Speedo cable ratio

[thunder_taz]

I am looking to fit an aftermarket mechanical speedo to my fightered Ace and I am not sure which ratio I need. There are several that are 1:1, 2:1 and some that say 60 mph:2240 RPM and 2:1:1.

After alot of unsuccessful dicking around with digital speedos i just want a simple analog speedo that will work with the existing speedo drive.

Any input would be appreciated.

PS this is the sort of thing I mean

http://www.ebay.co.uk/itm/MINI-SPEEDO-C ... 2c630f3805

[Solorider]

If you have a cable driven speedo then any speedo for a Japanese bike should work except for some 70s Hondas as they all use the same ratio.