RADBMX.CO.UK
Technical & Reference Section => Tech and Restoration => Topic started by: Rob1 on March 21, 2012, 10:18 AM
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Has anyone ever fixed a pair of forks where the thread has been stripped ?
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First of all, have you tried a spacer before thiniing of repairing the stripped thread? A 5mm spacer may be sufficient. Failing that, metal epoxy can be uesd to re-build the stripped area and then it can be re-threaded. the difficulty will be finding someone who can re-thread to 1" as it is quite a large thread.
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Anything can be fixed. I personally wouldn't touch metal epoxy. Defiantly not on a pair of forks. The best thing to do is to take them to an engineering shop and have them machine the head tube out of the legs. Then have a new head tube made up and welded in place. Or remove one from another set of fork. And have that welded in place. But check the headtube is the right length first. This may sound a lot of work. But if they are a rare set of forks then it's worth getting it done properly. :daumenhoch:
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Or go to a decent welder and have him fill weld over the affected area and then have then re-threaded; Park Tools do a thread kit for re-tapping threads on forks so a decent bike shop that uses Park tools should be able to do the repair for you.
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the park tools toll is about £160 :idiot2: i have a die and handle for fork threads, but andy (58delray) has it at the mo. pop up a pic of the damage. i had a chunk of damaged thread on my kuwahara exhibitionist forks, but after a few pases with the die, they adjust and ride beautifully :daumenhoch: it was just the last few threads that were really causing the problem, so a run down them may work for you too :)
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the damaged part could be welded up and the remachined,however this would be difficult to do as the steerer needs to be held in the chuck.
Hence the fork legs must go INSIDE the chuck and down the lathe spindle,so that work can be done on the threaded portion sticking out :daumenhoch:
You need to find a BIG lathe that will allow the fork leg to go down the spindle :daumenhoch:
welding in a new steerer may be the best option :)
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Filler or braze weld then this...
http://www.ebay.co.uk/itm/Workshop-1-steerer-tap-retro-road-mtb-bmx-bikes-/270941450793?pt=UK_Spots_Leisure_Cycling_Tools_RepairKits&hash=item3f155e7229
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Here`s a pic:
(http://www.radbmx.co.uk/archive/albums/oo355/bigbadken/Hutchforks001.jpg)
Whether they are rare or not , I`m sure one of you guys will know ; I think they are from 83-84 from a Hutch Expert .
(http://www.radbmx.co.uk/archive/albums/oo355/bigbadken/Hutchforks002.jpg)
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non drilled....yumee.
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looks like there's plenty of thread higher up to try the spacer suggestion by 750 rush.
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looks similar to the damage i had on mine. are you coming on the london ride? if i get my tool back off of andy il bring it with me :)
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Personally I would go for removing the old steerer tube and welding a new one in place which I could do myself so would cost me pennies in gas and a filler rod. I'm sure someone on here has an old set of forks they may donate to the cause if you go down that path. It may be cheaper to just look for a replacement fork though.
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Personally I would go for removing the old steerer tube and welding a new one in place which I could do myself so would cost me pennies in gas and a filler rod. I'm sure someone on here has an old set of forks they may donate to the cause if you go down that path. It may be cheaper to just look for a replacement fork though.
Wow, that has to be the most extreme solution; surely if you are handy with a welder then filler weld over the existing threads and retapping the thread has to be the most cost effective and LEAST intrusive way of repairing them? Hundreds of bike shops do that kind of repair (I know we used to at Heff's Bike Shop), replacing the steerer tube I suspect would hardly ever be done unless it was bent or cracked in some way; surely?
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Personally I would go for removing the old steerer tube and welding a new one in place which I could do myself so would cost me pennies in gas and a filler rod. I'm sure someone on here has an old set of forks they may donate to the cause if you go down that path. It may be cheaper to just look for a replacement fork though.
Wow, that has to be the most extreme solution; surely if you are handy with a welder then filler weld over the existing threads and retapping the thread has to be the most cost effective and LEAST intrusive way of repairing them? Hundreds of bike shops do that kind of repair (I know we used to at Heff's Bike Shop), replacing the steerer tube I suspect would hardly ever be done unless it was bent or cracked in some way; surely?
+1. Well said that man...
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Its the cheapest method for me personally and I could do the work myself.
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one way is to find a set of donor forks and cut off top section and weld in new piece,just make
sure you do the join near the bottom or you will struggle getting a stem in :daumenhoch:
here's a pair i extended the steer tube by 1"
(http://www.radbmx.co.uk/archive/albums/y77/sawzall717/IMG_1474.jpg)
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Good heads up on the stem insertertion if I ever have to do this, it hadn't crossed my mind that.
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one way is to find a set of donor forks and cut off top section and weld in new piece,just make
sure you do the join near the bottom or you will struggle getting a stem in :daumenhoch:
here's a pair i extended the steer tube by 1"
(http://www.radbmx.co.uk/archive/albums/y77/sawzall717/IMG_1474.jpg)
If your cutting of the tube and welding is precise, then you will not have a problem with the stem; even if the joint is just below the threads. :daumenhoch: :daumenhoch: :daumenhoch:
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one way is to find a set of donor forks and cut off top section and weld in new piece,just make
sure you do the join near the bottom or you will struggle getting a stem in :daumenhoch:
here's a pair i extended the steer tube by 1"
(http://www.radbmx.co.uk/archive/albums/y77/sawzall717/IMG_1474.jpg)
If your cutting of the tube and welding is precise, then you will not have a problem with the stem; even if the joint is just below the threads. :daumenhoch: :daumenhoch: :daumenhoch:
Think Phil has put a splicer tube in there ???
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dan if they are going to be riden on i would put a shim inside fork tube
where weld is for extra strength :daumenhoch:
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dan if they are going to be riden on i would put a shim inside fork tube
where weld is for extra strength :daumenhoch:
you may clag a shim in there, but a good tig weld below the threads will be more than sufficient for the fork to be thrashed.... :daumenhoch: :daumenhoch: :daumenhoch: