RockMate-The Rock Climbing Phone Holster




Introduction: RockMate-The Rock Climbing Phone Holster

In a family of avid climbers, you start to pinpoint issues of convenience with outdoor climbing. On my older brother's recent trip to Yosemite, where he climbed Half Dome in hiking shoes... well that's another story... he found an issue with carrying his iPhone up the walls with him. He wanted to have his phone for pictures, but obviously didn't want to drop it with thousands of feet between him and the Valley floor. With this in mind, I set out to make a product that allows you to access your phone while climbing without fear of dropping it. The RockMate was my solution- a phone case/holster that is on a retractable string, and attaches to your harness. And the best part is- it fits on any phone because it's completely adjustable! So if you want to keep your phone on a retractable string and be able to clip it to almost anything- the RockMate is for you!

Don't worry this is a cheap and quick (around 1 hour) build! If you have to buy all the materials it should cost no more than $20. The most required of you is tying some relatively simple knots. Don't know knots? Tie alot!

Here are the materials I used to make it, next to each is a link to where I bought it.


1. 8ft of reliable cord (I used Parachute Cord)--

2. A retractable ID Holster--

3. A double hole cord lock--

4. 6" of Mason twine (can be purchased at most hardware stores)

5. 1 Sewing Needle (will be ruined after)

6. Your Phone

7. A carabiner (doesn't need to be climbing grade)

8. A lighter

9. Scissors

10. Pliers

11. A Measuring tape

12. 1' of friendship bracelet string (optional)

Step 1: Making the Base

1. Cut two 17" lengths of parachute cord.

2. Seal the ends of the cord with a lighter.

3. Tie a slipknot on each cord.

4. Open up the loop created by the slipknot, and tighten it down around your phone. The actual knot should be at the center of the back side of your phone.

5. With the leftover tails of the rope tie an overhand loop knot using both tail ends together, the loop should be slightly snug around your thumb.

Here is a link for how to tie the overhand loop knot- and again tie the same knot in the video just with both strings together- thus connecting the loops.

Step 2: Add Exterior Lines

1. Cut four 9 and a 1/2" lengths of parachute cord and burn to seal ends.

2. Take one of the 9 and a half inch lengths, and wrap it in a circle (under, and then over as pictured) around one side of the slip knot loop on the back of your phone.

3. Flip over your phone so the screen is facing upwards.

4. Take the away-facing end of the cord you just looped, and tie an overhand knot around the the slipknot loop (refer to pictures). Also if you are using Parachute cord make sure the cord remains flat and not twisted.

5. Repeat step 4, three more times- refer to pictures to see what it should look like by the end of this step.

Step 3: Finish Up the Phone Wrap

1. Get out the double hole cord lock.

2. Put facing ends of the "exterior lines" through each hole of the cord lock--So two cords in each hole. It might take some pushing and shoving, but the 1/8" parachute cord makes it through.

3. Using the cord lock, tighten down the lines so the wrap is snug on your phone.

4. Now either tie an overhand knot at the end of each string, OR add some color to the RockMate by taking friendship bracelet string and wrapping it several times around each pair of cords.

5. (For friendship bracelet string option) To finish the friendship bracelet string wrap, simply tie a slip knot at the end of the string. and tighten it down over the rest of the wrap.

Step 4: Making the ID Holster Usable

Depending on whether you bought the same holster system as me, you may not need to do this step, or may need to come up with a different method. If you have a different system, I will tell you it's final purpose and you can decide if additional steps are necessary. The retractable string end of the holster will attach to the phone wrap via the overhand loop knot you made in Step 1. From there, the holster itself must somehow attach to your harness. For Example-- Using the holster I purchased-- A key-chain ring attaches the string to the phone. Holes where a belt clip used to be are thread through with mason twine, tied, and then a carabiner goes through the twine loop to clip to your harness.

Using my Holster:

1. Using pliers pull the pin that holds the belt clip out.

2. Using pliers get a firm hold on a needle, and use a lighter to heat it up until it burns red. Quickly stick the hot needle in the holes that the belt clip pin once went through and burn the holes so the radius is larger. *** Be careful not to burn yourself, and also not to burn open the holes. You may have to repeat this step several times until the holes are large enough for mason twine.

Step 5: Mason Twine and Carbiner Attachment

Again- if you are using a different ID Holster this might not apply to you.

1. Thread the 6" mason twine through the holster holes and then tie a figure eight knot to create a loop.

Figure eight knot how to-

2. Cut off any excess twine and burn it to seal.

3. Take a carabiner and clip it to the mason twine loop.

4. Take the key ring and connect it to the overhand loop of the wrap.

You're done!! Now you can adjust the wrap to different phones using the slip knots and cord lock. Get out there and send your projects and take some sweet victory pics. If you have any questions just comment, and I'll get back to you! Thanks for building!

Hack Your Day Contest

Participated in the
Hack Your Day Contest

Be the First to Share


    • Mason Jar Speed Challenge

      Mason Jar Speed Challenge
    • Bikes Challenge

      Bikes Challenge
    • Remix Contest

      Remix Contest

    7 Discussions


    3 months ago

    it seemed like a good idea! so i did it. twice, actually. the first try was with ~3.5mm rope, which seems to be to thick for some of the knots and i ended up using 2 cord-locks, since the rope is too thick for just one. recently i was at the climbing shop. saw some 2mm rope, and thought i'd give the phone-harness a second try.
    this time, it worked much better, and this is what you see in the pictures. i ended up using about 2m of the cord, for a rather large CatS61. I would also highly recommend to FIRST make the given part with all the knots and THEN cut the piece of rope, since your phone might have different dimensions. it is very well possible.

    first issue i have, the phone is dangling in a "flat" horizontal fashion. i guess it's more protective of the screen this way. also, one could solve this by adjusting the back know accordingly, so it's a minor thing.
    second issue, after some thought, the phone is still very much exposed. last time i tried a combination of quickdraw and (amazon) bag/pocket, which worked surprisingly well. if one likes to be really safe, you could use both at the same time to by sure the phone doesn't fall of (the CatS61 survived already 3 drops from 15m+ over rocks, but i don't want to push it any further).

    anyway, thanks for the instructable, i think this can be a very neat starting point for some projects. my first harness now hangs under my hangboard for the phone to show me the stopwatch ;)

    4 years ago

    I have climbed many years, the best place for your phone is in a back; put away and in some sort of crush proof, waterproof and dust proof container. Anyone belaying me and answering the phone would likely not make back to the parking lot and would be a missing person. SAFETY FIRST put the phone away.


    4 years ago

    I have climbed many years, the best place for your phone is in a back; put away and in some sort of crush proof, waterproof and dust proof container. Anyone belaying me and answering the phone would likely not make back to the parking lot and would be a missing person. SAFETY FIRST put the phone away.

    DIY Hacks and How Tos

    That looks like a fun phone holster even without the rock climbing.


    Reply 4 years ago

    Thank you!


    4 years ago

    This is really handy! can't tell you how many times ive slammed my butt from an awkward fall though. how's it handle the swinging??


    Reply 4 years ago

    Hahaha thanks! I choose an especially strong retractable holster so it actually can retract with the weight of your phone. I imagine if you took a whipper the string would fly out some, but its easily fixable with the push of a button. I know what you mean though if you're getting ground up in a crack, you're probably gonna want a sturdy case on your phone to protect from scratches. Let me know if this helped, I haven't actually taken any big falls with it yet.