Description of Surly MDS horizontal Dropouts - silver
When you get an MDS equipped Surly frame you are getting the option to set it up however you want.
This article includes horizontal Singlespeed chips made from 304 stainless steel.
Also available are 12x142 mm thru-axle rear ends with a direct mount Shimano hanger, 12x142 mm thru-axle slotted type and standard 10x135mm QR (vertical) with Shimano/SRAM hanger (sold separately).
The way this will work is that Surly's complete bikes that feature the MDS will ship with whatever chip is compatible with derailleur spec. For instance, the complete Instigator 2.0 ships with the 12 x 142 mm thru-axle Shimano chip. If you want to change it to a singlespeed later (and why wouldn’t you?), all you have to do is get the SS chip (separately available). Frames will ship with three MDS chips (12x142 mm TA slotted, 135 mm QR, Mighty Singlespeed) so pick your poison.
The offered chips are made of 304 stainless steel, because the two words "aluminium" and "singlespeed" should never be too close to each other.
As you can see, the MDS gives you not just different build options, it lets you use a more varied selection of parts for your frame up builds. The MDS is featured on most of Surly's trail bikes and frames. That is right; Krampus Ops, Karate Monkey Ops, Instigator 2.0 and Ice Cream Truck frames all sport these puppies.
Fact Sheet of Surly MDS horizontal Dropouts - silver
The MDS dropout system is designed to allow for different rear axle configurations. You can run 12x142mm thru-axle rear ends with direct mount Shimano hanger, 12x142 mm thru-axle slotted type or standard 135mm QR with Shimano/SRAM hanger.