Fox 36 compatibility 2019-2023

I believe I know the answer to this: Is a Fox 36 2019 factory fork compatible with fox 36 2023 rhythm lower assembly.

I know they are different part numbers form 2021, but is that just the bleed valves on the back or will it not be compatible for other reasons?

Thanks!

IIRC…. lowers fit across anything new enough…. up top Rhythm forks use a different air spring (same as Z1)… same dampers… different axle if newer lower is floating hub (ie with bleed valves).

It looks as though Fox carried over the same CSU for the 2023 Rhythm as they used in 2019.. however the Factory CSU in 2019 was a 2018 carry over. 2020 was all new chassis for non-rhythm forks

Fox says a 2023 Rhythm lower is a 2021 carry over, in which case its the old style rhythm arch, so maybe cross compatible.
There are some images of the “rhythm” 36 with rounded crown, but the 2024 site doesn’t show a 36 rhythm product any more.

I’d think if you’re looking at at rounded arch lower with bleed valves then no, almost certainly wont work. as the lowers and csu’s span different generations

Square arched fork then maybe, but Fox have used different stanction wall thicknesses between ranges (normally only I.D. differences) in the past so perhaps there’ll be slight bushing tolerancing

Ask Silverfish of Fox directly for best results.
Foxzochhi may also be an option with an M-arch

https://www.mtbr.com/threads/fox-36-rhythm-marzocchi-bomber-z1-lower-leg-compatibility-with-other-fox.1215695/

Wall thickness is ID only (hence the different air springs), so that shouldn’t matter for lowers, should it?

’23 Rhythm are old casting, no bleed valves… but the newer ones are supposed to be using the new castings (not seen one yet):

https://www.ridefox.com/fox17/img/help/page2905-7UM3/2024_FOX_36_Rhythm_29in_User_Spec_RevA.jpg

Ahh… read that mtbr link… offset different for models with bleed valves (and floating axle)… never knew that.