In Depth: Radical Design Seat Bags, Rack Bags and Pannier Systems

Brilliant Product

Radical Design Seat Bags, Rack Bags and Pannier Systems.

Manufacturer website: Radical Design

I keep Radical Design (“RD”) bags on hand because I think this company is making some of the most exciting products in the recumbent marketplace. I’ve used RD bags for the majority of my tours for the past five years. They replaced my prior favorites, Ortlieb panniers, which have been relegated to grocery shopping and hardware store duties.

There are several significant reasons I like Radical Design bags: they are aerodynamic, they enable a lightweight solution for carrying gear, the overall cost is similar to bags of equal quality, the quality is excellent and they are easy to carry unmounted from the bike.


Radical Design bags and panniers are aerodynamic in several ways. The seat back bags and the rack-top bags are mounted behind the seat. Not only do they add no wind resistance, they smooth out the airflow behind the seat. The panniers bags are mounted beneath the seat but then continue on behind the seat as shown in the photo, above. There is only one small cross-section hitting the wind straight-on and the rest of the bag follows in that airflow. This is contrasted with standard panniers which put the the full height and width of the bag in the wind, creating significant aerodynamic drag. If under-seat panniers are also mounted, those present a full second set of bag cross-sections to the air flow. This contrasts strongly with RD panniers which, even in the largest sizes, do not add significant air resistance as bag capacity increases. It’s an incredible experience to have a heavily-loaded bike that is still very fast on the downs and flats.

Going Lightweight.

There are four ways Radical Design bags establish the basis for a lightweight touring system: the fabric is light but strong Cordura nylon; they minimize the requirement for racks which add to bike weight (RD bags require no rack or only one rack instead of two); bag weight is dedicated to carrying capacity as opposed to rack mounting hardware; and RD bags have a low weight to capacity ratio.

Lightweight Fabric
Radical Design bags are made from lightweight Cordura nylon with a water-resistant inner coating on the fabric. This is a lighter solution than traditional fully-rubberized panniers, like Ortliebs. For additional water-proofing, I suggest putting your gear in dry bags (water proof stuff sacks) which you would then put into the panniers. One could also seam-seal the pannier seams to increase water-resistance. While dry bags add to the overall weight, contemporary dry bags are light and, anyway, many people use stuff sacks or dry bags inside their panniers anyway, regardless of whether the panniers are “waterproof.”

Lighter without a rack.

Racks are heavy so they can be strong (and Titanium racks are expensive so they can be strong). Your bike will be lighter if you have fewer or no racks. For example, while exact rack weights depend on the rack in question, consider that the Tubus Logo Evo, a high-quality rack that can carry 88 pounds, weighs 1.6 lbs. For recumbent bikes, the traditional luggage solution is to have a rear rack for basic payload needs and, if additional capacity is required, one adds an underseat rack. With two racks, one is easily 3-6 pounds to the naked weight of the bike.

Radical Design makes small seat-back bags (such as the Solo Aero) with 10-12 liters (2-3 gallons) capacity, that are perfect for day trips. They hang from the back of the seat and require no rack. If you need double that capacity, they have a 25 liter (~6 gallons) “banana racer” side pannier that hangs entirely from the seat, again requiring no rack. Then, if you need still more capacity, you can combine those two models for ~37 liters capacity. This is just shy of the capacity of two 20-liter Ortlieb roller rear panniers, all without needing to add the weight of a rack, as you’d need to do for the Ortliebs.

For Radical Design’s larger panniers, of 40 to 70 liters (10-17.5 gallons) a rear rack is required. However, no underseat rack is necessary. This provides as much capacity as a traditional FOUR pannier system (60-70 liters) based on the weight of TWO panniers and a single rack. You can also add an RD rack-top bag (20-30 liters/5-7.5 gal) or seat-back bag to the setup, expanding capacity without adding weight to the bike in the form of additional racks.

Life is Lighter without Mounting Hardware.

RD bags are also lighter than traditional panniers because they don’t have the weight of mounting hardware built into the panniers. Instead, the bags attach to the bike seat, frame and rack using light but strong nylon webbing and nylon plastic buckles and fasteners such as those found on hikers’ backpacks.

Low Ratio of Weight to Capacity
RD panniers are lighter than traditional panniers of equal capacity. A meaningful ratio is empty bag weight to capacity: how heavy does the vessel need to be to carry the things you want to carry? I’m going to continue picking on Ortlieb here because: 1) I respect them and sell and use their bags; 2) they’re arguably the world’s premier pannier manufacturer; and 3) I want to compare manufacturers who produce similarly high quality goods. It would be meaningless to compare Ortlieb to something that is lightweight due to lack of durability.

