Multiple Dropout Inlay (MDI)

With its Multiple Dropout Inlay generations I and II, ROTWILD introduced a system which allowed different axle standards and derailleurs (Shimano Direct Mount or SRAM Standard) to be installed simply by changing the inlays. The inlays additionally provide mechanical protection when mounting or removing the rear wheel and do not cause defects to the frame in the event of damage.  

The new third generation of the MDIs (MDI III as from frame model R.X1 and R.X+, model year 2016) additionally makes it possible to set a horizontal position for the chainstay length. Consequently, taking into account the wheel size, very short chainstay lengths of 422.5 mm and medium-length chainstays of 435 mm are possible.

Horizontal length adjustment with MDI III

Horizontal length adjustment and different wheel sizes at the focus of development

Length adjustment via MDI III takes place purely horizontally. This means that important dynamic geometrical dimensions such as height of bottom bracket, seat post and head tube angle are not affected.   

The different wheel sizes of 27.5” and 27+ can also be integrated without serious modifications to the geometry. For 27+ tyres with a breadth of 2.8” to 3.0”, the increased tyre deformation in comparison to standard tyres of 27.5” means that the statically effective radius of tyre to the ground remains practically identical, and consequently the effective height of the bottom bracket does so as well.  

You will find more on settings and configuration options for the MDI III in our knowledge database.

Dynamic influences on ride of different chainstay lengths

With the forward axle position, a very short chainstay length of 422.5 mm results, which leads to manoeuvrable, sporty riding characteristics at the same time as an agile and dynamic response when cornering. The rider is able to raise the front wheel more easily on trails in order to overcome obstacles. The chainstay length of 422.5 mm with 140 mm of travel and maximum possible tyre clearance with tyres of 2.4” in width represents the benchmark in the All Mountain sector. 

In the rear axle position, the chainstay length is 435 mm – a medium-length chainstay. This axle position leads to greater riding stability on fast descents and better uphill capabilities in steep terrain, as the front wheel stay in contract with the ground for longer. At the same time, tyres with a width of up to 3.0” (27+) can be mounted with this axle position.

Axle position adjusted to rider height


With the aid of the two inlay kits and the associated chainstay lengths, it is also possible to adjust the frame to a rider’s height. To optimize the theoretical distribution of the centre of gravity, we recommend a chainstay length of 435 mm for the frame sizes L and XL; however, the short configuration continues to be an option for the two large frames as well.

Overview table of axle position according to tyre size
Tyre dimensionChainstay lengthSMLXL
27.5 [max. 2.4] 422.5 mm x*x*xx
435 mm xxx*x*
27+ [2.8-3.0] 422.5 mm xx
435 mm xxxx

* Configuration as delivered from factory

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