Cibbersicks Posted August 19, 2009 Report Share Posted August 19, 2009 Normal bolts - A little bit of copper greese. Important bolts (i.e foot peg bolts), blue loctite. As per my manual. Radial caliper bolts - nothing. Just torqued up, then lockwired together so one cant come out by itself... I use green loctite studlock but definately +1 on lockwiring important bolts. If it's done properly its very reassuring! Link to comment Share on other sites More sharing options...
Doug_R1 Posted August 23, 2009 Report Share Posted August 23, 2009 If you buy titanium brake bolts they arrive with a sachet of copper grease, to prevent galling. Link to comment Share on other sites More sharing options...
Evilchicken0 Posted August 25, 2009 Report Share Posted August 25, 2009 I clean the threads ... then blow on them for luck, and us a smal amount of coppaslip Link to comment Share on other sites More sharing options...
lorenzo Posted August 25, 2009 Report Share Posted August 25, 2009 Why, especially when the OE ones give you a hint by coming with a preapplied bit of threadlock, would you want to apply copperslip to brake bolts? Link to comment Share on other sites More sharing options...
Tomfoolery Posted August 25, 2009 Report Share Posted August 25, 2009 I've never replaced a caliper bolt, just re-used them after cleaning with a dab of grease. Not copaslip though, some stuff Tom gave me. It's either lithium or moly or something, I forget. Link to comment Share on other sites More sharing options...
lorenzo Posted August 25, 2009 Report Share Posted August 25, 2009 Eeek! [runs off to the garage to check that his brake bolts are still there] Link to comment Share on other sites More sharing options...
gurninman Posted August 25, 2009 Report Share Posted August 25, 2009 If you buy titanium brake bolts they arrive with a sachet of copper grease, to prevent galling. Aye, I've got Ti caliper bolts (pinched 'em off a bike going for scrap) and I use copper grease to prevent galling but wouldn't use it on steel. I also only ever use a torque wrench on things like cam cap cap bolts, swingarm spindles etc. Link to comment Share on other sites More sharing options...
Mark/Foggy Posted August 25, 2009 Report Share Posted August 25, 2009 I've never replaced a caliper bolt, just re-used them after cleaning with a dab of grease. Not copaslip though, some stuff Tom gave me. It's either lithium or moly or something, I forget. Loving the irony with your current avatar Tom, won't be long eh! Link to comment Share on other sites More sharing options...
tootall Posted August 25, 2009 Report Share Posted August 25, 2009 If I'm feeling particularly efficiant I use a bit of copaslip on the unthreaded shoulder of the bolt, and a wee bit of thread lock on the threads. Doesn't happen often though. Link to comment Share on other sites More sharing options...
Mark/Foggy Posted August 25, 2009 Report Share Posted August 25, 2009 If I'm feeling particularly efficiant I use a bit of copaslip on the unthreaded shoulder of the bolt, and a wee bit of thread lock on the threads. Doesn't happen often though. Your staying on the wall mate Link to comment Share on other sites More sharing options...
Tomfoolery Posted August 25, 2009 Report Share Posted August 25, 2009 Loving the irony with your current avatar Tom, won't be long eh! That's what I mean. I'll order the bolts on payday. I've got some threadlock somewhere. Link to comment Share on other sites More sharing options...
Mr.Pigdog Posted August 25, 2009 Report Share Posted August 25, 2009 I copaslip the bolts and also the pins.Neither have managed to loosen up and fall out in 21 years of bike maintenance so far.Bet they do tomorrow now. Link to comment Share on other sites More sharing options...
Evilchicken0 Posted August 26, 2009 Report Share Posted August 26, 2009 Well as long as the bolt is torqued it's ok for me. Link to comment Share on other sites More sharing options...
