clocks for a scrambles tranny drive speedo?

[snowbeard]

So I am beginning to think that having either a speedo or a tach would be nice.  I have the brass drive from the mag for the tach, but have taken it off since I have no dial or cable, why wear it out, eh?

so I realized that my speedo drive is off the bottom front of my tranny.  it's a '57 spitfire scrambler with the original SC. T2 transmission (at least the cover is stamped XX over STD which I am told is the designation)



can anyone tell me what drive ratio I need?  the bike is a rider, not a restoration by far, so I think I am alright with a repro just to have a readout before the lights start flashing!!

thanks

[bsa-bill]

Looks like you need to spend some cash on that kickstart pinion

All the best - Bill

[snowbeard]

oh thanks, Bill    that was actually one of the very first things I fixed on this bike, flushed the tranny really really well, then replaced both the kickstart rachet and the return spring. 

but good eye 

[dpaddock]

my '57 Spit has a Smiths SSM 5007/02A magnetic unit with a nominal calibration of 1600.
Actually, Mark Bohman dialed it in to suit my rear tire rolling radius, so it's pretty much spot on.