New bike chain claims to be faster, more durable • Hacker News Board

Re: New bike chain claims to be faster, more durable

#191

Post by jmartinpetersen » Sun, Nov 29, 2020, 7:36 AM UTC

war1025 wrote: post #159

usrusr wrote: post #149

Earlier quoted context omitted.

Internal hubs are amazing for the kind of bike that's always outside and gets maintenance beyond occasional tire pumping about as often as summer olympics are opened. Unfortunately SRAM stopped production of the T3 years ago, it was the perfect drive for a low maintenance, low value practical utility bike, providing the easy 80% of everything you want from bicycle gears for short distance commuting. Derailleur system…

> Derailleur systems receiving a similar lack of maintenance are what turns people into short distance drivers. Funny, I thought it was my three young kids that did that. I always had a mountain bike growing up. Having now transitioned to more of a road bike, the difference in rideability is pretty stark. I guess it could be the derailleur, but I assumed it was the tires and gearset that made it a pain to get places.…

My nine year old isn't responsible enough to care for a derailleur (let alone park his bike instead of throwing it on the ground), but he can bike to school just fine with his internal hub and 15 % energy loss.

Re: New bike chain claims to be faster, more durable

#192

Post by mikewarot » Sun, Nov 29, 2020, 7:48 AM UTC

Chains stretch, thus any sprocket system will inevitably end up concentrating the load on the last link or two of contact.

There are systems that actually could produce less friction, however they can't handle ANY contamination, thus ruling them out.

Your best bet is to look elsewhere. I would try reducing the contact friction as the links engage. To do this, I would recommend using BAM coatings on the chain and sprockets. It has lower friction than Teflon, AND is almost as hard as diamond.

https://en.wikipedia.org/wiki/Aluminium_magnesium_boride

Re: New bike chain claims to be faster, more durable

#193

Post by Kliment » Sun, Nov 29, 2020, 8:48 AM UTC

rorykoehler wrote: post #179

FpUser wrote: post #87

Earlier quoted context omitted.

Some cyclists are indoctrinated to the point that they might actually buy this insanity.

HN is becoming more conservative by the day. Shouldn’t companies/people be applauded for thinking outside of the box and trying to innovate?

Innovation can be good, scamming other people into spending money on things that don't work, not so much. There's a whole lot of the latter masquerading as the former. There's also a whole lot of user/customer/community hostile innovation, like the entire advertising industry.

Re: New bike chain claims to be faster, more durable

#194

Post by NLips » Sun, Nov 29, 2020, 9:09 AM UTC

war1025 wrote: post #159

usrusr wrote: post #149

Earlier quoted context omitted.

Internal hubs are amazing for the kind of bike that's always outside and gets maintenance beyond occasional tire pumping about as often as summer olympics are opened. Unfortunately SRAM stopped production of the T3 years ago, it was the perfect drive for a low maintenance, low value practical utility bike, providing the easy 80% of everything you want from bicycle gears for short distance commuting. Derailleur system…

> Derailleur systems receiving a similar lack of maintenance are what turns people into short distance drivers. Funny, I thought it was my three young kids that did that. I always had a mountain bike growing up. Having now transitioned to more of a road bike, the difference in rideability is pretty stark. I guess it could be the derailleur, but I assumed it was the tires and gearset that made it a pain to get places.…

The only reasons for needing to reinflate every day should be:

1) using latex inner tubes. They’re lighter, but don’t hold air so well. Fine for racing, impractical for normal use

2) a slow puncture

Re: New bike chain claims to be faster, more durable

#195

Post by raverbashing » Sun, Nov 29, 2020, 9:24 AM UTC

jacobolus wrote: post #142

rdiddly wrote: post #91

Earlier quoted context omitted.

I like how it can mean either 'confused' or 'unimpressed' which in certain situations can almost be opposites of each other. But both apply to me with this chain system!

Nonplussed means “so confused that you are completely paralyzed”. Think deer stopped in headlights. Rough synonyms: confounded, flummoxed, bewildered, perplexed, stunned, shocked, dumbfounded, flabbergasted, thunderstruck. Using nonplussed to mean “unimpressed” or “apathetic” will leave listeners both unimpressed and confused.

> NOTE: The use of nonplussed to mean "unimpressed" is an Americanism that has become increasingly common in recent decades and now appears frequently in published writing. It apparently arose from confusion over the meaning of nonplussed in ambiguous contexts, and it continues to be widely regarded as an error.

https://www.merriam-webster.com/dictionary/nonplussed

My observation: "continues to be regarded as an error" is a bit of a "that's not how linguistics work" thing

Re: New bike chain claims to be faster, more durable

#196

Post by carlob » Sun, Nov 29, 2020, 9:26 AM UTC

colechristensen wrote: post #138

carlob wrote: post #19

Earlier quoted context omitted.