heds954 Posted September 2, 2009 Report Share Posted September 2, 2009 As MilleMille said, he may be using the "thats the way I have always done things, never had a problem in 30 years" mentality*. Things change though....let's hope that his public liability insurance is never put to the test as a result of his practice. To be on the safe side, I would always refer to the manufacturer's recommendations (even though they will be massively over-engineered and specified). V.true? *Interesting side note: in Chuck Yeager's autobiography he describes a case where he was flying an F-86 Sabre over a lake in the Sierra Mountains when he decided to buzz a friend’s house at a low altitude. During the slow roll, he suddenly felt his aileron lock, which is the movable part of the wing that helps stabilize the plane. A lesser pilot may have panicked, but Yeager slowly pushed up the nose and sure enough, the aileron unlocked. Climbing to 15,000 feet, Yeager attempted other manoeuvres in which the aileron stuck each time. Four other pilots had already died under similar circumstances, but to date, investigators had not discovered the source of the Sabre’s fatal flaw. Yeager presented his report to superiors who discovered that a bolt on the aileron cylinder was installed upside down. The culprit was located in a North American assembly plant. He was an older worker who ignored the instructions about how to insert the bolt, because he knew that bolts were always placed with the head up, never down (the thinking being that if the nut worked loose then at least the bolt wouldn't drop out). Doing something just cause it worked for the last 30 years can have consequences. So in essence it wasn't the bolt that was the problem, just the old nut fitting it!! Yeah, yeah, I know... I'll get m'coat If I'm feeling particularly efficiant I use a bit of copaslip on the unthreaded shoulder of the bolt, and a wee bit of thread lock on the threads. Personally I cover all bases by coating everything liberally in a mixture of two parts Loctite and three parts Copaslip.* *Not strictly true* **or at all... Link to comment Share on other sites More sharing options...
gary8 Posted September 5, 2009 Report Share Posted September 5, 2009 Steel bolts into alloy threads. If you use your bike in all weathers then some anti seize compound on the threads would be a good idea. Steel alloy and water don't get on very well and cathodic reaction occurs ending up with seized bolts. Also torquing the bolts is a good idea. Front caliper bolts on a K8 1000 are torgued at 39 n/m. With a 1/2 inch ratchet it is very easy to overtighten. I torgue every bolt on the bike that I can find a setting for. Link to comment Share on other sites More sharing options...
skyline Posted September 6, 2009 Report Share Posted September 6, 2009 When I get to remove/refit caliper bolts on my bike, I was going to use the copper grease, but getting a bit wary of doing that now... I'd heard before that copper grease was ok to use on caliper bolts as long as they are torqued correctly and that because of the reduced friction from having the grease on the threads, the torque setting should be reduced by 10% (ie 40nm becoming 36nm). Would putting copper grease on the threads and a dab of blue loctite at the end of the thread be any good? Also, me being thick here but what's a torque stripe? Cheers all Link to comment Share on other sites More sharing options...
alexp5 Posted September 7, 2009 Report Share Posted September 7, 2009 Also, me being thick here but what's a torque stripe? Cheers all You know when you see a new bike and all the fasteners are either marked with paint / marker pen... That's torque striping, that is. Torque-up said fastener, and mark with a stripe, you can see instantly if it's loosening. Link to comment Share on other sites More sharing options...
bignige Posted September 7, 2009 Report Share Posted September 7, 2009 lets go the whole hog and have them yellow plastic pointers like they have on bus wheels! touch of the 'slip on most bolts. thread lock on disc bolts. wd40 all over brake discs (keeps them shiny) ;-) Link to comment Share on other sites More sharing options...
Pete Posted September 7, 2009 Report Share Posted September 7, 2009 All interesting stuff this. Must admit, I've only ever used coppaslip on my caliper bolts, (this applies to the car aswell) and only ever tighten them with a torque wrench to the specified load (25Nm for the SV). It makes sense to locktite them in though and they were originally covered in blue when I first removed them many years ago. I simply use coppaslip as it helps the removal process. I dont use much, I service my brakes very regular and have never had a problem. The whole naval gazing engineering talk of replacing the bolts after so many torque tightenings or whatever is more than likely correct, in pure engineering terms. But, in the real world, over tightening an M8 or M10 steel caliper bolt by using a lubricant in place of a thread adhesive (so its maybe taking up to 10% more load than specified) will do sweet fanny adams. Navel gaze away Pete Link to comment Share on other sites More sharing options...
will#224 Posted September 7, 2009 Report Share Posted September 7, 2009 I use what ever fitting is in my bike, sometimes change it for Stainless or Ti if i'm feelin rich. I use copaslip and then lock wire it if its a safety feature. If i fit and remove the bolt regularly then i dont use a torque wrench. I work with tools all day every day and i reckon i've got a decent feel for it. Its my bike though and if i was doing something that was a safety feature for someone else i'd do it by the book, loctite and torque wrench. Link to comment Share on other sites More sharing options...
skyline Posted September 7, 2009 Report Share Posted September 7, 2009 You know when you see a new bike and all the fasteners are either marked with paint / marker pen... That's torque striping, that is. Torque-up said fastener, and mark with a stripe, you can see instantly if it's loosening. Ah cheers for that, I had done that with one of my carb bolts without knowing what it's called then! Link to comment Share on other sites More sharing options...
