Sponge Posted January 25, 2011 Report Share Posted January 25, 2011 (edited) Hey, I recently bought back an old frame I used to ride off the guy I sold it to years ago. Now it's back in my hands in a horrendous condition but I'd like to get it up and running. There are a few things that need to be fixed on it first though, so I'm hoping I could get some help from you guys! 1. Stuck BB- Sorted. Just had to bolt down a few washers to secure the BB tool. Splines had more bite than the jagged worn appearance gave off! 2. Helicoiling. This frame already has M6 threads instead of M5, but one of the threads has been stripped out. So I might as well helicoil all 4. I know there's a lot on helicoiling kicking around the forum from the past but to be more specific is there any way I can restore it to an M5 thread? Or am I stuck with M6 helicoiling? In any case, is it possible to install the helicoil without drilling? I noticed *some* helicoil kits come with everything minus the specific sized drill bit whilst others specifically come with it? 3. Seeing as Stagonset are going through changes, is there any other online store that sells bolts/hardware at a reasonable price and in individual quantities? I'm put off buying a bulk of 100 bolts from certain sites y'see! To be specific I need something in this size but in steel: http://www.tartybikes.co.uk/aluminium_bolts/probolt_m6_x_10_alloy_1/c522p10040.html (Unless, it's suitable for snail cam bolt stress? Yep, the guy tapped it out to M6!) 4. When it comes to helicoiling, what is the normal length of helicoil that people use for brake mounts? 10mm? or shorter? It wouldn't hurt to get as suitable a length as possible! Edited January 30, 2011 by Ares Quote Link to comment Share on other sites More sharing options...
forteh Posted January 25, 2011 Report Share Posted January 25, 2011 1. Stuck BB- Nasty square taper unit, Super tight, feels like it's seized in there but the non-drive side cup has its splines pretty much completely stripped/worn so the tool can't bite into it. The only saving grace is that about 2mm or so sticks out of the BB shell. I'm thinking maybe a cut-line and chisel with a screwdriver might work, but are there any other solutions you'd suggest? Find your local engineers supply (BSL Brammer is a major chain although smaller ones will be better suited for you), google for local bearing suppliers aswell if youre getting stuck. Get a tin of plusgas, its a releasing agent and over time will free up just about any thread - have the threads vertical so it can gravitate in, spray a little on, let it soak, try it, repeat. That should enable you to get the driveside cup and BB cartridge out (run some plusgas all around the the BB on both sides). I dont think you will successfully cut a screwdriver slot into the external section of the cup, however if you can get the cartridge out first I would be inclined to get a fullsize hacksaw, dismount the blade, slip it through the shell and remount it. Put a cut across the cup in 2-3 pieces and with a bit of luck you should be able to knock out the seperate pieces. Be carefull not to muller the BB threads with the hacksaw, it wont cause huge problems if you nick the threads as you can always run a BB tap through it. 2. Helicoiling. This frame already has M6 threads instead of M5, but one of the threads has been stripped out. So I might as well helicoil all 4. I know there's a lot on helicoiling kicking around the forum from the past but to be more specific is there any way I can restore it to an M5 thread? Or am I stuck with M6 helicoiling? In any case, is it possible to install the helicoil without drilling? I noticed *some* helicoil kits come with everything minus the specific sized drill bit whilst others specifically come with it? You can reduce the size with helicoils, you may be able to get a reducing timesert though, have a google for it - slightly more expensive but a better solution. You need to drill the hole to the correct size for tapping, even if the kit doesnt supply a drill bit, it should tell you what size to drill it; visit the aforementioned engineers suppliers to get a single drill bit in the right size. 3. Seeing as Stagonset are going through changes, is there any other online store that sells bolts/hardware at a reasonable price and in individual quantities? I'm put off buying a bulk of 100 bolts from certain sites y'see! To be specific I need something in this size but in steel: http://www.tartybikes.co.uk/aluminium_bolts/probolt_m6_x_10_alloy_1/c522p10040.html (Unless, it's suitable for snail cam bolt stress? Yep, the guy tapped it out to M6!) Aforementioned engineers suppliers should be able to offer a range of screws in black/BZP/stainless in single quantities, typically youre looking at pence per item. 4. When it comes to helicoiling, what is the normal length of helicoil that people use for brake mounts? 10mm? or shorter? It wouldn't hurt to get as suitable a length as possible! Normally 1D helicoils are used, that is an M6 helicoil will be 6mm deep, you can get 1.5D kits aswell but for brake mounts 1D is more than enough. Think that about covers it assuming you have basic workshop knowledge and some tools 1 Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted January 25, 2011 Report Share Posted January 25, 2011 You can mend those bolt holes with helicoils if there is any 6mm thread left, it will retap with the helicoil tap, bodge? yes, works? yes. fortehs idea for the bb is good. You could collapse the shell by smashing f**k out of it with a hammer and an old screwdriver you may need to put a few cuts through the bit that the tool fits in. Go for it. Quote Link to comment Share on other sites More sharing options...
