It is not absolutely necessary to use a replaceable derailleur hanger in titanium frames.
The reason is because derailleur hanger on titanium frames are not the weakest link in the chain, as is the case with carbon or aluminium frames. Furthermore, when using titanium frames you have the option of replacing the drop-out. In order to be on the safe side, however, you can opt for titanium drop-outs with an aluminium derailleur hanger. Vertical drop-outs differ mainly in terms of design, with certain types providing more rigidity than others due to their larger joining surface to seat and chain stays. When it comes to choosing the right titanium drop-out, you have free choice: from simple horizontal drop-outs to complex adjustable titanium drop-outs with integrated disc mount. When using an internal gear hub, we recommend a Rohloff drop-out with adjustable axle mount in order to maintain chain tension. When using single speed or track bikes, we recommend using a horizontal drop-out, potentially with a preload system. For mountain bikes, in particular full-suspension and 29ers, we offer the well-known X12 through-axle system to increase chainstay rigidity. Our disc mounts are either IS2000 or postmount. Please do not hesitate to contact us if you have any questions.