Some of you may have seen my post yesterday about regulating a Rich Factory (RF) Pepsi to superlative chronometer standards, so you could say i’ve been spending a lot of time staring at this part of the movement lately. I first noticed this while taking my comparison photos between the RF Starbucks submariner and VSF submariner, but as far as I know, no one else seems to have noticed this- JH, much like DD, uses an offset pallet fork design like the genuine rolex movements of this generation. A complaint that has for a long time been leveled against SH is that they use an inline pallet fork, which makes it an easy tell that the movement is not DD, and more importantly, makes it incompatible with gen parts for franken builds.  
Naturally, seeing this similarity between the DD and JH movements, I wondered if it’d be possible to convert a DD movement into a free sprung movement by taking the balance complete from a JH movement and placing it into a DD movement. This Evolved into a big swaparoo of different balances into different movements, as I took advantage of this opportunity to answer any related questions to these matters.

\- Conclusion 1:  
\- the JH free sprung balance complete is NOT compatible with DD movements, (fake free sprung DD or otherwise). I got it to run very poorly and not fully seated in the DD fake free sprung movement, but nothing more.

\- Conclusion 2:  
\- The DD “classic” and “fake free sprung” balance wheels ARE compatible with the JH free sprung movement. This was a straight swap with zero drama, and the watch was immediately ticking away quite happily. This might come in handy if anyone breaks a free sprung balance from JH, it should be a simple swap with a DD balance to get it up and running again. I assume getting parts from JH will be basically impossible for at least the next year, so this is useful info in the meantime

\- Conclusion 3:  
\- the “classic” and “fake free sprung” balances from DD movements are interchangeable. they both work in either movement that I placed them in. this is nice because it ensures backwards compatibility as DD starts to produce the fake free sprung balance movements as well as will enable people to repair new generation movements with older parts, nice!

\- Conclusion 4:  
\- When I saw the offset balance structure of the JH movement, i wondered if JH wasn’t just an offshoot of DD that was producing it’s new generation of movements as a separate company so that if anything went terribly (reliability, performance, etc), the negative press wouldn’t be associated with the DD name. The fact that the balances are not interchangeable in both directions suggests to me that this is not the case and that JH is truly an independent movement manufacturer. I’m sure there are others who know more on this topic than I do, so feel free to chine on this front!

Are JH and DD Balances Interchangeable? Let’s find out!