A plus (+) bridge lets you mount larger boots on a specific tube length.
Larger size boots on 17" blades
A 17" blade is standard equipped with a 170 clap arm, speedskating boots with a pitch 165, 170 and 175 like the Cádomotus 40, 41 and size 41½ blade shoes (*) fit on this clap arm. If you want to put a size 42, 43 or larger boot on your 17" skate you will need the 170+ arm.
An alternative is to mount a 180 clap arm by moving the wedge to the back. This is a feature on the R304 and R980 blades.
Larger size boots on 17.5" blades
A 17.5" blade is standard equipped with a 180 clap arm, speed skating boots with a pitch 175, 180 and 185 like the Cádomotus 41½, 42 and size 43 blade shoes (*) match perfectly. If you want to mount a size 44, 45 or larger boot on your 17.5" skate you will need the 180+ clap arm.
An alternative is to mount a 190 arm. This can be done by moving the wedge backward on R304 and R980 clap blades.
* For other speedskate brands, the pitch can be different.
Want to know more about the effect of moving the wedge. Then read this blog (in Dutch) where we explain why moving the wedge affects the stiffness of the skate, and thus the handling.