EP Cycles Posted April 11, 2007 Report Share Posted April 11, 2007 Here is a guide for you all should that beloved frame strip a thread.Please not these photos are not of a bike but a pure sliver base which had the same issue. The manner to the work is exactly the same.Helicoil has many applications and is a great way to replace a stripped thread.Stripping the thread is a common occurrence with all small and fine threads as usually they have a stainless steel bolts tightening down into a aluminum base which is a very soft metal so a turn to much can easily strip the thread from the softer metal - all is not lostThere are a couple of methods that could be used and my first thought was to simply re-drill and tap the offending hole but this would then have left the dilemma of finding a new larger stainless steel Hex bolt so decided to try using a Helicoil which essentially is oversize drilling and tapping the hole then using a Helicoil to plug the hole to the same size as it were previously.Closer inspection you can see clearly the thread was in fact stripped good and properSo first of all the hole was drilled out using a 4.1mm drillSo the hole was oversized like thisThen using a M4x.7 Tap, re-tapped the hole (2 turns in and 1 turn back to get rid of swarf)So your left with a nice rethreaded hole like this...This is a close up of the Helicoil which will be used to bring the hole back to the correct size.As you can see its basically a small spring with a dog leg on the end called a "tang" which is needed to screw the thing in place.A special tool is used to compress the spring so that it can be screwed into the hole - the idea is that once in the hole the helicoil will de-compress out over and attach itself to the threaded hole.To start off with the small Helicoil is screwed loosely onto the threaded shaft of the tool like so...Then the shaft is inserted into the body and screwed in so it compresses and just starts to protrude out the end of the tool which also has a threaded end - the Helicoil has no alternative but to compress in overso the end of the tool looks like this...That end is now placed firmly over the threaded hole on the block base and while keeping hold of the body of the tool, the shaft is screwed out which forces the Helicoil into the baseand from the other side of the base you can just begin to see the Helicoil coming into placeOnce the Helicoil is flush with the base and the "tang" is just protruding the shaft of the tool can be screwed back out leaving the Helicoil in place......and from the other sideAs you can see the existing bolt now fits back into the hole perfectlyUsing the tang removal tool which is essentially high tensile steel bar which fits the hole, it can be placed on a sturdy bench and hit with a hammer which removes the tang like so - leaving the hole flush to rest of the base with a perfect re threaded hole to accept the hex bolt.Just like new EP Cycles Link to comment Share on other sites More sharing options...
paul@rettotrials Posted April 11, 2007 Report Share Posted April 11, 2007 (edited) Wont the coil come out the other side? Because i want to do some cranks I've got. here is a link to the topic linky linky Could you help me out? As you seem to know what your doing. thanks paul. Edited April 11, 2007 by paul@rettotrials Link to comment Share on other sites More sharing options...
El Cristoff Posted April 11, 2007 Report Share Posted April 11, 2007 Validate him Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 Wont the coil come out the other side? Because i want to do some cranks I've got. here is a link to the topic linky linky Could you help me out? As you seem to know what your doing. thanks paul.Hi Paul,So you have a set of Echo CNC'd cranks, right hand thread for the pedal has stripped. Is that the threa in the crank or the pedal repaceable insert gone on the threads for the the pedal?The coil doesn't move once fitted and the tang removed.EP Cycles Link to comment Share on other sites More sharing options...
paul@rettotrials Posted April 11, 2007 Report Share Posted April 11, 2007 (edited) Its the threads in the crank arm that are gone and need re-tapping. But i dont kknow what size tap and coil i need. plus its oppisite threads. Edited April 11, 2007 by paul@rettotrials Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 Its the threads in the crank arm that are gone and need re-tapping. But i dont kknow what size tap and coil i need. plus its oppisite threads.9/16 inch x 20 tpi - Pedal threads- common three piece cranksHow ever the threads on pedals are back to front threads. Could get a steel insert made, have them lathe the threads on to it. Screw it to the pedal then into the the crank with some thread lock.Belive Edd Pots is the man here for enginering. I can ask some local guys what they can do for you too but i'm not sure how much it'll cost.EP Cycles Link to comment Share on other sites More sharing options...
paul@rettotrials Posted April 11, 2007 Report Share Posted April 11, 2007 thanks i just found this bike website that sell coils and a tool.linky linky Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 thanks i just found this bike website that sell coils and a tool.linky linkyAhy there what you need, however you need the tool to fit them, tap and a drill too. Have you looked on ebay at all? I got mine off there for silly cheap moneyEP Cycles Link to comment Share on other sites More sharing options...