gook184 Posted September 10, 2009 Report Share Posted September 10, 2009 Jeez. We're not flying jet planes. Has nobody heard of a weekly nut and bolt check? Does any body check lights, tyres, chain, fluids, search for loose bits before riding the bike? Or do the majority just wait for the yearly service/mot to highlight problems? I am one of those who copper greases their 13 year old caliper bolts, and i tighten them up to what feels about right. So far none have fallen off or even worked loose. Once a week i do a nut and bolt check that takes a few minutes. Nothing has fell off, ever. Minor things have worked loose and been rectified. Now sneaking off to shed to check caliper bolts. . . . . . . . Link to comment Share on other sites More sharing options...
MonkeyJim Posted September 10, 2009 Report Share Posted September 10, 2009 Jeez. We're not flying jet planes. Has nobody heard of a weekly nut and bolt check? Does any body check lights, tyres, chain, fluids, search for loose bits before riding the bike? Or do the majority just wait for the yearly service/mot to highlight problems? I am one of those who copper greases their 13 year old caliper bolts, and i tighten them up to what feels about right. So far none have fallen off or even worked loose. Once a week i do a nut and bolt check that takes a few minutes. Nothing has fell off, ever. Minor things have worked loose and been rectified. Now sneaking off to shed to check caliper bolts. . . . . . . . wrong, my friend, wrong. the R1 *is* a jet plane, and I am a pilot. It's a ground level motherfunking attack fighter bomber. On acid. I do a quick visual check of the bike before every ride. Lights, tyres, chain, fluids. Tyres get checked every week. it gets a more thorough looking over every time it gets a wash or I do some work on it. I've got a torque wrench and I'm not afraid to use it. I know the most popular torque wrench settings off the top of my head, that's how totally sad I am Link to comment Share on other sites More sharing options...
gook184 Posted September 10, 2009 Report Share Posted September 10, 2009 wrong, my friend, wrong. the R1 *is* a jet plane, and I am a pilot. It's a ground level motherfunking attack fighter bomber. On acid. I do a quick visual check of the bike before every ride. Lights, tyres, chain, fluids. Tyres get checked every week. it gets a more thorough looking over every time it gets a wash or I do some work on it. I've got a torque wrench and I'm not afraid to use it. I know the most popular torque wrench settings off the top of my head, that's how totally sad I am I feel somewhat like a spitfire pilot if i get home feeling victorious after a spirited ride I too have a torque wrench. it's got a blokes name on it who my mate stole it off. I don't use it that often, only after major surgery. There is a school of thought that goes like this. . . . . . Every time you torque something up it stretches the bolt a tiny bit. After some time said bolt will snap. Lorry wheel studs, for example. Eek! P.S. Hands up who's lost calipers or caliper bolts? Don't be shy! Link to comment Share on other sites More sharing options...
Jaybewan Posted September 10, 2009 Report Share Posted September 10, 2009 P.S. Hands up who's lost calipers or caliper bolts? Don't be shy! OOH me! I have! Though I might add through no fault of my own Many moons ago when I had some new rubber fitted to my then steed of choice (ooh nice moped mister), dropped it off, wandered off for an hour and then came back to a lovely new set of tyres, paid up and set off home via a few people's places (students eh?). Just as I got to my favourite set of bends I pull on the lever then feel a very strange sensation, an initial bite of pad on disc, a short click and then a whole lot of me not slowing down at all and trying not to lose my lower bowel contents before remembering I do have a rear brake (handy eh?). After pulling up at the side of the road and inspecting my (normally) trusty steed I note that there's a caliper mounting bolt missing and that the caliper has pivoted around the other bolt and slipped as far away from the disc as it can and is gripping an awful lot of thin air... The sods hadn't put the bolt back in!! Being only a wee lad at the time (and being rather shaken from the whole lack of brakes thing) my dad quite rightly took it upon himself to shout quite loudly down the phone at the place that did the work and happily got double the money back for all the trouble... You'll all be pleased to hear that they not only sacked the guy responsible but also are no longer trading... Taught me a lovely lesson nice and early, check yer stuff after you've had any work done Link to comment Share on other sites More sharing options...
