull" with minimal stretching. Specific to this product, how the hell would you keep the 20-30 "gear" bearings on the shaft clean and operating smoothly in anything but lab conditions?

I was looking at them and scratching my head too.

I hope these images are just for show, and that the real product will use shielded bearings or else they are going to get crunchy and destroyed fast.

Post reply on HN