Resetting the rear frame spacing on a steel framed bike is a worthwhile DIY project which can be performed by almost anyone who does NOT have arthritis in their arms/shoulders/hands ...
HOWEVER, it is important to know that while many advocate using additional leverage (
e.g., 2x4, hockey stick, etc.),
my experience is that a person should only use their upper body strength UNLESS it is a very, VERY inexpensive carbon steel frame which will have stays which are too robust to bend by normal humans without added leverage ....
Now, if one reads about Sheldon Brown's efforts, he recommends using a 2x4 ... and, he tweaks each stay individually. Eventually, he uses a string and a tape measure to measure-and-assess & tweak until both sides are set to his satisfaction.
The FLAT work bench/table which CAMPYBOB recommends undoubtedly becomes beneficial if one opts to tweak one stay at a time.
ALTERNATIVELY, if you are not physically limited, then you simply need a metric ruler (
or, a hub which has the O.L.D. spacing that you want -- in this case, 130mm) + either a normal (
~12" handle) pipe wrench or medium (
~8" handle) adjustable wrench PLUS a couple pieces of scrap PLYWOOD ...
Then,
I recommend that (
after either removing the chain or wrapping the chainstay with whatever you choose to protect it) while standing behind the frame, you simply grasp a dropout in each hand and exert whatever YOU deem to be about
30 lbs of force OUTWARD for about a second ...
Measure ...
You may see that you have only moved the stays 1mm-or-less!
REPEAT ...
Measure ...
When you have achieved a width of 130mm or when the hub fits smoothly into the dropouts, you have achieved the desired separation.
IF desired, a frame with 135mm dropouts can be reduced to 130mm-or-less by pressing inward by (again) whatever you deem to be about 30.lbs. of force.
If you spread the stays simultaneously then unless their is something peculiar about how the frame was fabricated (
which may-or-may-not be the case with a Pegoretti) the stays & dropouts will be symmetrical to the frame's central plane IF they were before the endeavor to spread the stays was begun.
NOW, you will want to tweak the dropouts so that they are parallel to one another rather than being splayed outward BECAUSE if you don't then the indexing will probably be dodgy AND you will probably wear through the upper jockey pulley faster than would normally occur.
Regardless of whether you use an adjustable crescent wrench or a pipe wrench, you will want to protect the dropouts from being marred ... so, you will sandwich the dropout being worked on with the two scrap pieces of wood ...
Tweak the dropout with whatever you perceive to be only about 5 lbs. of force ... with the pipe wrench using LESS force is probably a good idea because of the leverage which the perpendicular force will impart ...
Repeat on the OTHER dropout.
You want the dropouts to be PARALLEL to one another and the derailleur hanger to be vertical (
you can use the seat tube as a reference against which you eyeball the theoretical vertical).
Total time required is somewhere probably between 5-to-30 minutes ...
No need to hurry ... so, allow a half hour, or more.