Here is important information on "How To Use OLD GOLF CLUB SHAFTS cut down to size" as LEGS for modifying the EL-CHEAPO SEAT POST MOUNT REAR RACKS (as seen in the example of "number1bike" ).

One thing to know if you aren't familiar with golf clubs is that the AREA OF THE GOLF SHAFT where you see the "Grip".................YOU CAN USE A RAZOR BLADE KNIFE or BOX CUTTER, etc To CUT AND PEEL THE RUBBER GOLF GRIP, (or cut and unwrap the Leather Grip, if it has Leather rather than rubber grip)................ESSENTIALLY YOU CUT THE GRIP OFF, ALL THE WAY DOWN TO THE DOUBLE SIZED ADHESIVE MASKING TAPE (golf grip tape that when originally installed by the grip installer gets Wetted With LIGHTER FLUID ....e.g. RONSON lighter fluid-NAPTHA, or Gasoline, or Charcoal Lighter Fluid............................you see the golf grips get installed at the factory with a double sided masking tape known as golf club grip tape.............it looks very much like a simple roll of approx. 5/8" or 15mm wide masking tape, EXCEPT that there is adhesive on both sides instead of just one. .....the golf grip tape roll has a "Peel OFF" thin paper that covers the outer adhesive portion.................................They apply the "golf grip tape" just as you would any masking tape..................for golf club assembly-installing the grip.......they would wrap the "golf grip tape" around the shaft in Christmas Candy Cane fashion with slight gap between the spiraling single wrap that exposes some shaft chrome etc...................this is done to simplify the UNWRAPPING OF THE "Peel-Off" outer paper covering, that exposes the adhesive portion...............................THEN THEY SQUIRT LIGHTER FLUID or GASOLINE (golf grip solvent = Ronson lighter fluid) ON TO THE GRIP TAPE WRAPPED SHAFT.................Enough to wet, and make liquid the adhesive on the tape......................they then squirt some lighter fluid into the rubber golf grip while keeping a finger covering the tiny hole at the rear of the grip...................they swish the little amount of lighter fluid around, all inside the rubber grip, for just maybe three seconds or five seconds and then while the fluid is still inside the grip........proceeding to install said golf grip on the golf shaft with the wetted grip tape........
THEY HAVE ABOUT 45 seconds to INSTALL THE GRIP FROM THE FIRST MOMENT THAT THE GRIP TAPE IS WETTED or activated...............use more lighter fluid and you may have up to 25 additional seconds of time....................You see the lighter fluid makes the grip slide on very easy over the tape BUT IT SOON BECOMES LESS LIKE MELTED BUTTER and MORE LIKE CONTACT CEMENT if you dilly dally and wait too long to get it on.
....................OKAY, the point of this is to explain how in the heck do I clean the remaining grip tape and gook residue away, once I have cut the grip off the old shaft using my boxcutter. ***** LIGHTER FLUID (ronson.. Naptha..etc) or CHARCOAL LIGHTER FLUID , OR GASOLINE...........*******ONLY DO THIS OUTSIDE, AWAY FROM PETS AND CHILDREN, I suggest using a disposable aluminum baking pan, or other tv dinner tray etc to catch the FLUID SO IT DOES NOT GO INTO THE GROUND etc............................Wetting the old remaining adhesive residue/grip tape with lighter fluid or gasoline will easily remove it such that you get back to perfectly clean, shiny chrome golf shaft where the golf grip once was. It should take less than a minute to remove the remaining residue/grip tape after cutting the old grip off with a razor blade knife/box cutter.......................................Not using Lighter Fluid, etc for this removing of final residue/grip tape and you might be scraping the shaft with a razor blade for as much as forty-five minutes to get it clean.
I hope that information is useful...............you also know how to install golf grips too..................oh, the golf grip tape method can be used to permanently affix HANDLE BAR grips (think the type found on forties, fifties, sixties, seventies.....etc) on North Road style/cruiser handlebars..................the handlebar grip will not slide around once the grip tape adhesive has dried..............................you do a small candy cane type of wrap......peel the top paper layer away.....liberally wet the tape, and squirt some into the handle bar grip and swish it for a few seconds...............SLIDE IT ON..........align it the way you want it.......Let it dry for for a day before using................cut off any exposed grip tape that extends beyond the Grip................and it will appear perfect........................ you will to likely cut the handlebar grips off because the grip tape method affixes them at least as strong as using contact cement.....................the hairspray method is what you want IF you ever want to remove them without cutting them off, or resorting to injecting lighter fluid under the grip.....

