This innovation was designed in France to solve recurring problems that Riders have been facing for many years (hard spots, chain tension and changing the crown without disturbing the rear wheel).

IRC type ll: Only for Ø 20 mm frame dropouts (see photo) with chain tensioner integrated into the frame, to mount wheels with 15 or 10 mm axle when using the 10-15 mm adapters provided

The IRC System creates permanent tension on the chain thanks to the yoke which is fixed on a CNC stainless steel axle, articulated using two annular bearings and a stainless steel spring.
 Tension is exerted on the chain via a derailleur wheel (also mounted on an annular bearing and a stainless steel axle), which allows great fluidity and reduced resistance when pedaling.
The chain line is adjusted at the derailleur pulley. Being mounted on an axle, precise lateral adjustment is possible. Once the adjustment is optimal, the position of the axis can be locked via a 4mm intra-screw in the yoke.

The advantages offered by the IRC:
1.No longer have a hard point (caused either by the crown, the pinion or the crankset): in fact, the yoke is mounted on a spring, allowing you to automatically correct any defects in the machining of your transmission parts.

2.Change the crown without removing the rear wheel, which is very practical during training or races: it will only take you 2 minutes of handling and will save you precious time. ? **/!\WARNING/ !\** changing the crown without removing the rear wheel is only possible for young riders with little power (under 13 years old). It will be necessary to provide a high tension of the system for the older ones, an adjustment which will prevent rapid crown change because it involves modifying the chain length beforehand. 
 

Features : 
- Imagined, developed and tested in France.
- Available in two versions, to be adaptable to several standards of horizontal legs of Ø 20, 15 and 10mm.
- IRC completely removable with BTR and TORKX keys.
- Adjustable horizontal chain tensioner with 2 stainless steel BTR screws
- 11 tooth aluminum derailleur pulley, mounted on sealed bearing.
-CNC Z15Cn17 stainless steel body / yoke junction pin mounted on 2 annular bearings.
-Heat-treated stainless steel tension spring
- CNC derailleur pulley axle in Z15Cn17 stainless steel.
-Adapter from 15 to 10mm in CNC aluminum