Sizing charts for all three frame sizes are shown below.


small sizing chart

Small Sizing Chart


medium sizing chart

Medium Sizing Chart


large sizing chart

Large Sizing Chart

For a look at the geometry of each OS Bikes Blackbuck in all three sizes, including fork options, click on each pic. Thumbnails are arranged as follows: By height w/rigid fork and suspension travel in each size, left to right, beginning with Small. Note: axle to crown defines how ‘tall’ the rigid fork is as measured from the center of the front wheel to the bottom of the head tube. A smaller A/C number results in a lower front end and steeper head tube angle.

Small 80mm
Small 80mm


Small 100mm
Small 100mm


Small 435 A/C
Small 435 A/C


Small 455 A/C
Small 455 A/C


Small 475 A/C
Small 475 A/C

Small 435mm A/C
Small 455mm A/C
Small 475mm A/C
Small 80mm travel
Small 100mm travel

Medium 80mm
Medium 80mm


Medium 100mm
Medium 100mm


Medium 435 A/C
Medium 435 A/C


Medium 455 A/C
Medium 455 A/C


Medium 475 A/C
Medium 475 A/C

Medium 435mm A/C
Medium 455mm A/C
Medium 475mm A/C
Medium 80mm travel
Medium 100mm travel

Large 80mm
Large 80mm


Large 100mm
Large 100mm


Large 435 A/C
Large 435 A/C


Large 455 A/C
Large 455 A/C


Large 475 A/C
Large 475 A/C

Large 435mm A/C
Large 455mm A/C
Large 475mm A/C
Large 80mm travel
Large 100mm travel