Can I bolt a cargo cage to my fork, or does it need straps?
A fork cargo cage either finds a boss or settles for Tight
A cargo cage on the fork can be held on two different ways, and the catalogue carries one bag of each kind. One bolts to a boss. The other straps to the leg. The fit check asks a different question of each, and the two questions have different answers.
1 of 3reference frames that declare the three-pack mount the bolt-on cage needs
Two bags, two different questions
| Bag | Capacity | Needs a mount | Declared clearance |
|---|---|---|---|
| Bolt-on cargo cage | 4000 ml | 1 three-pack mount | none declared |
| Strap-on cargo cage | 3000 ml | none | 6 mm of strap purchase on a rigid fork leg |
Where the boss actually is
| Frame | Three-pack mounts |
|---|---|
| Small · 47 cm | none |
| Medium · The Mule | none |
| Large · 58 cm, three-pack fork | 2 |
The bolt-on cage is refused on the small frame and on the medium frame alike, and in neither case is room the reason. The refusal names the missing three-pack mount and carries no millimetre figure, because a boss is there or it is not. It fits only the large frame, the one reference frame built with that mount, and once the boss exists the check moves on to a different limit: in-frame volume, not the boss itself.
The strap-on cage doesn't ask the frame at all
| Frame | Verdict | Limiting | mm |
|---|---|---|---|
| Small · 47 cm | Tight | strap purchase on a rigid fork leg | 6 |
| Medium · The Mule | Tight | strap purchase on a rigid fork leg | 6 |
| Large · 58 cm, three-pack fork | Tight | strap purchase on a rigid fork leg | 6 |
Same verdict, same 6 mm, on the smallest frame and on the one frame built with a three-pack boss. A strap's purchase on a fork leg does not change with the frame around it, so this is the one row in the category where running the reference frames from small to large moves nothing at all.
What this cannot tell you
The check reads a declared boss or a declared clearance, not the bolt or the strap itself. It does not know whether a thread is stripped, whether a strap stays tightened once ridden, or what either cage weighs loaded. And the catalogue holds exactly one bag of each kind in this position — a third way of mounting a cargo cage to a fork, if one exists, is not something this check has seen.
Every claim above, and how it is known
- DERIVEDThe catalogue carries 2 bags in the fork / cargo category: one that bolts to a mount and one that straps on instead.
- DERIVEDThe bolt-on fork cargo bag is 4000 ml and needs 1 three-pack mount.
- DERIVEDOf the three reference frames, only the large one (58 cm) declares a three-pack mount, and it declares 2 of them.
- DERIVEDThe bolt-on bag is refused on the small and medium frames for want of the three-pack mount, and fits the large frame, limited by in-frame volume.
- DERIVEDThe strap-on fork cargo bag is 3000 ml and declares no mount requirement.
- DERIVEDThe strap-on bag comes out Tight on all three reference frames, limited to 6 mm of strap purchase on a rigid fork leg.
Other notes worked the same way
- What does expecting rain add to a bikepacking kit list?
A dry forecast takes dry-bags, a groundsheet and a rain jacket off the list
- What do I add to a bikepacking kit list for cold nights?
Cold nights add four lines at freezing, and the first step adds one
- I said bikepacking, not touring. Does that change what the planner tells me to carry?
Saying touring instead of bikepacking changes nothing on the list
Every figure here came out of the same rules that answer the interview, so it moves when they do. Yours differ wherever your answers differ.