Gearnalysis

Sea to Summit Spark 30F vs. Zpacks Solo Quilt 30F

A close look at two sleeping bags buyers cross-shop. The Spark 30F leans on warmth while the Solo Quilt 30F answers with low weight, so the pick comes down to which you value.

Sea to Summit
Spark 30F
85GearScore
Down · Bag
wins 2 specs
Zpacks
Solo Quilt 30F
63GearScore
Down · Quilt
wins 4 specs
Sea to Summit Spark 30FZpacks Solo Quilt 30F
GearScore85✓63
Comfort rating39 °F✓40 °F
Weight17.4 oz13.3 oz✓
Warmth-to-weight6.3 /100g8.0 /100g✓
Packed size4.5 Ln/s
Fill power850 FP950 FP✓
Price$449$419✓
FillDownDown
StyleBagQuilt
ShapeMummyQuilt

Highlighted cells mark the better spec: Spark 30F in blue, Solo Quilt 30F in amber. A blank spec is never counted as a win. A lower comfort rating in °F means a warmer bag, so the warmer bag takes that row. GearScore is the overall rating (0 to 100); re-weight it on the full bag comparison. Prices are current MSRP.

Put the Sea to Summit Spark 30F next to the Zpacks Solo Quilt 30F and the trade-offs are clear. The Spark 30F wins on warmth, and the Solo Quilt 30F pushes back on low weight and warmth-to-weight.

The Spark 30F is warmer (rated 39°F vs 40°F). The Solo Quilt 30F is 4 oz lighter, stronger on warmth-to-weight, and higher fill power (950 vs 850). On the default GearScore the Spark 30F leads 85 to 63.

Pick the Spark 30F if you care most about warmth, which makes it the better call for colder nights and shoulder-season trips. Pick the Solo Quilt 30F if low weight and warmth-to-weight matter more to you, or you are focused on counting grams on long miles.

Common questions

Which is warmer?

The Sea to Summit Spark 30F. It is warmer (rated 39°F vs 40°F) than the Solo Quilt 30F.

Which is lighter?

The Zpacks Solo Quilt 30F. It is 4 oz lighter than the Spark 30F.

Which has the higher GearScore?

The Sea to Summit Spark 30F, 85 to 63 on the default algorithm. You can re-weight the factors to match your trip.

Spark 30F or Solo Quilt 30F, which should you buy?

It depends on your priorities. Go with the Spark 30F for warmth, or the Solo Quilt 30F for low weight. The spec table above shows exactly where each wins.