Given a conventional chain can be up to 98% efficient then the maximum increase in efficiency is 1/.98 - 1 = 2.04%

A percentage of a percentage is an odd way to express a change, and at that picking the non-loss side as basis. One could say increasing efficiency by 1% equivalent to reducing existing losses by 50%, both of those are reasonable bases, making it a percentage of the existing efficiency feels off.

I disagree: my basis makes it easier to answer the question of how much faster can you go by exerting the same power. The point being that when you are already close to maximal efficiency the gains are very marginal.

Re: New bike chain claims to be faster, more durable

#197

Post by jacquesm » Sun, Nov 29, 2020, 9:31 AM UTC

rconti wrote: post #123

rdiddly wrote: post #66

I'll tell ya what I see: no rollers. Pins rubbing (wearing) both sides of the tooth. Including the back side, which will never exert any forward longitudinal force on a chain unless it's made of magnets. I also see a highly suspect FEA diagram on the right, where teeth not even engaged still show non-zero stresses (lighter blue, not the darkest blue), indicating that the color/stress scale has been changed compared t…

I don't know anything about FEA, but in reading this article and thinking it through, was the first time it hit me how bad a conventional chain and sprocket is. On a brand-new set with perfect tolerances, you might be able to use many of the front side of many of the teeth, but as SOON as the chain begins to stretch (wear) even fractionally, most of the stress goes to the 'first' teeth in any given power stroke, and…

A chain is an extremely efficient way of transferring power. A similar arrangement made with gears would be much less efficient (even if it could be made much more durable, but not at the same total weight).

Re: New bike chain claims to be faster, more durable

#198

Post by jacquesm » Sun, Nov 29, 2020, 9:33 AM UTC

calvinmorrison wrote: post #154

dharmab wrote: post #147

Earlier quoted context omitted.

Tangent: BMW has developed a new diamond-coated chain for motorcycles which they claim requires no regular maintenance. (Motorcycle chains, which are external and near the ground, have to be cleaned and re-lubricated every 300-500 miles for maximum life.) https://www.bmwblog.com/2020/08/27/m-endurance-motorbike-cha...

Another point: BMW Motorrad has used driveshafts on their bikes since the 80s. In a conventional setup much like a automobile. The only real majntaining is to lube the end gear which sits in a kind of differential housing (there's no diff, but imagine how a car's driveshaft connects to the rear axle). My bike (a k75) has it and well it's pretty cool!

Since the 80's? Much further back: 1923 to be precise.

Re: New bike chain claims to be faster, more durable

#199

Post by jacquesm » Sun, Nov 29, 2020, 9:36 AM UTC

teva wrote: post #144

rconti wrote: post #125

Earlier quoted context omitted.

Oh god. I have a Ghost commuter bike with belt drive (came with Continental, but it broke and couldn't be replaced, so it was swapped to gates). Not only is a it a huge pain in the ass to carry two identical heavy wrenches in case you have to remove the wheel+belt in the field, and tension is hard to get right even at home, but of course the cable is extremely hard to remove the first handful of times (and which gear…

Do you know you don't have to remove the wheel to repair a puncture ? Remove one side of the tire from the rim and pull the inner tube, then patch it.

Indeed. The only time you remove the wheel is to replace the tires.

Re: New bike chain claims to be faster, more durable

#200

Post by jacquesm » Sun, Nov 29, 2020, 9:37 AM UTC

mpol wrote: post #67

lostlogin wrote: post #26

Earlier quoted context omitted.

Internal hubs are amazing and so great to use, until you get a puncture. It’s such a nightmare and I went through so many of those dumb proprietary nuts that strip so easily. Bikes like the Cannondale Bad Boy have got me thinking, what if the single fork was at the rear? Then you could have an internal hub and change the tube without the extra suffering. Yes, the loading at the read would be significantly greater, bu…

I don't think internal hubs are amazing :) Derailer systems only absord energy in the chain and bearings, and a well maintained system can maybe lose 1.5% of energy. Internal hub gearing can lose around 15% energy. The shop keeper won't tell you this, he just wants to sell you a bike. If he starts talking difficult things, buyers might just go to the next shop to buy what they had already chosen.

The only internal geared hubs that lose 15% of energy are the ones that are constant variable ratio drives. The rest of them are extremely good and lose < 3% power, on par with a derailleur system that has seen regular maintenance, a bit worse than a derailleur in perfect (new!) shape.