Mounting Pullup Bar DIY Question

akira181

Apologies if this is the wrong section, felt it was more DIY than Health and Fitness related.

The doorframes/walls in my tenement flat are too thick for one of those leverage style pullup bars so I got some pipe to make one and want to mount it above a doorframe but I'm concerned the doorframe will develop cracks over time if I screw the bar directly to it.

Basically, I want to mount this 
   

to here 
 

Originally, I thought mounting a 4x2 to the horizontal door frame then screwing the bar through the 4x2 and into the frame (rough sketch below).  The bar flanges would be where the group of 4 screws are on either side of the 4x2.  All screws would be 6x100 multipurpose screws.

I then realised this wouldn't do anything for reducing rotational force on the doorframe, so cracking is still a concern.  Someone then suggested I cut the 4x2 in half and then mount them vertically at the top only, and bolt the bar to the 4x2 at the bottom only to reduce rotational forces seen on the doorframe (like below)

While that would help reduce rotational force seen by the frame, having it only supported at the top, if there's any movement from the vertical forces, it would potentially break the glass.  So my last idea before giving up on mounting this, is to have 2 studwork timbers along the verticals going to the floor.  

My thinking is that the floor will take the bulk of any vertical forces and the longer verticals will reduce or at least spread out the rotational forces seen by the frame.  

Will this help reduce the risk of cracking the doorframe or is there a better way to do it (very possible I'm overthinking this)?  Or best to leave it alone?

grumbler

Why cannot you fit the bar inside the frame, between the sides, with flange fixings? Would it be too low?

Also, did you hear about ceiling-mounted pull-up bars?

akira181

The other half doesn't want it on show so it needs go above the frame since that side of the door leads to a utility cupboard.

A ceiling mounted one is not possible unfortunately. My flat has high ceilings plus my missus would most definitely object 

grumbler

OK, IMO with such short cantilevers there are no reasons to worry about the rotational force (torque). Neither would I worry about the vertical load.

And with 100mm screws you can fix it well enough to the real frame through the decorative architrave covering it.

Extra vertical pieces of wood, as above, will do no harm despite increasing the total rotational force (while spreading it locally and protecting the architrave).

akira181

thanks, that was my initial thoughts but reading online stories of doorframes cracking over time made me overthink it.

Last question, should the bar be screwed into the frame through the extra verticals or just to the vertical pieces of wood?

greyteam1959

Probably all depend on how much you weigh to be honest.
Screwing bits of wood to the door frame is going to look a right bodge 
job.

akira181

I'm only 60kg, so not asking too much of it.  If it weren't for the glass window at the top, I wouldn't be as concerned.  That side of the doorway is usually out of sight unless you're coming out the utility cupboard so it'll be easily to hide.  Rather that than broken window panes at the top from the frame moving