How to determine if a Fernhill bag will fit your bike

We designed the LTL frame bag to fit on your bike anywhere you can find a space to strap it on. With attachment points circling the circumference of the bag, you can mount it in any orientation, using our supplied hook and loop straps, zips ties, Voile Straps, or anything you'd like.

4 straps are included with each bag. We've found that 3 is our ideal number of straps to secure a bag to a frame, but if you have an oversize downtube (as found on eMTBs) you can combine two of the straps together to make a strap that is longer in length. We've also found zip tires work quite well. 

Turbo Levo emtb s4

A 2023 Specializes Turbo LEVO size S4 with a large LTL frame bag mounted

Our preferred location for mounting is on the inside of the frame, but it is dependent on the suspension design as well as the frame size. Many frames have a space behind the head tube that fits our small or large bag quite neatly, and we measured a lot of frames before creating the two sizes we offer.

Some frames don't have space for a frame bag on the inside. When our bikes can't fit one there, we've had success mounting it by the seat post.

On this 2020 Norco Sight VLTc (size medium) there isn't quite enough space to squeeze a small LTL bag in... unless you use a Wolftooth B-RAD bottle relocation rail to move the bottle cage down and create a bit more space for the bag.

Determining fit

If you're interested in purchasing one of our LTL frame bags but aren't sure if one will fit, the dimensions of the bags are as follows:

  • Large: 8.75" inches long x 3.25" high (1.75" deep)
  • Small: 7.25" inches long x 3.5" high (1.75" deep)

Start by grabbing your tape measure and taking a few measurements of your frame to see if there is space for a bag. If you ride with a water bottle you'll want to measure the gap remaining while your usual water bottle is mounted.

If you're still not sure if one will fit, we created a paper template PDF you can download and print to get a better idea if it'll be a good match for your frame.

After printing the PDF at 100%, verify the measurements on the paper to make sure it was printed at the correct scale.

Then cut it out and hold it up to your bike to get a more accurate assessment of what you have to work with.

The bag has some structure thanks to the materials used in its construction but its still a soft bag, and can squish a bit into the space to fit. (if it's a tight squeeze note that it could effect how much stuff you can squeeze into the bag)

Our favorite ride carry items are a tube, plugs, tire levers, a small multi-tool. That load out can be tricky with the small bag, but if you carry one of the compact Tubolito tubes (yes they're expensive, but ideally it doesn't come to that, and its more of an insurance policy to avoid having to walk back to the car!) that'll give you a bit more space to work with.


Download the paper PDF here