porter_jamie Posted September 11, 2009 Report Share Posted September 11, 2009 What I know about bolts, which is very little. Typical bolt such as an M6 grade 8.8: 8.8 means 800N/mm2 ultimate strength, and the yield point has to be at least 80% of that. (10.9 then is 1000N/mm2 and 90% and so on) To find the strength of the M6 bolt: Find cross sectional area. Use root diameter ( this is not actually correct because of the helix, but near enough for the purposes of this) = 4mm because the pitch = 1mm Area = PI r2 2mm squared x PI = 12.5mm2 12.5mm2 x 800 = 10000N, or 1000kg (thereabouts). So an M6 bolt can hold 1tonne in tension before fracture, and 800kg before yield. (disclaimer - don’t try this at home) So, it would seem if you need 8000N of clamp force, slap in an M6 and crack on. Well, maybe. How do you get the fastener tightened to 8000N, and not 8500N (where it will be plastic). Lots of testing is involved. The most reliable method is to measure the tension v. stretch of the fastener. You have to do loads of testing to get the spread. Think of the bolt as an elastic band - more you stretch it the more clamp you get, to a point. But each bolt is ever so slightly different due to variation. The machine costs many dollar. There is some variation and you have to make sure the lowest gives you enough clamp, while the highest doesn’t put the bolt into yield. The way to give yourself more room to maneoure is use a larger bolt, so the yield point is futher away from your required tension. You then try and find how many turns from snug on the nut gives you that amount of stretch. This method handily ignores the variation in thread geometry and coating thickness and friction coefficients. This might give you a snug plus 200 degrees or similar. There will be some variation here too, again you need enough clamp, but you have to avoid yield. Maybe a bigger bolt helps. Because of variation you might be into a required clamp force of 800kg still, but need a bolt that has a yield point of say 12000N (mixing units, sorry), just so you can be sure you are not deforming anything plastically. I havnt mentioned torque yet? Torquing is the worst way of tightening bolts. You do a massive amount of testing on a torque tension machine to try and get a relationship between torque applied and tension in the fastener. Tiny variations in the condition of the bolt and nut, and the coating thickness and friction etc can have a massive effect on the tension in the joint. So again to be certain you are not yielding the fastener you might have to over spec it. So what? Imagine you make hundreds of thousands of vehicles (motorbikes) a year, all with overspecced bolts. (critical fasteners that is) Lets guess at 50 bolts per bike? All costing 50p too much? 100000 x 50 x 50p = 2.5million pounds. So you invest many dollar on testing and ludicrously expensive machinery which allows you fit smaller fasteners in a highly controlled manner, torque to yield etc. The bolts are lighter and cheaper, and so is your bike. Happy days. And then someone slathers copper grease on the threads and tightens it up in the shed, using a 100 quid torque wrench that has never been calibrated. Anything you apply to the threads will modify the friction, 90% of the torque applied is used to overcome friction - 40% in the thread, 50% bearing or underhead and 10% goes into clamp load. You can see that modifying the friction can get you into trouble. Also fasteners have a habit of coming undone, and reducing the friction will definately increase the likelyhood of this happening. I do what it says in the geniune manual, and nothing else. Back to the elastic band. Get a 100mm 'laccy band and pull it a. 50mm, and then back off b. 5mm. The difference in apparent tension is not huge Now grab the same band so the effective length is 25mm. It takes a lot less stretch to get the same force as before (a), and a lot less back off to get the same drop off in tension at b. The same is true for bolts. We are talking microns though. If the coating breaks down on the washer or the bottom of the nut, and the clamp length of the fastener is too short (so the tension drops of too much), the bolt will come undone. This is why things like head studs are so long. Point here is the joints were designed by engineers far cleverer than me, so just be careful if you change anything. Loctite doesn’t stop the clamp load falling away it just stops the bolt coming undone. Checking stuff regularly is good, but be aware if you keep nudging the bolt round you will eventually yield it. I spoke to a fastener engineer once who tried to tell me torquing to yield was better for fatigue, but I couldn’t keep up as his brain was the size of a planet and he could do stress calcs longhand with a pencil. Ps, all the above might be a figment of my imagination. Link to comment Share on other sites More sharing options...