Rob Leech Posted January 25, 2011 Report Share Posted January 25, 2011 Hey, I recently bought back an old frame I used to ride off the guy I sold it to years ago. Now it's back in my hands in a horrendous condition but I'd like to get it up and running. There are a few things that need to be fixed on it first though, so I'm hoping I could get some help from you guys! 1. Stuck BB- Nasty square taper unit, Super tight, feels like it's seized in there but the non-drive side cup has its splines pretty much completely stripped/worn so the tool can't bite into it. The only saving grace is that about 2mm or so sticks out of the BB shell. I'm thinking maybe a cut-line and chisel with a screwdriver might work, but are there any other solutions you'd suggest? 2. Helicoiling. This frame already has M6 threads instead of M5, but one of the threads has been stripped out. So I might as well helicoil all 4. I know there's a lot on helicoiling kicking around the forum from the past but to be more specific is there any way I can restore it to an M5 thread? Or am I stuck with M6 helicoiling? In any case, is it possible to install the helicoil without drilling? I noticed *some* helicoil kits come with everything minus the specific sized drill bit whilst others specifically come with it? 3. Seeing as Stagonset are going through changes, is there any other online store that sells bolts/hardware at a reasonable price and in individual quantities? I'm put off buying a bulk of 100 bolts from certain sites y'see! To be specific I need something in this size but in steel: http://www.tartybikes.co.uk/aluminium_bolts/probolt_m6_x_10_alloy_1/c522p10040.html (Unless, it's suitable for snail cam bolt stress? Yep, the guy tapped it out to M6!) 4. When it comes to helicoiling, what is the normal length of helicoil that people use for brake mounts? 10mm? or shorter? It wouldn't hurt to get as suitable a length as possible! How do, the bb will come out with a bar and a bit of man strength, always had trouble with bb's in that frame . M5 helicoils fit into an M6 thread, so if you run a tap through the hole thats in bad shape, you will be able to get them all back to M5 without much trouble. Could of told you this and guided you through it if you'd PM'd me btw . Josh. Quote Link to comment Share on other sites More sharing options...
Sponge Posted January 25, 2011 Author Report Share Posted January 25, 2011 Thanks for the suggestions so far, especially forteh . Re. the brake mounts threads, is there much of a difference between a helicoil and a timesert? I traced back to an old topic of mine years ago where the general consensus was that it was impossible to turn an M6 sized hole back into M5 using a regular helicoil as the actual hole size required for an M5 helicoil insert was something very fine in between 5mm and 6mm. Unless times have changed and now it is possible to get an actual M6-->M5 helicoil? If the BB cup's splines could actually fit a BB tool without it slipping all over, I'd happily put a bit of oomph in it. But stripped splines= not a possibility. No worries, I'll sort it out one way or another! It's the brake mounts I'm most concerned with. Quote Link to comment Share on other sites More sharing options...
