Hidden motors for road bikes • Hacker News Board

Re: Hidden motors for road bikes

#101

Post by impy » Tue, Mar 08, 2016, 10:40 PM UTC

nkurz wrote: post #87

Someone1234 wrote: post #72

Earlier quoted context omitted.

It literally says she was riding it. It doesn't say she is going to ride it.

I appreciate your quest for accuracy, but I think you are misinterpreting the material you quoted: "After one lap of the world championships, UCI took Femke’s bike in the pit area and tested it with some sort of tablet,” said Sporza journalist Maarten Vangramberen." I think it means "they took Femke's bike [that was] in the pit area", and not "they took Femke's bike in[to] the pit area". As your first quote says, thi…

I'm Belgian (Mother tongue Dutch) so for clatification here is the translation of that quote:

"After one lap on the WC, the UCI checked the bike of Femke at the pit area with a kind of tablet. The bike was immediately sealed and taken away"

While that source doesn't specifically say who took the bike into the pit area, other sources state that it was taken into the pit area by mistake (probably her entourage) and that it wasn't the UCI who took the bike into the ICU.

http://www.nieuwsblad.be/cnt/dmf20160130_02100012 [dutch]

So in short, it _isn't known_ if she used the bike in the WC, but the UCI _alleges_ that she did.

Re: Hidden motors for road bikes

#102

Post by nkurz » Tue, Mar 08, 2016, 10:49 PM UTC

impy wrote: post #101

nkurz wrote: post #87

Earlier quoted context omitted.

I appreciate your quest for accuracy, but I think you are misinterpreting the material you quoted: "After one lap of the world championships, UCI took Femke’s bike in the pit area and tested it with some sort of tablet,” said Sporza journalist Maarten Vangramberen." I think it means "they took Femke's bike [that was] in the pit area", and not "they took Femke's bike in[to] the pit area". As your first quote says, thi…

I'm Belgian (Mother tongue Dutch) so for clatification here is the translation of that quote: "After one lap on the WC, the UCI checked the bike of Femke at the pit area with a kind of tablet. The bike was immediately sealed and taken away" While that source doesn't specifically say who took the bike into the pit area, other sources state that it was taken into the pit area by mistake (probably her entourage) and tha…

Thanks. Part of the issue is that there is a distinction between "ride" and "use". By the UCI's definition, putting the bike in the pit is "use" even though she may not have ridden it during that race. Do you interpret the UCI's claim to be that she started with the motorized bike, rode it part of the way through the lap, and then switched to a legal bike?

Re: Hidden motors for road bikes

#103

Post by JoeAltmaier » Tue, Mar 08, 2016, 10:49 PM UTC

pmontra wrote: post #51

This is another method: wheel accelerated by induction, no gears, no noise. http://www.cyclingnews.com/news/electromagnetic-wheels-are-t...

and an "automatic transmission" that engaged when on a hill or sensed pedal tension could eliminate the switch! Then it would be truly invisible.

Re: Hidden motors for road bikes

#104

Post by sliverstorm » Tue, Mar 08, 2016, 11:05 PM UTC

jdietrich wrote: post #96

sliverstorm wrote: post #82

Earlier quoted context omitted.

The same thing has been said about Formula 1- the cars are power-limited, minimum-weight-limited, and so forth. But even a cursory look at racing history explains why. Group B Rally springs to mind. More power & lighter weight aren't really going to make racing that much more interesting, just more deadly. FIA has tried to shift innovation to other aspects, e.g. ruling that an engine has to last at least two race wee…

All frames and wheels used in UCI-sanctioned races must pass UCI safety tests. The weight limit was not introduced for safety reasons but as a result of the Lugano Charter, which stated that technological development was inherently antithetical to the sport of cycling. C.f. the hour record. Until recently, the rules essentially stated "the hour record must be attempted on a replica of Eddy Merckx's bike circa 1972".…

Right, I'm not saying it's specifically about safety, rather that a battle of technology was decided for some reason to be worse than the added marginal excitement of lighter bikes. In F1 that reason was (originally) safety, in bicycling it's something else.

Re: Hidden motors for road bikes

#105

Post by impy » Tue, Mar 08, 2016, 11:05 PM UTC

nkurz wrote: post #87

Someone1234 wrote: post #72

Earlier quoted context omitted.

It literally says she was riding it. It doesn't say she is going to ride it.

I appreciate your quest for accuracy, but I think you are misinterpreting the material you quoted: "After one lap of the world championships, UCI took Femke’s bike in the pit area and tested it with some sort of tablet,” said Sporza journalist Maarten Vangramberen." I think it means "they took Femke's bike [that was] in the pit area", and not "they took Femke's bike in[to] the pit area". As your first quote says, thi…

To reply to the following quoted message: "Thanks. Part of the issue is that there is a distinction between "ride" and "use". By the UCI's definition, putting the bike in the pit is "use" even though she may not have ridden it during that race. Do you interpret the UCI's claim to be that she started with the motorized bike, rode it part of the way through the lap, and then switched to a legal bike?"

The UCI never made any claim that she rode it, and I don't think they will do so either. My interpretation is that they find that a moot point and simply find the uncovering of a motorized bike to be unacceptable.

Re: Hidden motors for road bikes

#106

Post by ansible » Tue, Mar 08, 2016, 11:10 PM UTC

orik wrote: post #5

I remember a Kickstarter that was popular that had a bicycle wheel with a motor in it that you could fit most bikes. I'd be far more interested in a solution like this for a daily commute, seems very elegant.

