[Kartbuilding] Fwd: Kart Speed now only 2 pages

Mon Oct 9 11:19:36 IST 2006

 Go-Kart MPH – KPH

Without a Speedometer

(c) 2004 by Dale Thomas

Printed with permission on the

 "Complete Kart Building Web Site"

Presented are two ways to find (using a cheap calculator) the speed of a
go-kart or mini-bike without a speedometer.  Method 1 requires riding at a
steady speed over a known, accurately pre-measured distance and keeping
exact time on a watch with a second hand.   Method 2 requires riding at a
steady speed and recording the tachometer rpm.  Observe sensible safety
precautions at all times.   Substituting the variables (Ta, Te, D and RPMe)
from actual vehicles may give results that differ from those used in the
examples below.

Method 1 - KPH

Say the ride was 4 Km and took exactly 8 minutes.  Use the formula  where S
is speed in KPH, D is distance in meters, T is seconds and F is 0.27778, a
conversion factor to change meters per second to kph.  One kph is equal to
0.27778 meter per second.  Substituting in the formula, .   Speed is 29.999KPH.

Method 1 - MPH

To find MPH use the same formula.  If the ride was 2-1/2 miles in 8 minutes,
convert the miles to feet by multiplying by 5280 (the number of ft. per
mile) and the minutes to seconds.  F is 1.46667, a conversion factor to
change ft. per second to mph. One mph equals 1.46667ft. per second.
Substituting
in the formula,  gives 18.75 MPH.

Method 2 – MPH

Our formula is where MPH is miles per hour, RPMe is the average engine rpm
while riding, Te is the number of teeth on the engine clutch sprocket,  (or
PI) is 3.1416, D is the drive wheel outside diameter in inches, Ta is the
number of axle sprocket teeth, and 1056 is the number of inches traveled in
one second at 60 mph.

For example, assume the kart has a drive wheel that's 15 inches in diameter,
the engine clutch sprocket has 10 teeth, the axle sprocket has 60 teeth and
the tachometer shows an average engine speed of 3000 rpm.  Making
substitutions in the formula, Ta is 60, times 1056 equal 63360. Next, RPMe,
Te,  and D are all multiplied then divided by 63360.  So 3000 times 10 times
3.1416 times 15 is equal to 1,413,720, divided by 63360 equals 22.3125 MPH.

Method 2 – KPH

A formula for kph is where KPH is kilometers per hour, RPMe is engine rpm,  (or
PI) is 3.1416, D is the drive tire diameter in Mm, Ta is the number of axle
sprocket teeth, and Te is the number of engine clutch teeth.

Use the kart from the previous example and substitute in the formula for
KPH.  The 15 inch diameter tyre is 381Mm, but RPMe, Ta, and Te are the same
as before.   Ta divided by Te is inside parenthesis, so do that calculation
first, then multiply by 1,000,000 the result is 6,000,000.  Next multiply
RPMe, and D which gives 3590848.8, divided by 6000000 equals
0.5984748.  Multiply
0.5984748 (kilometers of vehicle travel in one minute) times 60 to find the
distance traveled in one hour, 35.91 KPH.

More to come on torque converters and expanded formulas.

I hope you find this article interesting and useful.

Happy karting,

Dale Thomas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image012.gif
Type: image/gif
Size: 73 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image010.gif
Type: image/gif
Size: 167 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0001.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image015.jpg
Type: image/jpeg
Size: 2845 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image004.gif
Type: image/gif
Size: 592 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0002.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.gif
Type: image/gif
Size: 385 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0003.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image014.gif
Type: image/gif
Size: 1175 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0004.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.gif
Type: image/gif
Size: 639 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0005.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image008.gif
Type: image/gif
Size: 978 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0006.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.wmz
Type: application/x-ms-wmz
Size: 315 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.wmz
Type: application/x-ms-wmz
Size: 328 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0001.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image005.wmz
Type: application/x-ms-wmz
Size: 344 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0002.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image007.wmz
Type: application/x-ms-wmz
Size: 392 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0003.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image009.wmz
Type: application/x-ms-wmz
Size: 249 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0004.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image011.wmz
Type: application/x-ms-wmz
Size: 134 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0005.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image013.wmz
Type: application/x-ms-wmz
Size: 428 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment-0006.wmz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: oledata.mso
Type: application/octet-stream
Size: 2920 bytes
Desc: not available
URL: <http://lists.burkesys.com/pipermail/kartbuilding/attachments/20061009/c67b08cc/attachment.obj>