Hidden motors for road bikes • Hacker News Board

Re: Hidden motors for road bikes

#91

Post by semi-extrinsic » Tue, Mar 08, 2016, 10:09 PM UTC

arprocter wrote: post #56

bliti wrote: post #34

I'd never would have thought to use a worm ring geared motor hidden in the frame. Reminds me of how nitrous bottles are hidden inside roll cages and cooling systems in racing cars. Cheating is an art of itself.

https://en.wikipedia.org/wiki/Toyota_Celica_GT-Four#ST205_.2... "During the 1995 World Rally Championship season, Toyota was caught using illegal turbo restrictors at the Rally Catalunya and were given a one-year ban by the FIA. FIA president Max Mosley called the illegal turbo restrictor "the most sophisticated device I've ever seen in 30 years of motor sports.""

See also the "McLaren Snorkel"[1] in Formula 1. Not actually cheating, but it was also a brilliant piee of engineering, and it was banned pretty quickly.

TLDR: in F1 you're not allowed to have a variable rear spoiler (i.e. high downforce in corners but low drag on straights). But the rules only specified hydraulic or mechanical devices were banned. McLaren engineers came up with the idea to stall the rear spoiler on the straights using a flexible tube which led air from the front spoiler to the rear. The driver would use his knee inside the cockpit to block or open the flow in the hose, so no mechanical or hydraulic mechanism was used.

[1] https://scarbsf1.wordpress.com/2010/03/11/235/

Re: Hidden motors for road bikes

#92

Post by VLM » Tue, Mar 08, 2016, 10:15 PM UTC

njharman wrote: post #28

Don't bicycle races have inspections? Safety or otherwise? I'm more familiar with motorcycle and car races where there are long lists of "class", safety, and weight requirements. Would be trivial to detect either by weight or looking down seat tube.

Various theoretical methods include moment of inertia in various axis and simple center of gravity measurements.

Hmm... moment of inertia and CG measurements indicate that dude's crank is a couple kilos heavier than everyone else crank.

If carbon fiber is RF transparent enough then low level microwave radiation tends to react interestingly with semiconductor junctions.

After EMP sensitive gear (if any) were removed from the bike, old fashioned microwave RF zorching or fancier "real EMP" could make the issue moot. Once the electronics and wiring are blown, a motor is just an expensive piece of ballast.

The last technological way I can think of is a careful magnetic analysis of the bike.

I would imagine a very permanent long term solution would be a careful stress analysis and small holes drilled into all frames for a COTS borehole camera.

Re: Hidden motors for road bikes

#93

Post by revelation » Tue, Mar 08, 2016, 10:19 PM UTC

alistairSH wrote: post #77

peter303 wrote: post #48

I read a good rider can sustain 250 watts for hours and peak at twice that. (power is weight dependent) So if you have an effective 100 watt assist, that can be helpful.

250 watts is an output a fairly average amateur racer will produce at threshold (where threshold is their one-hour max sustained effort). The pros are significantly higher than that (estimated 350W or more for the latest batch of 1-hour records). But, an extra 100 watts for even a few seconds can make a significant difference. In cycling, staying in the draft is a major factor. If that short burst of assistance helps…

The one hour record is actually about 470W from Wiggins.

(Though not a record of power for a single hour, just distance ridden on a track in one hour. But it ends up measuring more or less the same.)

Re: Hidden motors for road bikes

#94

Post by kazinator » Tue, Mar 08, 2016, 10:26 PM UTC

davidw wrote: post #37

buro9 wrote: post #35

Earlier quoted context omitted.

> Here's the thing. No one to date has actually been caught using one. Actually 6 weeks ago Femke Van den Driessche was caught with a motor in the Cyclocross World Championships. The UCI are pushing for a lifetime ban and a very hefty fine for Van den Driessche, so there is a significant disincentive: http://cyclingtips.com/2016/03/uci-seeking-lifetime-ban-and-...

> Actually 6 weeks ago Femke Van den Driessche was caught with a motor in the Cyclocross World Championships. He discussed that: she was not caught using one.

Just like you're not driving if you're drunk, and only sit behind the wheel of your car. In some United States, you can be charged with DUI.

Re: Hidden motors for road bikes

#95

Post by brudgers » Tue, Mar 08, 2016, 10:27 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.

I remember watching Miguel Indurain blow past great climbers without leaving the saddle during the 1990's. His resting heart rate was recorded at 28 beats per minute. The best cyclists are outliers among outliers.

Re: Hidden motors for road bikes

#96

Post by jdietrich » Tue, Mar 08, 2016, 10:29 PM UTC

sliverstorm wrote: post #82

whistlerbrk wrote: post #49

A few other commenters have touched on it, but I'll go ahead and say it -- the UCI really needs to drop the minimum weight limit which I think will be an effective disincentive (along with more draconian life time bans). They are artificially holding back the state of the art in a way that promotes cheating (if you need to add weight to your bike to make the limit, why not a motor instead of dead weight.)

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". Rules for the hour record banned streamlined helmets, aero bars, disk wheels and frames with non-round tubing. These rules were introduced directly as a reaction to the battle of engineering an ingenuity between Obree and Boardman.

http://oldsite.uci.ch/imgarchive/Road/Equipment/The%20Lugano...

