Comments on: Derailing the Carbon Drivetrain http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/ Pro Cycling News, Commentary and Special Features Fri, 05 Dec 2008 03:14:14 +0000 http://wordpress.org/?v=2.1 By: spokejunky http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2616 spokejunky Wed, 29 Aug 2007 23:28:41 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2616 Yeah, but imagine this carbon drivetrain mounted to a NuVinci: http://www.cyclingnews.com/tech.php?id=/photos/2007/tech/news/01-31/NuVinci_cutaway hub, while riding my white carbon commuter, listening to my mp3 shorts: http://www.pearlizumi.com/product.php?mode=view&product_id=758231 sloshing down my Starbucks with my coffee mug: http://www.somafab.com/morningrush.html all the while emailing my friends on my bike mounted blackberry: http://www.ram-mount.com/index_files/ramb149zaq2.jpg Yeah, but imagine this carbon drivetrain mounted to a NuVinci:

http://www.cyclingnews.com/tech.php?id=/photos/2007/tech/news/01-31/NuVinci_cutaway

hub, while riding my white carbon commuter, listening to my mp3 shorts:

http://www.pearlizumi.com/product.php?mode=view&product_id=758231

sloshing down my Starbucks with my coffee mug:

http://www.somafab.com/morningrush.html

all the while emailing my friends on my bike mounted blackberry:

http://www.ram-mount.com/index_files/ramb149zaq2.jpg

]]> By: Kevin http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2632 Kevin Thu, 30 Aug 2007 16:12:40 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2632 ^^ Sweeeeeet... Now THAT'S how to ride a bike... ^^

Sweeeeeet… Now THAT’S how to ride a bike…

]]> By: gtveloce http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2651 gtveloce Sat, 01 Sep 2007 01:46:41 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2651 Setting aside the carbon marketing spin, I've no problem with people investigating alternative drive chain methods. Although as Phil has pointed out this is hardly new. The Johns Hopkins research (original source article <a href="http://www.jhu.edu/news_info/news/home99/aug99/bike.html" rel="nofollow">here</a> with more pics) doesn't compare belts with chains, and I'm no engineer, but however elegant chains may be they are made from many, many more moving parts than a belt. All of which pose frictional, wear and lubrication challenges. From a practical point of view removing one row of cam-drive chain from a car engine will release 3-5 additional horsepower and allow the engine to rev more freely. Replacing the chain with a belt appears to also release a few extra horses and will definitely reduce maintenance. The chain in my old Alfa is a wonderful, noisy and fiddly thing to adjust, but the belts in modern cars need no adjustment or lubrication, are quieter, last longer and are replaced 'just in case'. They also retain cam timing spec far longer, which keeps the engine within exhaust pollution standards. But there's little in common between a car revving to 8,000 rpm and delivering umpteen kW and a bike rider spinning at 100 rpm. Other than the inevitable chain stretch, the need for lubrication, wear and quite frequent replacement. A belt drive may or may not be more efficient but it will require less maintenance, is simpler and will probably last forever. Combined with hub gears or some other gearing method belts may well have a big future on bikes. Or maybe shaft drive will deliver even greater benefits? Mind you, the UCI will probably ban it anyway. Setting aside the carbon marketing spin, I’ve no problem with people investigating alternative drive chain methods. Although as Phil has pointed out this is hardly new. The Johns Hopkins research (original source article here with more pics) doesn’t compare belts with chains, and I’m no engineer, but however elegant chains may be they are made from many, many more moving parts than a belt. All of which pose frictional, wear and lubrication challenges.

From a practical point of view removing one row of cam-drive chain from a car engine will release 3-5 additional horsepower and allow the engine to rev more freely. Replacing the chain with a belt appears to also release a few extra horses and will definitely reduce maintenance. The chain in my old Alfa is a wonderful, noisy and fiddly thing to adjust, but the belts in modern cars need no adjustment or lubrication, are quieter, last longer and are replaced ‘just in case’. They also retain cam timing spec far longer, which keeps the engine within exhaust pollution standards.

But there’s little in common between a car revving to 8,000 rpm and delivering umpteen kW and a bike rider spinning at 100 rpm. Other than the inevitable chain stretch, the need for lubrication, wear and quite frequent replacement. A belt drive may or may not be more efficient but it will require less maintenance, is simpler and will probably last forever.

Combined with hub gears or some other gearing method belts may well have a big future on bikes. Or maybe shaft drive will deliver even greater benefits? Mind you, the UCI will probably ban it anyway.

]]> By: gtveloce http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2652 gtveloce Sat, 01 Sep 2007 01:50:46 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2652 Of course it wasn't Phil who said that, I'm just losing my mind and confusing my bike bloggers. But I still think belts are interesting ;-) Of course it wasn’t Phil who said that, I’m just losing my mind and confusing my bike bloggers. But I still think belts are interesting ;-)

]]> By: frank scurlock http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2821 frank scurlock Mon, 10 Sep 2007 05:04:41 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-2821 Would dig passing on some "real" information about the belt system. Geez, rough crowd in here. Frank Scurlock Carbon Drive Systems frank@spotbikes.com Would dig passing on some “real” information about the belt system. Geez, rough crowd in here.

Frank Scurlock
Carbon Drive Systems

frank@spotbikes.com

]]> By: Jim http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-7689 Jim Fri, 05 Sep 2008 15:06:45 +0000 http://cyclocosm.com/2007/08/derailing-the-carbon-drivetrain/#comment-7689 Re gtveloce - most engine manufacturers have now gone back to chain drive for cams, mainly for reliability, they seldom snap, belts do this frequently, do not need changing and frictional losses are minimal - certainly not in the 3-5 bhp range you quote. (I worked for Lancia, Lotus and Vauxhall) The Chain cam 2.0 Fords are significantly more powerful than the previous cam belted versions despite near similar architecture, and chains do not suffer the slap that belts can when decelerating rapidly, and in my experience hold cam timing far more accurately than belts, you seldom see chains jump a tooth or two, yet this is common with cam belts. Yes maintaining tension can be fiddly, my duratec V6 needs this nearly every 60,000 miles...but this is far cheaper and quicker than replacing a belt. Drive belts don't work that well on motorbikes, and yes I have ridden both and had a chain snap on a motorbike. For a cycle you would have to make it split somehow to get it inside the frame, or design a completely new drive train outside of the frame. A chain has had 100 years development and refinement, are cheap, and adjusting and lubing must take at least 20 minutes a month... Re gtveloce - most engine manufacturers have now gone back to chain drive for cams, mainly for reliability, they seldom snap, belts do this frequently, do not need changing and frictional losses are minimal - certainly not in the 3-5 bhp range you quote. (I worked for Lancia, Lotus and Vauxhall)

The Chain cam 2.0 Fords are significantly more powerful than the previous cam belted versions despite near similar architecture, and chains do not suffer the slap that belts can when decelerating rapidly, and in my experience hold cam timing far more accurately than belts, you seldom see chains jump a tooth or two, yet this is common with cam belts. Yes maintaining tension can be fiddly, my duratec V6 needs this nearly every 60,000 miles…but this is far cheaper and quicker than replacing a belt.

Drive belts don’t work that well on motorbikes, and yes I have ridden both and had a chain snap on a motorbike. For a cycle you would have to make it split somehow to get it inside the frame, or design a completely new drive train outside of the frame. A chain has had 100 years development and refinement, are cheap, and adjusting and lubing must take at least 20 minutes a month…

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