Need to know bike speed from engine rpm

[H100S]

Any websites out there you could suggest?

Ideally I could enter tyre size and gearing to determine this. Two different bikes with non standard gearing.

Reason pit lane has a 20mph limit with penalty if exceeded. Naturally I'm don't want to incur any penalties.

Motorbike does not have a speedo. I figured if using 1st gear I could work out 20mph from engine rpm.

Race is this weekend.

[Prof Prolapse]

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Hooli]

Prof Prolapse said:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I've linked that one back to this, lets see if the internet implodes

[Prof Prolapse]

[Big Al.]

Prof Prolapse said:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...