Author Topic: Newton's Laws and perpetual motion engines  (Read 331 times)

Andre Jute

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Newton's Laws and perpetual motion engines
« on: January 31, 2019, 03:35:50 PM »
(Reminds me of the person who asked me if the dynahub on the front wheel charged my e-bike battery ;)  )

You get used to it. Even before my bike was electrified, people would ask whether the Rohloff was an electric motor. When I had a waterbottle-shaped battery on the downtube to drive a front hub motor, they wanted to know if the front hub was a generator for my phone. And now that the battery is hidden in a rackpack and the hub dynamo is back on the bike because I have a centre motor, they wonder if the hub dynamo drives the motor.

I suppress the instinct to say something about Newton's Laws and perpetual motion engines.

Whole lotta folk aren't ready for the wonderful world of bicycling yet.

Mike Ayling

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Re: Newton's Laws and perpetual motion engines
« Reply #1 on: February 03, 2019, 10:59:28 PM »
We have been asked on several occasions if the Rohloff hub on our tandem was an electric motor.

Mike

Andre Jute

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Re: Newton's Laws and perpetual motion engines
« Reply #2 on: February 04, 2019, 06:16:21 AM »
We have been asked on several occasions if the Rohloff hub on our tandem was an electric motor.

"Of course not. Nobody yet makes an electric motor that runs the other way round for application Down Under."

mickeg

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Re: Newton's Laws and perpetual motion engines
« Reply #3 on: February 04, 2019, 07:17:33 PM »
Bold text added for emphasis:

We have been asked on several occasions if the Rohloff hub on our tandem was an electric motor.

"Of course not. Nobody yet makes an electric motor that runs the other way round for application Down Under."

I fail to see the connection to Coriolis force in e-bikes or in internally geared hubs.

Andre Jute

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Re: Newton's Laws and perpetual motion engines
« Reply #4 on: February 04, 2019, 07:51:20 PM »
Bold text added for emphasis:
We have been asked on several occasions if the Rohloff hub on our tandem was an electric motor.

"Of course not. Nobody yet makes an electric motor that runs the other way round for application Down Under."

I fail to see the connection to Coriolis force in e-bikes or in internally geared hubs.

There isn't one. It's a hub-gearbox cyclist's version of the well-known (in Oz anyway) crack about bathtub water swirling anti-clockwise down the plughole in the Southern Hemisphere compared to clockwise in the Northern Hemisphere.

jags

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Re: Newton's Laws and perpetual motion engines
« Reply #5 on: February 05, 2019, 12:41:34 PM »
 ??? huh  ::) ::)

why would a fella care what others think if it's a motor or not each to there own.
and you know that old saying when someone is being a nosy bugger if your going to tell a lie tell them a god one. ;) ;)

mickeg

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Re: Newton's Laws and perpetual motion engines
« Reply #6 on: February 05, 2019, 05:56:57 PM »
I took my truck to a shop to have it worked on.  Put my Nomad on the bike rack on back so I had it to ride home from teh shop.  The shop owner looked at my bike and asked where the battery was, then a long pause and he asked if the Rohloff was a motor or something else.  Since he is a mechanical engineer by training and worked as an engineer before taking over the family auto repair business, I assumed he would be interested so I explained how it had 14 gears, etc.  He was amazed.  He also was not familiar with dynohubs, so had to explain that too.  And the S&S couplings.  He got the full tour.


Andre Jute

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Re: Newton's Laws and perpetual motion engines
« Reply #7 on: February 05, 2019, 11:25:52 PM »
Since he is a mechanical engineer by training and worked as an engineer before taking over the family auto repair business, I assumed he would be interested so I explained how it had 14 gears, etc.  He was amazed.  He also was not familiar with dynohubs, so had to explain that too.  And the S&S couplings.  He got the full tour.

Buy a Rohloff, become an unpaid hub-gear educator and prosetylizer.

