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Is my new hangboard design structurally sound (Rock Prodigy Forge)?


Original Post
PlanchePRO · · Houston, Texas · Joined Sep 2014 · Points: 50

My old design was a 2"x12"x48" with 8 bicycle hooks. I chose 12" because I was considering placing additional holds. However, it snapped in half while I was doing my third workout due to what I perceive to be wood rot or I made the "pocket" cut too big. Originally I was just going to do four 3"x3" pocket cuts to accommodate the Z-MAX 14-Gauge Galvanized Deck Joist Tie, but I wanted to be able to adjust the spacing and mimic the French Cleat design suggested by the Anderson Bros. So I decided to make a 3"x36" rectangle cut with a jigsaw. I chose 36" because each half of the Forge is 14" wide and the suggested spacing is 4"-8". The head of the screws on the Z ties kept getting jammed at the top, so I made the cut bigger - 4"x36". I couldn't cut a straight line with the jigsaw, so I kept carving at the board until it became a 6"x36" and gave up. I cut too much already and I had to tuck my legs because the board was too low to the ground. I was just going to place shims under the Z ties to level the boards.

For my new design, I'll be making a 36" straight cut 1.5" away from the edge and then a 14.5" cut at the center top, so I can place each hangboard in the center and slide each piece to the left and right like so. I'll only be using only 6, maybe 4 bicycle hooks this time. Can I get away with 4 hooks? Should I be using a circular saw instead of a jigsaw? I used 2"x6" for the Forge. Can I use another 2"x6" or should I go with a 2"x8"? The 2"x12" felt too heavy.

(Not to scale). 


brian n · · Manchester, WA · Joined Sep 2016 · Points: 87

I'm a former cabinetmaker and have a degree in sculpture and I work in wood, frequently.  I don't think using a solid piece of wood for that is the way to go.  Because of the wood grain direction, you have a weak spot on each side at the thinnest point of your last picture/design drawing, even without a bad / rotted piece of wood.

Use plywood. Take two 3/4" pieces and glue them face to face. Make sure the glue coverage is complete.  Then cut out your design. Yeah, circular saw.  Also, your bicycle hooks should be screwed into pre-drilled holes that are the size of the shaft of the hook not including the threads.  That will prevent splitting and separation by wedging the wood apart.

All that being said, ... yer gonna die.

PlanchePRO · · Houston, Texas · Joined Sep 2014 · Points: 50
brian n wrote:

I'm a former cabinetmaker and have a degree in sculpture and I work in wood, frequently.  I don't think using a solid piece of wood for that is the way to go.  Because of the wood grain direction, you have a weak spot on each side at the thinnest point of your last picture/design drawing, even without a bad / rotted piece of wood.

Use plywood. Take two 3/4" pieces and glue them face to face. Make sure the glue coverage is complete.  Then cut out your design. Yeah, circular saw.  Also, your bicycle hooks should be screwed into pre-drilled holes that are the size of the shaft of the hook not including the threads.  That will prevent splitting and separation by wedging the wood apart.

All that being said, ... yer gonna die.

Are 4 bicycle hooks enough? Should the pre-drilled holes be in the center of the two glued together plywood or should I put it on one piece before gluing them both together? Can I get away with just one 3/4" plywood lol. 


TBlom · · Unknown Hometown · Joined Jun 2004 · Points: 360

Why not just build a dedicated board for the training holds?  no cut outs, no joist hangers, no modular slots... the whole design is very convoluted and destroys any bit of strength the lumber initially had.

Mount a board (2x10, 2x12, whatever fits) directly to studs with 4.5" structural screws.  mount your hang boards to that.  

Attempting a plunge cut with a circular saw is dangerous, and based on what I'm seeing you are not equipped to do it safely (no offense).  Gotta keep yer digits for climbing!  

If you must use bike hooks, 2 should work if they are pre drilled into good lumber.  If you want to be able to use different holds or training boards just build a separate board for each set.

The plywood idea could work well, but I'm not fond of the idea of drilling down the seam and then driving hooks between the boards.  1.5" screws through the two ply sheets would help though.

might be worth hiring or befriending a carpenter.

Doug S · · W Pa · Joined Apr 2012 · Points: 55

4 hooks are enough. Locate 2 hooks about 4 inches apart on the left side of the board and likewise on the right. Don't place hooks in the center if you are making a cut/slot also. That will create a weakness.


