Straightening cycle parts

My yokes were well bent and i straightened them just with the aid of a big vice on a strong bench and an old fork staunchion. I did the job cold back then . i would heat it up now.

Not Bash ! ,plenty of leverage , a scafolding putlock is a usefull section of tube about 5ft long !. Take it slightly past the angle you need .Fit the staunchions and check with a couple of straight edges . and a critical eye.

Hi David,

    This is a method that has worked for me in the past, so might be worth a try.

Remove the front wheel and mudguard, handlebars, top yoke, headlamp and brackets, stanchions and sliders as units and lower shrouds. This leaves the bottom yoke in situ. Refit the top yoke and stanchions/legs loosely (no top nuts) and also push fit the wheel spindle in the legs with-out the nut. Now turn each stanchion tube individually full circle and observe the lower legs to see if there is any uneven movement as this will mean the tubes are bent. 
   When you are sure the tubes are O.K. remove the spindle and stanchion/leg assemblies, turn the top yoke out of line to the bottom, and then fit the tubes/legs into the top yoke only and tighten the top tube nuts. With the top yoke in the straight ahead position, you should be able to see their relationship to the frame front down tubes and check the parallel alignment with (as Robert says)  2 straight edges across top and bottom of the tubes. If you need to tweak these, a piece of 3"x2" timber should be strong enough if you have someone to hold the bike. 
   Next, remove the tubes/legs from the top yoke and fit into the bottom yoke so the top taper is just below the top yoke so it does not touch and tighten the pinch bolts. Do the same checks as for the top yoke, you can heat up the yokes with a DIY heat gun, but just enough so not to damage the paint.

If the forks are off the bike the diagram below is a simple guide which I found somewhere (my notes and dimensions added)
New Commando stanchions were used to check my 73/8" Atlas yokes . Amazingly both were spot on.
I use a small propane bottle and plumbers gas torch for heat if forks or frame are badly bent.