Comparison of the weight of Radical Design and Ortlieb empty panniers to their carrying capacity:

Radical Design Banana Large side-panniers
1,080 grams weight : 70 liters capacity
15.43 grams per liter capacity

Ortlieb Back-Roller Pro Plus panniers
2,007 grams weight : 70 liters capacity
28.67 grams per liter capacity

Ortlieb Back-Roller Classic panniers
1,900 grams weight : 40 liters capacity
47.5 grams per liter capacity

Overall cost is similar to bags of equal quality.
It may seem that RD bags cost more than pannier systems of equal capability. However, the cost of the bag is only one of several costs for mounting a luggage system on a bike. Additional costs are: cost of the rack, cost of labor (yours or the shop’s) to install the racks and, the cost incurred by equipment failure.

To create a comparison, here are several luggage systems of similar quality on an HP Velotechnik Street Machine Gte in descending order according to carrying capacity.

1) 70 liters capacity
$ 6.07 : 1 liter
Radical Design Banana Large side-panniers (70 liters): $ 276 (at current exchange rate)
Street Machine Gte rear rack: $ 149
Cost for 70 liters capacity: $ 425

2) 70 liters capacity
$ 5.70 : 1 liter
Ortlieb Back-Roller Pro Plus rear panniers (70 liters): $ 250
Street Machine Gte rear rack: $ 149
Cost for 70 liters capacity: $ 399

3) 65 liters capacity
$ 9.51 : 1 liter
Ortlieb Back-Roller Classic rear panniers (40 liters): $ 180
with Sport-Roller Classic front panniers (25 liters): $ 160
Street Machine Gte rear rack: $ 149
Street Machine Gte under seat rack: $ 129
Cost for 65 liters capacity: $ 618

4) 40 liters capacity
$ 8.22 : 1 liter
Ortlieb Back-Roller Classic rear panniers (40 liters): $ 180
HP Velotechnik Street Machine Gte rear rack: $ 149
Cost for 40 liters capacity: $ 329

5) 37 liters capacity
$ 9.46 : 1 liter
Radical Design Banana Racer side-panniers (25 liters): $ 215
Radical Design Solo Aero narrow (12 liters): $ 135
No rack required.
Cost for 37 liters capacity: $ 350

6) 25 liters capacity
$ 8.60 : 1 liter
Radical Design Banana Racer side-panniers (25 liters): $ 215
No rack required.
Cost for 25 liters capacity: $ 215

7) 18 liters capacity
$ 19.94 : 1 liter
Ortlieb Recumbent Backpack (18 liters): $ 210
Street Machine Gte rear rack: $ 149
Cost for 18 liters capacity: $ 359

Quality and the High Cost of Failure.
Panniers designed for serious usage are built not to fail. The most common failures I’ve seen with panniers are mounting brackets falling apart, buckles breaking, seams tearing, fabric wearing out in the corners, and straps wearing through. You get some warning as materials wear out and seams tear because you may see it happening. Mounting brackets, however, can fail suddenly when a bolt falls out or a spring mechanism breaks.

There are several costs present here. There’s a cost for over-building the mounting system so it doesn’t fail. There’s an additional cost in terms of what else gets broken when something fails: Does your laptop get broken when your pannier falls into the street? And there’s a cost in terms of secondary damage: Does the pannier fall into your wheel, causing an accident?

I like Radical Design bags’ mounting system because they are simple. Very little can suddenly go wrong: the attachment system is webbing and buckles. And it’s easy to repair if it fails: if a strap tears, the field repair is to sow or re-tie it with thread or dental floss. Repairing a mounting bracket or replacing (or finding!) a lost screw is harder.

I don’t know how to calculate the cost of “risk of failure,” but I value peace of mind.  I get a lot of that from the simple RD strap-mounting system.

Radical Design panniers are easy to carry with one hand, when unmounted from the bike.

RD panniers are like two small duffel bags attached to one another by straps. These straps may be used as carrying handles. The largest, 70-liter, size has carrying handles sewn in. So, when you need to carry your bags off your bike, it’s as easy as carrying one duffel. This feature is particularly valuable in situations where you need to manage the bike with one hand and your luggage with the other. Traditional panniers, each of which is an independent bag, require you to manage multiple separate bags, instead of just one “bag unit.”

Manufacturer website: Radical Design