Glue the two layers of plywood together like Brian said. Use wood glue and get good positive coverage. Place weight on top the two layers as they dry. AFTER you make your cuts, you could add some screws layer to layer. Then pre-drill the holes for your hooks as Brian said, in the center (on the seam in other words).


slim · · Unknown Hometown · Joined Dec 2004 · Points: 1,107

it broke the first time because wood is weak in cross-grain tension loading.  if you build it like you have shown, it is just going to break again in the same place.

a much simpler solution would be to just use the plain 2x12 with the z max on top.  you only need supports at the end - use a 3/8" eye-screw at each end.  then use a carabiner through the eye screw clipped to a small piece of webbing that is tied around the pullup bar.

brian n · · Manchester, WA · Joined Sep 2016 · Points: 87
PlanchePRO wrote:

Are 4 bicycle hooks enough? Should the pre-drilled holes be in the center of the two glued together plywood or should I put it on one piece before gluing them both together? Can I get away with just one 3/4" plywood lol. 


4 hooks should work.  Use just 2 and they will bend.  As stated already the holes for the hooks should be in the center(on the seam) of the 2 pieces of plywood.  One piece of plywood would result in the catastrophic failure.  If you are not adept at using a circular saw, use the jigsaw with the widest and sharpest blade you can get.  Keep the speed of the blade as high as possible, but push forward slowly.  That way you can keep a more strait line and the blade will be less likely to bend sideways and cut on an angle.

Charlie S · · Ogden, UT · Joined Aug 2007 · Points: 1,718

I think you'd be better off with a French Cleat system instead, and totally get rid of the giant cutout.

If you keep the cutout, figure out how to make those cuts straight.  A steady had with a circular saw can go a long way.  Use big (YUGE!) radii at the transitions to keep the stress concentrations down.  Consider a metal reinforcing plate where you broke it previously.

PlanchePRO · · Houston, Texas · Joined Sep 2014 · Points: 50
slim wrote:

it broke the first time because wood is weak in cross-grain tension loading.  if you build it like you have shown, it is just going to break again in the same place.

a much simpler solution would be to just use the plain 2x12 with the z max on top.  you only need supports at the end - use a 3/8" eye-screw at each end.  then use a carabiner through the eye screw clipped to a small piece of webbing that is tied around the pullup bar.

Is this what you were suggesting? I tried to reuse the bottom half of the wood; I put one eye screw on each end and then a carabiner + chain (since I don't have any webbing) to wrap around my pull up bar. Since I'm living in an apartment with my parents, I'm required to use a towel and styrofoam to protect the doorframe. I'm going out tomorrow to get a new 2"x8" because when I tested the makeshift design, it kept tilting forward. Does is it need to be 2"x12" again?
Rob Gordon · · Hollywood, CA · Joined Feb 2009 · Points: 105

I'm glad you're a pro at planching because woodworking does not seem to be your calling. 

slim · · Unknown Hometown · Joined Dec 2004 · Points: 1,107

definitely use a new piece of 2x8.  my guess is that you are going to have problems with it rotating forward because the styrofoam is too thick and not stiff enough.  a thin piece of some sort of more dense foam or rubber, maybe like a piece of yoga mat would be better, but still not perfect.  this will also allow the hangboard to hang more closely to being directly under the pullup bar, instead of way out front (which is less stable).

if you did use the 2 pieces of plywood (like Brian N suggested) would probably work ok but be more expensive and more difficult to make.  

PlanchePRO · · Houston, Texas · Joined Sep 2014 · Points: 50
slim wrote:

definitely use a new piece of 2x8.  my guess is that you are going to have problems with it rotating forward because the styrofoam is too thick and not stiff enough.  a thin piece of some sort of more dense foam or rubber, maybe like a piece of yoga mat would be better, but still not perfect.  this will also allow the hangboard to hang more closely to being directly under the pullup bar, instead of way out front (which is less stable).

if you did use the 2 pieces of plywood (like Brian N suggested) would probably work ok but be more expensive and more difficult to make.  

Can you suggest a branch/model for the webbing?

Like would either of these work?

https://www.backcountry.com/black-diamond-nylon-sewn-runners?skid=BLD00HR-RD-S30CM&ti=U2VhcmNoIFJlc3VsdHM6bnlsb24gc2xpbmc6MToxOm55bG9uIHNsaW5n

https://www.backcountry.com/metolius-18mm-open-nylon-sling?skid=MET0335-ASS-S22IN&ti=U2VhcmNoIFJlc3VsdHM6bnlsb24gc2xpbmc6MTo0Om55bG9uIHNsaW5n

Should I use the shortest one? What would be the ideal length?


slim · · Unknown Hometown · Joined Dec 2004 · Points: 1,107

easiest thing would probably be to just buy about 10 ft of 9/16 inch webbing. then you can tie it to whatever length you like.

Guideline #1: Don't be a jerk.

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