|Fork||RST F1RST Air 24"||28mm Rockshox SID|
|Axle to crown in 60mm mode||around 420mm||430mm|
|Brake mounts||v-brake and PM||v-brake and IS mount (adapter required for 24" v-brake use)|
|Price||$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||Unknown|| 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;
- 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).