What's The Best Bag For Commuting By Bike? Saddle Bag Vs. Panniers Vs. Backpack
Why Bicycles Stack Exchange recommends it
Bicycles Stack Exchange answerers point people to it as measured evidence on how backpacks, panniers and saddle bags affect aerodynamic drag, especially in headwind and bag-choice questions.
Recommended by 2 people across 2 different months, 2018 to 2020.
What it is
Global Cycling Network takes a commuter bike and rider into a wind tunnel at Politecnico Milano to compare the aerodynamic drag of a backpack, panniers and a bikepacking-style saddle bag. The presenters discuss the results and what they mean for real commuting speeds.
What people said
Recommends Rider_X · 2019-09 · Bicycles Stack Exchange · on “Road bike drag decrease with bulky backback”
Your very question has actually been answered by GCN [LINK] (below) and Specialized [LINK] and has been partially answered in What's more aerodynamic on flat bars: backpack or pannier? [LINK] Essentially the in order of fastest to slowest: Large saddle bag (i.e., bike packing bags) Back pack Pannier By far the panniers will be the slowest option as you are hanging the bag out in the full wind. Backpacks are pretty fast, but do affect wind transferring over your back. If you don't have a lot to carry bike packing bags are the fastest option as they are tucked away the most. Over the last 2 years I have switched completely to bike packing bags and a fast road bike for my 45 km commute (2 way)
Recommends Chris H · 2020-08 · Bicycles Stack Exchange · on “Headwind issues”
When your biggest problem is a headwind, being more aerodynamic helps. In a severe headwind, it becomes more important than many other considerations. I posted a link in the comments to GCN's commuting aero challenge [this video] . This shows that panniers are bad into the wind, backpacks much better, and a bikepacking saddlebag better still. Yes they went fast, 40 km/h, but if you try to ride at 25km/h into a 25km/h headwind the power lost to drag is about the same. There are a few more conclusions we can draw either directly from the video or after watching it (including the discussion at the end). A backpack isn't bad in its own right, but is worse the more aero (lower) you get, as it's expose
Cites David Richerby · 2018-07 · Bicycles Stack Exchange · on “What are the differences between a seatpost-mounted and frame-mounted rear rack”
RoboKaren's answer [LINK] is great on the pros and cons, so I'll restrict myself to explicitly answering ... why would someone get the seatpost-mounted rack over the frame-mounted rack? Really, the only reason is that your bike won't support a frame-mounted rack: for example because it has rear suspension. In engineering terms, a frame-mounted rack supports the weight of what you're carrying from below by being attached to the bike somewhere near the rear axle, and the connection near the saddle is mostly to keep the rack in the correct orientation. A seat-post-mounted rack supports the weight entirely by torsional forces through the seat-post, which isn't nearly as sturdy. That means the ra
Cites Rider_X · 2018-10 · Bicycles Stack Exchange · on “How quickly can the body restore energy reserves mid-ride/post-bonk, and how do we optimise this?”
I'm interested in how we can maximise restoring energy stores (mainly glycogen, but I'm deliberately being vague) either between closely spaced rides or on long rides. On a ride Here your ability to actually rebuild glycogen stores are compromised as your body is trying to fuel the activity not rebuild your stores. Exercise actually alters your physiology, for example the blood flow to the gut is restricted. As such, severe or exhaustive exercise actually inhibits gastric emptying and interferes with gastrointestinal absorption. This makes it difficult to absorb food, why easily digestible foods such as gels were invented. Your insulin response is also greatly reduced during exercise as your
Cites R. Chung · 2019-09 · Bicycles Stack Exchange · on “Road bike drag decrease with bulky backback”
Here is a partial answer: a backpack is better than panniers but worse than a saddlebag bikepack. [this video] What's missing from this is the size of the advantage for going to a road bike from a MTB. Typically, however, road bike tires have lower rolling resistance, are lighter, and have lower aerodynamic drag than MTBs so with the same cargo-carrying location the road bike will have lower drag.
Cites Chris H · 2020-08 · Bicycles Stack Exchange · on “Headwind issues”
See the GCN Commute Aero Challange [this video] . Panniers (or I would assume a backpack on a rack) are *less* aero than wearing a backpack; bikepacking luggage is best though expensive and hard/slow to pack.