I have previously used an e-bike for commuting to work. The goals were to get to work less sweaty and more quickly.

It had its ups and downs. I certainly wasn't fresh as a daisy upon arriving at work, even with the e-bike's help.

The model I chose was rather longer and heavier than a regular bike, and that was a definite inconvenience. Going up stairs, storage, etc. And that's not getting into the mechanical reliability issues I had (Chinese off-brand import).

It was an interesting experiment, but I wouldn't do it again. You'll need to carefully consider all the factors before choosing something like this.

Re: Hidden motors for road bikes

#107

Post by outericky » Tue, Mar 08, 2016, 11:18 PM UTC

TheTon wrote: post #50

dabeeeenster wrote: post #6

There are two videos on Youtube that have been regarded by bike fans as suspicous. I will let HN readers make their own minds up! https://youtu.be/8Nd13ARuvVE?t=3m35s and https://www.youtube.com/watch?v=ideiS-6gBAc I would love to hear smart people's thoughts!

Here's Cancellara winning Strade Bianche this past Sunday: https://youtu.be/X8YJH23dIAc I think it looks pretty similar in terms of terrain, style, and effort, and it was a win over a tough field. With all the concern about mechanical doping, they checked his bike and there was no motor in it. Of course there's no way to know what happened in 2010 for sure, but he has shown he doesn't need a motor.

Yes, Fabian is a beast. While those older videos seem intriguing, he is definitely very talented. But like Lance showed us, you never can tell.

Re: Hidden motors for road bikes

#108

Post by mrow84 » Tue, Mar 08, 2016, 11:26 PM UTC

pge wrote: post #86

sharpercoder wrote: post #55

Earlier quoted context omitted.

The second video is very suspicious. Cycle shoes attach to the pedal by a click system. When you fall, you usually detach from the pedal by one foot. The other one detaches very dependent on the situation, or not at all. You see this happening: Hesjedal falls, one foot clicks out. His second foot stays clicked in. After Hesjedal falls, you clearly see the kinetic energy stopped of the back part of the bicycle at one…

I think what creates the confusion in the hesjedal video is that he is on a steep slope, but the angle of the video obscures that. That explains both the spinning wheel (caused by the bike slipping down the slope a bit while the wheel was touching the ground, causing the wheel to spin) and his somewhat awkward motion when he stands up.

What makes you say he was on a steep slope? Nothing about the background suggests that this is so (for example, all of the cars in the car park below). Also, if he was on a hill, the bike would have to have somehow had enough angular momentum to spin back up hill, as it appears to do in the later part of the clip.

Re: Hidden motors for road bikes

#109

Post by syassami » Tue, Mar 08, 2016, 11:27 PM UTC

dabeeeenster wrote: post #6

There are two videos on Youtube that have been regarded by bike fans as suspicous. I will let HN readers make their own minds up! https://youtu.be/8Nd13ARuvVE?t=3m35s and https://www.youtube.com/watch?v=ideiS-6gBAc I would love to hear smart people's thoughts!

re: Hesjedal https://www.youtube.com/watch?v=RngO2YlFYCA

Re: Hidden motors for road bikes

#110

Post by bch » Tue, Mar 08, 2016, 11:45 PM UTC

bch wrote: post #99

laxatives wrote: post #90

Earlier quoted context omitted.

A light wheel with low resistance, like a highly tuned performance bike, can hold energy for a long time. My entry level road bike will spin for well over a minute with a light tug, maybe equivalent to 5-10 mph. He's going well over 30 mph in that video. I'm not arguing whether this may or may not be an assisted bike, but what you're saying about a wheel is patently wrong.

Are you talking about light resistance in the bearings? I think you are (forgive me if I'm wrong), but that doesn't matter. That is not an example of the wheel "doing work". That wheel in the video looked stopped at the end of the crash, and even if it wasn't stopped, the video looks really awkward. Sure, his crash started at 30mph, but ended at 0, and his wheel looks to be firmly placed on the ground, immobile. For…

This is not my area of expertise, but to get things started, I went to a site[0] and looked up some formulas and specs, and came up with:

outside circumference of wheel ~2200mm (700c wheel w/ tire) 30 mph == 0.5 mpm (Miles per minute). 0.5 mile == 804500mm a 2200mm circumference will need to roll ~365.68 times to cover that distance. If that distance is covered in 1 minute, that means 365.68 rotations per minute.

This: Ef = 1/2 I ω2

wants I and ω.

I = m r squared.

m == 700g (this isn't properly distributed here, but it's a start)

r (at 2200mm circumference) == 350.14

0.7kg * ((350.14mm)(0.001m/mm))^2 == 0.7 * .122598019 == 0.085818613 kg/m2

1 rad/s = 9.55 r/min (rpm) 365rpm == 38.29 rad/s

so if this is at all correct:

Ef = 0.5 * 0.085818613 * 38.29^2 == 0.5 * 0.085818613 * 1466.1241 == 62.910368373 Joules

1J/s == 1watt. So with this fudgey math above (assuming it's even correct) we're working w/ ~60 watts(max, for an instance, then decreasing). I don't even know if that's enough to spin a bicycle around like was shown. I hope somebody that actually understands this field can chime in and fix my bad assumptions (which I think err to supporting this was strictly the spinning wheel (not a motor)) and what this means. I'll do practical tests later when I have my bike.

[0] http://www.engineeringtoolbox.com/flywheel-energy-d_945.html