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 or AXEO 23 and run the travel limited cartridge with a stock front wheel. The AXEO21 or 23 cartridges will perform equivalent to a standard AXEO 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.