Welcome to NSR-WORLD, "jetblackonetenth".

That's a very good question, with one problem being having the bike officially certified once any work is complete.

My best guess would be an electronic resistor in the RC Valve circuit, to limit the valves from fully opening.

I really don't know how it could be made plug'n'play though, or [relatively] tamper-proof, to achieve certification.

Another idea would be a slightly different [sized] RC Valve pulley, that physically opens the valve less. This would be far more inconvenient to reverse.
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Andy.
NSR-WORLD.COM

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