Thorn Cycles Forum

Community => Non-Thorn Related => Topic started by: phopwood on April 14, 2014, 07:05:53 PM

Title: Some interesting figures
Post by: phopwood on April 14, 2014, 07:05:53 PM

I cycled 25.8 miles today and uploaded my data to garmin connect.  It gives some figure which got me thinking.

It told me my cranks had rotated 8388 times so I took this to the next step.  The 25.8 miles is 41521075mm and my wheels are 2023mm in diameter this means the wheels turned 20,524 times.

At this point I felt a bit sorry for those little ball bearings, just going around in cycles.

Peter

Title: Re: Some interesting figures
Post by: Andre Jute on April 14, 2014, 07:23:08 PM

Quote from: phopwood on April 14, 2014, 07:05:53 PM

At this point I felt a bit sorry for those little ball bearings, just going around in cycles.

You are truly a caring, sharing, compassionate man, Peter.

Title: Re: Some interesting figures
Post by: geocycle on April 14, 2014, 07:38:43 PM

Which reminded me of the two men in a ball bearing factory.  One of them lost his bearings, the other one lost his temper....

Title: Re: Some interesting figures
Post by: Danneaux on April 14, 2014, 07:39:54 PM

 ;D ;D ;D to all the above...!

All the best,

Dan. (...who suddenly feels joyful for the reading)

Title: Re: Some interesting figures
Post by: jags on April 14, 2014, 08:29:35 PM

this must be the comedians thread ;D

Title: Re: Some interesting figures
Post by: geocycle on April 14, 2014, 08:33:18 PM

Back to the OP I wonder how many times each ball bearing rotates. One for Jim perhaps?

Title: Re: Some interesting figures
Post by: rualexander on April 14, 2014, 08:39:17 PM

Quote from: phopwood on April 14, 2014, 07:05:53 PM

I cycled 25.8 miles today and uploaded my data to garmin connect.  It gives some figure which got me thinking.

It told me my cranks had rotated 8388 times so I took this to the next step.  The 25.8 miles is 41521075mm and my wheels are 2023mm in diameter this means the wheels turned 20,524 times.

At this point I felt a bit sorry for those little ball bearings, just going around in cycles.

Peter

2023mm diameter wheels? Is this a penny farthing?

(think you meant circumference?!)

Title: Re: Some interesting figures
Post by: phopwood on April 14, 2014, 09:30:23 PM

Quote

2023mm diameter wheels? Is this a penny farthing?

(think you meant circumference?!)

Yes good point, very valid and we'll delivered.  ;D

Quote

this must be the comedians thread Grin

Yes it is but I am worried it may turn in to a circular conversation

Title: Re: Some interesting figures
Post by: bikerta on April 14, 2014, 09:42:40 PM

[quote
Yes it is but I am worried it may turn in to a circular conversation

[/quote]


This is turning into a 'wheelie' funny thread     :D

Title: Re: Some interesting figures
Post by: JimK on April 15, 2014, 12:08:26 AM

Quote from: geocycle on April 14, 2014, 08:33:18 PM

I wonder how many times each ball bearing rotates.

I think the ball bearing revolves around the axle half as many times as the wheel goes around. Then multiply that times (axle diameter / ball bearing diameter) to get the number of times the ball bearing rotates around its own axis.

Title: Re: Some interesting figures
Post by: Andybg on April 15, 2014, 07:41:39 AM

I think the calculation would be:

Rb=((V/pyeDw)*pyeDa)/pyeDb

Where:

Rb =rpm bearing
V - velocity of the bike
Dw = Diameter of the wheel
Da = effective Diameter of the axle (diameter of contact between bearing and axle)
Db = diameter of bearing

If my 3rd year maths is still somewhere in there - lol

Andy

Title: Re: Some interesting figures
Post by: Andybg on April 15, 2014, 07:52:19 AM

where pye is actualy Pi or 3.14159265 and if anyone can remember pi to more decimal places from memory they must be sadder than I