Modern XC bikes have become considerably longer, and the Specialized Epic is a good example. That matters when choosing a bike box because the old assumption that an XC bike will automatically fit the smaller MTB option no longer holds true.
The Buxumbox Stelvio is the right box for the Specialized Epic, but whether you need the Standard or Long Wheelbase version depends on the generation and frame size.
Which bike box size does the Specialized Epic need?
The primary measurement is wheelbase. The Stelvio Standard accommodates bikes from 1028 to 1209 mm, while the Stelvio Long Wheelbase takes bikes from 1210 to 1410 mm. Specialized’s current Epic 9 geometry is:
- Small: 1148 mm, Standard Stelvio
- Medium: 1184 mm, Standard Stelvio
- Large: 1223 mm, Long Wheelbase Stelvio
- XL: 1264 mm, Long Wheelbase Stelvio
So although the Epic 9 is firmly an XC race bike, two of the four sizes exceed the Standard Stelvio’s maximum wheelbase. Specialized describes it as a 120 mm-travel XC race bike, but the Large and XL demonstrate why riding discipline alone is no longer a reliable way to choose an MTB bike box.
This is why we always recommend measuring the bike rather than choosing a Stelvio purely from its intended riding discipline.
What about the Epic 8?
The same point applies to the previous Epic 8. Its published wheelbases are:
- XS: 1117 mm, Standard Stelvio
- Small: 1147 mm, Standard Stelvio
- Medium: 1179 mm, Standard Stelvio
- Large: 1210 mm, Long Wheelbase Stelvio
- XL: 1243 mm, Long Wheelbase Stelvio
The Large is exactly 1210 mm, placing it in the Long Wheelbase model according to the Stelvio sizing limits. The XL also requires the longer box.
It is a useful example of why a few millimetres matter. A Large Epic 8 should not be squeezed into a Standard box simply because it is an XC bike.
And the Epic World Cup?
The Epic World Cup is shorter than the Epic 8 and Epic 9 at every comparable frame size. Its published wheelbases are:
- XS: 1089 mm, Standard Stelvio
- Small: 1124 mm, Standard Stelvio
- Medium: 1150 mm, Standard Stelvio
- Large: 1181 mm, Standard Stelvio
- XL: 1212 mm, Long Wheelbase Stelvio
That means every size up to and including Large uses the Standard Stelvio, while the XL crosses into Long Wheelbase territory.
Again, frame size matters as much as the model name.
Packing a Specialized Epic into the Stelvio
The Stelvio was designed specifically around modern mountain-bike geometry. The frame and fork are secured to dummy hubs on the box mounting points using the bike’s front and rear thru-axles. The wheels and handlebars are removed for travel, while the seatpost can remain installed if it fits within the box when fully lowered.
On the current Epic 9, Specialized uses a 15 x 110 mm Boost front axle and 12 x 148 mm rear axle. These are standard MTB sizes accommodated by the appropriate Stelvio mounting brackets. The Epic 9 also uses a 120 mm fork, so it is well below the 170 mm-plus territory where some bikes may need their fork compressed slightly to reduce overall height.
If the Epic has a dropper post, it can often remain installed and simply be lowered to its shortest position. If the saddle still sits too high once lowered, the post can instead be removed from the frame and secured alongside the bike.
The Stelvio’s B1 and B2 cockpit-to-axle measurements should also be checked before ordering. Both have a maximum of 770 mm.
Standard or Long Wheelbase?
Based on wheelbase, the Epic 9 Small and Medium use the Stelvio Standard, while the Large and XL require the Stelvio Long Wheelbase. For the Epic 8, the XS, Small and Medium use the Standard, while the Large and XL require the Long Wheelbase. On the Epic World Cup, every size apart from the XL uses the Standard Stelvio.
That is perhaps slightly counter-intuitive for an XC race bike, but it reflects how much modern cross-country geometry has changed. Check the wheelbase first, then confirm the remaining measurements against the Stelvio sizing guide, and choose the box around the actual bike rather than the category it belongs to.
Specialized Epic images courtesy of Francois Schippers.