Regarding the selection of the tower base

HG: Compatible with standard Shimano freehubs, classic universal freehub, suitable for both road and mountain bikes. Speeds: 8-12 speeds (Shimano road/mountain, SRAM 11-speed road). Minimum cassette: 11T.

XDR: Only compatible with SRAM 12-speed road/gravel bikes, incompatible with Shimano. Speeds: SRAM 11-12 speed road XG cassette.

MS: Only compatible with Shimano 12-speed mountain bikes (including GRX gravel). Cannot install road cassettes. Speeds: Only compatible with Shimano 12-speed mountain bike cassettes (SL/XT/XTR).

HG: Universal 8-12 speeds, minimum 11T. Compatible with Shimano/SRAM 11-speed, most convenient.

XDR: SRAM 12-speed road bike, minimum 10T. Only compatible with XG cassettes.

MS: Shimano 12-speed mountain bike, minimum 10T. Only compatible with MTB 12-speed.

For Shimano 8-11 speeds or mixed models: Choose HG. For SRAM 12-speed road bikes (Force/Red): Select XDR.

For Shimano 12-speed mountain bikes (SLX/XTR): Select MS.

88mm wheelset / Suitable for track/road/TT/triathlon：

60mm wheelset / Suitable for track/road/TT/triathlon 

50mm wheelset / Suitable for track/road/TT/triathlon

45-50mm black ice crack pattern wave wheelset / suitable for road/Gravel bikes：Three-spoke carbon wheelset, suitable for track bikes/road bikes:

45-50mm wave wheelset - carbon spokes + ceramic bearings: suitable for MTB/road/track/gravel/TT Bike：

50mm carbon wheelset - carbon spokes + ceramic bearings: suitable for mountain/road/track/gravel bike：