Buying task · Bags
Bike bags
Choose bike bags by where they go and what your bike offers: frame space, top-tube bosses, rack tube size and the lower of the rack's and bag's stated load limits.
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Short answer
Decide where the bag goes first, then check what your bike offers there: frame space, top-tube bolts, a seatpost, bar room or a rack with the right tube size. Size frame bags by the frame, not by liters. On a rack, stay under the lower of the rack's and the bag's stated load limits.
What this topic covers
A bike bag either fits the place you put it or it does not. Volume in liters is the least useful number when you buy: it tells you nothing about frame clearance, hook size or load. We report how each maker says its bag attaches, the load it states and any IP rating with its condition.
The decisions, in order
1. Where it goes. Frame, top tube, saddle, handlebar or rack. Each place has its own limit: frame space for a frame bag, bolts or straps for a top-tube bag, seatpost and tire clearance for a saddle bag, bar room for a handlebar bag, and rack tubes for a pannier.
2. What your bike offers. Apidura's Expedition Bolt-On Top Tube Pack attaches with two bolts to top-tube bosses plus a strap around the steerer, and Apidura sends bikes without top-tube bolts to its strapped version.[1] For panniers, ORTLIEB's QL2.1 system uses 16 mm upper hooks with inserts for 8, 10 and 12 mm rack tubes.[2] Its QL2.2 system lists tool-free hooks for 8-16 mm tubes and a 12.5 kg maximum load.[2]
3. Size by frame, not liters. Apidura says frame pack size should be chosen by the dimensions of the frame, not by how much you want to carry.[3] Its sizing guidance asks riders to include water bottles and frame-mounted accessories when they photograph the bike, for accurate clearance.[4] See how to size a frame or top-tube bag.
4. The attachment's range. A rack must fit the frame before a bag fits the rack. Topeak says the TetraRack M2 HD needs seatstays over 15 mm in diameter, 95-125 mm apart and angled over 25 degrees, and does not recommend TetraRack for carbon forks and seatstays.[5] Basil says its separate MIK Carrier Plate fits carriers with 8-16 mm tubes and 100-170 mm outer width.[6] Brompton Electric uses a dedicated front carrier block, so Brompton says it needs an Electric-compatible front bag with space for the battery.[7]
5. The lower load limit wins. ORTLIEB lists the Back-Roller pair at 20 L per bag with a 9 kg maximum payload per bag.[8] Topeak lists a 22 kg (48.5 lb) maximum total load for the TetraRack M2 HD.[5] Basil lists 15 kg for its MIK adapter plate,[6] and Brompton says its front bags can carry up to 10 kg.[7] See rear racks: frame fit, load limits and top bags.
6. The maker's IP rating and its condition. IEC 60529 classifies the protection an enclosure gives, as an IP code.[9] ORTLIEB rates the Back-Roller IP64 (dust-tight, splash-protected) provided the closure is rolled down three to four times and secured downward.[8] That is not an immersion rating.
Saddle bags
Saddle bags hang from the seatpost and saddle rails, so they need room above the rear tire. Restrap's 18-liter Saddle Bag attaches to the seatpost without mounts or screws, using a holster with a separate dry bag.[10] Restrap lists an IP6K6 rating for it.[10] Restrap's page states no maximum load, no tire or saddle clearance and nothing about dropper posts, so treat those as unknown and check your own bike. A seller's broad fit wording is not a fit statement.
Handlebar bags
A bar bag competes with lights, a computer mount, cables and your hands. We found no maker source that states handlebar-bag clearance in numbers, so we cannot give one. Before buying, check the space between the brake hoods or grips, the cable runs, and where your light and mount sit. If a bag's maker gives no bar diameter or load, treat both as unknown.
How to choose
Pick the bag for the place your bike has room, then confirm the maker's attachment method on its own page. On Amazon, check that "Ships from / Sold by" shows Amazon.com or the brand. The bags below are approved for this site; we have not yet verified their makers' figures, so check the maker's page for size and attachment.
Picks that fit3 products
For a strapped top-tube bag behind the stem, choose the Topeak Fuel Tank in Large, the Topeak Tri DryBag in Medium, or the ROCKBROS 039BK in STYLE 1.
More on choosing
Measure your top tube behind the stem first. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
Smaller strapped top-tube bag
Picks that fit4 products
For a seatpost bag, choose the Topeak BackLoader 10 L in black, or the larger BackLoader X in 15 L green with its holster, and check the room above your rear tire.
