prelit Posted June 16, 2014 Report Share Posted June 16, 2014 Hi Guys, I'm trying to remove the 5 10mm studs that secure the sprocket to the hub on what I thinks is a 242 rear hub. I believe this hub is common to the 200 & 247. Sprocket 1 side, brake plate on the other. I've welded nuts to the studs and gently heated the boss inside the hub but they won't budge. Before I try more heat and more force I just thought I would ask on hear if anyone has ever removed them Thanks in advance, Simon. Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted June 16, 2014 Report Share Posted June 16, 2014 i have a wheel where some one has removed them and replaced with bolts but looks like there has been some hassle ,, you may find it pulls the threads out with the stud possibly lock tightened in Quote Link to comment Share on other sites More sharing options...
prelit Posted June 17, 2014 Author Report Share Posted June 17, 2014 i have a wheel where some one has removed them and replaced with bolts but looks like there has been some hassle ,, you may find it pulls the threads out with the stud possibly lock tightened in Thanks for the reply, I'm sure most of the liquid 'loctite' products disintegrate with heat. Perhaps I'm not getting the hub hot enough but I fear that the studs may have a boss which is cast in. I will try it a little bit hotter and give it a bit more force. I know dis-similar metals corrode but I've not ever had anything this seized/tight before. Thanks again, Simon. Quote Link to comment Share on other sites More sharing options...
mags Posted June 18, 2014 Report Share Posted June 18, 2014 (edited) Hey Simon, I can add a few tips... I play with loctite!!! It does denature with heat... the temp is about 150-160 deg C for most products they have for thread locking. How you apply the heat can make a big difference. For example if the thing its connected to is a giant heat sink or transfers heat really well you may have to apply a little more heat than first thought. A small butane torch can be invaluable for denaturing loctite in a controlled and concentrated fashion. The pic below is me denaturing loctite on a disc rotor before attempting to remove the fastener. The thin beam torch concentrates the heat down through the fastener and into loctite on its way to heat sink surrounding it. Another little tip is to set a torque wrench to fastener value but in the undo position. Heat fasteners with butane torch and take to temp.... think hot baking tray in an oven doing the roast... thats about the temp! Count seconds to heat it ...say 40 secs, then apply torque. If unsuccessful up torque by 5% and the heat time by 20%... and go again.... Eventually the method should undo the fastener with the LEAST risk of stripping the fastener.... its just applied in a methodical and controlled way to give you the best chance of success. Good luck! Mags Edited June 18, 2014 by mags Quote Link to comment Share on other sites More sharing options...
prelit Posted June 18, 2014 Author Report Share Posted June 18, 2014 I can add a few tips... I play with loctite!!! It does denature with heat... the temp is about 150-160 deg C for most products they have for thread locking. How you apply the heat can make a big difference. For example if the thing its connected to is a giant heat sink or transfers heat really well you may have to apply a little more heat than first thought. A small butane torch can be invaluable for denaturing loctite in a controlled and concentrated fashion. The pic below is me denaturing loctite on a disc rotor before attempting to remove the fastener. The thin beam torch concentrates the heat down through the fastener and into loctite on its way to heat sink surrounding it. Another little tip is to set a torque wrench to fastener value but in the undo position. Heat fasteners with butane torch and take to temp.... think hot baking tray in an oven doing the roast... thats about the temp! Count seconds to heat it ...say 40 secs, then apply torque. If unsuccessful up torque by 5% and the heat time by 20%... and go again.... Eventually the method should undo the fastener with the LEAST risk of stripping the fastener.... its just applied in a methodical and controlled way to give you the best chance of success. Good luck! Mags Thanks for taking the time to reply, I've heated the studs until they are a dull red, I've tried heating the boss from inside the hub with a welding torch on a soft flame. I've got the hub in a lathe chuck and made a bar which picks up on 2 studs and jams onto the lathe bed to prevent rotation. I'm using a large breaker bar and applying as much force as I dare but they are stuck fast. I keep thinking they must be cast in, but logic says they can't be as the surface the sprocket sits on is machined !!!!! Surely not a left hand thread? I've applied some force this way but they still won't budge. Thanks again, Simon. Quote Link to comment Share on other sites More sharing options...
mags Posted June 18, 2014 Report Share Posted June 18, 2014 Simon, Apologies! Sounds like you have it well in hand! Might be time to mill them off and helicoil??? Like you know, could be serious Galvanic Corrosion but you would think one would be less corroded and "give"! I've never seen a left hand thread in a hub...MMMMMmmmm! If you eventually have to machine, try one left? I had some trouble with Yamaha components and the military grade orange loctite they use. Geez it takes some undoing at times but you are past that! Post final result. Once again apologies if I came off patronising... didn't realise your level of experience. Mags Quote Link to comment Share on other sites More sharing options...
zerorev3rev4 Posted June 23, 2014 Report Share Posted June 23, 2014 (edited) the bolts in my hub are right hand thread if you look inside the hub theres no space for anything to be any larger than the stud , ( i dont think ) could you drill in the inside to get some wd40 in the back also a good few wacks squarely on the end with hammer to get some shock through it can help Edited June 23, 2014 by zerorev3rev4 Quote Link to comment Share on other sites More sharing options...
prelit Posted June 23, 2014 Author Report Share Posted June 23, 2014 the bolts in my hub are right hand thread if you look inside the hub theres no space for anything to be any larger than the stud , ( i dont think ) could you drill in the inside to get some wd40 in the back also a good few wacks squarely on the end with hammer to get some shock through it can help Hi Guys, Tried every thing!!! Left to soak in paraffin for 3 days, twatted the end of the studs every day whilst in soak, heated stud/boss as hot as I dare. Never had anything this stubborn before. Well I gave up and had to machine out on a dividing head & re tap. It looks as if they were just normal studs, after I machined the core out then the thread could be picked out. After I re tapped the threads look ok and I'm happy enough to use on my Bantam project as this hub will give me a right foot back brake. Thanks for you help, Simon. 1 Quote Link to comment Share on other sites More sharing options...
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