John Saxby

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Re: Newton's Laws and perpetual motion engines
« Reply #8 on: February 05, 2019, 11:29:38 PM »
Appearances can be deceiving...

On our annual spring charity run a couple of years ago, I passed a guy stopped at the roadside, who had a fatbike fitted with what looked to me like a Rohloff -- it was black enamel, and about the size of a Rohloff, with a single sprocket & chain ring, and no cassette at the rear.  So, I wheeled around to ask him if he'd fitted a Rohloff to his bike. "No," he said, "that's an electric motor."  He was moving on, so I didn't look  closely at the device, nor ask him any more questions.

There may well be more of these hubs around Eastern Ontario than Rohloffs, so perhaps it's not so unusual for people to think that our bikes are e-bikes.

(Anto, maybe you could get a used Rohloff, and lotsa people would think you had an e-bike   ;)  ;D  )


mickeg

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Re: Newton's Laws and perpetual motion engines
« Reply #9 on: February 05, 2019, 11:55:12 PM »
In USA, Rohloff hubs are quite rare.  I have seen one other on a new Tandem that a bike shop was setting up for the new owner.  I know some people that also have a couple other hubs, but have not seen the hubs.  And as of a few months ago according to CrazyGuyOnABike there are two new Thorn Ravens a few miles from my home but I have not seen them yet.

Thats all the Rohloffs that I know of in a community of about a third of a million people.  And to reiterate, other than mine I have only seen one other with my eyes.  A neighbor is a bike mechanic and mine is the only one he has seen.

Based on that, I am surprised that more people do not ask me where the battery is.

jags

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Re: Newton's Laws and perpetual motion engines
« Reply #10 on: February 05, 2019, 11:55:46 PM »
wishful thinking john  ;D

Danneaux

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Re: Newton's Laws and perpetual motion engines
« Reply #11 on: February 06, 2019, 12:08:30 AM »
I live in a town with two bicycle factories. One fits Rohloff and Pinion gearboxes to a large number of its offerings, the others just a few. Even so, I rarely see another Rohloff locally, as these companies sell most of their stock outside the area.

More often, the birds (Rohloff's mascot is the raven) fly away rather than nest close to home.

Best,

Dan.

energyman

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Re: Newton's Laws and perpetual motion engines
« Reply #12 on: February 06, 2019, 04:07:50 PM »
Talking of Pinions, anybody got one and what are they like to ride ?

onmybike

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Re: Newton's Laws and perpetual motion engines
« Reply #13 on: February 07, 2019, 12:13:05 AM »
Talking of Pinions, anybody got one and what are they like to ride ?

I recently hosted a German tourist riding a new Pinion bike. He'd previously toured on a Rohloff bike. I asked him how he found the Pinion and his initial response was the correct one; "ask me in three years". He then elaborated based on the few months he'd been using the Pinion with comment that he liked the extra gear range (he had the 18 speed version) and preferred the feel of the bike when it was unladen as the lighter back wheel didn't feel as 'thumpy' on rough tracks. Apart from that he thought he probably should have stuck to chain drive rather than belt, if only to keep spares commonality with his wife's Rohloff bike and save himself from having to carry a spare belt because of the obvious scarcity of replacements in rural Australian bike shops.

I can understand his 'ask me in three years' comment. As much as I appreciated my Rohloff from the get-go, its best qualities (reliability and low maintenance) get further emphasized with each passing year. Hell, after 10 years and 55,000km+ mine is about to receive its first ever cable change and even then only because I have to replace the twist grip rubber as it's been worn down to a sticky rounded nub, and figured I may as well do the cables at the same time.

Andre Jute

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Re: Newton's Laws and perpetual motion engines
« Reply #14 on: February 07, 2019, 01:38:30 AM »
I live in a town with two bicycle factories. One fits Rohloff and Pinion gearboxes to a large number of its offerings, the others just a few.

Dan, do you know the price difference between a Rohloff and a Pinion gearbox on roughly the same frame by function from either maker?

Do you know which gearbox do they sell more of?