Evilchicken0 Posted September 11, 2009 Report Share Posted September 11, 2009 Well I'm glad we're all sorted now ... any other business ? Link to comment Share on other sites More sharing options...
billysbones Posted September 11, 2009 Report Share Posted September 11, 2009 What I know about bolts, which is very little. Typical bolt such as an M6 grade 8.8: 8.8 means 800N/mm2 ultimate strength, and the yield point has to be at least 80% of that. (10.9 then is 1000N/mm2 and 90% and so on) To find the strength of the M6 bolt: Find cross sectional area. Use root diameter ( this is not actually correct because of the helix, but near enough for the purposes of this) = 4mm because the pitch = 1mm Area = PI r2 2mm squared x PI = 12.5mm2 12.5mm2 x 800 = 10000N, or 1000kg (thereabouts). So an M6 bolt can hold 1tonne in tension before fracture, and 800kg before yield. (disclaimer - don’t try this at home) So, it would seem if you need 8000N of clamp force, slap in an M6 and crack on. Well, maybe. How do you get the fastener tightened to 8000N, and not 8500N (where it will be plastic). Lots of testing is involved. The most reliable method is to measure the tension v. stretch of the fastener. You have to do loads of testing to get the spread. Think of the bolt as an elastic band - more you stretch it the more clamp you get, to a point. But each bolt is ever so slightly different due to variation. The machine costs many dollar. There is some variation and you have to make sure the lowest gives you enough clamp, while the highest doesn’t put the bolt into yield. The way to give yourself more room to maneoure is use a larger bolt, so the yield point is futher away from your required tension. You then try and find how many turns from snug on the nut gives you that amount of stretch. This method handily ignores the variation in thread geometry and coating thickness and friction coefficients. This might give you a snug plus 200 degrees or similar. There will be some variation here too, again you need enough clamp, but you have to avoid yield. Maybe a bigger bolt helps. Because of variation you might be into a required clamp force of 800kg still, but need a bolt that has a yield point of say 12000N (mixing units, sorry), just so you can be sure you are not deforming anything plastically. I havnt mentioned torque yet? Torquing is the worst way of tightening bolts. You do a massive amount of testing on a torque tension machine to try and get a relationship between torque applied and tension in the fastener. Tiny variations in the condition of the bolt and nut, and the coating thickness and friction etc can have a massive effect on the tension in the joint. So again to be certain you are not yielding the fastener you might have to over spec it. So what? Imagine you make hundreds of thousands of vehicles (motorbikes) a year, all with overspecced bolts. (critical fasteners that is) Lets guess at 50 bolts per bike? All costing 50p too much? 100000 x 50 x 50p = 2.5million pounds. So you invest many dollar on testing and ludicrously expensive machinery which allows you fit smaller fasteners in a highly controlled manner, torque to yield etc. The bolts are lighter and cheaper, and so is your bike. Happy days. And then someone slathers copper grease on the threads and tightens it up in the shed, using a 100 quid torque wrench that has never been calibrated. Anything you apply to the threads will modify the friction, 90% of the torque applied is used to overcome friction - 40% in the thread, 50% bearing or underhead and 10% goes into clamp load. You can see that modifying the friction can get you into trouble. Also fasteners have a habit of coming undone, and reducing the friction will definately increase the likelyhood of this happening. I do what it says in the geniune manual, and nothing else. Back to the elastic band. Get a 100mm 'laccy band and pull it a. 50mm, and then back off b. 5mm. The difference in apparent tension is not huge Now grab the same band so the effective length is 25mm. It takes a lot less stretch to get the same force as before (a), and a lot less back off to get the same drop off in tension at b. The same is true for bolts. We are talking microns though. If the coating breaks down on the washer or the bottom of the nut, and the clamp length of the fastener is too short (so the tension drops of too much), the bolt will come undone. This is why things like head studs are so long. Point here is the joints were designed by engineers far cleverer than me, so just be careful if you change anything. Loctite doesn’t stop the clamp load falling away it just stops the bolt coming undone. Checking stuff regularly is good, but be aware if you keep nudging the bolt round you will eventually yield it. I spoke to a fastener engineer once who tried to tell me torquing to yield was better for fatigue, but I couldn’t keep up as his brain was the size of a planet and he could do stress calcs longhand with a pencil. Ps, all the above might be a figment of my imagination. that's just what I was going to say. Link to comment Share on other sites More sharing options...
heds954 Posted September 11, 2009 Report Share Posted September 11, 2009 What I know about bolts, which is very little. <snip> Hmm, any chance you could expand on that, I think you left out a few details? Good post BTW Link to comment Share on other sites More sharing options...
gook184 Posted September 11, 2009 Report Share Posted September 11, 2009 that's just what I was going to say. +1 Are we still on earthbound subjects or have we shifted onto the design spec of the space shuttle yet? LIGHTEN UP GUYS THEY'RE JUST BIKES!!!!!!!!!!!!!!!!!!!!! Link to comment Share on other sites More sharing options...
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