I'd like a smaller speedo on the K100, probably a Daytona or koso.
Is this simply a question of connecting the existing wires to the new unit? I understand that I'll need to pull in the clutch to start it if I don't add relays, but this is ok.
The indicator, oil, battery lights. Do they just plug into the new unit and work?
The neutral light is through the gear indicator, does this mean that the light won't work without the set of relays?
I'll probably go for the magnet type speed sensor for a simple installation.

buy a bag of fuses before you start . ive a acewell speedo only got speedo high beam and indicators wired up didn't bother with neutral or rev counter you don't need neutral for a mot , bit of trial an error wiring it up hence the bag of fuses
 lol

Speedaddictedberk wrote:I'd like a smaller speedo on the K100, probably a Daytona or koso.
Is this simply a question of connecting the existing wires to the new unit? I understand that I'll need to pull in the clutch to start it if I don't add relays, but this is ok.

Wiring is very dependent on the speedo that you choose.  It is probably a direct connection with the existing wiring for most functions but there can be exceptions for each manufacturer's speedos.

See my blog for K75 wiring mapping. This will be similar for K100s as well.

Speedaddictedberk wrote:The indicator, oil, battery lights. Do they just plug into the new unit and work?

Yes.  Be aware of polarity for LEDs.  Most modern units don't use incandescent bulbs and wiring polarity is critical.

Speedaddictedberk wrote:The neutral light is through the gear indicator, does this mean that the light won't work without the set of relays?

Correct.  There is a circuit in the old instrument cluster that detects neutral and enables the start circuit and drives the neutral light.

Some builders have removed the particular circuit from the K100 instrument cluster and wired it up to get the functionality.  This renders the cluster unsalable later.

Other builders have used three relays in a configuration that enables the start curcuit.

I chose to use an Arduino based computer to give me that functionality.

Speedaddictedberk wrote:I'll probably go for the magnet type speed sensor for a simple installation.

There is a simple circuit that will allow you to reuse the existing VR sensor in the final drive with modern day speedos.  This is a much cleaner solution.

I'd like a rev counter, obviously not that important but it makes me happier.
Neutral light will be handy for avoiding those embarrassing traffic light moments.
I'll look into the stuff for the speedo cable too then.
Thanks for the useful info.

Oops double post

Koso speedo bought http://www.digital-speedos.co.uk/dl-03sr-563-p.asp, as well as clip on bars.
It'll be uncomfortable!