Mechanical doping

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Pale Rider

Legendary Member
The fact that the towel is in, coupled with those suspicions about her earlier performance, makes the case a bit more compelling than speculating that she was unlucky enough to be caught first time.

Scrutineering must have been very lax for her to have used the bike on multiple occasions.

Anyone with a modicum of cycling experience, let alone training for the job, could tell in seconds the bike wasn't right.

The simplest test would be to try to turn the wheel backwards, there will be noticeable resistance.

As you may know, I use an ebike most of the time and they all make a noise, particularly under load.

So even if every scrutineer was worse than incompetent, anyone stood the other side of the tape as she climbed a grassy bank would hear the whirr of the motor, as would any other riders within a few metres.

The noise might not be so apparent in the general clatter of a roadie peloton, but I honestly cannot believe it would go unnoticed in a cyclocross race.
 
The noise might not be so apparent in the general clatter of a roadie peloton, but I honestly cannot believe it would go unnoticed in a cyclocross race
That might explain why her and dad and brother needed the parrot from the pet shop, to fly next to her going 'Pretty Polly', CAW..... and drown out the noise of the motor.
 

Pale Rider

Legendary Member
Just a small technical point, but there's nothing different about the wheel, the motor drives a bevel through the bottom bracket.

I didn't explain that too well

On a crank drive ebike, pushing the bike backward causes the chain to move under tension, which turns the motor over causing drag.

Leaving that aside, as far as I can gather the bevel drive in the girl's bike is permanently engaged, so turning the pedals at rest would also produce drag.

Turning the pedals backwards exaggerates the drag because the reduction ratio of the bevel drive is working in reverse.

You are also turning the motor, which is more drag due to the 'notching' effect of the magnets.

As I child, I recall even the tiny motors in my Scalextric cars produced drag when spun unpowered.
 
I didn't explain that too well

On a crank drive ebike, pushing the bike backward causes the chain to move under tension, which turns the motor over causing drag.

Leaving that aside, as far as I can gather the bevel drive in the girl's bike is permanently engaged, so turning the pedals at rest would also produce drag.

Turning the pedals backwards exaggerates the drag because the reduction ratio of the bevel drive is working in reverse.

You are also turning the motor, which is more drag due to the 'notching' effect of the magnets.

As I child, I recall even the tiny motors in my Scalextric cars produced drag when spun unpowered.

It also wouldn't be difficult to have the drive on a clutch so that it will pedal backwards like normal.
 

screenman

Legendary Member
Scrutineering must have been very lax for her to have used the bike on multiple occasions.

Anyone with a modicum of cycling experience, let alone training for the job, could tell in seconds the bike wasn't right.

The simplest test would be to try to turn the wheel backwards, there will be noticeable resistance.

As you may know, I use an ebike most of the time and they all make a noise, particularly under load.

So even if every scrutineer was worse than incompetent, anyone stood the other side of the tape as she climbed a grassy bank would hear the whirr of the motor, as would any other riders within a few metres.

The noise might not be so apparent in the general clatter of a roadie peloton, but I honestly cannot believe it would go unnoticed in a cyclocross race.

The amount of noise my lungs made in a cross race it would have covered the noise of a V8 without an exhaust on.
 

deptfordmarmoset

Full time tea drinker
Location
Armonmy Way
Scrutineering must have been very lax for her to have used the bike on multiple occasions.

Anyone with a modicum of cycling experience, let alone training for the job, could tell in seconds the bike wasn't right.

The simplest test would be to try to turn the wheel backwards, there will be noticeable resistance.

As you may know, I use an ebike most of the time and they all make a noise, particularly under load.

So even if every scrutineer was worse than incompetent, anyone stood the other side of the tape as she climbed a grassy bank would hear the whirr of the motor, as would any other riders within a few metres.

The noise might not be so apparent in the general clatter of a roadie peloton, but I honestly cannot believe it would go unnoticed in a cyclocross race.
I imagine that the identical bike ploy (''It's not my bike. I sold it to a friend.'') was an attempt to sidestep the scrutineers. No idea how often it could have worked before a mechanic happens by, spots the bike by the truck and takes it back within their range of inspection. I would have thought that a mechanic would have been surprised by the extra weight though. I mean, CX bikes will have heavier wheels and tyres anyway so they're not the lightest of steeds but there would still be a noticeable increase in weight, wouldn't there?

The ex-racer who claimed ownership of the bike has not exactly raised the integrity profile of the previous generation's racers.
 

Pale Rider

Legendary Member
Iwould have been surprised by the extra weight though. I mean, CX bikes will have heavier wheels and tyres anyway so they're not the lightest of steeds but there would still be a noticeable increase in weight, wouldn't there?

I believe this was a standard bike converted, so would have weighed more.

However, it is possible to use an illegally light - and probably dangerously fragile - bike, convert that, making the total weight feel about right.

Another way to tell if a Vivax system is fitted is the motor locking pin through the seat tube - it needs one of those or the motor assembly would spin around rather than the cranks.

The pin is difficult to hide from a close inspection because to work it must protrude a tiny bit past the thin walled tube.
 

raleighnut

Legendary Member
I believe this was a standard bike converted, so would have weighed more.

However, it is possible to use an illegally light - and probably dangerously fragile - bike, convert that, making the total weight feel about right.

Another way to tell if a Vivax system is fitted is the motor locking pin through the seat tube - it needs one of those or the motor assembly would spin around rather than the cranks.

The pin is difficult to hide from a close inspection because to work it must protrude a tiny bit past the thin walled tube.
You mean like a bottle cage boss, hollow pin (that accepts a bottle cage bolt) :whistle:
 

jarlrmai

Veteran
I admit I'm a bit of a sucker when it comes to conspiracy theories, but that video of Hesjedal's bike at the bottom of the article looks pretty clear cut?!
Though I don't get why he'd be using the motor going into a corner on a descent...

That's normal the weight and momentum of the bike settling causes the pedals to move which moves the rear wheel.

That clip is the least convincing clip in my opinion.
 
the weight and momentum of the bike settling causes the pedals to move which moves the rear wheel

I'm not sure I understand you correctly - are you saying it's residual pedal movement (independent of any crank movement) that is causing the back wheel to spin? i.e the pedals spinning on the ends of the cranks, whilst the cranks remain more or less stationary?
 

jarlrmai

Veteran
He's probably doing quite a good speed before he comes off, look at the handle bars they are at 90deg that back wheel and crank system has a lot of momentum and the light carbon fibre bike is resting on the rear wheel the front wheel and a small point on the handlebars there's nothing stopping the rear wheel from going around and dragging the bike around with it.

ala this video


View: https://youtu.be/aN7HjwZI-k0?t=31
 
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