Earlier I mentioned old aluminum shafts, well I don't think the super-tiny weight difference on say an approx. 40cm (16 inch) section of any old golf club shaft is gonna make any difference, as whatever eyebolts etc will be your heaviest weight contributor............. Chromed Steel Golf shafts rust on the inside of the shaft where climate is high humidity, or clubs exposed to moisture etc and the butt end of the grip is torn or missing.............there is no coating on the inside of the shaft, but still even for chromed steel True Temper golf shafts as old as from the early 1940's, IF THE EXTERIOR CHROME APPEARS IN GOOD CONDITION, THE SHAFT IS STILL STRONG ENOUGH TO SWING. HIT ON THE DRIVING RANGE, OR PLAY..... and will hold up to any reasonable load that you give the approx 16 inch section that you may be using for LEGS of a rear bicycle carry rack.
Golf shafts did come in different flexes................(R) or Med for REGULAR shafts .................Regular shafts of the fourties, fifties, sixties, seventies, and eighties ARE STIFFER in flex than Today's Stiff Shaft Flex clubs. ...............(S) stiff shaft........(X) extra stiff (rare some 1960's - early 1980's PGA Tour Pros did use them)...........................There are the (L) for Whippy shafts or Ladies flex shafts... PRO-LINE GRADE-TOP OF THE LINE stuff of yesterday, e.g. WILSON Staff Dynapower irons, HaigUltra irons, Wilson X-31 irons, PowerBilt Citation irons, MacGregor Tourney irons, Titleist Tour Model irons, Hogan Apex irons, the list would go on too long................ BUT NONE OF THESE TOP OF THE LINE irons came WITH ANYTHING LESS THAN TOP GRADE (R) regular flex or (S) stiff flex SHAFTS................you could special order a Whippy LADIES/old person Flex or for additional cost a custom (X) extra stiff flex set........................Often folks would get a custom (S) flex set that had been "tipped" or cut at the skinny end too, thus making the shafts more rigid and stiff than otherwise.............UNLESS YOU WERE TOUR PRO CALIBER AND ALSO SUPER STRONG, THESE SHAFTS WOULD HAVE BEEN IMPOSSIBLE TO HIT BY ANYONE WHO COULD NOT BREAK 80.
.............So in a nutshell, yesterday's REGULAR shafts are much stiffer in shaft flex than today's stiffest off the shelf offerings by a wide margin.
.............................Any old chrome plated steel golf club shaft will be more than strong enough for anything you can probably do to the approx 16 inch section that you'll choose to use. You'll obviously have decisions to make as to what part of the shaft you wish to use.............the fatter part nearer to the grip butt end or as the step downs get closer together and end nearest the iron's hosel.
This is RECYCLING at its finest, and MacGyvering 101.

Simple ordinary HACK SAW and a bit of masking tape or electrical tape or duct tape or even a piece of scotch tape, about an inch long piece wrapped wedding band style around the portion of shaft that you wish to cut.....................WHY? because the tape will keep your hack saw blade from skidding across the chrome plating while you are trying to begin the cut. DON'T WORRY ABOUT CUTTING UP VINTAGE GOLF CLUBS BECAUSE ALTHOUGH MANY ARE STILL SUPERB QUALITY IRONS FOR THOSE LIKE SOME TOUR CALIBER/Low Handicap-Scratch Golfers THAT FAVOR TRADITIONAL BLADES("blade style" irons = typical choice of many who can break 73)...........there are so many vintage sets available and unless the set has perfect groove lines on the clubhead face and it is from one of a few desireable top of the line manufacturer's iron sets, there is no value or demand for these. There is very minor demand for vintage wedges from top of the line clubs because today's sets have less loft on the iron clubs.....due to the rage of marketing to joe average that their clubs hit farther than the competition...............this stupidity is why today's 9 iron is equal to a 7 iron from forty years ago, and today's PW is equal to an 8 iron of forty years ago...........so for really good players, you'll still need clubs to fill in the gaps between the modern PW and the sand wedge in loft...................thus old wedges are prized more than the specialty gap wedges that are in the marketplace.................the only thing with old vintage wedges is that in the hands of a good player, they get worn away (wear out...because the scoring grooves are gone from hitting thousands of shots....... When the USGA outlawed Square Grooves that were first seen on irons at the end of the eighties, and on most everything until the mid-2000's, it gave the public ten years notice before the deadline. Most every golf club Iron from1988 to around circa 2006, possibly more recent has the banned Square Grooves and thus are ILLEGAL for use in any Amateur Tournament..........nobody can use them legally in any form of competition........................now who is gonna really check.............maybe nobody cares in the get together to Benefit Alzheimers or Cancer Research but you can bet that if you're in competition in the Championship flight of your city amateur championship or your club's championship, somebody will bring it up.
Thus about twenty years of wedges (and irons too) are OUTLAWED and illegal for use in any tournament play.
YOU THUS HAVE TO GO WITH VERY OLD wedges or very new. Not many people care to play really old irons and those people don't mind playing more recent but now illegal clubs. The benefit to the very good player is the lofts on the very ancient (legal) wedges...........no benefit to the average hacker that can't break 80. Oh, more useless trivia, some popular top of the line older stuff that was favored by great players during the beginning of the square groove era was modified from a standard v groove to a square u groove...............many were modified during the twenty year period that square grooves were in place....thus making it nearly impossible to tell if somebody is cheating because their clubs may pre-date the square groove era BUT have been modified to square groove specification and thus now illegal although from appearance as to year model they would fly under the radar because those clubs appear legal for play as originally manufactured based on cosmetic details/markers that tell the year of manufacture.