Si-man Posted April 11, 2007 Report Share Posted April 11, 2007 Apply thread lock to the thread before inserting the helicoil... Link to comment Share on other sites More sharing options...
paul@rettotrials Posted April 11, 2007 Report Share Posted April 11, 2007 i just looked and i can't find a left hand tap for it, dont know if you can give me a link to one thanks. Link to comment Share on other sites More sharing options...
Si-man Posted April 11, 2007 Report Share Posted April 11, 2007 Try and get a time sert for the cranks.Tadaa! Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 £35 retail is a good price on the Park Tools Pedal Tap Set Right And Left Tools. Link to comment Share on other sites More sharing options...
Danny Posted April 11, 2007 Report Share Posted April 11, 2007 Cheers for the post Pete Nice use of copy and paste http://coolercasesuk.co.uk/showthread.php?t=1211 but cheers anyway. Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 Cheers for the post Pete Nice use of copy and paste http://coolercasesuk.co.uk/showthread.php?t=1211 but cheers anyway.Perfectly allowed and there nothing of use on here showing anyone how or what the parts are so i though it'd be a good idea to show it off.You pick me up via my IP?Also you going to respond to any of my e-mails the Danny or sit high and proud? Link to comment Share on other sites More sharing options...
Adam-Griffin Posted April 11, 2007 Report Share Posted April 11, 2007 THIS BOY NEEDS VALIDATING! Link to comment Share on other sites More sharing options...
SCOTTY___ Posted April 11, 2007 Report Share Posted April 11, 2007 THIS BOY NEEDS VALIDATING!your a fanny, look up above. hes used a website and hes another person in disguise... Link to comment Share on other sites More sharing options...
EP Cycles Posted April 11, 2007 Author Report Share Posted April 11, 2007 your a fanny, look up above. hes used a website and hes another person in disguise...No just a new account for a new company. I maybe have copied soemthing but i contrubited something to the forum of which the forum did not have at all what so ever of which it has helped one person out so far.All within the rules and regs of the forum i do belive when i looked at them when i set this account up.EP Cycles Link to comment Share on other sites More sharing options...
Bionic Balls Posted April 11, 2007 Report Share Posted April 11, 2007 too good to be true ey..anyways- if you're helicoiling a hole that isn't open the other side, do you leave the tang on? Or can you get it out?adam Link to comment Share on other sites More sharing options...
Dan6061 Posted April 11, 2007 Report Share Posted April 11, 2007 When I got my Magura mounts helicoiled, the guy bashed the tang out, doubt it really matters though? Link to comment Share on other sites More sharing options...
Simpson Posted April 11, 2007 Report Share Posted April 11, 2007 Cheers for the post Pete Pete Wright? or am i confussed? the high tech computering forum kinda made me think....? Link to comment Share on other sites More sharing options...
paul@rettotrials Posted April 11, 2007 Report Share Posted April 11, 2007 (edited) 9/16 inch x 20 tpi - Pedal threads- common three piece cranksEP CyclesSo if the threads are 9/16 would i cut it the next size up from that?Witch i think is 5/8 Edited April 11, 2007 by paul@rettotrials Link to comment Share on other sites More sharing options...
tomturd Posted April 11, 2007 Report Share Posted April 11, 2007 No just a new account for a new company. I maybe have copied soemthing but i contrubited something to the forum of which the forum did not have at all what so ever of which it has helped one person out so far.All within the rules and regs of the forum i do belive when i looked at them when i set this account up.EP CyclesYou're banned, 100% remember. Goodbye! Link to comment Share on other sites More sharing options...
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