Revelate Designs Terrapin Seat Bag Review

About the Revelate Designs Terrapin Seat Bag

Terrapin is a third-generation modular seat bag system from Revelate Designs that features a removable drybag, which fits into a shaped, waterproof seat pack.

Everything is held in place via two straps: one that attaches to your seatpost, and another on top of the pack that fits through your saddle’s bottom rails. Dubbed their “Indie-Rail” attachment system, these connect to cinch straps on the side panels, which also boast a rigid internal structure and active cam buckles. 

Combined, Revelate promises the Terrapin will remain firmly in place while you ride, without the need for external hardware, while delivering the ease of use and durability you require.

Here, I’ll talk about my experience using the Terrapin Seat Bag system on a ride across Missouri along the Katy Trail, so you can decide whether or not it’s right for you.

First, let’s quickly cover the system’s basics.

How Does the Terrapin Seat Bag System Work?

Revelate designed the Terrapin seat pack (15oz) with a wedge-shaped profile that’s narrower toward the front, where it connects with your seat post, and gradually widens as you move toward the back. It’s here where the similarly shaped dry bag (5oz) inserts, which is made from 200-denier waterproof TPU laminated ripstop nylon and features radio frequency welding and an air purge valve.

Underneath the pack’s exterior, you’ll find tons of features to help it battle the elements: foam-stiffened side panels with fiberglass compression stays, along with a composite top frame sheet.

On the outside, the Terrapin pack boasts Revelate’s abrasion-resistant RevX-PAC panels, a protective plastic bottom frame sheet to help prevent your tire from causing damage, and aluminum hardware at high-stress points. There’s also an external webbing-and-loop system that houses a bungee for easily accessible external storage.

Bringing it all together, Revelate’s Indie-Rail system loops through your saddle’s rails to virtually eliminate sway, without the need for additional hardware, which attaches using active cam buckles for reduced slippage. Their website explains this “transmits the vertical load to the seatpost connection” for a more reliable and stable platform.

Important Note: Revelate emphasizes that the Terrapin seat bag system is not designed for use with dropper posts. Even then, you should check tire clearance before use with full suspension bikes.

My experience Using the Terrapin 14L Seat Bag System

My wife and I rode 225 miles across Missouri along the Katy Trail using our 14L Terrapin seat bag systems. Mine was attached to my Canyon Inflite AL gravel bike, whereas my wife used hers with her Yeti SB4.5.

Overall, I’d say that the Terrapin system is well worth the money, and delivers on many of its performance promises. It’s well-constructed, boasts quality craftsmanship, and comes with essential features you don’t even know you need, yet—just like my experience with most of Revelate’s gear.

However, it’s not perfect. Stick with me for a couple of minutes, and I’ll outline some of the Terrapin’s potential pros and cons based on my experience.

Fitting & Mounting the Terrapin System

Even during my first attempt, setting up the Terrapin system didn’t take more than 15 minutes. It’s super easy: simply thread the Indie-Rail strap through the underside rails on your saddle, and then clip the straps into place on the side.

After adding your items to the dry bag, unthread the air bleed valve, roll the top down until tight (while making sure that the clips remain parallel), close the valve, and then clip each side.

Next, the dry bag fits into the seat pack, both of which feature the same wedge shape. You’ll pull the rear straps over the back of the drybag, clip them into place, pull tight, and then affix them into place with the cam buckles.

Using & Cleaning the Terrapin Seat Pack and Dry Bag

On the third day of our Katy Trail trip, we were continually rained on for 70 miles, and the Terrapin’s drybag kept our gear bone dry—which was a welcome relief after a chilly, soggy day in the saddle.

Unpacking the Terrapin is just as easy as packing it—simply unbuckle the pack’s rear straps, remove and unclip the dry bag’s straps, and take out your stuff. There’s plenty of room to store your goodies (and then some), and since you don’t have to completely detach the pack from your bike to access your contents, everything is super smooth and convenient.

Once our packs dried, we just wiped them clean with damp cloths to remove some of the excess mud and other debris.

With all of this said, the Terrapin system noticeably swayed from side-to-side underneath us as we biked. In other words, although Revelate Designs boasts about the seat pack’s stability, it’s not entirely movement-free, which would require additional hardware in the form of a metal mounting bracket.

Furthermore, the sag from my wife’s full suspension MTB caused the bottom of her Terrapin bag to rub against the top of her rear tire regularly. While I’d imagine it would take thousands of miles of friction to rub through the pack’s plastic bottom frame sheet, it can become bothersome when riding hundreds of miles.

My Overall Impressions About Revelate’s Terrapin System

Based on its performance, I feel that the Terrapin seat pack is competitively priced, looks great, boasts durable construction, holds a lot of gear, and is super easy to mount and use. Together, I believe it can get you out bikepacking, with as little fuss as possible.

Just keep in mind that if you have a full suspension setup, the Terrapin system might rub against your rear tire, so make sure that everything works properly before heading out on your adventure. And if you plan to use your dropper post during your tour, you’ll need to look at options other than the Terrapin.

Speaking of which, how does Revelate’s Terrapin seat pack system compare to competing models?

Revelate Designs Terrapin vs. Competing Bikepacking Seat Packs

There’s no shortage of seat packs competing with the Terrapin system, which features a variety of weights, sizes, prices, and designs. And like most other cycling purchases, choosing the “best” one will primarily come down to which model most closely meets your specific combination of needs and preferences.

With this said, here’s a quick table that outlines their key differences on paper:

Let’s go ahead and bring everything together.

My Final Thoughts About the Revelate Designs Terrapin Seat Bag System

With an MSRP of $155, the Terrapin system is priced at the upper end of the spectrum compared to competing bikepacking seat packs. Based on my experience, it also tends to move more than models that attach via a rigid rail mechanism (as an example). And it requires greater minimum clearance between the rear tire (8.5”) that many competing models.

However, the Terrapin system also delivers higher volume than many other models, includes welded construction and an air-valved drybag with your purchase, and comes with mostly positive online customer feedback.

Bottom line: I’ve been very pleased with my Terrapin seat pack system, and I recommend it to other cyclists. I’m itching for another—much longer—tour, so I’ll hopefully get to use it again soon.