Re: Hidden motors for road bikes

#97

Post by kazinator » Tue, Mar 08, 2016, 10:33 PM UTC

bbarn wrote: post #15

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 the thing. No one to date has actually been caught using one. The banned woman was caught having one, on a spare bike in the pit. She claims it's owned by a friend (who corroborated) and that her mechanics mistakenly put it in the pit, etc.. it's a pretty shaky story, but the fact remains they have never actually caught someone using one during a race. There's a large number of people who think it just wouldn'…

There is no forced cadence. The motor is not fixed at a particular RPM; if the motor were unloaded, it would spin a lot faster than it does. It supplies a certain amount of power, and the bike hits a certain ground speed, and through the gear ratio, that determines the motor's speed.

If you only want to go that fast, then you don't have to crank the pedals, and it's awkward. However, you can crank the pedals to go even faster.

That's the point of using the motor. You + motor is faster than you alone or motor alone. Or: you + motor requires a lot less effort on your part to maintain a certain speed than you alone. Suppose that you can go 30 mph, but with great difficulty and not for very long. Suppose that a given motor by itself can go 20 mph. If you use that motor and your own muscles together, you can go 30 mph with a lot less effort, and sustain it a lot longer. The cranking of your pedals and cadence will be natural; you're cranking 50% faster than what the motor can do by itself. It will be like cycling in the slip-stream of a truck, or down a slight downgrade. To the spectators, you will just look like a strong cyclist.

About the 100W, almost any amount of cheat torque can make the difference between placing N-th and N+1st. Every second counts.

Even a 2.5W power boost could be a game changer. If your muscles put out 250W, 2.5W is 1% more, which is significant. It's about 36 seconds shaved off a one hour haul. The game has changed from a neck-and-neck race to the front runner having a 36 second lead.

A tiny, light-weight motor of just a few watts that would be useless in a commuting bike used by someone who is out of shape and cannot climb hills could nevertheless win trophies for a cheater.

One minute you're racing just beyond your lactate threshold. Flip a concealed switch, and a tiny power boost drops you within your threshold.

Re: Hidden motors for road bikes

#98

Post by recursive » Tue, Mar 08, 2016, 10:33 PM UTC

jcoffland wrote: post #20

jzwinck wrote: post #8

Earlier quoted context omitted.

Easier than that, simply X-Ray the bikes at the finish line. Don't even announce which races will do it, that way partial enforcement can work.

I'm sure all these health conscious road bikers will love being blasted with X-rays. Millimeter waves sound so much more friendly.

I don't think pro cyclists are particularly health conscious. They're performance conscious, which is a very different thing.

Re: Hidden motors for road bikes

#99

Post by bch » Tue, Mar 08, 2016, 10:35 PM UTC

laxatives wrote: post #90

bch wrote: post #66

Earlier quoted context omitted.

Rotating a light wheel that takes less energy, too, but that means too that wheel isn't a big power store. A light weight wheel is precisely the opposite of a flywheel; it should stop nearly immediately because it's _not_ a heavy rotating mass with lots of stored energy. If we're talking about Ryder Hesjedals video, he's still attached (right foot) to his bike, everything appears to be static (he's not sliding anymor…

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 sake of understanding though, it'd be interesting to know what power could be stored in a theoretical wheel that could stand in for Ryder's.

Eg. a pair of Mavic Cosmic Carbone Ultimate[0] apparently weight 1185g. The rear will weight a bit more (because hub/drive/gears), although that weight will be at the center of the spin, so I _guess_ not contribute significantly to the velocity of the wheel (angular momentum). So, how many watts are stored in a ~700g wheel that was moving at 30mph? That will determine the ability to do work (like spin a bicycle on the pavement).

[0] http://www.bikyle.com/MavicRoadWheels.asp

edit: expand point, suggest exercise

Re: Hidden motors for road bikes

#100

Post by Retric » Tue, Mar 08, 2016, 10:38 PM UTC

bch wrote: post #66

Retric wrote: post #44

Earlier quoted context omitted.

Rotating a light bike like that takes a lot less energy than you might think. Kinetic energy is also V^2 and the out edge of that wheel is probably doing 30+mph as it's down hill, so IMO it's actually believable. Granted, it would be much easier to get a motor to do the same thing.

Rotating a light wheel that takes less energy, too, but that means too that wheel isn't a big power store. A light weight wheel is precisely the opposite of a flywheel; it should stop nearly immediately because it's _not_ a heavy rotating mass with lots of stored energy. If we're talking about Ryder Hesjedals video, he's still attached (right foot) to his bike, everything appears to be static (he's not sliding anymor…

Your assuming the wheel stopped rotating while it was lightly touching the side of the road. Visually you don't see the spokes on the low wheel, but you do on the vertical one, so it was still rotating.

If you think about it there was probably under 1 kg of force between the side of the wheel which has minimal grip and the road surface while he was attached for what 2-5 seconds?. Spin a wheel and try and slow it down from lightly touching the sides like that and it's going to spin for a while.

Further, while on the side the contact point of the wheel had a ~5 feet of leverage to the pivot point of the handlebars and the other contact point was a wheel. So, it would take very little force to get the bike rotating.

PS: I don't have a bike right now, but it should be easy to test if you do.