58 tooth chainring?

[Angelfishsolo]

I have no doubt about the HD speed or anything else TBH. Most measuring apparatus are accurate to a few MPH and if you know a routes distance you can easily tell if the calibration is out.

Anyway bottom line is you are calling Gaz a Bull Shitter. Correct? I take it that this is because you can not attain those speeds.

 

[Rob3rt]

I don't think he is lying at all, these speeds are possible.

Go look at the times of the fastest riders in the world on the track and in the tour. They only just touch these speeds.

I have no doubt about the HD speed or anything else TBH. Most measuring apparatus are accurate to a few MPH and if you know a routes distance you can easily tell if the calibration is out.

Anyway bottom line is you are calling Gaz a Bull Shitter. Correct? I take it that this is because you can not attain those speeds.

None of us can hit a 45mph flat sprint.

 

[MacB]

Well if I go flat out and almost blind myself with pain I can hit 30mph, on the flat, for about 10 yards

 

[Angelfishsolo]

Go look at the times of the fastest riders in the world on the track and in the tour. They only just touch these speeds.



None of us can hit a 45mph flat sprint.

He doesn't say a 45mph FLAT sprint to be fair!

 

[Rob3rt]

Well if I go flat out and almost blind myself with pain I can hit 30mph, on the flat, for about 10 yards

MacB, your not alone in your inadequacy, I can only hit low 30's (<35mph) and cant hold that for long.

 

[Rob3rt]

He doesn't say a 45mph FLAT sprint to be fair!

True, he didnt. But since he had already seperated downhill speeds from flat speeds, and the sprint comment was attached to the flat speed comment then its sort of implied.

 

[Angelfishsolo]

True, he didnt. But since he had already seperated downhill speeds from flat speeds, and the sprint comment was attached to the flat speed comment.

So do you think it is more likely to be computer error of genuine bullshitting?

 

[Rob3rt]

So do you think it is more likely to be computer error of genuine bullshitting?

Computer error. Wrong wheel size entered, using gps for speed, etc. All contributers.

Even with a wheel sensor and correct data entered, data cannot be trusted blindly, one example would be when I am riding fixed and I trackstand with the magnet in the right place the readings will go nutty (I trackstand with the non-drive side crank facing backwards so it will be around the cadence sensor, hence why even though I may stop at 20 sets of lights, cadence will only hit zero on maybe 5-6 occasions). The wheel will also sometimes be tripping the sensor.

 

[Angelfishsolo]

He does, there, he says hills are bad.




You're in IT, you must know how inaccurate GPS is for a moving target. According to mine I can sprint at 125mph, I can give you proof if you wish...

I was in IT and I do know how inaccurate any computing device can be. It is easy to validate however. Start time, finish time and distance covered. Schoolboy maths.

 

[Rob3rt]

I was in IT and I do know how inaccurate any computing device can be. It is easy to validate however. Start time, finish time and distance covered. Schoolboy maths.

That only gives average speed, not instantanious speed, which is what a flat out sprint measurement calls for.

 

[Angelfishsolo]

Computer error. Wrong wheel size entered, using gps for speed, etc. All contributers.

Even with a wheel sensor and correct data entered, data cannot be trusted blindly, one example would be when I am riding fixed and I trackstand with the magenet in the right place the readings will go nutty.

Possible I agree. However as I said previously it is pretty easy to verify if the readings are accurate. Start time, finish time and known distance covered will give you an average speed.

 

[Angelfishsolo]

That only gives average speed, not instantanious speed, which is what a flat out sprint measurement calls for.

Granted. However if the average speeds tally then it is a fair indicator that the other readings are also valid.

 

[Rob3rt]

Granted. However if the average speeds tally then it is a fair indicator that the other readings are also valid.

Depends how the device works, a garmin measures distance by gps, time as a timer, and speed, from the rear wheel if there is a sensor present (at least i THINK this is the case because to measure distance on a turbo, you have to turn gps off for it to calc distance from the wheel, at least on my unit your do, maybe with gps on it does some sort of correction based on wheel distance to gps distance but not wheel distance directly?), as Gaz is measuring cadence, them I'm assuming he is using the garmin cadence/spd sensor, like the one I use.

So given the above its probly fairly easy to confuse them.

 

[zizou]

Anyway bottom line is you are calling Gaz a Bull Shitter. Correct? I take it that this is because you can not attain those speeds.

That makes it sound like an insult, i didnt mean it that way!

Anyway i cant attain these speeds - if i could i would be hoping to get a place in Team GB alongside Chris Hoy and Jason Kenny.

He doesn't say a 45mph FLAT sprint to be fair!

And to be fair my first post was "so unless you were drafting, had a huge tailwind or were gravity assisted i call bs"

Everyone of us could claim sprints of speeds in the 40s if we were to include ones going down nice big hills

 

[Angelfishsolo]

Depends how the device works, a garmin measures distance by gps, time as a timer, and speed, from the rear wheel if there is a sensor present (I know this because to measure distance on a turbo, you have to turn gps off for it to calc distance form the wheel, at least on my unit your do), as Gaz is measuing cadence, them I'm assuming he is using the garmin cadence/spd sensor, like the one I use.

So given the above its fairly easy to confuse them.

Ok Robert fair enough that is a valid point. To my knowledge I have not seen devices that use a mixture of GPS and "standard" cycle computer technology. As you me explain it I can see where issues may arise.