More on choosing
For the bars, choose the Rhinowalk RK9300 harness with its dry bag (RK9301 is the harness alone); on the listing from Rhinowalk's own store, pick the harness with the dry bag, not 'Base'. Check cable and light clearance. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
Seatpost bag with a holster, larger size
Handlebar harness with dry bag
Handlebar harness with dry bag, from Rhinowalk's own store
Rhinowalk handlebar harness with 12 L dry bag (RK9300 set, Rhinowalk's Amazon store)
Every page on bags
Guides
- How to size a frame bag or top-tube bag for your bike
- Pannier fit: hook sizes, rack tube diameters and e-bike racks
- Rear racks: frame fit, load limits and MIK or MTX top bags
- Brompton front bags: standard vs Electric carrier blocks
- Commuter bike kit checklist
Shortlist
Bike pages
Key terms
Rear rack, QUICK-LOCK, MIK system, MTX QuickTrack and IP code.
Everything in this topic
Guides
- Brompton front bags: standard vs Electric carrier blocksHelps Brompton owners tell whether a front bag and carrier block suit their line, especially on a Brompton Electric.
- How to size a frame bag or top-tube bag for your bikeHelps you measure your frame triangle and top tube so a frame or top-tube bag fits around your bottles and fittings.
- Pannier fit: hook sizes, rack tube diameters and e-bike racksHelps you match a pannier's hook system to your rack's tube diameter and stay inside the stated load per bag.
- Rear racks: frame fit, load limits and MIK or MTX top bagsHelps you check a rear rack's frame requirements and load limit, and pick a top bag that matches the rack's system.
Shortlists
- Bike bags with published mounting and volumeHelps you pick a bag by the place your bike has room for one, and check the attachment and space before you order.
Common questions
Will a regular Brompton bag fit a Brompton Electric?
Brompton says the Electric uses a dedicated Front Carrier Block, so it needs an Electric-compatible Front Bag with space for the battery. Check each bag's listing for Electric compatibility. More in Brompton front bags: standard vs Electric carrier blocks
How much can a Brompton front bag carry?
Brompton says its Front Bags can carry up to 10 kg, with the load sitting on the frame rather than the handlebars. More in Brompton front bags: standard vs Electric carrier blocks
Which Brompton lines take the standard Front Carrier Block?
Brompton's US listing gives fitment for the A Line, C Line Mk5 and Mk6, P Line Mk1, T Line and G Line. It lists no Electric models. More in Brompton front bags: standard vs Electric carrier blocks
Can I fit a Front Carrier Block myself?
Brompton's listing names a 5 mm and a 4 mm Allen key and a Phillips screwdriver as the tools required. If you are unsure, ask a Brompton dealer or bike shop to fit it. More in Brompton front bags: standard vs Electric carrier blocks
How do I measure my bike for a frame bag?
Measure the inside of the frame triangle along each tube and note where bottle cages and other fittings sit. Apidura says to choose frame pack size by the frame's dimensions, not by how much you want to carry, and offers a sizing tool and a printable template. More in How to size a frame bag or top-tube bag for your bike
Will a frame bag fit with water bottles?
Only if you size for them. Apidura's sizing instructions ask riders to include water bottles and frame-mounted accessories in the bike photo so clearance is accurate. More in How to size a frame bag or top-tube bag for your bike
Do I need bolts on my top tube for a top-tube bag?
Only for a bolt-on bag. Apidura's bolt-on top-tube pack uses two top-tube bolts plus a steerer strap, and Apidura directs bikes without those bolts to its strapped version. More in How to size a frame bag or top-tube bag for your bike
Is there a standard bolt spacing for top-tube bags?
We found no source that sets one. Apidura gives no bolt spacing in its text and advises riders on smaller frames to check pack length, so compare your own bolt positions with each bag's. More in How to size a frame bag or top-tube bag for your bike
Questions
What size frame bag do I need?
One sized by your frame, not by liters. Apidura says frame pack size should be chosen by the frame's dimensions, and asks riders to include bottles and frame-mounted accessories when they measure. See how to size a frame or top-tube bag.[3][4]
Will panniers fit my bike?
Only if your bike has a rack whose tubes match the bag's hooks. ORTLIEB's QL2.1 hooks come with inserts for 8, 10 and 12 mm rack tubes, and it offers 20 mm hooks for 17-20 mm tubes, which it says are often used on e-bikes. See pannier hooks and rack tube sizes.[2]