Bikepacking Hack: Extra Bottle Cages on a Surly ECR/Troll/Ogre

Need extra water capacity for a big bikepacking trip? Here’s a hack to add two additional bottle cages using Surly’s do-all, horizontal slot dropouts—tested on rough tracks in East Africa.

Sometimes it’s necessary to carry a lot of water—such as a weekend ride in the desert, or on a big bikepacking trip where sourcing clean water is a challenge. One great thing about the Surly fleet of dirt-touring bikes, namely the ECR, Troll, and Ogre, is that each has a full cadre of bottle cage bosses—one per fork leg, one on the underside of the down tube, and two in the triangle—five in total. However, if you are using a frame bag and an Anything Cage Bag, that takes three out of the equation. A hydration pack may be used to supplement, but for long days in the saddle some folks prefer to not rely on a backpack. So, why not use the rear end of the bike?

Bikepacking Pack List and Gear

Before we get too far into it, let’s make the scenario clear. This is a hack and has not been recognized by Surly as a legitimate way of carrying water. And, although it was vigorously tested on the Trans-Uganda and Congo Nile Trail, we make no claim that this hack is safe and will work for everyone, without fail. So, now that that’s out of the way, here’s how to add two extra bottle cages using the seat stays and Surly’s rear-loading ‘swiss army knife’ horizontal slot dropouts. They have it all—a derailleur hanger, disc caliper mounting slots, rack bosses, fender bosses, bosses for mounting a Rohloff, holes for installing a trailer mount… and one hidden use for those rear fender bosses.

Surly ECR - Rohloff dropout

This is what you’ll need:

  • Electrical tape: about a half roll, or less
  • Two pieces of innertube: 2 x 6″ (5 x 15cm)
  • Two ‘rack’ bolts: M5 x 0.8 x 16
  • Two spacers or washer stacks: Each equaling about 5 or 6mm
  • Two bottle cages: Lezyne Power cages worked perfectly for this.

Step 1: Mark the Seat Stay

Ultimately you are going to tape the neck of the cage onto the seat stay with a formed spacer in between. So the first thing you’ll do is bolt the cage to the back fender mount on the dropout to mark where the neck of the cage will meet the seat stay. With the 5mm spacer between the bottom cage hole and the dropout, loosely affix the cage with the M5 bolt. Mark where the neck will contact the seat stay and rotate the cage out of the way. Here’s a photo of the finished product so you can get the gist (and a photo of the M5 with the spacer in the correct non drive-side boss, cage not included, for clarity):

Extra Bottle Cages - Surly ECR, Troll, Ogre
  • Extra Bottle Cages - ECR, Troll, Ogre
  • Extra Bottle Cages - ECR, Troll, Ogre

Step 2: Make the Seat Stay Spacer Block

Double the slice of inner tube over lengthwise making a 1×6″ strip; then roll into a flat one inch square block. Attach the spacer block to the seat stay by wrapping electrical tape around the spacer and seat stay. Four or five wraps will do. Note that the photo below shows the condition once the cage was untaped; this was after two months of abuse.

Extra Bottle Cages - Surly ECR, Troll, Ogre
  • Extra Bottle Cages - ECR, Troll, Ogre
  • Extra Bottle Cages - ECR, Troll, Ogre

Step 3: Tape the Cage Neck

Next, rotate the cage back in place so the spacer block fits squarly against the neck. Then tightly apply 10-15 winds of electrical tape around the seat stay and bottle cage neck. Now tighten the M5 bolt, insert bottle, and ride.

Note: I used a 5mm spacer to move the cage away from the dropout and allow plenty of room for the rubber spacer at the top of the cage. The main reason it was done in this fashion was to eliminate any unnecessary stress on the stay or the dropout… and to provide plenty of flex via the DIY rubber spacer.

Overall this solution has worked well and provided the ability to carry 4 liters of water with one fork leg still dedicated to an Anything Cage and bag. Theoretically this method could be used with other bikes that feature a large dropout design with a fender boss.

Extra Bottle Cages - Surly ECR, Troll, Ogre
  • Extra Bottle Cages - Surly ECR, Troll, Ogre
  • Extra Bottle Cages - ECR, Troll, Ogre


  • It’s a simple way of adding two liters of water to your setup.
  • There’s plenty of room for full 1L Zefal Magnum bottles with no heel clearance issues (tested on a size large ECR frame, US 10 shoe size).
  • It keeps water weight down low, which is nice for maintaining a good center of gravity.
  • The cage placement keeps the bottle spouts clean; a factor in countries where livestock shares the trail.


  • This method places water bottles in a prime location for soaking up the warmth of the sun; drinking warm water is never fun.
  • Someone with large feet riding a size small or medium may have issues with heel interference; however, this could be avoided by using shorter bottles.
Extra Bottle Cages - Surly ECR, Troll, Ogre

Please keep the conversation civil, constructive, and inclusive, or your comment will be removed.

Bikepacking Collective

We're independent
and member-supported.
Join the Bikepacking Collective to make our work possible:

Join Now