If you currently have a stock front wheel, and plan to go with a 21" or 23" front wheel in the future, you can still purchase the AXEO21 High-Performance or AXEO 23 High-Performance and run the travel limited cartridge with a stock front wheel. The AXEO21 or 23 cartridges will perform equivalent to a Standard AXEO High-Performance kit, you will just have less travel available, as the AXEO21 and AXEO23 kits are travel-limited to accommodate the larger diameter front wheel and reduced clearance between the fender and lower triple tree.