any cures for choppy ride on 83 Nighthawk 650sc?

[Willie]

Thanks Bob. Looks like I'll be looking into replacing the shocks.
I'll post my findings, decision and results if anyone is interested.

[Bob H]

Hagen also makes good shocks for vintage bikes, out of England.
People with Triumphs in Australia like IKON (used to be called Koni).

The distributor for YSS in United States was listed on my review thread.
The manager Mike was very helpful, patient, and willing to research proper bushing sizes etc. to ensure fitment.

I started to look at Ohlins because they make twin shocks that "may" have fit my Nighthawk - but the price was crazy.

[Gene]

My 85 has adjustable damping on the shocks, does yours?

[Larry Fine]

Hagen also makes good shocks for vintage bikes, out of England.

It's Hagon. I like the Hagon shock/spring set that I put on my '96 CB750ST. They were selected by Dave Quinn (now retired) based on the bike's luggage setup, my weight, and an occasional passenger.

[Bob H]

The late-model 91-2003 Nighthawk 750 rear shocks have no damping adjustment, only preload.

Honestly I am not that familiar with the shocks on other models. I just found this article that explains that the 650 Nighthawk had "a pair of shock absorbers that offered both rebound and compression damping adjustments" which is awesome.

I am not that familiar with the 700s shocks either - and I just learned that they had rebound damping adjustment per this spec article.

So maybe I was wrong about the 700s shocks being as bad as the late model 750 NH. That spec article said the 700s rear shocks were made by Kayaba. I know the late model ones had a Showa label when I took mine off.

When I was doing a deep dive on replacing my rear shocks, I ran across an article (or maybe video) that said rebound was the most important adjustment to have for rear shocks. Previously I never had any adjustment for rebound and kind of assumed compression was the thing I would want to adjust. But after simply changing shocks and leaving the new YSS at the recommended middle position on rebound - instantly I could feel the difference.

With decent rebound damping, the back end of my bike felt like it was soaking up the bumps instead of uncontrollable chaotic movement. It's not like it was bouncing forever after a hit, but something was "off" on my stock, non-adjustable shocks especially with 40,000 miles on them.

My new YSS shocks are adjustable for rebound and preload. It is my understanding that they have some valving (like a cartridge in front forks - rather than just shooting oil through a hole). They were a big improvement for me.

You were complaining of a "Choppy" ride - have you tried adjustments?

[Gene]

Did you ever come to a fix? I know my 85 650 rear shocks work great,  and are adjustable for damping and preload

[Steppin Razor]

Hagons are pretty reasonably priced.
4into1 has unlabeled Chinese shocks for even less.

Ikon is more expensive, but they used to be Koni, so pretty good quality.
YSS was pretty steep last I checked.