1980 GS1000G speedometer needle bounce

[Guest]

Just got a NOS 140mph speedometer for my bike. Hated the old 85mph speedometer out of principle. The speedo was from a 1979 750, I think and had the guts installed in my original speedo case so it would fit into the stock cluster. Morris of West Valley Instruments did a nice looking job in making the switch. Installed new speedometer and took bike for test ride. Noticed at around 60 that the needle would bounce and even more at high speeds. Also noticed when sitting still at idle, needle would bounce when I revved the throttle
Got to be something internal. Morris said to send it back. Would like to
wait till end of season since don't want to be waiting 2-3 weeks and not ride the bike.
Will I be damaging anything internal by riding and letting the needle bounce?

[Nessism]

Needle bounce is common with old gauges. You might want to remove and lube the cable to be sure it's not contributing to the issue.

[shark]

What is interesting is the needle bounce when the throttle is revved in neutral.
A friend mentioned there are small springs inside that dampened the needle movement. Don't know what was done when the guts were swapped. Absolutely no buzzing noise makes me feel that the problem isn't too severe.
Got this bike running last year after sitting in my garage for 25 years. Just hate to miss a day riding it while speedometer is getting fixed.
Bike runs like new by the way.

[Nessism]

The cable turns a metallic dome/disc inside the speedometer. There is a magnetic device that picks up the rotation of the metal dome and translates that into movement of the needle. The needle itself is damped in some way, but that's not done with a spring.

[roeme]

By my experience; mostly caused by dried out lubrication, can be alleviated to a certain extent by opening the speedo, removing the old gunk and regreasing (as far as possible without taking the whole thing apart).

Didn't want to go all the way yet with mine since these speedos apparently were built to a price and not intended to be serviced. Couldn't yet figure out how lube the miniscule sleeve bearings without destructive teardown.

Currently leaning towards building a more service-friendly gauge completely from scratch. Another member in here is already attempting to create new gauge faces, and is slowly making progress.

No, needle bounce wont destroy the speedo.