I wonder how the R6 internals compare to the SP ones?

Probably the "same" but shorter. The SP are 20mm cartriges

Front spindle is different size and the wheel is a later type

Kurlon wrote:I wonder how the R6 internals compare to the SP ones?

A lot of the R6 internal parts are made from alloy instead of steel. The valves are still the old crappy design, but can be easily upgraded to something like K-Tech or Goldvalves. I found the R6 springs to be good improvement.

Bringing this back up as it was suggested to do a cartridge swap for weight savings in the front end seeing as the SP's internals are all heavy steel.

So, to that end, anyone know if any of the aftermarket cartridges fit? Also, anyone know if R6 or another common bike's fork caps fit SP tubes, if so that'd make cartridge swaps easier to figure out.

I think the forks are the same it[s just the R6 is longer - so the main cartridge and stanchion probably won't work

the problem with the sp 20mm dampers is that they simply wear out due to being soft alloy. i replaced them with some out of some r6 forks, but had the damper tuber cut down to the same size as the sp, then rethreaded to accept the spring stop. its a bit more complicated than you think when you start swapping the sp dampers valves and rods etc. difficult to get right, and even harder to know if what youve done has improved things. dont get to lost in trying to slow the comp and rebound dampening too much as this isnt really what you want. quite honestly you are better off buying some k tech valves and replacing the damping tubes, the r6 standard dampers are arnt much better than the sp ones

I won't be doing the work, I'll be going through a suspension shop. The challenge is there is no info on the SPs over here so any info I can nail down before hand saves trial and error costs. Specifically, if R6 or another common fork's caps fit the SP tubes, that eliminates a ton of custom work to do a cartridge swap with something like a KTech setup.

Of course, once we measure everything, the numbers may lean us towards a full front end swap, who knows. That'll be step one in trying to nail down the right geometry, then we start playing.