For what it's worth, I just put an Ohlins rear shock on my 1990 SP, but had it completely revalved and resprung by Ed Sorbo at le-suspension. It definitely has the "bling" factor and works phenomenally, but I just bought another NSR, a 1993 MC21 SE, and the stock rear shock is shot. When I talked to Ed, he told me I didn't need to buy a new rear shock as long as it had rebound and compression adjustments. He said he could just revalve and respring it to do what he/I want and to to save the money investing in a new shock. I think the Ohlins does have height adjustability though if that's something you're looking for. Lucky me my new SE did come with RS250 USD forks .
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