RST F1RST Air 24" versus 28mm Rockshox SID

Quick comparison:

ForkRST F1RST Air 24"
28mm Rockshox SID
Axle to crown in 60mm mode
around 420mm
Brake mounts
v-brake and PM
v-brake and IS mount (adapter required for 24" v-brake use)
$200-250 new
$50-100 used
Parts availability
Unknown - can't find a basic or full service kit online
Basic or full service kits still available (see RS SID service kits)
Travel adjustment
Can adjust in 10mm increments using all-travel spacers. 50mm - 80mm travel easily available.  Some SIDs can go to 100mm as well.

Conclusion: get a SID...

The SID has a lot going for it over the RST F1rst:

  • dual air spring - more tunable for light riders;
  • lighter weight;
  • cheaper;
  • easier to maintain - readily available spare parts and full service manuals directly from SRAM;
  • can be used on a 26" wheel bike later.

The RST F1rst does have some advantages:

  • available new;
  • will work straight out of the box with 24" v-brake rims.

However, working with 24" v-brake rims is not a huge advantage when you consider that for the money saved using a SID you can probably build a 24" disk front wheel to use with the SID (and not worry about making a special adapter bracket to get it to work with 24" rim brakes).

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