Revolver Posted January 25, 2011 Report Share Posted January 25, 2011 I was under the impression a helicoil required a tapped M6 hole, into which you screw the M5 helicoil. So in effect it spaces a M6 thread to M5. Quote Link to comment Share on other sites More sharing options...
Sponge Posted January 25, 2011 Author Report Share Posted January 25, 2011 I've dug up some info but in short: The hole needs to be drilled/tapped out to 5.2mm with 0.8mm thread pitch, seems the current M6x1.0 thread pitch won't allow an M5 helicoil. Quote Link to comment Share on other sites More sharing options...
forteh Posted January 25, 2011 Report Share Posted January 25, 2011 (edited) An M5 coarse thread is 0.8mm pitch, an M6 coarse thread is 1.0mm, therefore you cant correctly fit an M5 helicoil into an M6 tapped hole. The emphasis here is on the word correctly, you more than likely can bodge it in but the thread pitch will be slightly out on the M5 and cause potential for binding. A timesert is a solid bushing that is installed in a similar fashion to a helicoil but it provides a much better fit, this website has the information for timeserts, I think you will need to use an M5 bigsert which requires a 6.25mm hole to be drilled; I dont think a normal timesert will work. Heres a video of installation I dont know if timeserts will be an economical repair, you might be able to find a local engineers/workshop who can do it for some cash, the expensive bit will be buying the kit, especially if its a bigsert you need. Edited January 25, 2011 by forteh 1 Quote Link to comment Share on other sites More sharing options...
Sponge Posted January 30, 2011 Author Report Share Posted January 30, 2011 (edited) Thanks very much Forteh, that Timesert method looks like the perfect solution! Are bigserts readily available at most specialist high street tool stores? One thing I wonder is, would it be safe/alright to put blue loctite around the bigsert's outer threads first? At least for helicoils I hear it's not a wise idea to use anything like loctite or copper grease since it is essentially a spring instead of a full-on solid insert. I suppose I could eBay around for a bigsert kit, but if it's available on the high street I wouldn't mind getting it there if it's not that much more than on the Bay! EDIT: For the M5 size, what is the outer diameter of the timesert as opposed to the 6.25mm of the M5 bigsert? Edited January 30, 2011 by Ares Quote Link to comment Share on other sites More sharing options...
LukasMcNeal Posted January 30, 2011 Report Share Posted January 30, 2011 (edited) Cant help with the helicoiling, but for bolts eBay is great! Just search M5 x 25 Allen head and they are guaranteed to have them. I bought some bolts all I needed was one but I got 20 for the same price tarty charge for one Edited January 30, 2011 by LukasMcNeal Quote Link to comment Share on other sites More sharing options...
Luke_zoo Posted January 30, 2011 Report Share Posted January 30, 2011 2. Helicoiling. This frame already has M6 threads instead of M5, but one of the threads has been stripped out. So I might as well helicoil all 4. I know there's a lot on helicoiling kicking around the forum from the past but to be more specific is there any way I can restore it to an M5 thread? Or am I stuck with M6 helicoiling? In any case, is it possible to install the helicoil without drilling? I noticed *some* helicoil kits come with everything minus the specific sized drill bit whilst others specifically come with it? I had this problem, all I ended up doing was jaming a nut down the mount so it would not come out then I put a m5 bolt back in and worked a treat. Quote Link to comment Share on other sites More sharing options...
Tony Harrison Posted January 30, 2011 Report Share Posted January 30, 2011 You can also look at Würth thread inserts. My dad fixed a stem of mine with them - it had odd bolts in it anyway, around M6 size but not, and it ended up M5. The inserts should come with information on what drill/tap combination to use. Quote Link to comment Share on other sites More sharing options...
Sponge Posted January 30, 2011 Author Report Share Posted January 30, 2011 You can also look at Würth thread inserts. My dad fixed a stem of mine with them - it had odd bolts in it anyway, around M6 size but not, and it ended up M5. The inserts should come with information on what drill/tap combination to use. Surely the exact same as the Wurth 'Timeserts' on their site? Though all the merrier if what you actually mean is a whole other thread fix option ! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.