Gregory Reactor

3 reviews
5-star:   2
4-star:   0
3-star:   1
2-star:   0
1-star:   0


Weight 1 lb 5 oz / 600 g



The Gregory Reactor 9 racing pack is fantastic. It's…

Rating: rated 5 of 5 stars
Design: Adventure racing pack
Size: 700 cu in / 11 liters
Number of Pockets: 2 compartments, 2 side mesh, 1 back mesh, 2 small mesh on waistband (plus compartments within main compartment including water reservoir if desired)
Max. Load Carried: I don't know but specs say 28 lbs
Height of Owner: 5'8"
Price Paid: $34.97

The Gregory Reactor 9 racing pack is fantastic. It's extremely lightweight yet rugged, has lots of places to put things, yet gives the straps you need to hold it all together compactly. Very easy on the back. Sternum strap can be adjusted for your body's shape.

I have a herniated disk. I just ran 16.5 miles with the Gregory 9 packed to the gills, including 1.5 quarts of water, and never felt a thing. And hours later, it's clear I'm not going to either. It's the perfect running pack. It even has cool mesh pockets in the waistband.

I disagree with the first reviewer, who gave it only 3 stars because it's not good for carrying books and because he couldn't access the main compartments quickly enough because of the straps.

1. It's not a bag for carrying a bunch of books. It's for running.

2. The straps just pop in and out very very easily. I'm sure they are a big factor in why the pack is so compact when running with it. In my book that makes them a plus not a minus. The split second it takes to snap them open and shut is nothing compared to hours and hours of comfortable running.


I received this pack as swag at Primal Quest Utah…

Rating: rated 3 of 5 stars
Design: Panel load day pack/hydration pack
Size: 700 cu. inches
Number of Pockets: 5 external 2 internal including hydration pocket
Max. Load Carried: Approx. 25 pounds
Height of Owner: 5' 9"
Price Paid: Free - Primal Quest swag

I received this pack as swag at Primal Quest Utah in '06.

The pack is very light and is deceptively roomy. The helmet pocket easily holds a full size helmet or a folded jacket. The mesh side pockets are plenty large for 1 litre bottles.

If the pack is fully loaded with heavier items such as books, the minimally padded shoulder straps are not very comfortable.

The side compression straps are handy for keeping the load from shifting, but they must be undone in order to fully open the main, or outer compartment zippers. If rapid retrieval of gear is a priority, the straps can and do get in the way.


This pack has been awesome. I've had it since January…

Rating: rated 5 of 5 stars
Number of Pockets: 5, the helmet pocket can hold anything!!!
Max. Load Carried: 12lbs
Height of Owner: 6.2
Price Paid: retail

This pack has been awesome. I've had it since January 06 and have used as my daily pack here in NYC. I'll carry a bunch of stuff in it and max it out or maybe just a book. But it does it all well. I took this pack to Thailand with me and it served it daily requierments to a T. I've also used it to carry my climbing shoes and basic gear for a day in Central Park. Really a bitchen pack, don't worry about its durability!!!

Retailers' Descriptions

Here's what other sites are saying:

The Gregory Reactor hydration-compatible daypack is built for ultra-marathoners as well as everyday athletes. Carries your ultralight essentials and a hydration reservoir (sold separately). G Fabric is a high-tenacity nylon fabric impregnated with silicone so its fibers stretch under pressure instead of locking together and tearing. Pack has a front zippered pocket, 2 side mesh pockets and a larger front mesh compression pocket for storing water bottles, jacket and energy food. Right at your fingertips, mesh waist zippered pockets on hipbelt is great for stashing energy bars or gels. Canted bottom prevents sagging and positions pack's load higher on your back for ideal carrying. Bottom compression straps and front bungee cord allow you to lash on and carry various technical gear. When teammates bonk during races, use the tow loops to literally tow your teammates in need. Wrapping the waist is the laminated, diecut waistbelt with zippered essentials pocket. Aero-Tech™ mesh on back panel helps move moisture away to keep you dry. Hydration sleeve with an exit port holds a reservoir (sold separately) for hands-free hydration on the trail. Reflective tape improves visibility in low light. Closeout.


On Sale. Free Shipping. Gregory Reactor Daypack (Fall 2008) Updated to include a larger capacity front compression pocket, the reactor is designed for fast moving, on the go outdoor pursuits like sprint length adventure racing. Mesh waistbelt pockets, V-Pull compression straps and a large mesh front pocket for light weight organization. One size: 700 cubic inches / 11 liters 1 lb. 6 oz. / .7 kg Suspension;/p> Yoke style harness Breathable Aerotec lined backpanel Sport waistbeltPack Large front mesh compression pocket New Canted Bottom Silicone impregnated G 30 fabric V-pull compression straps Hydration sleeve and port Mesh waistbelt pockets Reflective tape

- Moosejaw

The Gregory Ultralight Reactor daypack is designed for fast-moving outdoor pursuits like sprint-length adventure racing. Features self healing G30 pack fabric, waist belt pockets, and a hydration sleeve. Yoke-style harness for great stability as you run. Breathable Aerotec-lined back panel. Sport waistbelt is thin and light; mesh waistbelt pockets. Large-capacity front mesh compression pocket. Two main compartments. G30 fabric body is 75% lighter than other pack cloths, but it is injected with silicone, so its fibers stretch under pressure instead of locking together, creating greater tear resistance. All major stress points are reinforced with an extra row of stitching. Reflective tape.


Gregory Reactor Pack : Sprint length adventure race pack with self healing G 30 fabric, waistbelt pockets for fuel storage and a hydration sleeve large enough to accommodate 100 oz’s of water. Features V-pull compression straps Yoke style harness Breathable Aero-Tech mesh backpanel Gullwing™ waistbelt Dual waistbelt pockets Large front mesh compression pocket Canted Bottom Hydration sleeve and port Reflective tape Materials: Fabric: Silicone coated G 30 fabric with 210d high tenacity nylon reinforcements Volume: 700 IN3 / 11 L Weight: 1 LBS 6 OZ / 0.62 KG

- OMCgear

Adventure racing is tough enough without the distractions of flimsy gear. That's why Gregory designed their Reactor racing pack with a lightweight and stretchy G 30 fabric that remains resilient to the rigors of constant motion. While the G 30 fabric is more than 75% lighter than the materials found in other Gregory packs, it's also coated with a silicone treatment that makes the fibers stretch instead of shredding. Because the Reactor is designed to accommodate a 120-oz. hydration reservoir (not included), the pack has a structured yoke harness, contoured backpanel and a comfortable Gullwing waist belt for load transfer and stability. Despite the extra refinements, the entire pack barely weighs over a pound, so when you're racing, you're only hauling the essential stuff that will get you to the finish line. If you need a racing design that's large enough to accommodate a helmet, check out Gregory's Iso pack.

- Altrec Outdoors

Gregory Reactor


The Reactor has been discontinued.

previously retailed for:
$39.93 - $69.00

The Gregory Reactor is not available from the stores we monitor. It was last seen January 5, 2010 at REI.

If you're looking for a new daypack (under 2,000 cu in), check out the best reviewed current models.