Instrument needle resting position

[evan_calgary]

Hi All,

Took apart a cluster not thinking I should mark the balls on the backs of the tach and speedo before removing the needles. Couple questions

The needle rests against the pins on the face but needs to be pre-wound slightly in order to get that nice return. What is the final resting place of the 2 needles if they're allowed to bypass the stop?

Does it matter where the final resting place is? Ie, does 2k rpm or 50kph relate to specific winding of the spring? If it does then i'll need to get a fairly precise starting point from someone hopefully!

Hoping I can get these right the first time (I guess 2/3rd now) and not have to take them apart once on the bike.

Thank you!

[MK]

Slightly bend the needle over the resting pin. Then mark the equilibrium position.
This is where you put the needle back on after repairs/resto.

[evan_calgary]

Slightly bend the needle over the resting pin. Then mark the equilibrium position.
This is where you put the needle back on after repairs/resto.

Hey Martin,

That's definitely the smart way to do it! Is there a standard 'resting position' that can be used when the needles were removed prior to checking this? Unfortunately i've taken the needles off before allowing them to find their resting position so I can't really go back to that!

[MK]

On the RD350 tach and speedo that resting position is a few mm behind the pin.
Something between 2 and 5 mm should be in the ballpark.

It can be calibrated later with your smartphone and a GPS speedo app.
For the rpm calibration you could get a cheap tach from Alibaba and hook that up.

[evan_calgary]

Thank you Martin!